Conference Agenda

Overview and details of the sessions of this conference. Please select a date or location to show only sessions at that day or location. Please select a single session for detailed view (with abstracts and downloads if available).

 
 
Session Overview
Date: Wednesday, 06/Sept/2023
 Ausstellung Geoparke
Location: Wiwi 102
 Exhibition "Life conquers a planet: Example Earth" | Gesteins-Ausstellung: Leben übernimmt die planetare Steuerung: Beispiel Erde
Location: Foyer (Henry Ford Building)
Session Chair: Christoph Heubeck, Friedrich-Schiller universität Jena
8:30am - 9:20amPlenary Lecture by Timothy W. Lyons "How Earth’s early oceans and atmosphere help guide the search for life beyond"
Location: Audimax
Session Chair: Georg Feulner, PIK
 
Topics: Plenary Talk

How Earth’s early oceans and atmosphere help guide the search for life beyond

Timothy W. Lyons

University of California, United States of America

Life and life-sustaining environments, including oceans, have existed on a dynamic Earth for more than four billion years despite the multitude of challenges that come with stellar, solar system, and planetary evolution. Each of our many past planetary states, or alternative Earths, was associated with a particular atmospheric composition, and those atmospheres contained gases such as oxygen and methane that were produced by early life. Using ancient Earth to understand when and how these biosignature gases accumulated is allowing us to select targets and techniques for exploring the many Earth-like planets beyond our solar system. Further, Earth scientists and prebiotic chemists are working together in new ways to understand how and where life first emerged. This new perspective could also help guide the search for life elsewhere in the solar system and far beyond.

This presentation is about the coevolution of life and its environments on Earth over billions of years, touching on key evolutionary innovations, the steps and dynamics of biospheric oxygenation, potential tectonic controls, and nutrient cycling—among other first-order patterns and drivers. The focus will include biosignatures emphasizing early Earth and its relevance in the search for life on exoplanets. Among the many lessons learned, early Earth has taught us about false negatives—that is, the possible absence of detectable atmospheric biosignatures above an ocean brimming with life. Overall, however, the evolution of life and its ecological impacts are direct reflections, through cause-and-effect relationships, of the chemical and physical evolution of solid and surficial Earth.

 
9:20am - 9:40amAwards: Prof. Dr. John Donald Bruce Dingwell, LMU München – Gustav-Steinmann-Medaille I Prof Dr. Victor Ramos, University of Buenos Aires, Argentina – Leopold-von-Buch-Plakette
Location: Audimax
9:30am - 11:30amSeminar Geo-Karrierepfade/ career pathways in geosciences (Hold in English.)
Location: Wiwi 103
Session Chair: Laura Krone, Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum GFZ
9:40am - 10:00amCoffee Break
Location: Foyer (Henry Ford Building)
10:00am - 11:15am-
Location: Hall A (HFB)
10:00am - 11:15am3.14-1 Applied stratigraphy of Central European basins
Location: Hall B (HFB)
Session Chair: Thomas Mann, Bundesanstalt für Geowissenschaften und Rohstoffe (BGR)
Session Chair: Jochen Erbacher
 
10:00am - 10:30am
Invited Session Keynote
Topics: 3.14 Applied stratigraphy of Central European basins

The Cretaceous Period in 2023 - progress and challenges

Andrew Scott Gale

University of Portsmouth, United Kingdom

Over the past 30 years, our knowledge of Cretaceous stratigraphy and timescale has expanded exponentially. This has been based partly on the greater refinement of biostratigraphy, including the utilisation of groups of fossils previously poorly known or ignored (microcrinoids, inoceramid bivalves, diverse microfossil groups) and also the development of geochemical and geophysical stratigraphies, most notably stable carbon isotope- and magnetostratigraphy. These two methodologies have enabled previously impossible correlations to be made, independent of facies and sometimes in the absence of biostratigraphical evidence. The identification of orbital cycles in Cretaceous sediments, integrated with new radiometric dates, now provides a high-resolution timescale for intervals of the Cretaceous. Work continues apace to extend and refine the timescale and integrate this with new stratigraphical data. Additionally, data generated primarily for the purpose of correlation, such as stable carbon isotope curves, provide direct evidence of the Cretaceous carbon cycle and allow a better understanding of palaeoenvironmental changes.



10:30am - 10:45am
Topics: 3.14 Applied stratigraphy of Central European basins

Integrated stratigraphy, facies patterns and palaeogeography of the lower Elbtal Group: a re-evaluation of the Cenomanian transgression in Saxony, Germany

Markus Wilmsen, Birgit Niebuhr

Senckenberg Naturhistorische Sammlungen Dresden, Germany

Until very recently, it was generally assumed that the marine flooding of the Saxonian Cretaceous Basin (SCB) was largely related to the naviculare Transgression of the early Late Cenomanian. However, based on the detailed investigation of 39 Cenomanian sites at surface and subsurface, and considering new macrobiostratigraphic data and existing palynological facts, a completely revised integrated stratigraphic framework and palaeogeographic reconstructions of the lower Elbtal Group are presented (Niebuhr & Wilmsen 2023, ZDGG 174, DOI: 10.1127/zdgg/2023/0376). Demonstrably, Cretaceous sedimentation started already in the early Early Cenomanian, indicated by the contemporaneous onlap of non-marine (Niederschöna Formation) and marine strata (Oberhäslich Formation). The Cenomanian transgressions advanced from the north, at first following the course of roughly south–north-discharging palaeovalleys of a fluvial palaeodrainage system. Sequence stratigraphic analyses demonstrate the presence of four complete, unconformity-bounded Cenomanian depositional sequences (DS) and a fifth one, DS Ce-Tu 1, which started in the mid-Late Cenomanian and lasted into the Early Turonian. The depositional sequences comprise five major transgressive phases that overstepped each other, culminating in an earliest Turonian climax of the 2nd-order Cenomanian transgressive hemicycle. The maximum thickness (100–120 m) equates to the accommodation generated by eustasy and regional subsidence during the entire 6-myr-long Cenomanian age (sedimentation rate ≤20 m/myr). Thickness changes within the lower Elbtal Group can quite simply be related to pre-transgression topography and sequence stratigraphic onlap patterns. Thus, the new stratigraphic and palaeogeographic framework of the lower Elbtal Group also demonstrates that tectonic inversion in the SCB was essentially a post-Cenomanian process.



10:45am - 11:00am
Topics: 3.14 Applied stratigraphy of Central European basins

New insights into global carbon cycle disturbances: a shallow marine record of the Middle Oxfordian Excursion (MOxE) in the Lower Saxony Basin

François-Nicolas Krencker1, Deyan Zhang1, Stefan Huck1, Philipp Ulke1, Michael Schramm2, Ulrich Heimhofer1

1Institute of Geology, Leibniz University Hannover, Germany; 2Federal Institute for Geosciences and Natural Resources, Hannover, Germany

The Oxfordian period is characterized by a long-term (ca. 6 Myrs) trend of increasing stable carbon isotope values, punctuated by three short-lived (ca. <1 Myrs) carbon isotope excursions (CIEs) at the Callovian/Oxfordian boundary, in the lower Oxfordian (Quenstedtoceras mariae ammonite zone), and in the middle Oxfordian (Gregoryceras transversarium ammonite zone), also known as the MOxE. This pattern is evident worldwide in both organic and inorganic carbon (δ13Corg and δ13Ccarb) in terrestrial and shallow marine environments, indicating recurrent global carbon cycle disturbances affecting the entire ocean-atmosphere system. However, previous sedimentological and chemostratigraphic studies on Oxfordian strata in the Lower Saxony Basin (LSB) of northern Germany, have failed to identify the three CIEs cited above, hindering their correlation with the global carbon isotope record. In this study, we provide, for the first time, a high-resolution δ13Ccarb record revealing the MOxE expressed in a positive CIE of 3.8‰. We collected data from drilling core samples of the Korallenoolith Formation in the Konrad 101 borehole, located in the southwestern part of the LSB. This exploration drilling is biostratigraphically well constrained, unlike many other sections in the LSB that are characteristic of shallow tropical marine depositional settings. This particularity enables us to compare the Konrad 101 δ13Ccarb pattern with other localities distributed worldwide incl. Europe, western Asia, and the Gulf of Mexico. Our high-resolution δ13Ccarb reflects a major synchronous change in the exogenic carbon cycle, with no satisfying explanation so far for the triggering mechanisms, in the context of already published datasets.



11:00am - 11:15am
Topics: 3.14 Applied stratigraphy of Central European basins

Stratigraphy und evolutionary patterns in middle jurassic ammonites

Eckhard Mönnig

Naturkunde-Museum Coburg, Germany

The biostratigraphy of the Jurassic system has made many advances in recent years. We can distinguish over 50 successive faunal horizons in the Callovian, which corresponds to a resolution of perhaps 75,000 to 100,000 years. The distribution of the ammonite genus Kepplerites in space and time has been extensively studied. This example illustrates the importance of a precise stratigraphy for paleontological and sequence-stratigraphic questions.

The beginnings of the ammonite genus Kepplerites can be traced back to the Subboreal sea of NW Canada in the late Bathonian (Middle Jurassic). Thereafter the evolution can be followed over Greenland, the Russian platform over the Caucasus to Central Europe, up to its abrupt extinction at the beginning of the Callovian. Only a small population survived, probably in what is now the Caucasus. From here, a few specimens reached Central Europe and the Russian platform, where new species emerged (genetic drift). At the beginning of the Koenigi Zone, a species migrated from Russia via the Caucasus to Central Europe, where they mixed again. From this, separate lines developed in England and Central Europe (gradualism), the seas of Greenland were also settled again. At the end of the Koenigi Zone, Russian species immigrated again and replaced the weakened populations in Central Europe and England. By the end of the Early Callovian, all sea straits were open and a unified Subboreal faunal province of NW Europe, Greenland and the Russian Platform was established. This scenario was controlled by sea level rises and falls and short-term climatic changes.

 
10:00am - 11:15am1.07 Understanding reactions and transport in porous, fractured, and tight media - from field work to rock analytics and predictive modelling
Location: Hall C (HFB)
Session Chair: Benjamin Busch, Karlsruhe Institute of Technology
Session Chair: Michael Kühn, Deutsches GeoForschungsZentrum (GFZ)
Session Chair: Sebastian Fischer, Federal Ministry for Economic Affairs and Climate Action
 
10:00am - 10:30am
Invited Session Keynote
Topics: 1.07 Understanding reactions and transport in porous, fractured, and tight media - from field work to rock analytics and predictive modelling

Understanding coupled fluid transport for de-risking geological carbon and hydrogen storage

Andreas Busch

Heriot-Watt University, United Kingdom

Carbon Capture and Storage (CCS) as well as subsurface energy storage in the form of hydrogen are measures to lower carbon emissions to the atmosphere. Large-scale implementation is underway, especially for CCS, and first hydrogen storage projects have been announced recently.

With most CCS projects being planned for offshore locations, public acceptance is less of a determining factor than it used to be 10-20 years ago, where discussions were rather for onshore locations. CO2 leakage has always been a risk highlighted in the public debate, while no or minimal leakage has been reported for current CCS projects worldwide. However, as scientific community, we need to realistically highlight the risk of leakage across sealing units for any fluids stored in the subsurface to inform various stakeholders like regulators, the public and of course also operating companies.

Caprock leakage needs to be studied across various length and time scales, considering the undisturbed matrix as well as fracture networks and faults; we need to consider advective and diffusive flow and transport and incorporate mineral alterations, potentially leading to changes in hydraulic or mechanical properties.

This talk will highlight the current state of research, advancements and future research required for a realistic evaluation of caprock leakage. It will be based on past research related to matrix transport as well as current research focusing on single and multiphase flow along faults and fractures.



10:30am - 10:45am
Topics: 1.07 Understanding reactions and transport in porous, fractured, and tight media - from field work to rock analytics and predictive modelling

Ternary fluid infiltrating with constant composition produces more than twelve reaction sequences controlled by rock composition

Johannes Vrijmoed1, Yury Y. Podladchikov2

1Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany; 2Institute of Earth Sciences, University of Lausanne, Lausanne, Switzerland

In many applications a fluid is injected into rocks for example for CO2 storage, in enhanced geothermal reservoirs, or during oil and gas recovery. The fluid may be out of equilibrium with the rock resulting in chemical reactions at depth. The correct prediction of reaction front velocities depends on a thorough understanding of the theory of chromatography and the changes of density and porosity in reactive transport models. We study the systematics of reaction fronts in multi-component systems. The methodology is based on a finite difference approach for solving the transport problem in combination with precomputed thermodynamic equilibria. These lookup tables are calculated using Gibbs’ minimization and a linear programming approach. They are validated against full analytical solutions of the Gibbs minimization problem. Porosity and density evolution is predicted based on mass conservation. We focus on ternary ideal fluid or melt solutions in equilibrium with pure phases as exact solutions are feasible and here first consider the isothermal case. For a fixed incoming fluid composition, over twelve reaction sequences may form depending on initial rock composition. Within one type of reaction sequence, bulk rock composition still plays are role in determining the speed of the reaction front as well as the fluid compositions that develop along the path. This theoretical understanding allows better predictions of the formation of reaction sequences and the consequences on rock properties upon injection of fluids with dissolved chemical components.



10:45am - 11:00am
Topics: 1.07 Understanding reactions and transport in porous, fractured, and tight media - from field work to rock analytics and predictive modelling

Reservoir quality and diagenesis of limestones from the Upper Cretaceous (Beckum-Fm.) of the Münsterland Cretaceous Basin

Jasemin Ayse Ölmez, Benjamin Busch, Christoph Hilgers

Karlsruhe Institute of Technology, Germany

The Upper Cretaceous Campanian limestones from the Ahlen-Fm. (Beckum-Fm. Submember) of the Münsterland Cretaceous Basin in NW Germany are former high porosity limestones, which consist mostly of detrital components. This study focuses on the petrophysical assessment of these limestones in combination with diagenetic studies to understand the potential interaction with rising mine-water as they unconformably overlie Upper Carboniferous coal-bearing strata. Therefore, outcrop analyses were carried out and samples were taken to study the heterogeneity and controlling factors, as well as diagenetic para-sequence in tight limestones. We show that diagenesis, compaction, authigenic cementation and the detrital composition affect petrophysical properties. Mechanical compaction is seen by elliptically deformed calcispheres and foraminifera at the transition to ductile clay laminae, forming compaction bands. Mechanical compaction and early diagenetic precipitation of inter- and intragranular sparry ferroan calcite reduces porosity and permeability. Porosity ranges between 1.0% to 18.7%, permeability between <0.0001 mD to 0.2 mD, and p-wave velocity ranges between 2089 m/s and 5843 m/s. Furthermore, natural fractures are filled by either ferroan calcite and/or strontianite. Thus, the studied lithologies of the Beckum-Fm. can be considered as seals for potential rising mine-water levels. Furthermore, results indicate, that they may not be potential targets for geothermal utilization. However, open fractures formed during exhumation overprinted the rocks which may enhance the reservoir quality by generating potential fluid pathways close to the present day surface.



11:00am - 11:15am
Topics: 1.07 Understanding reactions and transport in porous, fractured, and tight media - from field work to rock analytics and predictive modelling

Hydrogeochemical impact of Opalinus Clay system shown in metres migration length of uranium

Theresa Hennig1, Michael Kühn1,2

1GFZ German Research Centre for Geosciences, Potsdam, 14473, Germany; 2University of Potsdam, Institute of Geosciences, Potsdam OT Golm, 14476, Germany

Models and simulations allow a prognosis of how processes in the geosphere might occur in the future, considering physical and chemical processes. They are the only way to test future scenarios and hypotheses and to evaluate the long-term evolution of a repository site, e.g. by quantifying potential radionuclide migration in the hydrogeological system of the containment providing rock unit.

An example is used to demonstrate the extent to which simulated migration lengths can vary for a million years, depending on the model concept as well as on the underlying data and parameters. In the case of uranium in the potential host rock Opalinus Clay (Switzerland), the range extends from 5 m applying experimentally determined transport parameters, over 50 m using process-based approaches and taking hydrogeology into account and up to 80 m depending on the thermodynamic data set used.

The degree of reliability of the models is derived from comparison with laboratory tests and data from boreholes and underground laboratories. This is the only way to assess the simulation results. In addition, indications can be provided where new data need to be collected. To reduce the uncertainty related to the migration length of uranium in the Opalinus Clay, the calcite-carbonate ion system as well as the hydrogeological setting at a potential disposal site need to be known, whereas the amount of clay minerals plays a subordinate role as long as it is enough, which is the case in argillaceous formations.

 
10:00am - 11:15am1.14 Secondary raw materials: Geoscientific approaches to enable a circular economy
Location: Hall D (HFB)
Session Chair: Katharina Schraut, Bundesanstalt für Materialforschung und –prüfung (BAM)
Session Chair: Paul Mählitz, Bundesanstalt für Geowissenschaften und Rohstoffe
 
Topics: 1.14 Secondary raw materials: Geoscientific approaches to enable a circular economy

Mine waste: Nuisance or important metal resource for the future?

Elisabeth Eiche1,2, Luca Schindler1,2, Elena Kubiak1,2, Meike Lindner1,2, Benjamin Walter1,2, Jochen Kolb1,2

1Chair of Geochemistry and Economic Geology, Institute of Applied Geosciences, Karlsruhe Institute of Technology. Karlsruhe, Germany; 2Laboratory for Environmental and Raw Materials Analysis, Institute of Applied Geosciences, Karlsruhe Institute of Technology, Karlsruhe, Germany

Germany has a long history in metal ore mining stretching over a period of more than 1000 years. Both small and large heaps or dumps remain in the mining districts typically without any safety measures (coverage, monitoring etc.). Often these sites are still a considerable point source for pollutants like metals, metalloids or processing chemicals. However, extraction technologies have been much less effective in the past and for certain elements (e.g. Ge) no technical application has been known. As such, mine waste including historic waste or ore dumps and tailings may represent a considerable and easily extractable future resource especially for technology critical elements.

We investigate the mineralogy, geochemistry and leaching behaviour of different types of mine residues in former mining districts of the Black Forest, Wiesloch and the Donnersberg area. With respect to the critical raw materials Ge, Sb, barite and fluorite, several of the investigated mine waste seem to be of potential economic interest. But elements like Pb, Zn (both in the wt% range) or Ag (>100 mg/kg) are also promising with regard to reprocessing in some of the investigated districts. From an environmental point of view, Pb, Zn, As, Cd, Sb und Tl are of concern regarding their concentration and leachability. Both, the content and potential mobility largely depend on the ore type, the period of extraction and the processing technique applied. We think that extracting raw materials from mine residues has the advantage of gaining metals locally and giving back space to nature and society at the same time.



Topics: 1.14 Secondary raw materials: Geoscientific approaches to enable a circular economy

Slags from DRI-EAF steel making – a case study on upcoming by-products from the decarbonized steel industry

Lars Hans Gronen1, Derik Demond1, Dirk Pflaeging2, David Algermissen1

1FEhS Institut für Baustoff-Forschung e.V., Germany; 2ArcelorMittal Eisenhüttenstadt Recycling GmbH

Due to the Green Deal proposed by the European Union, several industry sectors in Europe are forced to change the production techniques towards a zero-carbon dioxide emission until 2050. For the steel industry the substitution of fossil fuel, used in the blast furnace (BF), by hydrogen as reduction agent relates to the introduction of new technologies and aggregates. Nowadays, only a small amount of shaft furnaces using natural gas for reduction of iron ores to produce direct reduced iron (DRI). However, this combination is one of the favoured future hydrogen operated routes of alternative steel making in the European Union. The crude steel is, thereby, produced from solid DRI together with scrap molten within the electric arc furnace (EAF). Thus, the minor and trace element composition of the produced EAF slags is directly inherited from the input materials because no density driven phases separation takes place in the DRI which is one major difference to the traditional BF route.

Here we present the results of mineralogical, chemical as well as construction technological investigations carried out on one exemplary slag from the EAF route were app. 2/3 of the input material was sponge iron. The main emphasis of the presented study lies on the ongoing applicability of the EAF slags produced in the future as secondary product in the context of steel industry feature the planned reduction of carbon dioxide emissions.



Topics: 1.14 Secondary raw materials: Geoscientific approaches to enable a circular economy

Production of an alite-rich material from reduced basic oxygen furnace slags

Katharina Schraut1, Burkart Adamczyk1, Christian Adam1, Dietmar Stephan2, Sebastian Simon1, Julia von Werder1, Birgit Meng1

1Bundesanstalt für Materialforschung und –prüfung (BAM); 2Technische Universität Berlin

Basic oxygen furnace slag (BOFS) is a by-product of steelmaking of which about 10.4 Mt are produced annually in the EU. BOFS is mostly used in road construction, earthwork and hydraulic engineering. However, in this use, the iron bound in BOFS is lost and the opportunity to produce higher value products from BOFS is forgone.

In recent decades, many researchers have investigated the production of both Portland cement clinker and crude iron from BOFS via a thermochemical reductive treatment. The reductive treatment of liquid BOFS causes a reduction of iron oxides to metallic iron, which separates from the mineral phase due to its higher density and can be recovered. An advantage of this process is that simultaneously the chemical composition of the reduced BOFS is adapted to that of Portland cement clinker and the hydraulic reactive mineral alite (Ca3SiO5) is formed.

In this study, German BOFS was reduced in a small-scale electric arc furnace and a low-iron mineral product rich in alite was produced. Despite a chemical and mineralogical composition similar to that of Portland cement clinker, the reduced BOFS produced less heat of hydration, and its reaction was delayed compared to Portland cement. However, adding gypsum accelerated the hydration rate of the reduced BOFS.

Further research to improve the hydraulic properties of the reduced BOFS is essential. If successful, the production of a hydraulic material and crude iron from BOFS could have economic and ecological benefits for both the cement and steel industry.



Topics: 1.14 Secondary raw materials: Geoscientific approaches to enable a circular economy

Pure brick sand from Construction and Demolition Waste (CDW) through magnetic sorting

Annett Lipowsky, Jenny Götz, Jan Rybizki, Anette Müller

Weimar Institute of Applied Construction Research, Germany

In the processing of construction and demolition waste (CDW), the sorting of the delivered mixtures is one of the decisive process steps in order to produce pure recyclates, which can be used, for example, as a cement substitute or as a raw material component for the brick production. A previously unused method for the separation of fine brick particles as sand utilises rare-earth magnets. This method is based on differences in magnetic susceptibility, which have been confirmed by measurements on bricks and concretes. Sorting tests carried out using a roll magnetic separator with a field strength of 1,4 Tesla at a belt thickness of 0,7 mm confirmed the separability of brick-concrete-mixtures and provided insights into the most important influencing variables. In addition to manual sorting the quantification of the contents of concrete or brick in the magnetic and non-magnetic fractions was determined with laser-induced breakdown spectroscopy (LIBS) and artificial intelligence-based optical quality assurance. Thus, in addition to the proof of seperability, a first step to faster ways for quality control has been accomplished.

 
10:00am - 11:15am1.10-1 Lithiumresources
Location: Wiwi 101
Session Chair: Jochen Kolb, KIT
Session Chair: André Stechern, Bundesanstalt für Geowissenschaften und Rohstoffe (BGR)
 
10:00am - 10:30am
Invited Session Keynote
Topics: 1.10 Lithiumresources

Challenges and opportunities for lithium extraction from geothermal systems in Germany

Valentin Goldberg, Fabian Nitschke

Karlsruhe Institute of Technology, Germany

The growing lithium demand and the dependence on poorly diversified oversea sources point towards a high strategic importance of domestic resources. Furthermore, potentially lower CO2 emissions and reduced areal use during production favor local co-production of geothermal energy and lithium.

Based on a technology comparison for direct lithium extraction from geothermal fluids and the current state of geothermal energy production in Germany, different scenarios for the extractable amount of lithium carbonate were considered. In the most optimistic scenario, taking into account all currently active wells, a maximum production of 4700 t/a of lithium carbonate equivalent is expected. This could cover 2 – 13% of the annual demand of the planned German battery cell production.

Uncertainties in the resource assessment regarding its size, and the sustainability of its management, are still considerable. Yet a full-scale Li extraction from geothermal brines is missing and thus long-time behavior is not clear. For this purpose, a generical model, based on Upper Rhine Graben geothermal settings was developed, and a Li extraction over a 30-year operation time was simulated. Despite a significant Li depletion, a mean Li production of 231 t/a (1230 t/a LCE) is achieved, for a current state-of-the-art geothermal power plant.

This could significantly increase the economics of a geothermal power plant as well as, if transferred to several plants, a partly independency from global imports. The strongest influence on productivity is the achievable flow rate, which provides access to the raw material, highlighting the importance of good geological reservoir exploration and development.



10:45am - 11:00am
Topics: 1.10 Lithiumresources

The highly saline lithium-rich brines in the Muschelkalk aquifer of the Molasse basin in SW-Germany: a future geothermal lithium play?

Jens Carsten Grimmer1,3, Ingrid Stober2, Michael Kraml3

1Karlsruhe Institute of Technology (KIT), Germany; 2University of Freiburg, Germany; 3Vulcan Energy Subsurface Solutions GmbH, Germany

Highly saline lithium-rich hydrothermal fluids occur in the deep calcareous Muschelkalk aquifer of the northern Alpine foreland basin. We have combined geologic, hydraulic, hydrochemical, and stress field data of the Triassic Muschelkalk aquifer beneath sediments of the Molasse basin of SW-Germany for a synthesis to constrain the origin and development of these brines. In contrast to the regional southeast plunge of Mesozoic and Cenozoic strata, low gradient groundwater flow in the Upper Muschelkalk aquifer is to the north, induced by regional recharge from west, south, and east. North trending maximum horizontal stress axes might provide development of fracture permeability in the competent carbonates of the Upper Muschelkalk aquifer for northward flow. The highest lithium concentrations and total dissolved solids (TDS) can be found in the southeastern parts of the Muschelkalk aquifer, close to the Vindelician High, whereas during northward transport TDS and lithium concentrations are increasingly diluted. We argue that the highly saline lithium-rich fluids originate from fluid-rock interaction of meteoric water with Variscan crystalline basement rocks and entered the Muschelkalk aquifer by permeable faults and fractures. The marginal calcareous sand-rich facies of the Muschelkalk enables the inflow of brines from crystalline basement faults and fractures into the aquifer. We thus argue for an external origin of these brines into the aquifer. Potentials are considered as 100±25 t Li/yr per well.



11:00am - 11:15am
Topics: 1.10 Lithiumresources

Interactive web-based platform for efficient water management in the lithium mining industry based on FEFLOW and MIKE Operations

Robin Dufour, Ferdinand Flechtner

DHI WASY GmbH, Germany

Lithium mining operations based on direct lithium extraction from brines often use groundwater models such as FEFLOW or MODFLOW for their resource estimation, especially as the amount of extractable lithium (or LCE) depends on how much water can be extracted by pumping wells. At the same time the environmental impact of the pumping (e.g., drawdown) and in some cases the injection (e.g., dilution) needs to be assessed, also using groundwater models.

To effectively use the groundwater models for the mining operation, they should directly be connected to measured data, such as water level data, pumping rates, lithium concentration, to constantly reconcile the measured data with the predictive models. Furthermore, the groundwater model should not be a “black box” that can only be used by specialists, but be interactive and accessible by the mine operators, to run and analyze different mine plan scenarios themselves.

Therefore, an interactive web-based platform was developed based on FEFLOW and MIKE Operations. With the platform the user can, in a simple way, create new groundwater model scenarios by changing pumping rates or adding additional pumping wells, without having to open the software GUI. The model will then run automatically in the Cloud and the results are shown in an interactive map view and dashboard. At the same time the system includes all relevant monitoring and operational data, to easily compare the model data with the monitoring data.

This way the lithium mining operator has the necessary tools and data in one place to make effective decisions.

 
10:00am - 11:15am-
Location: Wiwi 104
10:00am - 11:15am-
Location: Wiwi 104a
10:00am - 11:15am3.30 Recent advances in geoscientific investigations of the ocean floor
Location: Wiwi 105
Session Chair: Gerhard Bohrmann, University of Bremen
 
10:00am - 10:30am
Invited Session Keynote
Topics: 3.30 Recent advances in geoscientific investigations of the ocean floor

The impacts and legacy of the 2022 eruption of Hunga Volcano, Kingdom of Tonga

Isobel Alice Yeo1, Michael Andrew Clare1, Sally Watson2, Richard Wysoczanski2, Sarah Seabrook2, Kevin Mackay2, James Hunt1, Emily Lane2, Peter Talling3, Edward Pope3, Shane Cronin4, Marta Ribó Gene5, Taaniela Kula6, David Tappin7, Stuart Henrys8, Cornel de Ronde8, Morelia Urlaub9, Steffan Kutterolf9, Miros Charidemou1, Mike Edwards1, Rebecca Garnett1, Cian McGuire1, Mike Williams2

1National Oceanography Centre, United Kingdom; 2NIWA, Aotearoa New Zealand; 3Durham University, UK; 4University of Auckland, Aotearoa New Zealand; 5Auckland University of Technology, Aotearoa New Zealand; 6Ministry of Lands and Natural Resources, Kingdom of Tonga; 7British Geological Survey, UK; 8GNS Science, Aotearoa New Zealand; 9GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany

The climax of the 2021-2022 eruption of Hunga Volcano (also called Hunga Tonga – Hunga Ha’apai) on the 15th January 2022 was the most explosive volcanic eruption this century. The eruption generated pressure waves that travelled around the planet multiple times, ash clouds that reached the mesosphere, tsunamis with run-ups over 10 m and severed the subsea telecommunication cables that connected the Kingdom of Tonga to the rest of the world.

Hunga Volcano, 70 km offshore from Tongatapu, is an almost entirely submerged caldera volcano. The 2023 eruption was the most explosive in recent history, and resulted in substantial modification to the seafloor. By comparing bathymetric datasets from before the eruption with datasets acquired by this team and autonomous vehicles in the months immediately after the event, we are able to identify the impacts of the eruption on the seafloor and the processes that caused the damage to the cables and, by combining this with auxiliary datasets, provide new constraints on the speed and dynamics of volcanic triggered submarine flows.

The eruption deepened the caldera floor by 800 m, with a loss of > 6 km3 of material, while high energy submarine density flows, focussed into gullies, caused upwards of 90 m of erosion higher up the flanks and deposited large lobes of material at the bases of them. These flows travelled hundreds of kilometres from the volcano at some of the fastest speeds ever measured for submarine density flows and were responsible for the damage to the subsea cables.



10:30am - 10:45am
Topics: 3.30 Recent advances in geoscientific investigations of the ocean floor

Venting induced by magma-sediment interaction at Jøtul field – first discovery of hydrothermal seafloor venting along the 500-km-long Knipovich spreading ridge

Gerhard Bohrmann1,2, Katharina Streuff2, Miriam Römer1,2, Stig-Morton Knutsen3, Daniel Smrzka1, Jan Kleint2, Aaron Röhler2, Thomas Pape1,2, Nils Rune Sandstå3, Charlotte Kleint2, Christian Hansen1,2, Wolfgang Bach1,2

1Faculty of Geosciences, University of Bremen, Germany; 2MARUM - Center for Marine Environmental Sciences, University of Bremen, Germany; 3Norwegian Petroleum Directorate, Stavanger, Norway

During expedition MSM109 in July 2022, a new hydrothermal vent field was discovered, which is the first active field found along the 500-km-long ultra-slow spreading Knipovich Ridge. The so-called Jøtul hydrothermal field is not located on an axial volcanic ridge (AVR) but is associated with the eastern bounding fault of the rift valley. A hydrothermal plume with methane concentrations between 100-1000 nmol/L emits hot fluids into the water column above the hydrothermal field, and is being drifted north with the bottom current. These high methane emissions are likely related to interactions between magmatic intrusions and sediments of the Svalbard continental slope produce unusually high release of thermogenic methane. Further investigations during MSM109 using ROV Quest show a wide variety of fluid escape sites such as diffusive venting from sediments, as well as seepage from joints and cracks within igneous rocks. Additionally, new inactive and active mounds with abundant hydrothermal precipitates and chemosynthetic organisms were discovered. Fluids were sampled from an active black smoker emitting fluids with temperatures > 316°C, and from three other sites with venting temperatures between 8°C and 272°C. The fluids are characterized by high methane, carbon dioxide, and ammonium concentrations, as well as high 87Sr/86Sr isotope ratios, indicating a strong interaction of the fluids with sediments from the continental margin of Svalbard. Locations with such intense magma/sediment interactions are of particular importance for the carbon cycle, and a focus of the Bremen Cluster of Excellence "The Ocean Floor – Earth’s Uncharted Interface".



10:45am - 11:00am
Topics: 3.30 Recent advances in geoscientific investigations of the ocean floor

Similarities of the Scotia and Caribbean Plates: Implications for a common plate tectonic history?!

Christian Burmeister1, Paul Wintersteller2, Martin Meschede1

1University of Greifswald, Germany; 2University of Bremen, MARUM/Geoscience department, Germany

The active volcanic arcs of the Scotia- and Caribbean Plate are two prominent features along the otherwise passive margins of the Atlantic Ocean, where subduction of oceanic crust is verifiable. Both arcs have been important oceanic gateways during their formation. Trapped between the large continental plates of North- and South America, as well as Antarctica, the significantly smaller oceanic plates show striking similarities in size, shape, plate margins and morphology, although formed at different times and locations during Earth’s history.

Structural analyses of the seafloor are based on bathymetric datasets by multibeam-echosounders, including data of GMRT, AWI, BAS, MARUM/Uni-Bremen, Geomar/Uni-Kiel and Uni-Hamburg. Bathymetric data were processed to create maps of ocean floor morphology with resolution of 150-250 meters in accuracy. The Benthic Terrain Modeler 3.0, amongst other GIS based tools, was utilized to analyse the geomorphometry of both plates. Furthermore, we used bathymetric datasets for three-dimensional modelling of the seafloor to examine large-scale-structures in more detail. The modelling of ship-based bathymetric datasets, in combination with the GEBCO 2014 global 30 arc-second grid, included in the GMRT bathymetric database, delivered detailed bathymetric maps of both areas.

With the help of the fine- and broad-scale bathymetric position index, we present the first detailed interpretation of combined bathymetric datasets of the entire Caribbean, the Scotia Sea and adjacent areas, such as the South Sandwich Plate. We identified typical morphological features of the abyss, based on determination of steep and broad slopes, ridges, boulders, flat plains, flat ridge tops and depressions in various scales.



11:00am - 11:15am
Topics: 3.30 Recent advances in geoscientific investigations of the ocean floor

Hidden periodic states in gas hydrate systems causing spontaneous gas release without external triggers

Ewa Burwicz-Galerne1, Shubhangi Gupta2

1MARUM, University of Bremen, Germany; 2University of Malta, Msida, Malta

Natural marine gas hydrate deposits are one of the largest solid carbon-sequestrated reservoirs on Earth. Here we show that, remarkably, over 80 percent of all natural hydrate-bearing systems exhibit stable periodicity (i.e. periodic growth and dissolution of massive gas hydrate layers) without any external forcing such as the bottom water warming or sea level fluctuations. This stable periodicity is the manifest of the intrinsic gas hydrate system dynamics related to a complex, kinetically controlled interplay between three phases, e.g. the free gas, solid gas hydrate, and methane-saturated pore fluids. Our results state that, globally, periodic (cyclic) states are present for wide range of marine sediment type and sedimentation regimes and the length of each cycle can last from tens to hundreds of thousands of years with cyclic variations in gas hydrate concentration from 20 vol. % to 60 vol. %. Each cycle is also associated with periodic release of the free methane gas in large quantities without the presence of any external forcing. The apparent existence of the periodic states has profound implications setting hard limits on hydrate predictability and implies a systematic source of uncertainty embedded within hydrate dynamics. Moreover, the anthropogenic climate perturbations may overprint the natural gas hydrate cycle and push formerly stable hydrate reservoirs to new periodic states with large p-T-s fluctuations, thereby significantly increasing the risks of uncontrolled gas escape and geomechanical failures, or formerly periodic states towards chaotic states, making long-term predictions extremely challenging.

 
10:00am - 11:15am4.10-1 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?
Location: Wiwi 107
Session Chair: Sylke Hlawatsch, Richard Hallmann Schule
Session Chair: Dirk Felzmann, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau
 
10:00am - 10:30am
Invited Session Keynote
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?

Earth systems education - Four decades of Research-Development-Implementation

Nir Orion

Weizmann Institute of Science, Israel

This presentation describes the milestones of four decades of Earth Science Education (ESE) research. It will describe the evolution of the ESE Group in the Department of Science Teaching at the Weizmann Institute of Science, Israel. This evolution is derived from dozens of quantitative and qualitative studies and channeled into the holistic earth systems educational approach that incorporates integration of the outdoor learning environment as a central component of the learning sequence, a model for the integration of learning environments, the development of environmental insight through a holistic earth systems approach; development of a layered systems thinking model; and the notion of learning as an instinct. Integration of these components led to the development of the learning instinct theory, which contradicts the essentialist–reductionist paradigm, which still dominates universities and schools worldwide.

The holistic Earth systems approach is an effective platform for developing environmental insight. However, the low status of ESE in schools worldwide prevents the educational treatment needed to reduce environmental crises. Thus, climate change is an educational crisis. It results from the continuing failure of the environmental education paradigm that ignores the Earth systems and environmental insight approach.

The climate crisis should have been a turning point in raising the awareness of Earth Sciences as a scientific discipline and the importance of raising the profile of Earth science teaching in schools.

The academic geoscience community is a keystone for bridging the disturbing gap between the importance of Earth science to humanity and its low profile in schools worldwide.



10:30am - 10:45am
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?

State of the Art: Summary of the geoscientific content in German curricula

Alexandra Mauerberger1,2, Tamara Fahry-Seelig2, Sylke Hlawatsch3

1EIfER European Institute for Energy Research, Germany; 2Dachverband der Geowissenschaften; 3Richard Hallmann Schule

We analyzed the curricula of the natural science teaching subjects of all federal states in Germany regarding their geoscientific content. With this information we can better address the demand of teacher trainings and provide the corresponding geoscientific topics. We can also approach the ministries of education to develop geoscience curricula for all 16 federal states as well as the national Kultusministerkonferenz (KMK) in order to include geoscience education in standards for education and teacher training.

To provide a quantitative evaluation, we compared the German curricula with the International Geoscience Syllabus (IGS) and developed a classification scheme. The higher the ranking, the larger is the combability with the IGS which can be regarded as a good standard. Classification criteria are geoscientific content, education time, interdisciplinary relation to other subjects, application examples, experiments, level of guidance and grade.

The curricula in Germany are highly heterogeneous, both in their content and their level of description. Geoscience school syllabuses are available for upper secondary schools (SEKII) in Baden-Württemberg and Bayern. In these states also the teacher education and trainings have been organized during the past years. Need of improvement is especially seen for Hamburg and Niedersachsen where we found hardly any geoscientific references and also the description of the curricula is very poor.



10:45am - 11:00am
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?

Strategies for Developing Student Geoscience Identity

Sharon M Locke

Southern Illinois University Edwardsville, United States of America

Countries around the world are reporting a decline in student interest in geoscience careers, even as the need for trained geoscientists who can help solve global challenges in sustainability is becoming more urgent. This “geoscience crisis” is attributed to learners’ insufficient exposure to geosciences in the school curriculum, resulting from both lack of content and low teacher confidence in geoscience topics. Our team developed and studied an extracurricular programme of field excursions and mentored research to increase geoscience career interest among students who were in their first or second year of university but had not yet chosen their degree programme. Using the conceptual framework of social influence, the research team employed longitudinal surveys and interviews to examine geoscience identity and sense of belonging in the geosciences. The results showed that the programme had positive outcomes, with student geoscience identity emerging or increasing as students progressed. Field excursions led by an interdisciplinary faculty team were the pivotal component for increasing students’ belief that they could become a geoscientist and for enhancing student awareness of the importance of geosciences to society. The project affirms the critical need to increase teacher knowledge and skills to teach earth system science in field settings at primary and secondary level, well in advance of students choosing their university major. Field trip design should include activities that ask students to apply geoscience understandings to future Earth scenarios. This teaching approach reinforces for students that the geoscience profession has a role in our sustainable future.

 
10:00am - 11:15am4.07 Data-driven digital twins of the subsurface and their applications
Location: Wiwi 108
Session Chair: Mikhail Tsypin, GFZ
Session Chair: Judith Bott, GFZ German Research Centre for Geosciences
Session Chair: Ajay Kumar, GFZ Potsdam
Session Chair: Magdalena Scheck-Wenderoth, GFZ Potsdam
 
10:00am - 10:30am
Invited Session Keynote
Topics: 4.07 Data-driven digital twins of the subsurface and their applications

The LOOP Project: towards multi-scale digital twins of geology?

Laurent Ailleres1, Lachlan Grose1, Mark Jessell2, Fernanda Alvarado-Neves1, Angela Rodrigues1, Rabii Chaarani1, Vitaly Ogarko2

1Monash University, Australia; 2University of Western Australia, Australia

To support a socially-licensed greener future, one of the biggest challenges of the next decade is to improve our ability to predict subsurface geology. For example, the mine of the future must have a reduced footprint and economic, socially-accepted mineral resource discoveries will depend on how well we are able to characterise the subsurface geology. This requires the ability to probabilistically forecast sub-surface geology, allowing for rapid model updates.

We present the current state of the Loop project, an open-source interoperable, integrative, probabilistic 3D geological modelling platform. Map2loop is a library that automatically extracts geological information from maps and generates parameters for the modelling library. In LoopStructural, we have defined a parameterisation of 3D geological models in a forward modelling sense. LoopStructural is based on the concept of the structural frame: a coordinate system defined for each object (faults, intrusions) or geological events (folding). These coordinate systems consist of 3 perpendicular scalar fields that are interpolated and fitted to data in 3D and then combined according to the geological history. The structural frames are conformable conformable to layering throughout the models. We present the concept for LoopResources, our proposed property modelling library. Using this deformed cartesian coordinate system, we propose to adapt geostatistical and interpolation methods to curvilinear coordinate systems using classical XYZ-UVW transformations. This will ensure that lithological anisotropies are enforced during resource estimation and property modelling to provide better digital twins of the subsurface and characterise geological uncertainty throughout the entire workflow.



10:30am - 10:45am
Topics: 4.07 Data-driven digital twins of the subsurface and their applications

Using structural frames to build complex 3D geological models in LoopStructural

Lachlan Grose1, Laurent Ailleres1, Gautier Laurent2, Fernanda Alvarado-Neves1, Angela Afonso Rodrigues1

1Monash University, Australia; 2University of Orleans

In order to transition to more sustainable technologies, we as society need to improve our ability to find and manage natural resources. One of the biggest challenges for managing natural resources is our ability to characterise the subsurface distribution of geological objects including mineralisation, structures and stratigraphy. Standard approaches for quantifying the geometries of these objects interpolate these geometries using mathematical interpolation techniques which generally cannot incorporate geological rules and knowledge. Here we use a time aware modelling approach where the most recent geological feature is modelled first. The geometry of the first feature is then used to build a structural frame, a curvilinear coordinate system aligned the geometry of the feature for example capturing the fault surface and slip direction or fold axis and axial surface. The structural frame can then be used as a reference frame and combined with a conceptual model conditioned to geological observations to model the geometry of the older geological features. Using appropriate overprinting relationships and geological rules it is possible to combine multiple structural frames to characterise complicated geological objects for example refolded folds, overprinting fault networks and duplex faults. We demonstrate the application of structural frame to modelling folds, faults and intrusions with different case studies demonstrating how incorporating the structural frames allow for geologists to use models to test geological hypotheses to further understand subsurface geometries.



10:45am - 11:00am
Topics: 4.07 Data-driven digital twins of the subsurface and their applications

Linking Coseismic Groundwater Elevation Changes to Stress and Pore Pressure Evolution through 2D Hydro-Mechanical Coupled Dynamic Distinct Element Modelling

Anne Elizabeth Strader1, Jian Zhou2, Stefan Bredemeyer1, Jeoung Seok Yoon1, Soo-Gin Kim3, Hyun-Jin Cho3, Jae-Yeol Cheong3, Jeong-Hwan Lee3

1DynaFrax UG haftungsbeschränkt, Germany; 2Beijing University of Technology, China; 3Korea Radioactive Waste Agency, South Korea

Coseismic responses in groundwater level have often been observed following earthquakes worldwide. These responses have often been attributed to coseismic static and dynamic changes in volumetric strain and pore pressure, caused by slip on the ruptured fault. On 12. September 2016, the ML 5.8 Gyeongju earthquake ruptured a branch of the Yangsan fault network in southeastern Korea, triggering hydrological responses near the mainshock epicenter. To better understand the connection between volumetric strain, pore pressure and groundwater level (GWT) levels, we developed a hydro-mechanical coupled dynamic distinct element model (dyn-DEM) to simulate the Gyeongju earthquake rupture process and subsequent fluid pressure response, using 2D Particle Flow Code v7. The rock mass was modeled using an assembly of circular particles, bonded to each other by contacts with the potential to break, collectively simulating the hydro-mechanical effects of a seismic event upon application of an in-situ stress field. The hydraulic fracture process was represented by a pipe network model, where fluid flow was simulated through a network of flow channels which connected pore spaces storing fluid volume and pressure. During the simulation, the finite volume method was used to solve for the pore pressure evolution due to poroelastic effect. Overall, we observed a positive correlation between coseismic GWT level changes near the Gyeongju earthquake epicenter and modeled stress and pore pressure changes. This result supports the use of hydro-mechanical coupled dyn-DEM in reliably quantifying changes in the stress and pore pressure fields throughout the dynamic rupture process of a simulated seismic event.

 
11:15am - 11:30amBreak
Location: Foyer (Henry Ford Building)
11:30am - 1:00pmPlenary Discussion: Should we colonize Mars (or the Moon)?
Location: Audimax
Session Chair: Lena Noack, Freie Universität Berlin
Session Chair: Georg Feulner, PIK
No other planet seems to be in such demand as Mars - but why, actually? Out of curiosity if there is or once was life there? As a "plan b" for humanity? What plans do actually currently exist on how to use Mars? And can the Moon serve as a new gateway to the Solar System? Where can we specifically mine raw materials or even establish colonies? And should we? Which scientific, political or ethical restrictions need to be considered when talking about "using" or colonizing Mars or the Moon? This panel discussion brings together experts from different disciplines that will add arguments both pro and con these various aspects of going to Mars or the Moon.
1:00pm - 2:00pmFS Geodidaktik Treffen
Location: Wiwi 103
Session Chair: Sylke Hlawatsch, Richard Hallmann Schule
Session Chair: Dirk Felzmann, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau
1:00pm - 2:00pmLunch Break | Exhibition and CO2-Live Injection Event @ Wintershall Dea Booth
Location: Foyer (Henry Ford Building)
2:00pm - 3:30pm3.21-1 Tectonic Systems - TSK Open Session
Location: Hall A (HFB)
Session Chair: Armin Dielforder, Leibniz Universität Hannover
Session Chair: Michael Stipp, Martin-Luther-Universität
 
2:00pm - 2:30pm
Invited Session Keynote
Topics: 3.21 Tectonic Systems - TSK Open Session

Sedimentary basins: Fingerprinting the lithospheric-scale processes

Nevena Andrić-Tomašević

Karlsruhe Institute of Technology, Institute of Applied Geosciences, Karlsruhe, Germany

This talk focuses on disentangling the signatures of the lithospheric scale processes such as slab break-off and/or tearing within the sedimentary basin architecture. Sedimentary basins are sensitive recorders of the interplay between dynamic processes controlling the deformation of the lithosphere, climate and sea-level variations. Variations in sedimentary succession, recorded as variable grading, thickening and/or depositional trends across the basin or series of basins, are often attributed to a wide range of lithospheric-scale processes. This cause-and-effect relationship is based on deductive reasoning and so far, a direct link and quantitative assessment of the effect of these processes on the basin(s) architecture are missing. The inversion of basin fill data to derive the dominant mechanism responsible for the observed basin architecture is complicated by incomplete preservation in the geological record or sparseness in data coverage. Furthermore, many processes may have operated coevally or at different spatiotemporal scales or at different amplitudes, making retrieving the information challenging. Therefore, to distinguish slab break-off and/or tearing-induced signals within sedimentary basins from other signals (e.g., climate, sea level variations) an interdisciplinary approach is needed. In this talk, field observations and results of 3D geodynamic and stratigraphic numerical models inspired by the Molasse Basin and Dinaridic Lake System are combined to understand the set of parameters leading to the preservation of these signals in sedimentary records.



2:30pm - 2:45pm
Topics: 3.21 Tectonic Systems - TSK Open Session

The Importance of Rift Inheritance in Understanding the Early Collisional Evolution of the Western Alps

Gianreto Manatschal1, Pauline Chenin1, Gianluca Frasca2

1University of Strasbourg, CNRS, ITES UMR 7063, F-67084 Strasbourg, France; 2Institute of Earth Sciences and Georesources, National Research Council (IGG-CNR), 56124 Torino, Italy

We reassess the architecture and tectonic history of the Western Alps based on recent knowledge developed at rifted margins. First, we replace the main Alpine units of our study area into a synthetic rifted margin template based on diagnostic petrologic, stratigraphic, and structural criteria. We find that some units previously attributed to the internal part of the thick-crusted Briançonnais domain may rather derive from the thin-crusted Prepiemonte hyperextended domain. We assert that the Briançonnais and Prepiemonte domains were separated by a mega-fault scarp. Second, we revisit the Paleogeography of the Alpine Tethys, suggesting that the Briançonnais was a ribbon of little thinned continental crust between two overstepping en-échelon rift basins, namely the Valais domain to the northwest and the Piemonte domain to the southeast. We affirm that this uneven-margin architecture can explain most of the Western Alps’ complexity. In our kinematic model, convergence between Adria and Europe was mainly accommodated by strike-slip movements in the Western Alps until the late Eocene. Orogeny began with the reactivation of the mega-fault scarp between the Briançonnais and Prepiemonte domains, which we name Prepiemonte Basal Thrust. Once hard collision started, the main shortening stepped inboard into the Valais/Subbriançonnais domain along the Penninic Basal Thrust.



2:45pm - 3:00pm
Topics: 3.21 Tectonic Systems - TSK Open Session

The Cadomian Orogeny in the northern Bohemian Massif – geochronology, basin development, crustal growth, and geotectonic setting

Ulf Linnemann1, Mandy Zieger-Hofmann1, Johannes Zieger1, Jessica Gärtner1, Andreas Gärtner1, Linda Marko2, Richard Albert Roper2, Axel Gerdes2

1Senckenberg Naturhistorische Sammlungen Dresden, Germany; 2Institut für Geowissenschaften, Goethe-Universität Frankfurt, Germany

During Ediacaran to earliest Cambrian times, the Cadomian Orogen formed a system of magmatic arcs and marginal basins at the northern periphery of the Gondwana supercontinent. The orogenic belt was structured in the geotectonic style of the recent western Pacific. The Saxo-Thuringian Zone forms part of the northern Bohemian Massif and contains a number of good preserved fragments derived from the peri-Gondwanan Cadomian Orogen (e.g. the Schwarzburg Antiform, the Lausitz Block, the Eastern Sudetes). Here, we present a massive dataset of LA ICP-MS U-Pb ages and Hf-isotopes from detrital and magmatic zircon of sedimentary and igneous rocks from these areas. Sedimentary rocks are represented by arc-derived greywacke and mudstone turbidites in a back-arc and retro-arc setting. Further, glacio-marine diamictites and high-mature quartzites display passive margin deposits situated more proximate to the cratonic hinterland. U-Pb ages of detrital zircon form populations, which point to a West African hinterland during the time of deposition. The stratigraphic age of the basin fillings is bracketed between the maximum depositional age of the sedimentary rocks at c. 560 Ma and the age of intrusion of c. 539 Ma old granodiorite plutons, which intruded the isoclinal deformed greywacke-mudstone deposits of the marginal basins in the Cadomian orogenic system. The Cadomian crustal evolution is dominated by the recycling of continental crust from the West African hinterland as suggested by the dominance of zircons with negative εHf values. Juvenile arc magmas became contaminated by the recycling of Eburnian and Archaean crust during long Cadomian magmatic arc activity.



3:00pm - 3:15pm
Topics: 3.21 Tectonic Systems - TSK Open Session

Zircon U-Pb-Hf isotope systematics of southern Black Forest gneiss units (Germany) – implications for the Pre-Variscan evolution of Central Europe

Armin Zeh1, Magdalena Zimmermann1, Kirsten Drüppel1, Richard Albert Roper2, Axel Gerdes2

1KIT, Germany; 2FIERCE, Frankfurt, Germany

We present the first systematic U-Pb-Hf isotope data of detrital zircon grains from gneiss units of the southern Black Forest, preserving different stages of the pre-, syn- and post-Cadomian evolution. Protoliths of Murgtal metagreywackes were deposited during the Ediacarian at <550 Ma and sourced from the Avalonian-Cadomian Belt (550-700 Ma; ~70%) and Sahara Metacraton (760-1045 Ma, 1850-2250 Ma, 2720-3230 Ma; ~30%). In contrast, metasedimentary rocks of the Wiese-Wehra and Todtmoos gneiss units reveal late Devonian depositional ages at <370 Ma, but in different geotectonic settings. Wiese-Wehra metagreywackes provide evidence for the existence of pre-Cadomian oceanic crust formed at 610 Ma (εHft = +5 to +8), accreted to the Cadomian Belt at ca. 540 Ma, and successively reworked between 490 and 430 Ma (εHft = +1 to +6). Finally, these rocks became part of an early Variscan arc-back arc system with juvenile input at 370 Ma (εHft = 0 to +10). Todtmoos metaarkoses mainly reflect subduction-related magmatism at 490-420 Ma (~88%), and at 380 Ma (~10%) in an evolved continental arc setting (εHft = -2 to -8). In combination, existing data from the Black Forest and other basement units throughout Europe provide evidence for the amalgamation of pre-Cadomian juvenile terranes along the northern margin of Gondwana until 540 Ma, followed by a complex rift history, accompanied by subduction between 500 and 400 Ma. They further point to the existence of an oceanic arc-back arc system, which has been located south of the Armorican terrane assemblage at 380-365 Ma.



3:15pm - 3:30pm
Topics: 3.21 Tectonic Systems - TSK Open Session

Microstructures and absolute ages of brittle structures in the Weschnitz Pluton (Southern Odenwald, Germany)

Filip Loeckle1, Axel Gerdes2, Gernold Zulauf3

1BGR Hannover, Germany; 2FIERCE-Lab, Goethe University Frankfurt, Germany; 3Institute for Geosciences, Goethe University Frankfurt, Germany

We present new microstructural evidence and geochronological data from brittle structures sampled in an active quarry located in the Weschnitz Pluton in the southern Odenwald Crystalline Complex (OCC). Open joints and fractures are the primary pathway for fluids in crystalline rock and thus crucial in the utilization of crystalline formations for geothermal energy and long term nuclear storage.
The quarz-monzodioritic wall rock was emplaced around 344.4+-0.6 Ma ago into a considerably thickened crust in in about 18 km depth in a continental arc setting (Altenberger & Boesch, 1993; Altherr, 1999; Henes-Klaiber, 1992). Visean lamprophyre dikes bound to NNE-SSW striking normal faults relate to post-orogenic collapse and mark the onset of a multiphase history of extension and uplift, during which pre-existing variscan structures were repeatedly reactivated (von Seckendorff et al., 2004). While the variscan evolution is fairly well constrained (e.g. Todt et al., 1996; Krohe, 1996; Reischmann, 2001; Stein et al., 2022), brittle structures in the southern OCC have not yet been dated directly.
Most of the sampled joints measure between 2 and 10 mm and are sealed, one specimen has a thickness of 15 cm and is not sealed completely. In thin section, several types of joint mineralizations were identified, with syntaxial elongate blocky quartz with growth zoning and syntaxial blocky calcite with growth zoning being the most common types. Fractured calcite veins are often associated with hematite indicating later reactivation. U-Pb data obtained from LA-ICP-MS analyses on 15 samples splits into 2 age groups of around 300 Ma and 60-50 Ma.

 
2:00pm - 3:30pm3.14-2 Applied stratigraphy of Central European basins
Location: Hall B (HFB)
Session Chair: Markus Wilmsen, Senckenberg Naturhistorische Sammlungen Dresden
 
2:00pm - 2:15pm
Topics: 3.14 Applied stratigraphy of Central European basins

Sedimentology and sequence stratigraphy of the lower Aalenian Opalinuston Formation from southern Germany

Thomas Mann1, André Bornemann1, Jochen Erbacher1,2

1Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Hannover, Germany; 2Landesamt für Bergbau, Energie und Geologie (LBEG), Hannover, Germany

Aalenian sedimentary deposits in southern Germany have accumulated in a shallow-marine, epicontinental shelf environment. These accumulations are dominated by thick claystones and argillaceous siltstones, with increasing percentages of sandstones towards the top. Aalenian sediments are likely to represent a relatively complete stratigraphic record, however, the sedimentary evolution and paleoclimatic significance of these typically poorly exposed deposits remain largely unexplored. Here we present a suite of high-resolution x-ray fluorescence (XRF) core scanning data from southern Germany to identify Transgressive-Regressive cycles during the Aalenian stage. Results are based on three scientific drill cores of 200 – 250 m length that have been analyzed with an Avaatech XRF Core Scanner at a 10 mm sampling interval (10 keV, 500 µA). Resulting trends in elemental Si/Al ratios, which are indicative for subtle grain-size variations, combined with sedimentological observations on ichnofacies and bedform development were used to reconstruct shoreline trajectories and establish a sequence stratigraphic framework for the thick and largely homogenous lower Aalenian Opalinuston Formation.



2:15pm - 2:30pm
Topics: 3.14 Applied stratigraphy of Central European basins

Detailed multi-stratigraphic correlation of the continental latest Permian to Middle Triassic across Central Europe

Michael Szurlies

BGR, Germany

In Central Europe, the about 1 km thick Buntsandstein was deposited in the large intracratonic Central European Basin (CEB). The Buntsandstein sedimentary succession displays a striking cyclicity of varying magnitude. The most obvious cycle is the 10 to 20 m thick small-scale cycle (wet-dry cycle) that is ascribed to changes in lake level (base-level) and assumed to be controlled by astronomical forcing of climate.

Combined with wireline logs, these cycles can be mapped over large parts of the Central European Basin providing a high-resolution cyclostratigraphic framework. Hence, the cycles represent basin-wide events. The isochronous character of this framework has been proven by magneto- and biostratigraphic means. The detailed magnetostratigraphy spans the upper Zechstein to lowermost Muschelkalk. Compared with available radioisotopic ages for the base and top of the marine Early Triassic, a Buntsandstein duration of about 6 Ma is derived.

Within the more central part of the CEB, the synchronous character of the cyclostratigraphic framework has been proven by magnetostratigraphic and biostratigraphic means. Based on an integrated comparison, radioisotopic ages obtained from Tethyan sections, have been referred successfully to the Buntsandstein cyclostratigraphy, substantiating the hypothesis that the pronounced small-scale cycles correspond to solar-induced ~100 ka eccentricity cycles. Hence, the duration of the Buntsandstein has been calculated to span some 6 Ma. The Buntsandstein cyclostratigraphy offers good potential to constructing a reliable astronomically calibrated Early Triassic geomagnetic polarity timescale.



2:30pm - 2:45pm
Topics: 3.14 Applied stratigraphy of Central European basins

Time indications in the Rotliegend and the Permian ‘Pangaea Gap’

Manfred Menning, Johannes Glodny

Helmholtz-Zentrum Potsdam, Deutsches GeoForschungsZentrum GFZ

Time indications in the Rotliegend Group of Germany are integrated and presented in a new way (Menning et al. 2022, ZDDG 173: 3–139). (1) U-Pb CA-ID-TIMS radio-isotopic age determinations from the Thüringer Wald (Lützner et al. 2021, Int. J. Earth Sci.), (2) the recalculated Rb-Sr age for the Donnersberg-Formation of the Saar-Nahe Basin (Menning et al. 2022) utilizing the recently revised 87Rb decay constant (Villa et al. 2016, Geochim. Cosmochim. Acta), (3) the newly calculated mean age for the U-Pb SHRIMP data of Breitkreuz & Kennedy (1999, Tectonophysics) of 298.6 ± 1.9 Ma for the Central European Basin (CEB), which reduces the time span for the Altmark Subgroup volcanic succession from 302–290 Ma to ≈ 300.5–296.5 Ma, (4) the Re-Os age of 257.3 ± 1.1 Ma for the Kupferschiefer (base Zechstein Group), (5) the age of ≈ 265 Ma of the Illawarra Reversal of the Earth´ magnetic field, and (6) highly different palaeomagnetic properties of the sediments of the underlying Müritz Subgroup and the hanging Havel Subgroup are significant evidence for an extensive stratigraphic gap or a very gap-rich time span (≈ 295/293.5–266 Ma = Middle Rotliegend). In Central Europe, this gap forms part of the longest Phanerozoic time span without significant marine layers (≈ 311 Ma to ≈ 257.3 Ma = ≈ 54 Ma). The gap is most probably related to the amalgamation and the associated immense uplift of Pangaea in Central and Western Europe and thus termed the ‘Pangaea Gap’.



2:45pm - 3:00pm
Topics: 3.14 Applied stratigraphy of Central European basins

Givetian to Tournaisian substages – significance, multi-disciplinary approaches, and GSSP potential in the Rhenish Massif (Germany)

Ralph Thomas Becker1, Zhor Sarah Aboussalam1, Felix Saupe1, Sven Hartenfels2

1Westfälische Wilhelms-Universität, Germany; 2Geologischer Dienst NRW

The Global Time Scale of the International Commission on Stratigraphy includes subdivisions of systems down to stages but substages can be recognized once all stages are ratified. Devonian substage progress slowed down since the inevitable Pragian/Emsian boundary revision has not yet been achieved. Formal substage definitions are urgent since variable versions are used widely, in different regions, and by different authors. This hampers the precise correlation of climatic changes, sea-level fluctuations, geochemical cycles, rates of evolution, and extinction/radiation events. Precise and unequivocal time-scales are the pre-condition for advances in multidisciplinary Earth System research and geological mapping. Our recent studies led to progress in the case of Givetian to Tournaisian substages, which all shall be placed close to 2nd/3rd order global events, which importance is often hidden by their timing within stages.

The future Upper Givetian base shall be placed at the top of the global Taghanic Crises (base of hermanni Zone) while the Lower/Middle Frasnian boundary should coincide with the anoxic Middlesex Event. The best boundary marker, Ancyrodella nodosa, provides correlation with the Alamo Impact of Nevada. Revision of the controversial conodont scale at Martenberg, a potential GSSP, confirmed the semichatovae Transgression (nasuta Subzone) as the best Upper Frasnian base. Other Rhenish sections are suitable for the definitions of the Middle (base marginifera Zone, Beringhauser Tunnel), Upper (Lower Annulata Event, Effenberg), and Uppermost Famennian (e.g. Oese, base ultimus ultimus Zone). The anoxic Lower Alum Shale (base crenulata Zone) should re-define a Middle Tournaisian substage following the classical Belgium chronostratigraphic scale.



3:00pm - 3:15pm
Topics: 3.14 Applied stratigraphy of Central European basins

Blocks of fault-bounded imbricate stacks of Devonian limestones, a diagnostic field-criterion for a predominantly tectonic origin of chaotic rock fabrics in the Harz Mountains (Eastern Rhenohercynian Belt, Germany).

Carl-Heinz Gerd Friedel1,4, Edmund Lars Cunäus2, Julia Kreitz3, Bernd Leiss4, Michael Stipp5

1Karl-Marx-Str. 56, 04158 Leipzig; 2Baugrunduntersuchung Naumburg GmbH, Wilhelm-Franke-Str. 11, 06618 Naumburg; 3Smart Asphalt Solutions GmbH, Goethestraße 2, 37120 Bovenden; 4Geowissenschaftliches Zentrum der Universität Göttingen, Strukturgeologie und Geodynamik, Goldschmidtstr. 3, 37077 Göttingen; 5Institut für Geowissenschaften und Geographie, Martin-Luther-Universität Halle-Wittenberg, Von‑Seckendorff‑Platz 3, 06120 Halle

The distinction between sedimentary and tectonic processes in the formation of chaotic rock units is especially difficult in orogenic belts, where sedimentary structures are usually strongly overprinted by tectonic deformation (e.g. Fiesta et al. 2019). This also applies to the chaotic rock units, which are widespread in the allochthonous domain of the Harz Mountains. For these units, it has been assumed that their chaotic rock fabric was initially sedimentary in origin and was merely tectonically overprinted by subsequent Variscan deformation (e.g. Schwab & Ehling 2008). In contrast, it could be shown, that tectonic processes were crucial for the formation of the chaotic rock fabric (Friedel et al. 2019). This is particularly evident in the structural characteristics of Devonian limestone blocks.

In chaotic units, blocks of (hemi)pelagic condensed limestone of different Devonian age are widely incorporated in a slaty-clayey matrix. So far, the blocks were mostly regarded as olistoliths and thus considered as clear evidence for a sedimentary origin of the chaotic rock units (olistostromes). However, our investigations show that the limestone blocks are fault-bounded, folded and internally imbricated stacks of limestone strata, whose final fragmentation and isolation occurred subsequently to tectonic folding.

Such blocks of fault-bounded imbricate stacks of rock strata are a diagnostic field-criterion to identify a strong tectonic overprint or even a tectonic origin of chaotic rock fabrics. Since such blocks are regionally distributed, they support, together with other structural features, a predominantly tectonic origin of these units and argue against widespread submarine mass-flow deposits.

References:
Fiesta et al. 2019, Gondwana Research, 74, 7-30
Friedel et al. 2019, Intern. Journal of Earth Science, 108, 2295-2323
Schwab & Ehling 2008, Karbon, 110-140; in Bachmann et al. (Hrsg.) Geologie von Sachsen-Anhalt, Schweizerbart



3:15pm - 3:30pm
Topics: 3.14 Applied stratigraphy of Central European basins

Lithostratigraphic mapping of Palaeozoic units in the northern Rhenish Slate Mountains and the contribution of LithoLex

Sascha Sandmann, Stephan Becker, Sören Stichling, Sven Hartenfels

Geological Survey of North Rhine-Westphalia, Germany

The Rhenish Slate Mountains are one of the classical outcrop areas for stratigraphic research in Devonian and Carboniferous strata. Lithostratigraphic mapping of German parts of the Rhenish Slate Mountains has been performed systematically for over 100 years starting with a mapping campaign implemented by the Prussian Geological Survey in the 1920s. Today, geological mapping is performed by the Geological Survey of North Rhine-Westphalia and published in an output scale of 1 : 50 000. Results are made available via a modern geodata infrastructure for the use by digital map display. We present sedimentological facies models for the time spans of the Middle to Upper Devonian and the Mississippian. On the one hand the lithostratigraphic lexicon LithoLex is the data source of definitions of lithostratigraphic units and on the other hand results of field mapping are needed to classify lithostratigraphic units that are not yet implemented in the lexicon. Our models can work as links between results of field mapping of the northern Rhenish Slate Mountains east of the river Rhine and help to classify lithostratigraphic units, where it is still needful.

 
2:00pm - 3:30pm1.05-1 Aquifer thermal energy storage (ATES): Potential, technologies and geoscientific challenges for a sustainable energy transition
Location: Hall C (HFB)
Session Chair: Sebastian Bauer, Christian-Albrechts-Universität zu Kiel
Session Chair: Thomas Neumann, TU Berlin
Session Chair: Traugott Scheytt, TU Bergakademie Freiberg
Session Chair: Lioba Virchow, GFZ German Research Centre for Geosciences
 
2:00pm - 2:15pm
Topics: 1.05 Aquifer thermal energy storage (ATES): Potential, technologies and geoscientific challenges for a sustainable energy transition

DemoStorage – planning and monitoring of an ATES demonstrator site in an urban environment

Detlev Rettenmaier1, Roman Zorn1, Alexandra Mauerberger1, Blum Philipp2, Herrmann Matthias2, Viernickel Michael3, Eichelbaum Fabian3, Fleuchhaus Paul4, Stoeck Thorsten5, Katzenmeier Sven5, Breiner Hans-Werner5, Hahn Hans-Jürgen6, Fuchs Andreas6

1EIfER Europäisches Institut für Energieforschung; 2KIT Karlsruher Institut für Technologie; 3eZeit Ingenieure GmbH Berlin; 4tewag GmbH; 5RPTU Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau; 6IGÖ Institut für Grundwasserökologie GmbH

Aquifer thermal energy storage (ATES) is comparatively rarely used in Germany. Since there is a lack of demonstration plants nationally, the goal of our BMBF-funded joint project “DemoSpeicher” (Development and Monitoring of Seasonal Heat and Cold Storage for the Demonstration of Aquifer Storage) is to implement and scientifically accompany a near-surface LT-ATES. Within the scope of the project, the entire construction cycle of an LT-ATES is to be covered, which ranges from design and planning to grid integration and commissioning to thermal energy supply. Legal admission requirements are developed in the process. An urban site in Germanys capital Berlin-Mitte was selected for the implementation of the demonstration plant. An extensive monitoring program is planned for the thermal-hydraulic underground processes. Another focus of the project will be possible changes in groundwater chemistry and temperature-sensitive groundwater ecology because of thermal loading. Monitoring of energy flows is also planned to estimate the thermal energy exchange between the aquifer reservoir and the building's systems engineering. This will include a heating and cooling demand analysis, as well as an assessment of potential synergistic use effects with other technologies that could be used, for example, for thermal loading of aquifer storage. All results will be presented in a coupled thermal-hydraulic modeling. The project and the first results of the implementation of an LT-ATES in a densely populated urban area will be presented and discussed in this presentation.



2:15pm - 2:30pm
Topics: 1.05 Aquifer thermal energy storage (ATES): Potential, technologies and geoscientific challenges for a sustainable energy transition

Integration aspects of ATES in urban district heating networks

Nikolai Strodel, Tobias Zimmermann, Henrik Pieper

HIR Hamburg Institut Research gGmbH, Germany

In progressively decarbonized district heating systems with high shares of renewable energies, seasonal large-scale heat storage systems are a central component for overcoming the seasonal offset between heat generation and demand. In addition to Pit Thermal Energy Storages (PTES), which often encounter high spatial resistance in urban contexts, Aquifer Thermal Energy Storages (ATES) in the three geothermal regions in Germany offer a suitable solution for large-scale and cost-effective thermal energy storage with high surface area efficiency. Currently, however, there is no operating high-temperature ATES in Germany that is integrated into an urban heating network. The focus of this presentation is on aspects of interaction between aquifer storage, large-scale heat pumps and district heating networks in Germany.

The framework conditions for the technical integration of heat from aquifer storage are subject to constant change. On the one hand, district heating systems are usually operated with sliding supply and return temperatures, on the other hand, the temperature continuously decreases during discharging period.

This requires different solutions for the integration of aquifer storage, which are to be systematized and classified. Central integration possibilities are the direct use in supply line, the increase of the return temperature as well as the use of large heat pumps.

The lecture will present the findings from the research project "OptInAquiFer" on reasonable integration possibilities of aquifer storage in German district heating networks. In addition, current research on large-scale HP configurations will be highlighted to identify suitable and efficient HP capacities, refrigerants and HP configurations for ATES applications.



2:30pm - 2:45pm
Topics: 1.05 Aquifer thermal energy storage (ATES): Potential, technologies and geoscientific challenges for a sustainable energy transition

City-scale residential heating and cooling with Aquifer Thermal Energy Storage (ATES)

Ruben Stemmle, Haegyeong Lee, Philipp Blum, Kathrin Menberg

Karlsruhe Institue of Technology, Germany

Achieving sustainable and climate-friendly space heating and cooling is essential to the energy transition. Aquifer Thermal Energy Storage (ATES) is a promising technology to significantly reduce greenhouse gas emissions compared to conventional heating and cooling technologies. Therefore, in this study the technical potential of shallow low-temperature ATES systems is quantified for the city of Freiburg im Breisgau, Germany in terms of reclaimable energy. Using 3D heat transport models, heating and cooling power densities are determined accounting for several different ATES configurations in various hydrogeological subsurface conditions. High groundwater flow velocities of up to 13 m d-1 lead to a significant loss of stored energy limiting power densities to a maximum of 3.2 W m-2. Nevertheless, comparing these power densities to the existing demands of heating and cooling energy reveals that substantial heating and cooling supply rates are possible with ATES. While heating energy supply rates of larger than 60 % are determined for about 50 % of all residential buildings, the cooling energy demand could be supplied entirely by ATES systems for 92 % of the buildings. For ATES heating alone, this results in greenhouse gas emission savings of up to 70,000 tCO2eq a-1. This equals about 40 % of the current greenhouse gas emissions caused by space and water heating in the study area’s residential building stock. In the future, the application of the modeling approach proposed in this study for other regions with similar hydrogeological conditions could obtain estimations of local ATES supply rates supporting city-scale energy planning.



2:45pm - 3:00pm
Topics: 1.05 Aquifer thermal energy storage (ATES): Potential, technologies and geoscientific challenges for a sustainable energy transition

Experimental results of a high-temperature aquifer thermal energy storage test site - storage efficiency and thermal impact on the environment

Johannes Nordbeck, Klas Lüders, Götz Hornbruch, Sebastian Bauer

CAU Kiel, Germany

High-temperature aquifer thermal energy storage (HT-ATES) in the geological subsurface can help bridge the temporal mismatch between production and demand of energy from renewable sources. Despite great importance for energy system transformation in the heat supply sector, HT-ATES faces some challenges and risks such as regulatory challenges. The heat input experiments at the TestUM –Aquifer test site provide a basis for characterization and verification of hydraulic, thermal, geophysical, microbiological, and geochemical process understanding. A HT-ATES system was experimentally simulated at the field site, representing three phases with varying loading and unloading cycles at injection temperatures of 80°C. More than 500 thermocouples were used to record temperature data over a 579-day period between July 2021 and February 2023. A total of eleven operating cycles divided into three phases were performed, representing a total heat input of 155 MWh. The temperature records are highly resolved spatially, especially in the vicinity of the injection well, with intervals as low as 0.5 m in the vertical and horizontal directions, and a temporal resolution of 10 min. Thus, the temperature distribution in the subsurface and the position of the heat plume is well characterized at any time. Results show, that the temperature distribution is affected by density driven convection, caused by the temperature differences, as well as heat loss to the confining unit. The storage efficiency was determined by measuring return flow rates and temperatures, showing that storage efficiency decreases with cycle length and with downtimes between charging and discharging.



3:00pm - 3:15pm
Topics: 1.05 Aquifer thermal energy storage (ATES): Potential, technologies and geoscientific challenges for a sustainable energy transition

From baseline to post operation: two year monitoring of thermo-hydraulic induced geochemical effects of a cyclic HT-ATES field test at the “TestUM” test site

Klas Lüders, Götz Hornbruch, Ralf Köber, Johannes Nordbeck, Andreas Dahmke

Kiel University - Institute of Geosciences, Germany

Seasonal ATES systems enable the efficient integration of climate-neutral heat sources into urban heat-supply systems. However, secure and efficient operation presupposes the detection as well as realistic evaluation and prediction of induced hydraulic, thermal, geochemical and microbial effects and their impacts on operation and environment.

To provide the database for extending field-scale process understanding and deriving suitable monitoring strategies, a cyclic HT-ATES field test was conducted. In six fortnight-long charging periods ~300 m³ of water were infiltrated (~15 L/min; ~80 °C) into the storage aquifer (6-15 bgs) and recovered directly or after 21 storage days. Induced hydrogeochemical effects and their reversibility were tracked with a temporal and spatially high-resolute monitoring of ~90 measurement points.

Within ~7 m around the „hot well“, superimposition of formerly stratified calcium and sulphate concentrations in combination with the spatial spreading-patterns of elevated silica concentrations point towards the build-up of a density-driven convection cell, which was also predicted by accompanying numerical thermo-hydraulic simulations. In storage periods, but more so in post operation, decreases in temperature go along with a decline of previously elevated concentrations of e.g. silica, potassium, selenium and vanadium. Moreover, potassium and selenium concentration-peaks drop after the first cycles, indicating depletion of their releasable pools. Although simulated tracers indicate passage of infiltrated water, no induced temperature or concentration changes were monitored 30 m downstream so far.

Overall, highly dynamic flow conditions dominate the hot well’s vicinity and despite scale dependent low heat recovery rates, reversibility of induced effects keeps the wider surrounding geochemically unaffected.



3:15pm - 3:30pm
Topics: 1.05 Aquifer thermal energy storage (ATES): Potential, technologies and geoscientific challenges for a sustainable energy transition

Carbonate aquifers for thermal energy storage: A critical analysis of clogging and scaling using temperature-controlled batch and column experiments

Alireza Arab1, Leonie Gabler1, Martin Binder1,2, Traugott Scheytt1

1Technische Universität Bergakademie Freiberg, Institute of Geology, Chair of Hydrogeology and Hydrochemistry, Gustav-Zeuner-Str. 12, 09599 Freiberg (Saxony), Germany; 2University of Basel, Department of Environmental Sciences, Hydrogeology / Applied and Environmental Geology, Bernoullistrasse 32, 4056 Basel, Switzerland

Throughout the past two decades, aquifer thermal energy storage (ATES) has grown increasingly into focus as a suitable geo-energy storage method. In this context, many carbonate aquifers are useable for storing and later retrieval of thermal energy due to their potential natural porosity and adequate permeability. However, numerous ATES projects suffer from operational and maintenance issues or failures. For instance, a reduction in reservoir permeability and clogging (caused by scaling, sintering, flocculation, and microbial growth) belong to the main threats to sustainable and reliable functioning.

In the BMBF-funded research project “UnClog-ATES”, both the aforementioned threats and their practical countermeasures (e.g., adding scaling inhibitors, acids, CO2) are thoroughly investigated using a combination of flow-through column and batch experiments. These experiments are temperature-controlled to simulate realistic ATES cycles of alternating heating and cooling while monitoring them continuously.

A critical point when assessing ATES systems specifically for carbonate aquifers is that significant inconsistencies exist regarding the kinetics and intensities of mineral dissolution/precipitation processes observed in the laboratory (using pure/synthetic minerals) and those observed in reality. This is because factors such as specific surface, dislodgement from equilibrium, presence of inhibitors as well as the rock’s chemical purity play important roles. For that reason, i.e., to represent natural ATES materials and to gain realistic reaction data, limestone from the Malm (Upper Jurassic), Germany (“Treuchtlinger Marmor”), is used for our experiments.

The overall project results aim towards gaining a variety of insights that are essential for planning, effective implementation, and sustainable operation of ATES in carbonate aquifers.

 
2:00pm - 3:30pm3.29 Latest achievements in scientific drilling and ocean-continental feedbacks
Location: Hall D (HFB)
Session Chair: Arne Ulfers, Bundesanstalt für Geowissenschaften und Rohstoffe (BGR)
Session Chair: Rasmus C. Thiede, Christian Albrecht Universität zu Kiel
Session Chair: Cindy Kunkel, GFZ German Research Centre for Geosciences
Session Chair: Henrik Grob, Kiel University
 
2:00pm - 2:30pm
Invited Session Keynote
Topics: 3.29 Latest achievements in scientific drilling and ocean-continental feedbacks

The marine sediment archives of Himalayan erosion

Yani Najman1,2, Mike Blum3, Chris Mark4, Guangsheng Zhuang5

1Lancaster University, United Kingdom; 2University of Colorado Boulder, USA; 3University of Kansas, Lawrence, USA; 4Swedish Museum of Natural History, Stockholm, Sweden; 5Dept of Geology and Geophysics, Louisiana State University, Baton Rouge, USA

Marine sediment archives provide invaluable records of continental erosion and dynamics, important for understanding both crustal deformation and climatic processes. Yet these archives are influenced by autogenic and allogenic processes. Rigorous interpretation of these records therefore requires unravelling of these various intertwined factors, and a good understanding of source-to-sink.

The Bengal Fan is the largest marine sedimentary fan in the world. It, and its smaller “sister” the Indus Fan, as well as the Nicobar Fan, archive the erosional history of the Himalayas, the largest mountain belt in the world. Various IODP, and previously DSDP expeditions have cored the fans, and the material extensively studied to elucidate the history of the fans’ hinterland tectonics, source to sink dispersal patterns, and climatic variations through time, with an emphasis on the response to the Asian monsoons. Yet unravelling the competing influences on the sediment archives in this tectonically active region is challenging.

In this talk I will provide an overview on the use of isotopic provenance studies to discuss aspects of the progress made in using the archives to determine Himalayan tectonics, as well as in deconvolving autogenic versus allogenic influences and in our understanding of source-to-sink.



2:30pm - 2:45pm
Topics: 3.29 Latest achievements in scientific drilling and ocean-continental feedbacks

Microbial life in an ultra-deep sulfate-methane transition zone on the Antarctic continental margin

Thorsten Bauersachs1, Jens Kallmeyer2, Zeyu Jia2, Mark Schmidt3, Lorenz Schwark4

1Heidelberg University, Heidelberg, Germany; 2GFZ Potsdam, Section Geomicrobiology, Potsdam, Germany; 3GEOMAR Helmholtz Centre for Ocean Research Kiel, Research Division 2Marine Biogeochemistry, Kiel, Germany; 4Christian-Albrechts-University, Institute of Geosciences, Kiel, Germany

Ocean sediments are considered to contain microbial biomass that equals the stock of organic matter on all the continents combined. Knowledge on the spatiotemporal distribution and abundance of microbial life in marine subsurface sediments, however, is still sparse. A region particularly understudied in this respect is the Antarctic continental margin, in which the deep biosphere is largely terra incognita. A 794 m-long sediment sequence (Site U1532), recovered during IODP Expedition 379: “Amundsen Sea West Antarctic Ice Sheet History” provides the unique opportunity to study the composition and abundance of the deep biosphere in polar regions of the Southern Hemisphere. Porewater profiles of sulfate and methane concentrations indicate that the sulfate-methane transition zone (SMTZ) is located at a depth of ~660 mbsf, making it one of the deepest SMTZ ever encountered. Stable carbon isotope measurements attest to the biological origin of the methane and provide direct evidence for an active deep-dwelling microbial community. Cell abundances decline with depth by three orders of magnitudes but increase again within the SMTZ. Complementary biomarker analysis indicates that this change in cell abundances is associated with a shift in the microbial community to predominantly methanogens throughout the SMTZ. Our data thus provides first insights into the microbial diversity and abundance of the deep biosphere in the yet largely unstudied marine subsurface sediments surrounding Antarctica. Combining our results with previous data of cell abundances in marine sediments suggests that current projections of microbial biomass appears to be overestimated and need to be downsized.



2:45pm - 3:00pm
Topics: 3.29 Latest achievements in scientific drilling and ocean-continental feedbacks

The role of basalts in the Earth’s carbon-cycle: lessons learnt from continental and ocean drilling investigations to tackle anthropogenic warming

Christophe Galerne1, Wolfgang Bach1, Nils Lenhardt2, Jörg Hasenclever3, Achim Kopf4, Wolf-Achim Kahl5, Christin Wiggers1, Annette Götz6

1University of Bremen, Germany; 2University of Pretoria; 3University of Hamburg; 4MARUM; 5MAPEX - Center for Materials and Processes; 6Georg-August-University Göttingen

Permanent carbonate mineralisation in basalt is a promising solution for Carbon Capture and Storage of anthropogenic greenhouse gases without the risk of leakage. While this process is known to occur at relatively low temperatures below 100°C, new research on Large Igneous Provinces (LIPs) and young rift basins suggests that much of the thermogenic gases mobilised during contact metamorphism can remain trapped and mineralised in the sills that mobilised them. This discovery is the result of two distinct drilling investigations on land (KARIN) and at sea (IODP Exp 385). It shows that basalts may not only trigger the sudden release of thermogenic gas, but also represent an important carbon sink. The two examples of carbonate trapping in sills presented here are from the Karoo and Guaymas basins. Results indicate that a large fraction of epimagmatic fluids charged with thermogenic gas systematically penetrated inside the sills during cooling. Our numerical solutions suggest that in both cases the higher permeability of the sill acquired during cooling and crystallisation compared to that of its host, ultimately dictates the fate of the thermogenic gas that accumulates in the igneous body. On this basis, we conclude on the role of basalts in the Earth’s carbon cycle from a geological and anthropogenic perspective.



3:00pm - 3:15pm
Topics: 3.29 Latest achievements in scientific drilling and ocean-continental feedbacks

Comparing lacustrine sedimentation rates and their response to climatic and environmental change

Christian Zeeden1, Luc Grandcolas1, Mathias Vinnepand1, Arne Ulfers1, Mehrdad Sardar Abadi1, Simona Pierdominici2, Thomas Wonik1

1LIAG, Leibniz Institute for Applied Geophysics, Stilleweg 2, 30655 Hannover, Germany; 2Helmholtz-Centre Potsdam, German Research Centre for Geosciences – GFZ, Telegrafenberg, 14473, Potsdam, Germany

Continuous limnic archives may record millions of years of climatic and environmental change at their locality. Typically, such archives reflect environmental conditions in the lakes’ catchments, but also the imprint of large-scale atmospheric systems e.g. related to insolation and/or global ice-sheet dynamics. These parameters may vary considerably in space and time, and our understanding on patterns across continents that relate to this forcing is still incomplete. Comparing sedimentation rates from limnic archives covering fundamental changes in the Earth’s system like the Mid-Pleistocene transition (change from 41kyr to 100kyr cycle world) has potential to shed light into spatial differences in Earth’s climate response, if applied carefully.

To better understand the sedimentation history of lakes, and especially their reaction to climate transitions, we compare sedimentation rates from lakes. In a second step, we systematically align several records to facilitate best comparability. We focus on limnic records that have been investigated during ICDP projects, and specifically assess the influence of the Mid-Pleistocene transition and the Mid-Brunhes transition on sedimentation rates.



3:15pm - 3:30pm
Topics: 3.29 Latest achievements in scientific drilling and ocean-continental feedbacks

Drilling in a World Heritage Site

Nonkululeko Phumelele Mashele1, Christoph Heubeck2, BASE Onsite Geoscience Team2, Astrid Christianson3

1University of Johannesburg, South Africa; 2Friedrich-Schiller Universität Jena, Germany; 3Barberton Community Tourism, South Africa

The ICDP-Project BASE investigated Archean Surface Environments by coring the ca. 3220 Ma Moodies Group of the Barberton Greenstone Belt, South Africa, Oct. 2021 – August 2022. This unit represents some of the oldest shallow-water and terrestrial siliciclastic strata worldwide; it contains fossil microbial life. Because the BGB had repeatedly seen intensive gold exploration and features several active gold mines along its northern margin, the eight BASE drill sites, largely located within the 2018 declared Barberton-Makhonjwa Mountains WHS, had to counter initial suspicion that they masked a gold exploration project, largely controlled by foreign interests. We obtained goodwill, interest, and permits from the local population and from local, regional, and national government, respectively, and ensured safe and incident-free drilling operations by designing and executing a multi-faceted approach: Prior to project start, we contributed regularly to local and regional newspapers, had the planning workshop extensively covered by media, and cultivated contacts with stakeholders and local property owners. The Education/Outreach/Publication program employed a Barbertonian geologist full time to work with traditional government, radio stations, TV, schools, and institutions of higher learning. We set aside half of our core processing space in downtown Barberton as an exhibition area, trained all staff as tour guides, maintained an open-door policy, and encouraged visitors to observe us as we processed core. Delegations, school classes, and associations could inform themselves first-hand on the core retrieval process on field trips to drill sites. After operations, BASE added a room to the local museum dedicated to WHS geoscience research.

 
2:00pm - 3:30pm1.10-2 Lithiumresources
Location: Wiwi 101
Session Chair: Jochen Kolb, KIT
Session Chair: André Stechern, Bundesanstalt für Geowissenschaften und Rohstoffe (BGR)
 
2:15pm - 2:30pm
Topics: 1.10 Lithiumresources

Lithium (Li) mineral characterization of drill cores and hand specimens: supporting exploration with rapid mineralogy mapping

Andrew Menzies1, Jorge Ferreira2, Paula Avila2, Nigel Kelly3, Roald Tagle1

1Bruker Nano Analytics GmbH, Germany; 2Laboratório Nacional de Energia e Geologia, Porto, Portugal; 3Bruker Nano Analytics, Denver, CO, USA

Batteries are a key part of the energy transition. Lithium(Li)-ion batteries are currently the main source of energy storage in the market and will likely remain so for the foreseeable future. Lithium is currently regarded as a “critical mineral” both for central role in rapidly developing electric technologies and a predicted shortfall in production versus expected demand. Therefore, identification of new resources is both economically and strategically important, driving a boom in Li exploration.

Like other metals, exploration for hard-rock lithium resources faces the challenge of how to bridge scales and dimensions of observations, from field-scale (in 3D-4D) down to laboratory-based imaging and analysis (3D-2D). Moreover, the ability to identify and characterize Li mineralogy present in a sample is important in understanding potential economics of a deposit, including the required mineral processing to extract the Li resource. Combined micro-XRF and Automated Mineralogy (AMICS) is capable of high-speed analysis at the micrometer scale that can identify a wide range of Li mineralogy non-destructively in minimally prepared drill core samples, thus providing valuable information early in exploration. This case study will present mineral characterization from a number of potential lithium resources in Portugal. Preliminary results suggest significant added value of the micro-XRF approach, where a much-improved mineral-textural understanding aids exploration and ongoing evaluation of deposit potential.

 
2:00pm - 3:30pm3.25 The links between deep-seated mechanisms, surface processes and landscape evolution
Location: Wiwi 104
Session Chair: Lorenzo Gemignani, Freie Universität Berlin
Session Chair: Riccardo Reitano, Univeristy of Rome "Roma Tre"
Session Chair: Silvia Crosetto, GFZ Potsdam
Session Chair: Alexander Rohrmann, Freie Universität Berlin
Session Chair: Richard F Ott, GFZ Potsdam
Session Chair: Romano Clementucci, ETH Zurich
 
2:00pm - 2:30pm
Invited Session Keynote
Topics: 3.25 The links between deep-seated mechanisms, surface processes and landscape evolution

Divide migration and escarpment retreat in Madagascar and the Western Ghats of India

Yanyan Wang1, Sean Willett1, Datian Wu2, Negar Haghipour1, Marcus Christl3

1ETH Zurich, Department of Earth Sciences; 2China Geological Survey, Shenyang Center; 3ETH Zurich, Department of Physics

A great escarpment is characterized with extremely asymmetrical topography with a steep and high-relief mountain range rimming a low-relief high plateau. Measured erosion rates contradict the observed high relief of the escarpments of Madagascar and India. We used cosmogenic nuclide (CN) 10Be concentrations to infer horizontal retreat rates of escarpments. Million-year scale retreat rates of Madagascar and India escarpments are ~1 km/Ma. CN 10Be-inferred retreat rates and escarpment morphology are consistent with steady retreating escarpment from modern coastlines since rifting for both margins.

The edge of the escarpment usually acts as the water divide. Previous studies conceptualize an escarpment as a migrating water divide. We studied the morphological features the escarpment and continental water divide of Madagascar and India, demonstrating that the continental water divide does not universally correspond to the steep rift escarpment due to river captures. We hypothesized that the heavily weathered plateau encourages frequent river capture and affects the morphology and rates of escarpment retreat.

We used 2D landscape evolution models to explore factors in controlling escarpment retreat. Model observations support the hypothesis that divide migration patterns control escarpment retreat patterns through the control of captured drainage area from the plateau. Through frequent river capture or divide advance into an erosional weak layer, rivers increase area and thereby increase the retreat rate. Measured escarpment retreat rates of eastern Madagascar and Western Ghats, India support this model and quantify the effect of captured area on escarpment retreat rate.



2:30pm - 2:45pm
Topics: 3.25 The links between deep-seated mechanisms, surface processes and landscape evolution

Rock-uplift history of the Central Pontides from river-profile inversions and implications for the evolution of the North Anatolian Fault

Simone Racano1, Taylor Schildgen2, Paolo Ballato3, Cengiz Yıldırım4, Hella Wittmann3

1University of Potsdam, Potsdam, Germany; 2GFZ German Research Centre for Geosciences, Potsdam, Germany; 3University of Roma Tre, Rome, Italy; 4Istanbul Technical University, Istanbul, Turkey

Major strike-slip fault systems on Earth, like the North Anatolian Fault (NAF), play an important role in accommodating plate motion, but little is known about their spatiotemporal evolution. In the Central Pontides, north of the central segment of the NAF, data from thermochronology suggest an exhumation phase occurred after 11 Myr. However, the precise onset of this uplift phase is poorly constrained. In this study, we define the spatiotemporal rock-uplift pattern within the Central Pontides over the last ~10 Myr by performing linear inversions of 19 river profiles draining the northern margin of the Central Pontides, from the Sinop Range to the Black Sea. We use 21 new 10Be-derived basin-average denudation rates to calibrate an erodibility parameter, necessary to infer rock-uplift histories from χ-transformed river profiles. Our results document an increase in rock-uplift rates after 10 Ma, with peaks of 0.15–0.25 km/Myr occurring between 4 and 2 Ma. Moreover, the spatiotemporal uplift variations suggest that rock uplift migrated westward over a period of 2–2.5 Myr. Linking the uplift to the transpression produced along the NAF central segment, we used the faster uplift onset to calculate the NAF propagation rate, estimated to be ~74±13 km/Myr. Combining our results with those from previous studies on the NAF age, we found differences in fault-propagation rates that coincide with differences in the orientation of the NAF relative to plate-convergence vectors. Fault segments with higher obliquity appear to have propagated at rates up to 2-fold slower than those oriented parallel to the plate-convergence vector.



2:45pm - 3:00pm
Topics: 3.25 The links between deep-seated mechanisms, surface processes and landscape evolution

Landscape processes and erosion in the Ordos Loess Plateau, central China: topographic response to the Cenozoic uplift of the Tibetan Plateau and climate change

Mengyue Duan1,2, Franz Neubauer1, Jörg Robl1, Xiaohu Zhou2

1Department of Environment and Biodiversity, Geology Division, Paris-Lodron-University of Salzburg, Hellbrunner Street 34, Salzburg 5020, Austria; 2State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Northern Taibai Street 229, Xi'an 710069, China

The Cenozoic uplift of the Tibetan Plateau leads to eastward lateral extrusion of fault-bounded blocks, which caused large surface uplift. To the northeast of the Tibetan Plateau, the development of the particular fluvial incision landscape on the internally stable Ordos Loess Plateau reflects the lateral extrusion and thrust loading by the adjacent Liupanshan Mts. in the west. In this study, we investigated the climate-mediated temporal evolution of surface uplift and the effect of activity along confining faults on the morphological evolution of the Ordos Loess Plateau by fieldwork, morphological analysis and integration of results from numerous previous studies. Field surveys show that the boundaries of the Ordos Loess Plateau are still tectonically active and fluvial channels are in a state of morphological disequilibrium, with steep channel segments towards the Weihe Graben and meandering low-gradient rivers in the central Ordos Loess Plateau. Morphological analysis shows that the shape of the longitudinal channel profile is straight and deviates from typical longitudinal channel profiles and the degree of erosion and plateau incision is more pronounced in the southeastern Ordos Loess Plateau. We conclude that the northeastern expansion of the Tibetan Plateau activated the boundary faults around the tectonically stable, craton-like Ordos Loess Plateau, which caused the drainage basins to tilt towards the overthrusting Liupanshan Mts in the southwest. The drainage systems reorganized to a principal southern flow direction towards the Weihe Graben caused by the ongoing E-W shortening and ca. N-S extension and thereby progressively incising in the Ordos Loess Plateau.



3:00pm - 3:15pm
Topics: 3.25 The links between deep-seated mechanisms, surface processes and landscape evolution

Controls on Island morphologic evolution

Anaé Lemaire1,2, Jean Braun1,3, Esteban Acevedo-Trejos1

1Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Potsdam, Germany; 2Institut Polytechnique UniLaSalle, Beauvais, France; 3Institute of Earth and Environmental Sciences, University of Potsdam, Potsdam, Germany

Islands are interesting geomorphic features because they possess a well defined base level. Non-volcanic islands, in particular, are the product of rifting of a small continental fragment such that they start their geomorphic evolution as a more or less elevated flat plateau. After tens of millions of years of evolution, some islands, such as Madagascar, still present a Pi-shaped form composed of large watersheds on top of a central plateau surrounded by smaller ones that connect the plateau to the coastline. Other islands, such as Sri Lanka have a more conical or Lambda-shape composed of a radial distribution of basins connecting the island summit to the coastline. Here we investigate the conditions that lead to the transformation of an initially plateau-shape island to either a Pi- or Lambda-shape by using a Landscape Evolution Model solving the Stream Power Law and talking into account flexural isostasy.

We find that to maintain a Pi-shape, an island must fulfil two criteria: firstly, its extent must be sufficiently large in comparison with the underlying effective elastic thickness (EET), and, secondly, it must be subjected to limited erosion. We introduce a morphometric index that allows to discriminate between the two types of morphologies and show how it evolves through time as a function of both EET and erodibility.

Constraining the time evolution of the morphology of an island is important to study the evolution of its bio-diversity. Our finding implies that the micro-endemism that characterises Madagascar is linked to the strength of the underlying lithosphere.



3:15pm - 3:30pm
Topics: 3.25 The links between deep-seated mechanisms, surface processes and landscape evolution

A Deeper Look Into the 2021 Tyrnavos Earthquake Sequence (TES) Reveals Coseismic Breaching of an Unrecognized Large-Scale Fault Relay Zone in Continental Greece

Vasiliki Mouslopoulou1, Henriette Sudhaus2, Kostas Konstantinou3, John Begg4, Vasso Saltogianni5,1, Benjamin Männel5, Onno Oncken5

1National Observatory of Athens, Greece; 2Institute of Geosciences, Christian-Albrechts- University, Kiel, Germany; 3Department of Earth Sciences, National Central University, Jhongli, Taiwan; 4J Begg Geo Ltd, Masterton, New Zealand; 5GFZ Helmholtz Centre Potsdam, German Research Centre for Geosciences, Potsdam, Germany

Large magnitude (Mw ∼ ≥6) earthquakes in extensional settings are often associated with simultaneous rupture of multiple normal faults as a result of static and/or dynamic stress transfer.
Here, we report details of the coseismic breaching of a previously unrecognized large-scale fault relay zone in central Greece, through three successive normal fault earthquakes of moderate magnitude (Mw 5.7–6.3) that occurred over a period of ∼10 days in March 2021. Specifically, joint analysis of InSAR, GNSS and seismological data, coupled with detailed field and digital fault mapping, reveals that the Tyrnavos Earthquake Sequence (TES) was accommodated at the northern end of a ∼100 km wide transfer structure, by faults largely unbroken during the Holocene. By contrast, the southern section of this relay zone appears to have accrued significant slip during Holocene. InSAR-derived displacements agree with the loci of eight subtle, previously undetected, faults that accommodated coseismic and/or syn-seismic normal fault slip during the TES. Kinematic modeling coupled with fault mapping suggests that all involved faults are interconnected at depth, with their conjugate fault-intersections acting largely as barriers to coseismic rupture propagation. We also find that the TES mainshocks were characterized by unusually high (>6 MPa) stress-drop values that scale inversely with rupture length and earthquake magnitude. These findings, collectively suggest that the TES propagated northwestward to rupture increasingly stronger asperities at fault intersections, transferring slip between the tips of a well-established, but previously unrecognized, relay structure. Fault relay zones may be prone to high stress-drop earthquakes and associated elevated seismic hazard.

 
2:00pm - 3:30pm3.12-1 Past climates and environments inform our future
Location: Wiwi 104a
Session Chair: Cécile Blanchet, GFZ Potsdam
Session Chair: Stefanie Kaboth-Bahr, Free University Berlin
 
2:00pm - 2:30pm
Invited Session Keynote
Topics: 3.12 Past climates and environments inform our future

Sclerochronology: Reconstructing short-term climate variability from mollusk shells

N.J. Winter1,10, B. Goudsmit-Harzevoort2,3, N. Wichern4, A. Johnson5, S. Goolaerts6, F. Wesselingh7, G.J. Reichart8, L. de Nooijer8, W. Boer8, J. Vellekoop6,9, N. van Horebeek9, P. Claeys10, R. Witbaard2, M. Ziegler3

1Department of Earth Sciences, Vrije Universiteit Amsterdam, the Netherlands; 2Estuarine and Delta Systems group, Royal Netherlands Institute for Marine Research, the Netherlands; 3Department of Earth Sciences, Utrecht University, the Netherlands; 4Institut für Geologie und Paläontologie, WWU Münster, Germany; 5College of Science and Engineering, University of Derby, United Kingdom; 6Royal Belgian Institute of Natural Sciences, Brussels, Belgium; 7Naturalis Biodiversity Center, Leiden, the Netherlands; 8Ocean Sciences group, Royal Netherlands Institute for Marine Research, the Netherlands; 9Deptartment of Earth Sciences, KU Leuven, Belgium; 10Analytical, Environmental and GeoChemistry group, Vrije Universiteit Brussel, Belgium

In the ongoing anthropogenic climate crisis, successful adaptation to future climate requires a detailed understanding of the response of Earth’s climate system to warming. Past warm climates constitute a valuable natural laboratory for studying this response, but reconstructions of past climate variability on human timescales (days to decades) remains challenging. Biogenic carbonates such as mollusk shells are uniquely suitable for these high-resolution climate reconstructions for three reasons:

Firstly, mollusk shells grow incrementally, depositing annual, daily, or even tidal laminae of carbonate marking time at unique detail.

Secondly, mollusks are diverse, abundant, and highly evolutionarily successful: Their fossil record spans the entire Phanerozoic and they produce shells of various shapes, sizes, mineral structures and compositions, making them versatile climate archives.

Thirdly, carbonate shells have a high preservation potential, retaining their original chemical composition, and the climate information locked therein, also on long geological timescales.

I will present some of the latest developments in sclerochronology, the study of reading the skeletal diaries of these fascinating invertebrates, and highlight how the information they reveal changes our understanding of past climate. A few case studies will showcase the full potential of fossil shells as climate archives. Finally, I will discuss some open questions in the field and the ongoing and future projects in which we hope to answer them. The goal is to demonstrate how collaborations between biology, marine science and (geo)chemistry enable us to unlock the full potential of these unique archives and contribute to understanding shallow marine ecosystems and climate.



2:30pm - 2:45pm
Topics: 3.12 Past climates and environments inform our future

Seasonal geochemical and growth rate variabilities in a Miocene giant clam

Iris Arndt1,2, Douglas Coenen1,2, Maximilian Fursman1,2, David Evans3, Willem Renema4,5, Wolfgang Müller1,2

1Goethe University Frankfurt, Germany; 2Frankfurt Isotope and Element Research Center (FIERCE), Frankfurt, Germany; 3University of Southampton, Southampton, U.K.; 4Naturalis Biodiversity Center, Leiden, The Netherlands; 5University of Amsterdam, Amsterdam, The Netherlands

Tridacna are important archives for (sub)tropical marine palaeoenvironmental conditions. Their longevity (up to 100 years), large aragonitic shells (up to 1m) and rapid shell accretion (mm-cm/year) make them ideal to give insights into region specific climate and environmental variability. Highly spatially-resolved analytical techniques such as LA-ICPMS mean that geochemical data can be retrieved at a high temporal resolution (subdaily). Tridacna, with their daily banding and growth rates of tens of µm/day, are ideal candidates for applying this methodology evaluating seasonality and extreme weather events in (sub-)tropical reefs since their appearance in the early Miocene. Studies of seasonal records and information on extreme weather events from past climate settings can help inform model assessment exercises regarding how seasonality might change in future climate scenarios. In this study we present a multiproxy record from a 250 mm large late Miocene Tridacna from East Borneo spanning several decades, with subseasonally resolved stable δ18O and δ13C data and sub-daily resolved elemental ratio data (B, Na, Mg, Sr, Ba to Ca). By applying Daydacna, a recently developed python script that enables daily cycle based internal age modelling, we can create an age model of the shell, which forms the basis for the temporal reassignment of the geochemical data. Displaying geochemical data against time rather than shell distance improves multi-annual as well as inter-organism comparisons for palaeoseasonality reconstructions. We reconstruct seasonal growth rate variability and compare it to the corresponding elemental and isotopic ratios to evaluate the relationships between geochemical signals, shell growth and environmental parameters.



2:45pm - 3:00pm
Topics: 3.12 Past climates and environments inform our future

Tropical Climate Variability and Coral Reefs - A Past to Future Perspective on Current Rates of Change at Ultra-High Resolution (SPP 2299)

Thomas Felis1, Miriam Pfeiffer2, Jessica Hargreaves1, Eleni Anagnostou3, Sonia Bejarano4, Patrick Boyden1, Thomas Brachert5, Hana Camelia1, Diana Diers6, Juan Pablo D'Olivo7, Andrew Dolman8, Nicolas Duprey9, Jan Fietzke3, Martin Frank3, Norbert Frank10, Daniel Frick2, Dieter Garbe-Schönberg2, Eberhard Gischler6, Sahra Greve10, Ed Hathorne3, Michael Henehan11,12, Saori {Sally} Ito2, Oliver Knebel6, Laura Lehnhoff7, Donghao Li1, Alfredo Martinez-Garcia9, Luisa Meiritz3, Ute Merkel1, Regina Mertz13, Wyatt Million14, Phyllis Mono5, Manfred Mudelsee15, Alessio Rovere16, Marlen Schlotheuber17, Christian Voolstra17, Marlene Wall3, Sophie Warken10, Takaaki {Konabe} Watanabe2, Christian Wild18, Yang Yu3, Maren Ziegler14

1MARUM, University of Bremen, Germany; 2Kiel University (CAU), Germany; 3GEOMAR, Kiel, Germany; 4ZMT Bremen, Germany; 5Leipzig University, Germany; 6Goethe University Frankfurt, Germany; 7FU Berlin, Germany; 8AWI Potsdam, Germany; 9MPI for Chemistry, Mainz, Germany; 10Heidelberg University, Germany; 11University of Bristol, UK; 12GFZ Potsdam, Germany; 13Johannes Gutenberg University Mainz, Germany; 14Justus Liebig University Giessen, Germany; 15University of Potsdam, Germany; 16Ca' Foscari University of Venice, Italy; 17University of Konstanz, Germany; 18University of Bremen, Germany

Climate change, in particular the rise in tropical sea surface temperatures, is the greatest threat to coral reef ecosystems today and causes climatic extremes affecting the livelihood of tropical societies. Assessing how future warming will change coral reef ecosystems and tropical climate variability is therefore of extreme urgency. Ultra-high resolution (monthly, weekly) coral geochemistry provides a tool (1) to understand the temporal response of corals and coral reefs to ongoing climate and environmental change, (2) to reconstruct past tropical climate and environmental variability, and (3) to use these data in conjunction with advanced statistical methods, earth system modelling and observed ecosystem responses for improved projections of future changes in tropical climate and coral reef ecosystems. The DFG Priority Programme “Tropical Climate Variability and Coral Reefs” (SPP 2299, https://www.spp2299.tropicalclimatecorals.de/) aims to enhance our current understanding of tropical marine climate variability and its impact on coral reef ecosystems in a warming world, by quantifying climatic and environmental changes during both the ongoing warming and past warm periods on timescales relevant for society. The programme aims to provide an ultra-high resolution past to future perspective on current rates of change to project how tropical marine climate variability and coral reef ecosystems will change in a warming world. Information on the organisational structure, research topics and preliminary results of this collaborative programme, which involves more than 40 scientists from ten universities, three Helmholtz Centres, one Max-Planck Institute and one Leibniz Centre from all over Germany, will be provided.



3:00pm - 3:15pm
Topics: 3.12 Past climates and environments inform our future

Molecular records of the Triassic-Jurassic and the early Toarcian climate events at the land-sea interface

Wolfgang Ruebsam, Tim Marten, Lorenz Schwark

University Kiel, Germany

The Triassic-Jurassic boundary (TJB) and the early Toarcian are characterized by greenhouse warming, caused by the emplacement of large volcanic provinces. Despite similar trigger mechanisms, the two events differ in their character. Most significantly, the early Toarcian records the genesis of an Oceanic Anoxic Event (T-OAE), while the TJB event lacks robust evidence for widespread marine anoxia and organic matter (OM) accumulation.

Here, we present bulk, isotope, and molecular geochemical data from a continuous drill core, taken in the northeastern part of the North-German Basin that spans upmost Triassic and Lower Jurassic strata (Rhaetian-Toarcian). The sediment archive represents a near-shore environment, proximal to an estuary. This setting at the land-sea-interface was particularly susceptible to sealevel, climate, and environmental change and records the response of a shallow marine environment to major Late Triassic-Early Jurassic climate events.

In contrast to the predominantly OM-lean Triassic-Jurassic strata, the TJB interval and the T-OAE are characterized by increased OM contents, but their compositions differ significantly. At the TJB, increased abundances of soil and land plant OM accumulated under semi-arid conditions in mesosaline and well-oxygenated shallow marine setting. By contrast, during the T-OAE, OM-rich sediments accumulated under short-lived anoxic-euxinic conditions. Development of oxygen-deficient conditions was favored by a high sea level and persistent freshwater stratification caused by enhanced riverine discharge under humid climate conditions. Land plant wax lipid, algal molecular fossils, and wildfire combustion residues further revealed that the TJB and the T-OAE were accompanied by substantial changes in both the continental and marine ecosystems.



3:15pm - 3:30pm
Topics: 3.10 Constraining the rate of change in the Earth System through integrated stratigraphic approaches

Serravallian-Tortonian hydrological isolation of the Eastern Paratethys from the perspective of the Caspian Basin: Sarmatian s.l. integrated stratigraphy and biotic record of Karagiye, Kazakhstan.

Sergei Lazarev1,2, Oleg Mandic3, Marius Stoica4, Pavel Gol'din5, Wout Krijgsman6, Davit Vasilyan2,1

1Department of Geosciences, University of Fribourg, Switzerland; 2JURASSICA Museum, Switzerland; 3Geological-Paleontological Department, Natural History Museum Vienna, Austria; 4Faculty of Geology and Geophysics, University of Bucharest, Romania; 5Schmalhausen Institute of Zoology, National Academy of Sciences of Ukraine, Ukraine; 6Department of Earth Sciences, Utrecht University, the Netherlands

The Eastern Paratethys (EP) is a former epicontinental basin that unified the Black Sea, Caspian Sea and the Dacian Basin and played a crucial role in shaping of the west Eurasian paleoecosystems.

In the late Middle-Late Miocene, during Sarmatian sensu lato Stage, the EP underwent a gradual hydrological isolation from the global ocean. This process was accompanied by adaptation and radiation of endemic faunas in the early and middle Sarmatian s.l. (Volhynian and Bessarabian) and by the near complete extinction of marine life forms in the late Sarmatian s.l. (Khersonian). The drivers of this ecological crisis still remain ununderstood. We present our integrated stratigraphic study of 130-m-thick outcrop Karagiye, Caspian Basin. The preliminary data demonstrate:

  1. Incomplete Volhynian record (12.3–12.05 Ma). Proximal lagoon with molluscs Obsoletiformes and Ervilia, ostracod zones Cytheridea hungarica and Euxinocythere turpe, foraminfera zones Veridentella reussi and Elphidium reginum, rich marine vertebrate fauna;
  2. Bessarabian offshore to lagoon record (11.9–9.8 Ma) with molluscs Plicatiformes plicatofittoni, Sarmatimactra vitaliana, ostracod zones Euxinocuthere grave odessoensis and Loxoconcha subcrassula, foraminifera zones Dogielina sarmatica and Porosononion aragviensis, rich marine vertebrate fauna.
  3. Khersonian shallow water barrier island to foreshore (9.4–7.6 Ma) with molluscs Chersonimactra caspia and Ch. bulgarica, ostracod zones – Euxinocythere immutata and E.dilecta, foraminifera and marine vertebrate fauna missing.

Our ongoing study for the first time provides well-dated mollusc and microfauna zonations of the Sarmatian s.l. substages in the Caspian Basin.

 
2:00pm - 3:30pm2.06-1 Interior, surface and atmosphere processes on rocky worlds
Location: Wiwi 105
Session Chair: Lena Noack, Freie Universität Berlin
Session Chair: Solmaz Adeli, DLR
 
2:00pm - 2:30pm
Invited Session Keynote
Topics: 2.06 Interior, surface and atmosphere processes on rocky worlds

Atmospheric Dynamics of a Near Tidally Locked Earth-Size Planet

Stephen Kane

University of California, Riverside, United States of America

The discovery and characterization of Earth-sized planets that are in, or near, a tidally-locked state are of crucial importance to understanding terrestrial planet evolution, and for which Venus is a clear analog. Exoplanetary science lies at the threshold of characterizing hundreds of terrestrial planetary atmospheres, thereby providing a statistical sample far greater than the limited inventory of terrestrial planetary atmospheres within the Solar System. However, the model-based approach for characterizing exoplanet atmospheres relies on Solar System data, resulting in our limited inventory being both foundational and critical atmospheric laboratories. Present terrestrial exoplanet demographics are heavily biased toward short-period planets, many of which are expected to be tidally locked, and also potentially runaway greenhouse candidates, similar to Venus. Here we describe the rise in the terrestrial exoplanet population and the study of tidal locking on climate simulations. These exoplanet studies are placed within the context of Venus, a local example of an Earth-sized, asynchronous rotator that is near the tidal locking limit. We describe the recent lessons learned regarding the dynamics of the Venusian atmosphere and how those lessons pertain to the evolution of our sibling planet. We discuss the implications of these lessons for exoplanet atmospheres and their detection with observations using JWST and other future facilities. We outline the need for a full characterization of the Venusian climate in order to achieve a full and robust interpretation of terrestrial planetary atmospheres.



2:30pm - 2:45pm
Topics: 2.06 Interior, surface and atmosphere processes on rocky worlds

A first look into the gallium-aluminium systematics of Early Earth's seawater: Evidence from banded iron formations

David M. Ernst1, Dieter Garbe-Schönberg2, Dennis Krämer3, Michael Bau1

1Constructor University Bremen, Germany; 2Christian-Albrechts University Kiel, Germany; 3Federal Institute for Geosciences and Natural Resources Hannover, Germany

We conducted the first study on Ga-Al systematics in Archaean and Palaeoproterozoic banded iron formations (BIFs). Adjacent Fe oxide, metachert and mixed-type bands were analysed comparatively with solution-based SF-ICP-MS and ICP-MS/MS and laser-ablation SF-ICP-MS on nano-particulate pressed powder tablets and polished sections. Furthermore, we conducted a matrix-matched two-component mixing experiment with the BIF reference material IF-G and pure synthetic quartz sand. Results of the three comparative analytical procedures and the two-component mixing experiment assure a high quality of our analytical data even in the trace metal-poorest (meta)chert samples. Furthermore, the results suggest that finely dispersed Fe oxide particles dominate the Ga and Al content in BIF (meta)chert bands. Regardless of the samples' mineralogy, the Ga/Al ratios of BIFs range between 2×10-4 and 1×10-3. A compilation of Ga/Al ratios in the investigated samples throughout time shows that during Precambrian global marine Ga/Al ratios were most likely rather constant. The BIF Ga/Al ratios are above those of potential detritus but below those of modern seawater. Two conclusions are conceivable: (i) Precambrian seawaters had lower Ga/Al ratios than modern seawater, possibly due to the reduced importance of organisms and organic compounds during weathering, riverine and estuarine processes. (ii) Ga and Al were fractionated during BIF formation, and BIFs did not preserve the original seawater Ga/Al ratios.



2:45pm - 3:00pm
Topics: 2.06 Interior, surface and atmosphere processes on rocky worlds

ExoMDN: Rapid characterization of exoplanet interiors with Mixture Density Networks

Philipp Baumeister1,2, Nicola Tosi1

1DLR Berlin, Germany; 2Technische Universität Berlin, Germany

Characterizing the interior structure of exoplanets is an essential part in understanding the diversity of observed exoplanets, their formation processes and their evolution. As the interior of an exoplanet is inaccessible to observations, an inverse problem must be solved, where numerical structure models need to conform to observed parameters such as mass and radius. Since the relative proportions of iron, silicates, water ice, and volatile elements are not known, this is a highly degenerate problem whose solution often relies on computationally-expensive and time-consuming inference methods such as Markov Chain Monte Carlo.

We present here ExoMDN, a new machine-learning-based approach to the interior characterization of observed exoplanets using Mixture Density Networks that improves upon our previous work (Baumeister et al., ApJ, 2020). This improved model, trained on a large database of 5.6 million synthetic interior structures, can make a complete probabilistic inference about possible planetary interior structures within a fraction of a second, without the need for extensive modeling of each exoplanet's interior. We can demonstrate how the model, trained on different sets of (potentially) observable parameters including the received irradiation at the planet’s orbit and the fluid Love number, can help to further constrain the interior of a large number of exoplanets. In particular, we can show how precisely these parameters need to be measured to well constrain the interior.



3:00pm - 3:15pm
Topics: 2.06 Interior, surface and atmosphere processes on rocky worlds

Redistribution of trace elements from mantle to crust is controlled by planet size

Julia Marleen Schmidt, Lena Noack

Freie Universität Berlin, Germany

Inside the upper mantle, incompatible trace elements are redistributed from solid mantle rocks into partial melt. The melt that accumulated the trace elements and that is less dense than the surrounding material rises towards the surface and as a result enriches the crust and depletes the upper mantle. In the case of heat producing elements, this process can affect the thermal evolution and crust production of a planet, whereas in the case of volatiles, the outgassing and atmosphere evolution can be influenced. With mineral/melt partition coefficients, we can quantify the amount of redistributed elements. Due to a lack of high-pressure models and experimental results, partition coefficients were generally taken as constant in mantel evolution models, however, they dependent heavily on pressure, temperature and composition.

In this study, we inserted a P,T,X-dependent clinopyroxene/melt partition coefficient model that is applicable for higher pressure [1] into a mantle evolution code and investigated the effects. Due to their implications for the thermal and atmosphere evolution, we focused both on heat producing elements (Uranium, Thorium, Potassium) and volatiles (H2O). As a result, we found that the planet size influences partitioning behavior due to differences in depth and temperature inside the melt zones in the upper mantle. With these results, we can infer the impact on various planetary processes, such as the outgassing of water, crust production, and thermal evolution.

[1] Schmidt, J.M. and Noack, L. (2021): Clinopyroxene/Melt Partitioning: Models for Higher Upper Mantle Pressures Applied to Sodium and Potassium, SysMea, 13(3&4), 125-136.



3:15pm - 3:30pm
Topics: 2.06 Interior, surface and atmosphere processes on rocky worlds

Core formation efficiency for rocky super-Earths

Lena Noack

Freie Universität Berlin, Germany

For rocky planets it is typically assumed that they are able to differentiate into a silicate mantle and a metal core, due to the fact that metals are denser than silicates and should sink towards the gravitational center, i.e. the core of the planet.

However, more massive planets experience a higher pressure and compressibility in their interior, which can strongly impact the differentiation of the planet, potentially leading to inefficient core formation and even to coreless planets (Elkins-Tanton and Seager, 2008; Lichtenberg, 2021). By using a mantle convection code, we show that even over geological timescales, and depending on the size and distribution of iron droplets forming during the magma ocean crystallisation or later on due to phase transition disproportionation in the silicate mantle, the iron may indeed never be able to sink to the centre of the planet to form a metal core. Since the ability to form a (large) core should decrease with increasing planetary mass, this study suggests that the mantle of super-Earths may be more iron-rich and therefore more reducing than for Earth, which would be reflected in their atmospheric composition and could potentially be confirmed by future observations of exoplanetary atmospheres.

References:
Elkins-Tanton and Seager, 2008, Coreless Terrestrial Exoplanets, ApJ 688, 628-635
Lichtenberg, 2021, Redox Hysteresis of Super-Earth Exoplanets from Magma Ocean Circulation, ApJL 914:L4

 
2:00pm - 3:30pm4.10-2 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?
Location: Wiwi 107
Session Chair: Sylke Hlawatsch, Richard Hallmann Schule
Session Chair: Dirk Felzmann, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau
 
2:00pm - 2:15pm
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?

Students’ Interest in Climate Change – Results of a Quantitative Questionnaire-Based Study in Germany

Steffen Höhnle, Hanna Velling, Jan Christoph Schubert

Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany

In addressing climate change as one of the key problems of humanity (IPCC 2014), the school subject of geography is of particular importance, as it is a leading subject for Education for Sustainable Development with a pronounced systemic character (DGfG 2020). In this highly relevant area, on the one hand, the interest of students is considered a decisive prerequisite for the success of learning processes. On the other hand, students’ interest is also regarded as an important goal of (geography) lessons (Krapp 1998) - yet there are hardly any differentiated findings on its characteristics regarding climate change.

Against this background, in a quantitative, questionnaire-based study N = 4627 students in the federal state of Bavaria were surveyed about their topic-specific interest in climate change, and the data were analyzed both descriptively and interference-statistically. Overall, the students show a high level of interest in climate change. However, there are remarkable differences regarding different aspects of climate change, as well as between genders and between students attending different types of schools. Aspects related to actions against climate change as well as to the global level are considered more interesting than aspects concerning spatial proximity and climate change measurement/methodology, and girls show an overall higher interest in climate change than boys do. Furthermore, students attending grammar school (“Gymnasium”) show a higher interest than students attending secondary school (“Realschule”), and these in turn than students attending lower-level secondary school (“Mittelschule”). These and the results of further analyses of the survey will be presented.



2:15pm - 2:30pm
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?

Conceptual Change Research in Geosience Education

Dirk Felzmann

Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Germany

Conceptual change research is an important field of science education research. This also applies to geoscience education (e.g. Guffey & Slater 2020). Despite the high importance of student conceptions for successful learning processes (Hattie 2017), a decline in conceptual change research can be observed in recent years (Potvin et al. 2020).

This presentation aims to provide an overview of conceptual change research in geoscience education. Building on the reviews by Cheek 2010, Francek 2013, Guffey & Slater 2020, the current state of reconstructing geoscience student conceptions will be outlined. Emphasis is placed on the specific challenges of learning geoscience content: the enormous temporal and spatial dimensions and the high complexity.

Finally, current approaches of conceptual change research (e.g. “embodied cognition”, cf. Amin 2015, “conceptual prevalence”, cf. Potvin & Cyr 2017) are discussed in their potential for further research in geoscience education.

The lecture is aimed at interested geoscientists who are only partially familiar with didactic theories. Examples from my own research on student conceptions (glaciers: Felzmann 2017, climate zoning) serve as illustration.



2:30pm - 2:45pm
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?

Development of new formats of Citizen Science with micrometeorites for multidisciplinary school education

Lutz Hecht1,2, Dieter Dominik1,2, Andrea Miedtank1,2, Alexandra Moormann1, Aria Tilove1

1Museum für Naturkunde Berlin - Leibniz-Institut für Evolutions- und Biodiversitätsforschung; 2Institut für Geowissenschaften, Freie Universität Berlin

In addition to its importance for basic scientific research, Citizen Science involving micrometeorites collected from the roofs of Berlin has a special potential for promoting scientific literacy and the understanding of science in general (Hecht et al. 2021). Yet, Citizen Science still occurs too rarely in schools and requires further development (GEWISS 2016). Moreover, earth sciences are only briefly addressed in school curricula. The Citizen Science approach can be applied very well to the Berlin framework curriculum due to its many links to geography, physics and chemistry lessons. Citizen Science can be an important part of geoscience or natural science education and even contribute to strengthening democratic participation and research (Burger 2016).

This project aims to develop and test a Citizen Science approach in a school setting. In cooperation with grade 9 students in a Berlin high school, we are conducting sampling and scientific processing of micrometeorites from a Berlin roof using almost all essential research steps. The project’s main setting is at school. In order to enable active participation in the use of large-scale equipment, we will test the remote control of such equipment by students in the classroom.

Burger, D. (2016): GW-Unterricht, 2(142), 18–27. https://doi.org/10.1553/gw-unterricht142/143s18

GEWISS (2016): Grünbuch. Citizen Science Strategie 2020 für Deutschland. Leipzig: FRITSCH Druck.

Hecht, L., Milke, R. & Greshake, A. (2021): GMIT 84, 7-21, https://doi.org/10.23689/fidgeo-4328.



2:45pm - 3:00pm
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?

Earth sciences for schoolchildren in the Museum Mineralogia Munich

Melanie Kaliwoda, Malte Junge, Felix Hentschel, Wolfgang Schmahl

Mineralogical State Collection Munich, Germany

The Museum Mineralogia München is the public part of the Mineralogische Staatssammlung München (MSM). The aim of the MSM is to provide knowledge transfer in natural science subjects, i.e. especially in the field of geosciences. The MSM has been trying to fulfill this task for over 16 years and has thus also gained a great deal of experience in the teaching-learning field. Since the geosciences are unfortunately not a school subject, but geoscientific topics are becoming more and more relevant for socio-political concerns, it is important to sensitize and inspire children and young people for the geosciences at an early age.
We offer a variety of activities: (1) volcanism, (2) the cycle of rocks, (3) meteorites, (4) the construction of a smartphone. In addition, special exhibitions on various geoscientific topics are included in the projects. In addition, there is a network with other science laboratories for schoolchildren both in Munich (Muc-Labs) and throughout Germany (LeLa). Participation, for example, in Girls' Day, Science Days (Forscha) or the Children's Culture Summer, as well as projects with other museums also strengthen the reach. In addition to national projects, international work (e.g. with Austria, Italy, Norway) is also carried out. As a further concept, internships are also offered to school students. In addition, the Mineralogische Staatssammlung München has successfully participated in two funded programs on ease-Corona (BMBF - catching up after Corona). In particular, children and adolescents with Corona- and Lock down-induced learning deficits should be supported.



3:00pm - 3:15pm
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?

Introducing the Disaster Risk Platform

َAbbas Kangi1, Jafar Rahnamarad2

1Department of Civil Engineering, Khayyam University, Mashhad, Iran; 2Mining engineering system of Sistan and Baluchistan province Department: Expert affairs of mines and minerals Country: Iran, Islamic Republic of E-Mail: jrahnama2003@gmail.com / jrahnama2003@yahoo.com, Iran, Islamic Republic of

The Disaster Risk Platform project is a humanitarian program aimed at digital disaster education based on articles published in scientific journals. The DRP project is a user-centered program and the information services provided are fully, open and free of charge to its users. The target group of this project is educational centers, managers and communities at risk. We are trying to bridge the large gap between advances in disaster science and public education. The Disaster Platform is designed in line with the Sendai Framework for Disaster Risk Reduction with a focus on educating at-risk communities. Five DRP services digitize data published in scientific products. This information is converted into the following training courses.

1- Flood risk assessment services

2- Earthquake damage estimation services

3- Tsunami hazard and risk assessment services

4- Landslide risk assessment and management services

5- Land subsidence vulnerability assessment services

 
2:00pm - 3:30pm4.03-1 Open Science and Data – challenges, opportunities and best practices
Location: Wiwi 108
Session Chair: Kirsten Elger, GFZ German Research Centre for Geosciences
Session Chair: Daniel Nüst, Technische Universität Dresden
 
2:00pm - 2:30pm
Invited Session Keynote
Topics: 4.03 Open Science and Data – challenges, opportunities and best practices

OneGeochemistry: Global Cooperation for FAIR Geoanalytical Data Policy and Practice

Kerstin Annette Lehnert1, Lesley Wyborn2, Marthe Klöcking3, Alexander Prent4, Dominik Hezel5, Kirsten Elger6, Lucia Profeta1, Rebecca Farrington4, Angus Nixon7

1Lamont-Doherty Earth Observatory, Columbia University, USA; 2Australian National University, Australia; 3Georg-August-Universität Göttingen, Germany; 4AuScope Ltd. Australia; 5Goethe Universität Frankfurt, Germany; 6Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Germany; 7AuScope Geochemistry Network, Australia

Geochemical data are pervasively acquired in the Earth, environmental, and planetary sciences, as they offer unique evidence for past and present processes in the natural world that advance scientific knowledge and enable solutions of societal relevance. But geochemical data today are difficult to reuse because of the heterogeneous and fragmented nature of the geochemical data landscape with incompatible data structures, inconsistent metadata, and disconnected databases. As new, data-driven and often interdisciplinary research approaches are rapidly expanding that promise to empower the next generation of scientific discoveries, the urgency for a new ecosystem of interoperable, machine-readable geochemical data is eminent. OneGeochemistry is an international initiative to promote data standards in geochemistry and advance a global network of geochemical data resources. OneGeochemistry has been pursuing a diverse array of strategic activities: engagement with data repositories, professional societies, science unions and associations, publishers and editors, funding agencies, government agencies, instrument manufacturers, and researchers; participation in the WorldFAIR project (https://worldfair-project.eu); providing open access to existing standards or best practices; and establishing an international governance for the initiative. The geochemical databases GEOROC, EarthChem, the Astromaterials Data System, and MetBase that participate in the OneGeochemistry initiative, are actively cooperating to harmonize their data models and create FAIR vocabularies for metadata that will enable interoperability between the systems and can be adopted more broadly. This presentation will provide an update on the status of activities and outcomes that pertain to technical and policy aspects of geochemical data standards.



2:30pm - 2:45pm
Topics: 4.03 Open Science and Data – challenges, opportunities and best practices

Data-driven Energy Transition: Why is subsurface data so critical for success?

Jürgen Grötsch

Friedrich-Alexander University of Erlangen, Germany

The amount of digital subsurface and geoscience data has grown exponentially over the past few decades with many companies, researchers and government organizations dealing with rapidly growing Petabyte-scales of data. On the other hand, hardware, storage solutions, technical applications and data management utilities have not kept up with these developments. This has resulted in a big gap and hampers the use of AI and data-driven workflows in complex subsurface projects, be it in hydrocarbon exploration and development, geothermal energy projects, CCS, H2-exploration & storage and the search for nuclear waste sites, but also integrated scientific research programs.

The Open Subsurface Data Universe (OSDUTM) project aims to address these critical challenges and has already resulted in fundamental changes to the way data is managed. OSDUTM is a consortium of over 230 companies and organizations that pool their expertise in geoscience, software development, data center management and associated services to address the challenges via an open-source and cloud-agnostic data platform. Government organizations, geological surveys and universities are also participating in the project. The main drivers behind geoscience data standardization and separating data from applications are the expected benefits for integration, simplification and automation of complex subsurface modelling and project workflows as well as the facilitation of AI/ML opportunities enabled via the data platform.

This talk will demonstrate why subsurface data and the OSDUTM data platform will play a critical role in the energy transition towards net zero emissions with the subsurface as a key component - even after the era of hydrocarbons.



2:45pm - 3:00pm
Topics: 4.03 Open Science and Data – challenges, opportunities and best practices

Why should researchers bother to use domain-specific data repositories?

Florian Ott, Kirsten Elger, Simone Frenzel

GFZ German Research Centre for Geosciences, Germany

Domain-specific research data repositories are digital archives that manage and preserve research data (and/or software) from specific scientific disciplines. These repositories are designed to meet the unique needs of researchers in that particular domain. They foster new scientific innovations and ideas by means of sharing, storing, and reusing research data. Furthermore, domain-specific repositories have a special emphasis on:

  • Metadata curation
  • Standardized, domain specific, rich metadata
  • Support of sharing and collaboration
  • Community engagement

The metadata curation processes and workflows implemented by domain-specific repositories ensure quality and metadata enrichment. As a consequence, scientists can rely on well-structured, high-quality data publications that have been verified by domain experts resulting in enhanced reproducibility and reliability of research results.

Domain-specific repositories support sharing and knowledge transfer among scientists within their particular field of research. This promotes transparency, collaboration, and the potential for interdisciplinary research. Scientists can also discover and explore datasets contributed by their peers, enabling new insights and discoveries.

Here we present the role of domain-specific data repositories, their role for Open Science. Introducing GFZ Data Services, a research data repository for the Earth System Sciences, we also highlight our metadata tools. In place since 2006, GFZ Data Services is embedded at the intersection between researchers and the modern digital data curation world. We consult researchers and make sure that data and metadata are ready to use for data-driven research. By publishing throughout us, scientists benefit from improved data accessibility, collaborative opportunities, long-term storage and subsequently an increased impact.



3:00pm - 3:15pm
Topics: 4.03 Open Science and Data – challenges, opportunities and best practices

QuARUm – Quality assessment of analytical data in the field of resource and environmental sciences

Malte Mues1, David Ernst2, Falk Howar1, Michael Bau2

1TU Dortmund, Germany; 2Constructor University, Germany

QuARUm is a BMBF- and EU-funded research project that aims to develop a prototype for a low-code environment enabling the researchers to construct pipelines that objectively and automatically assesses the quality of analytical data. In geochemistry, increasing amounts of data become available via journal publications and in numerous data repositories. While current efforts are focused on improving the availability of data, verifying the quality of the published data is equally important. The latter one, however, is in most cases rather complicated or just impossible because important information is missing in the publication (e.g., limits of quantification, measurements of reference materials or precision and accuracy). The tool developed during QuARUm will assess data quality using available metadata, statistical methods, and sample-specific criteria. The prototype can be applied in-lab on self-produced data, data published in journal articles or directly to data repositories. Furthermore, the tool will be designed in a low-code environment as an open box, fully visible and modifiable by computer science laypeople.

We will present key aspects, application fields, a road map and the first results of our QuARUm project.



3:15pm - 3:30pm
Topics: 4.03 Open Science and Data – challenges, opportunities and best practices

Improving Sample Metadata Descriptions in Earth and Environmental Sciences by using the FAIR SAMPLES Template

Alexander Brauser1, Mareike Wiezcorek2, Linda Baldewein3, Simone Frenzel1, Birgit Heim2, Ulrike Kleeberg3, Tim Leefmann3, Ben Norden1, Kirsten Elger1

1GFZ German Research Centre for Geosciences, Potsdam, Germany; 2Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Potsdam, Germany; 3Helmholtz-Zentrum Hereon, Geesthacht, Germany

Physical samples are key elements in the geosciences, providing tangible evidence of geologic and environmental phenomena and often represent the source for scientific findings. The International Generic Sample Number (IGSN) is a globally unique and resolvable persistent identifier (PID) for physical samples. It links the sample with its online description and enables the unambiguous identification, location, and citation of samples in digital research infrastructures.

The FAIR WISH project, funded by the Helmholtz Metadata Collaboration HMC, aims to further standardise IGSN metadata and support scientists in describing their samples for IGSN registration via standardised metadata that are human- and machine actionable. The FAIR SAMPLES template enables the provision of rich sample descriptions for different Geo-Bio-Samples. The template is built as a modular Microsoft Excel spreadsheet to meet the practices of the broader research community. It includes controlled vocabularies to describe sample types, sampling methodology, material, etc., and integrates persistent identifiers (ORCID, ROR) to acknowledge the persons and organisations involved in the sampling process as well as links to text or data publications relevant for the samples. The template further represents the basis for semi-automated creation of metadata XML files that are required for IGSN registration.

Currently, the template is being tested by several heterogeneous projects in the field of Earth and environmental sciences. The data processing workflows and software developed in this project will be completed by the end of 2023 and may serve as a blueprint for other organisations aiming to implement standardised procedures for registering physical samples.

 
3:30pm - 4:00pmCoffee Break
Location: Foyer (Henry Ford Building)
3:30pm - 4:00pmBook Launch Event at Springer Booth "Didaktik der Geowissenschaften"
Location: Foyer (Henry Ford Building)
4:00pm - 5:30pm3.21-2 Tectonic Systems - TSK Open Session
Location: Hall A (HFB)
Session Chair: Ruth Keppler, Universität Bonn
Session Chair: Kamil Ustaszewski, Universität Jena
 
4:00pm - 4:15pm
Topics: 3.21 Tectonic Systems - TSK Open Session

Do thermomechanical heterogeneities in the upper mantle control crustal deformation?

Judith Bott1, Magdalena Scheck-Wenderoth1,2, Ajay Kumar1, Mauro Cacace1, Sebastian Noe3, Jan Inge Faleide4

1GFZ German Research Centre for Geosciences, Germany; 2RWTH Aachen, Faculty of Georesources and Materials Engineering, Aachen, Germany; 3ETH Zürich, Department of Earth Sciences, Zürich, Switzerland; 4University of Oslo, Department of Geosciences, Oslo, Norway

The architecture of the crust in intracontinental Western and Central Europe is well constrained by multidisciplinary geoscientific data. This low-strain intraplate setting is known for its widely distributed seismicity with earthquake localization, however, being difficult to explain by the observed crustal configuration. Also, observed variations in crustal thickness do not provide clear evidence to explain lateral shifts in depositional and erosional centers over geological time. This raises questions regarding the underlying forces controlling crustal tectonics in this region, located far from active plate boundaries. Shear-wave velocity models obtained from seismic full waveform inversion methods show that the upper mantle is strongly heterogeneous pointing to thermomechanical contrasts that potentially could impact crustal tectonics. Therefore, we convert mantle shear-wave velocities to thermodynamically consistent temperature and density configurations by following a Gibbs's free energy minimization approach. We find spatial correlations between lithospheric thickness, respectively shallow lithospheric temperature and density variations, and crustal deformation patterns (including seismicity). This indicates that thermomechanical instabilities in the mantle could be the origin of relative vertical movements which would (i) cause laterally variable surface uplift and/or subsidence and (ii) facilitate strain localization in the mantle (ductile shear movements) above which the overlying crust would locally respond by brittle deformation.



4:30pm - 4:45pm
Topics: 3.21 Tectonic Systems - TSK Open Session

Detailed investigation of the Asse salt structure (Subhercynian Basin) based on new 3D seismic data

Michael Warsitzka1, Jan Witte2, Kai Gruschwitz3, Maximilian Scholze1, Christoph Nachtweide1, Christian Buxbaum-Conradi1

1BGE Bundesgesellschaft für Endlagerung, Germany; 2Falcon Geo-Consulting, Germany; 3Notting Hill Geoconsulting Limited

The Asse salt structure is a salt-cored anticline with steep, locally overthrusted flanks located in the Subhercynian Basin. It is an excellent example of salt structures in the North German Basin containing a wedge-shaped intrusion of Upper Permian into Upper Triassic salt (‘salt wedge’). The Asse is also known as a location for the disposal of low- and intermediate-level radioactive waste emplaced in the former salt mine Asse II during the 1970s. Detailed knowledge of the tectonic structures is indispensable for planning new retrieval infrastructure and for long-term safety analysis. The Asse salt structure has been thoroughly explored for over 100 years by surface geological mapping, 2D seismic and drilling. Ongoing exploration provides further insights into the salt structures and strengthens our understanding of its evolution.

A new 3D seismic data set (2019-2020) provides new insights into the details of this salt structure. Here we present first results of the seismic interpretation revealing substantial changes in the structural style opposing previous geological models. It can be shown that the sub-horizontal northern flank terminates at the base of the southern flank implying a north-ward instead of a south-ward directed overthrusting. Small-scale faults crossing the crest were previously interpreted as transpressional faults developed during the Late Cretaceous inversion. Ongoing kinematic modeling suggests that these faults originated as steeply dipping pre-Cretaceous normal faults that were overprinted during flank-rotation. These implications as well as observations of thickness variations and unconformities in Mesozoic layers will help to reconstruct the evolution of the Asse salt structure.



4:45pm - 5:00pm
Topics: 3.21 Tectonic Systems - TSK Open Session

Response of salt structures to loading and unloading by ice-sheets – insights from numerical modelling

Jörg Lang1, Andrea Hampel2

1Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Germany; 2Institut für Geologie, Leibniz Universität Hannover, Germany

Salt rocks are mechanically weak and behave like viscous fluids when deforming at geological time scales and strain rates. The weight of an ice sheet advancing into a salt-bearing basin may cause sufficient differential load to induce salt flow. Ice loading has been postulated as a trigger for Pleistocene deformation at a number of salt structures in the Central European Basin System. We conducted 2D-finite-element models (ABAQUS) with a setup representing a simplified salt diapir to test existing conceptual models and evaluate the controlling factors. Different parameter sets for the rheology of salt and overburden rocks, including linear versus non-linear viscosity of the salt, were tested. Model results show lateral salt flow into the diapir and diapiric rise during the ice advance, while a transgression of the diapir by the ice sheet leads to overall downwards displacement. During unloading, displacements are largely restored due to the dominance of the elastic response. Displacements never exceed few metres and are always larger in models with linear viscosity than in those with non-linear viscosity. Linear viscous salt behaviour seems reasonable, considering the low differential stresses caused by the load of a few hundred-metres-thick ice sheet and the time-scale of several thousand years. The elastic parameters also have a strong impact, with lower Young's moduli leading to larger displacements. Our findings demonstrate that both the viscosity and the elasticity exert a fundamental control on ice-load driven salt movement during glacial-interglacial cycles and highlight the importance of a careful parameter choice in numerical modelling.



5:00pm - 5:15pm
Topics: 3.21 Tectonic Systems - TSK Open Session

Insights Into the Edifice Stability of Anak-Krakatau (Sunda Strait, Indonesia) Before the Lateral Collapse in December 2018 from Direct Shear Experiments and Finite-Element Models

Fiene Matthies1, Morelia Urlaub1, Matt Ikari2

1GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel; 2MARUM Zentrum für Marine Umweltwissenschaften

The lateral collapse of oceanic volcanoes poses a high risk for the population living in coastal areas since the sudden displacement of large amount of material can trigger tsunami waves impacting the surrounding coastlines. One recent example is the lateral collapse of the SW-flank of Anak-Krakatau (Sunda Strait, Indonesia) in December 2018 that generated a tsunami wave impacting the Sunda Strait coastlines and causing several hundred fatalities. Even though, the lateral collapse of oceanic volcanoes are hazardous events, the precursors of such events are poorly understood. It is suggested that external triggers such as the movement of a décollement, the rise of magma during enhanced activity, or earthquakes can cause a lateral collapse. Yet, the internal state of stability of a volcano needs to be known to evaluate the impact of external triggers. We carry out direct shear tests on samples from Anak-Krakatau and implement the results into finite-element models to evaluate the influence of the volcano’s geometry and the rock mechanical properties on the stability of Anak-Krakatau’s flank before the collapse in 2018. The preliminary results suggest that the volcanic edifice of Anak-Krakatau was unstable before the collapse in 2018 solely due to the geometry of the volcano and the rock mechanical properties. Whether the instability of the volcanic edifice is enough to cause the lateral collapse of Anak-Krakatau in 2018 or whether an external trigger is needed, needs further testing.



5:15pm - 5:30pm
Topics: 3.21 Tectonic Systems - TSK Open Session

High-stress crystal-plasticity versus creep of rock-forming minerals – the importance of stress-loading rates indicated by deformation microfabrics

Claudia Trepmann

Department of Earth and Environmental Sciences, Ludwig-Maximilians-University Munich, Germany

There is ample evidence of transient high stresses of several hundred MPa at the base of the seismogenic zone in the continental crust, i.e. at greenschist-facies conditions. The microstructural evidence from these depths includes twinning and kinking of jadeite and amphibole, as well as quasi-instantaneous cataclastic deformation of garnet and quartz. At interseismic strain rates, known flow laws for dislocation creep of the rheological dominant mineral, quartz, and/or dissolution precipitation creep of crustal rocks predict lower stresses at the given pressure-temperature conditions. Thus, fast stress-loading rates are required to explain the inferred high-stress crystal-plasticity at greenschist-facies conditions, i.e. loading rates from few tens of MPa to several hundred of MPa within minutes, corresponding to the rupture times for major earthquakes in the seismogenic zone. Although high-stress crystal-plasticity is not allowing to accumulate a high amount of strain, as high stresses prevail only transiently, it provides a driving force for accelerated but rapidly decaying creep, where higher amounts of strain can be accumulated. The strength of both, fault rocks and their host rocks, is strongly depending on the stress conditions that control whether they behave by high-stress crystal-plasticity or creep at given pressure-temperature conditions. Thus, the rheology of crustal rocks is dependent on the stress-loading rates during the seismic cycle controlled by the distance to the tip of the seismic active fault.

 
4:00pm - 5:30pm3.10 Constraining the rate of change in the Earth System through integrated stratigraphic approaches
Location: Hall B (HFB)
Session Chair: Christian Zeeden
Session Chair: Nina Maria Annegret Wichern, Westfälische Wilhelms-Universität Münster
Session Chair: Stefanie Kaboth-Bahr, Free University Berlin
 
4:00pm - 4:30pm
Invited Session Keynote
Topics: 3.10 Constraining the rate of change in the Earth System through integrated stratigraphic approaches

Milankovitch cycles in 2.5-Ga iron formations as archive of the early Earth and Earth-Moon system

Margriet L. Lantink1,2, Joshua H.F.L. Davies3,4, Rick Hennekam5, Wytze K. Lenstra2, David McB. Martin6, Paul R.D. Mason2, Maria Ovtcharova4, Gert-Jan Reichart5, Urs Schaltegger4, Caroline P. Slomp2,7, Frederik J. Hilgen2

1University of Wisconsis-Madison, United States of America; 2Utrecht University, the Netherlands; 3Université du Québec à Montréal, Canada; 4University of Geneva, Switzerland; 5Royal Netherlands Institute of Sea Research (NIOZ), the Netherlands; 6Geological Survey of Western Australia, Australia; 7Radboud University, the Netherlands

Regular stratigraphic alternations in lower Paleoproterozoic iron formations (IFs) from South-Africa and Western Australia were recently linked to Milankovitch forcing (1, 2). Hence, valuable information may potentially be obtained from these ancient marine deposits about early Solar System dynamics and astronomical-forced climate change when Earth System was operating in fundamentally different ways compared to present-day and the Phanerozoic. In particular, the dominant imprint of long-period eccentricity observed in the Kuruman IF from South-Africa (2) implied a primary influence of climatic precession, while clear precession-scale variations were unfortunately not encountered in this unit. A clear and consistent expression of precession and eccentricity, however, is essential to investigate the climatic-environmental response to the precessional forcing directly, and to determine the precession frequency as to potentially constrain past Earth-Moon dynamics. Here we report results of cyclostratigraphic analysis and high-precision U-Pb dating of the 2.46-Ga Joffre Member of the Brockman IF, Western Australia, revealing exceptionally regular precession- and eccentricity-scale alternations identified in both outcrop and core. Based on the thickness ratio between the precession- and short eccentricity-related alternations seen in outcrop, we estimate a significantly shorter precession period at the time of deposition of the Joffre Member, translating to a shorter Earth-Moon distance and length-of-day (3). In addition, based on detailed geochemical analysis and modelling of the precession-related cycles identified from core, we present a first-order climate interpretation with possible implications for the redox evolution of the ocean-atmosphere (4).

(1) de Oliveira Rodriguez et al. 2019; (2-4) Lantink et al. 2019; 2022; 2023.



4:30pm - 4:45pm
Topics: 3.10 Constraining the rate of change in the Earth System through integrated stratigraphic approaches

Correlation of Neoproterozoic glacial diamictites in southern Namibia

Mandy Zieger-Hofmann1, Johannes Zieger1, Andreas Gärtner1, Axel Gerdes2,3, Ulf Linnemann1, Richard Albert2, Linda Marko2, Anja Sagawe1, Katja Mende1, Jessica Haschke1, Kombada Mhopjeni4, Helke Mocke4

1Senckenberg Naturhistorische Sammlungen Dresden, Germany; 2Goethe Universität Frankfurt am Main, Germany; 3Frankfurt Isotope and Element Research Center (FIERCE), Goethe Universität Frankfurt am Main, Germany; 4Geological Survey of Namibia, Ministry of Mines and Energy, Windhoek, Namibia

This talk presents a multi-method approach to construct a conclusive new correlation model for Neoproterozoic glacial units of southern Namibia. Therefore, ten different sections and a variety of samples were studied and analysed with respect to field relationships, whole-rock geochemistry, zircon U-Pb dating and Th-U ratios, Hf isotope measurements and zircon grain size analyses, combined with LA-ICP-MS U-Pb dating of cap carbonates.

Our analyses show that (1) sediments deposited during four Neoproterozoic glacial events in southern Namibia all have very similar detrital zircon characteristics, allowing the interpretation of continuous recycling of the same material over the most part of the Neoproterozoic, which is also supported by the whole-rock geochemical analyses, (2) cap carbonates can be analysed for their U-Pb isotope ratios and provide valuable age determinations, if reset and overprinted areas are recognised and avoided for laser ablation, (3) proving the Sturtian and the Marinoan age for the Numees Fm and the Namaskluft Mbr by U-Pb dating their overlying carbonate sequences was finally possible, (4) the Witvlei Grp sedimentation ends at 579 ± 52 Ma, which is the age of the stromatolites of the Okambara Mbr, representing the uppermost deposits of the Witvlei Grp, and this leads to (5) the onset of the Nama Grp sedimentation for southern Namibia is no earlier than 579 ± 52 Ma.



4:45pm - 5:00pm
Topics: 3.10 Constraining the rate of change in the Earth System through integrated stratigraphic approaches

Ordovician-Devonian black slates from the Rhenohercynian and Truchas basins – deposition and diagenesis

Edouard Grigowski, Tom McCann

University of Bonn, Germany

Mud-rich successions can be challenging to interpret accurately, since sedimentary structures such as cross-bedding and ripple marks are often scarce or absent. This makes it difficult to determine the exact environmental and depositional parameters. In order to gain a better understanding of the conditions of such environments, this study aims to compare two of the most important roofing slate deposits in Europe: The Devonian-age “Mosel Slates” and the Ordovician-Silurian-age Truchas Domain.

Until 2019, Rathscheck Schiefer mined the “Mosel Slates” from the Katzenberg mine in the SE Eifel, while companies such as Samaca actively exploit roofing slates near Valdeorras, making Spain one of the largest exporters of roofing slate. These slate mines provide a unique opportunity to gather new insights into the geology of the areas of Mayen (Rhenohercynian Basin) and Valdeorras (Truchas Basin). Both of these areas contain sediments which were deposited in marine shelf settings, although the precise mechanisms of deposition and the precise depositional environment are poorly understood.

This study presents the results of high-resolution facies analyses, both above and below ground, geochemical analyses, including XRD, XRF and CNS measurements, and micro-CT measurements of framboid populations. In both settings, deposition occurred in a low-energy regime on a passive continental margin. Sediments were derived and reworked from the Laurussian and Avalonian continents, respectively. Background sedimentation and density flows were the main mode of deposition. The water column was oxygenated and anoxia was restricted to the sediment in the “Mosel Slates” and to dysoxic episodes in the Spanish slates.



5:00pm - 5:15pm
Topics: 3.10 Constraining the rate of change in the Earth System through integrated stratigraphic approaches

Milankovitch climate control of hyperpycnal flow sedimentation in an Early Cretaceous succession (Ri Qing Wei Basin, China)

Yingjie Liu1, Christian Zeeden2, Linda Hinnov3

1China University of Petroleum (East China), Qingdao, People's Republic of China; 2Leibniz Institute for Applied Geophysics, Hannover, Germany; 3George Mason University, Fairfax, VA, USA

Milankovitch forcing exerts a major control on climate that is recorded in the sedimentary rock record. However, its influence on hyperpycnal flow sedimentation is largely unknown. Hyperpycnites, sediments resulting from hyperpycnal flows, which are related to climate through flood frequency and magnitude, may be valuable tools for understanding aspects of Earth’s paleoclimate. Their origin and distinctive layering have been explained by various mechanisms, including frequency of river breaches, sudden increase in the global hydrological cycle, sea-level fluctuations, and variations in sediment supply. Their potential link to paleoclimate variations commonly remains unexplored in detail. Here we use cyclostratigraphic analysis combined with published high precision U-Pb dating to investigate the influence of Milankovitch forcing on their deposition. A continuous drill core of the ~125-million-year-old Early Cretaceous Laiyang Formation (eastern China) reveals well-defined cyclic hyperpycnal flow patterns. The radioisotopic dating and magnetostratigraphy constrains the formation’s average sedimentation rate, and links the observed cycles to precession, obliquity and mainly orbital eccentricity cycles. Orbital parameters most likely paced the delivery of the hyperpycnal flow sediments mainly by river- and delta-supplied currents from non-marine basin immediately; we conclude that Milankovitch cycles exerted a primary control on hyperpycnal flow sedimentation. Sediment accumulation rates determined from 400 kyr cycle age model show a trend of decreasing and then increasing throughout the Laiyang Formation, which was synchronized with the evolution of sedimentary environment controlled by tectonic activity. This study shows that orbitally-induced climate change can also acted as principle driver on deep-marine terrigenous sediment accumulation within a tectonically active basin.

 
4:00pm - 5:30pm1.05-2 Aquifer thermal energy storage (ATES): Potential, technologies and geoscientific challenges for a sustainable energy transition
Location: Hall C (HFB)
Session Chair: Sebastian Bauer, Christian-Albrechts-Universität zu Kiel
Session Chair: Thomas Neumann, TU Berlin
Session Chair: Traugott Scheytt, TU Bergakademie Freiberg
Session Chair: Lioba Virchow, GFZ German Research Centre for Geosciences
 
4:00pm - 4:15pm
Topics: 1.05 Aquifer thermal energy storage (ATES): Potential, technologies and geoscientific challenges for a sustainable energy transition

Characteristics and inhibition of microbial induced corrosion and biofilm formation by thermal shocks under in-situ conditions in a geothermal heat-storage plant in Neubrandenburg (Germany)

Christoph Otten1, Sebastian Teitz2, Tobias Lienen3, Anne Kleyböcker4, Hilke Würdemann1

1Hochschule Merseburg, Germany; 2Teitz Laboranlagen, Sensorik, Automation, Dettmansdorf, Germany; 3Bundesinstitut für Risikobewertung, Berlin, Germany; 4Kompetenzzentrum Wasser Berlin, Germany

Geothermal facilities in the North German Basin are frequently affected by corrosion and scaling due to high salinity as well as microbial induced corrosion. To study biofilm formation, corrosion processes and countermeasures, a mobile bypass system was installed at the Neubrandenburg geothermal heat storage plant. The reservoir was located in a depth of 1300m in a saline aquifer (~130g/L NaCl). Operation was conducted in two different seasonal modes. In the warm months, heat was stored, while in the winter months the direction of flow was reversed and heat was recovered. At temperatures lower than 60°C, at the cold side of the aquifer, corrosion was promoted by microbial activity, which led to the formation of biofilms on plant components and pipes. Biofilms consisted mainly of various genera of fermentative, sulfate reducing and hydrogen consuming bacteria. Longer incubation time as well as inoculation with fresh biofilm showed an independency of seasonal mode and enrichment of highly adapted community composition with the dominating sulfate-reducing genus Desulfallas.

As a countermeasure to corrosion, heat shocks were evaluated in the bypass system and tested also two times at the large scale plant. Heat shocks led to significantly reduced biofilm formation on corrosion coupons and correspondingly reduced iron sulfide precipitates and corrosion rates from 0.538mm/a to 0.170mm/a over an observation period of 48 days. The impact of one heat shock lasted for more than four weeks. Overall the use of periodic heat shocks showed its preventative measure against microbial induced corrosion and scaling in geothermal plants.



4:15pm - 4:30pm
Topics: 1.05 Aquifer thermal energy storage (ATES): Potential, technologies and geoscientific challenges for a sustainable energy transition

Exothermic adsorption of oxo-anions by goethite

Michael Kersten

Johannes Gutenberg-University Mainz, Germany

Column and field tests related to ATES found significantly elevated Mo, V, and other oxo-anions that could not be explained by reductive dissolution of Fe oxyhydroxides. A common hypothesis levied was that the oxo-anion mobilization appears to be related to a thermal desorption process. However, for an accurate prediction of the concentration changes, there is a lack of thermodynamic parameters to prove that hypothesis which was the aim of this study.

Batch equilibrium adsorption experiments with oxo-anions such as molybdate and vanadate were performed using goethite suspensions with different concentrations, ionic strengths, pH values, and at four temperatures between 10 and 75 °C. The results of this large number (>500) of individual batch equilibrium experiments showed that the amount of an oxo-anion adsorbed decreased with increasing temperature. The experimental data were fitted using the CD-MUSIC surface complexation model framework. Temperature variations in the complexation constants were in turn fitted using the two-term van’t Hoff equation to obtain molar enthalpies and entropies. The enthalpies were negative, indicating that the adsorption of the oxo-anions is exothermic and therefore the adsorption affinity decreases with increasing temperature. The entropies could be correlated to the adsorbate molecule volumes together with those previously determined for other oxo-anions, which can be used to extrapolate the adsorption entropies of many other oxo-anions for which EXAFS-based adsorbate structures are available, but for which such data are not yet available. Hydration differences across the bivalent oxo-anion molecule series apparently affect the derived enthalpies and hence the adsorption energies for oxo-anions.



4:30pm - 4:45pm
Topics: 1.05 Aquifer thermal energy storage (ATES): Potential, technologies and geoscientific challenges for a sustainable energy transition

Push pull tests for evaluating the sustainability of ATES systems: lessons learned from sensitivity acknowledging parameter optimization

Elena Petrova, Guido Blöcher, Stefan Kranz, Simona Regenspurg, Ali Saadat

GFZ-Potsdam, Germany

A thorough characterization of aquifer parameters is crucial for long-term predictions of the ATES system's functioning. Single well tests, also known as push-pull tests, have been widely used to identify effective porosity, flow velocity, decay constants, sorption coefficients, and heat storage capacity of the aquifer. For more than fifty years, multiple analytical and numerical approaches have been developed to validate push-pull test data and to identify model sensitivity. Despite the relatively straightforward approach, the main bottleneck of the push-pull test calibration is the non-uniqueness of the inverse problem solution. Especially in a deep ATES system data scarcity induces the parametric uncertainty and thus calls for the stochastic parameter optimization. To address this issue, a sensitivity-acknowledging surrogate modeling-based optimization technique for stochastic parameter optimization has been developed. Based on the analytical solution for heat and conservative tracer, a surrogate modeling-based optimization approach was developed to identify the heat storage from the push-pull test data. The optimization procedure has been validated against a synthetic dataset with parameter ranges from one of the ATES sites in Berlin. Results confirm that doing a push-pull test with heat and conservative tracer together enables uncertainty reduction. At the same time, sensitivity acknowledging optimization results in a much narrower posterior parameter distribution than the instant fusion of all available data. The modeling procedure highlights that objective function selection, as well as measurement accuracy, define the confidence interval and calibration precision.



4:45pm - 5:00pm
Topics: 1.05 Aquifer thermal energy storage (ATES): Potential, technologies and geoscientific challenges for a sustainable energy transition

Analysis of the spatial distribution of low permeability layers on high-temperature aquifer thermal energy storage

Stefan Heldt, Sebastian Bauer

Christian-Albrecht-University Kiel, Germany

High-temperature aquifer thermal energy storage (HT-ATES) is a heat storage technology utilising the subsurface, which can reduce greenhouse gas emissions in renewable-dominated heating sectors. Since the temperature difference between the surrounding groundwater and the injected water (> 50 °C) leads to density differences, HT-ATES can induce buoyancy flow. This process results in uneven heat distribution across the aquifer thickness, lower storage efficiency, and increased thermal impacts. The occurrence and intensity of buoyancy flow depends on, among others, vertical and horizontal permeability.

The proposed HT-ATES storage site in Hamburg, Germany, utilizes the Miocene Lower Braunkohlensande (brown coal sands) as the storage aquifer. This geological formation was formed in a coastal transition regime between terrestrial and shallow marine settings and is primarily composed of sands. Layers of brown coal, silt, and clay, embedded in the main storage aquifer, as identified from borehole information, were formed from peat swamps and lagoons and may impede convection due to their low permeability. The influence of these low permeability layers, also considering their lateral extension and position relative to the warm well, on induced convection and on HT-ATES efficiency and thermal impacts is examined in this work by employing a site-specific numerical HT-ATES model representing the coupled thermo-hydraulic processes.

Results show, that including even thin low permeability layers can effectively hinder temperature induced thermal convection, thus increasing thermal efficiency of a HT-ATES. The scenario simulations also show, that convection is already significantly dampened if the layers extend only up to the thermal radius.



5:00pm - 5:15pm
Topics: 1.05 Aquifer thermal energy storage (ATES): Potential, technologies and geoscientific challenges for a sustainable energy transition

Mine water for thermal energy storage – An analysis of hydrogeochemical factors based on in-situ real laboratory stations

Martin Binder1,2, Alireza Arab1, Christian Engelmann1, Traugott Scheytt1

1Technische Universität Bergakademie Freiberg, Institute of Geology, Chair of Hydrogeology and Hydrochemistry, Gustav-Zeuner-Str. 12, 09599 Freiberg (Saxony), Germany; 2University of Basel, Department of Environmental Sciences, Hydrogeology / Applied and Environmental Geology, Bernoullistrasse 32, 4056 Basel, Switzerland

Aquifer thermal energy storage (ATES) is a promising technique for the short- to long-term storage of reusable thermal energy in the subsurface. Many ATES projects suffer from operational issues or failures. Main causes are clogging, mineral precipitation and corrosion affecting both the aquifer matrix and technical infrastructure (e.g., pipes, heat exchangers), as well as unfavourable recovery rates due to convective and conductive heat energy losses across natural system boundaries.

While most systems address natural porous aquifers, a range of formerly active underground mines has been considered for ATES as well. The ongoing research project “MineATES” focuses on chances and limitations of such man-made systems.

Specifically, an in-situ real laboratory has been set up at the former silver mine “Reiche Zeche” in Freiberg, Germany, to simulate periodical heat exchange between mine water and surrounding rock. Hydro-/geochemistry changes will be logged simultaneously to the monitoring of heat propagation in both water and rock. In parallel, laboratory-scale flow-through column and batch experiments with multiple combinations of rock types and mine water compositions will be carried out at defined temperatures (~ 5°C to 50°C) to identify scales, types and locations of possible mineralization and further chemical alteration. Reference materials (rocks and mining waters) from the “Reiche Zeche” will be compared to materials from the Saxonian mines “Ehrenfriedersdorf” (former tin ore mine) and “Lugau/Oelsnitz” (former hard coal mine).

The project results are to be compiled into a criteria catalogue, providing guidelines for assessing if and how a mine could be used as an ATES system.



5:15pm - 5:30pm
Topics: 1.05 Aquifer thermal energy storage (ATES): Potential, technologies and geoscientific challenges for a sustainable energy transition

Thermal heat storage in abandoned coal mines in the Ruhr area

Mathias Nehler1, Florian Hahn1, Stefan Klein1, Stefan Stürmer1,2, Thomas Heinze2, Laura Blaes2, Tobias Licha2, Pascal Kosse2, Torsten Seidel4, Christoph M. König4, Thomas Grab3, Lukas Oppelt3, Timm Wunderlich3, Benedikt Ahrens1, Claudia Finger1, Rolf Bracke1,2, Marco Dietl1, Edith Nettmann2, Stefanie Erstling1

1Fraunhofer IEG, Germany, Am Hochschulcampus 1, 44801 Bochum; 2Ruhr Universität Bochum, Germany, Universitätsstraße 150, 44801 Bochum; 3Technische Universität Bergakademie Freiberg, Germany, Akademiestraße 6, 09599 Freiberg; 4delta h Ingenieurgesellschaft, Germany, Parkweg 67, 58453 Witten

The Winzer project investigates the opportunities and challenges of implementing ATES systems in old groundwater-filled coal mines. For this purpose, a near-surface (<80 m) small coal mine in Bochum, Germany at the Fraunhofer IEG is used as the pilot site. The mine was tapped by three boreholes through which the groundwater is lifted and reinjected. The implementation of geothermal reuse in the old mine building in combination with a concentrated solar power system (CSP) is unique in the world. This allows seasonal storage of fluids with temperatures up to 60°C. In addition, a comprehensive condition monitoring was implemented. The measurement data and findings obtained will be used to make qualitative and quantitative statements on the hydrochemical, microbiological, geo-mechanical and ecological conditions during cyclic operations. The newly developed concepts and technologies will enhance the efficiency of the existing ATES system with regard to scalings and biofoulings at the heat exchangers as well as the safety, i.e. with regard to the mobilization potential of contaminants. Within the project the upscaling from the pilot site at the IEG through the planned development of the site of the former Dannenbaum mine is evaluated. There the hydraulic and geomechanical properties and changes in the ATES system can also be examined during the seasonal heat storage. By including numerical simulations, an optimization of the operation management concepts for the overall system is achieved and potentials for transferability to many other cities and networks in former coal mining regions in Europe will be shown.

 
4:00pm - 5:30pm3.22 From the ocean floor to the deep mantle and the arc: Element cycling through subduction zones and in orogens
Location: Hall D (HFB)
Session Chair: Esther Martina Schwarzenbach, University of Fribourg
Session Chair: Ralf Halama, Keele University
 
4:00pm - 4:15pm
Topics: 3.22 From the ocean floor to the deep mantle and the arc: Element cycling through subduction zones and in orogens

Boron isotopic fractionation in subducted oceanic crust

Jie Xu, Horst Marschall, Axel Gerdes, Alexander Schmidt

FIERCE (Frankfurt Isotope & Element Research Center), Goethe University, Frankfurt am Main, Germany

Subducted oceanic crust plays an important role in controlling the chemical budget of the crust and mantle and in the composition of arc lavas. Oceanic eclogites represent fragments of oceanic crust that have been through a subduction zone and were subsequently exhumed and exposed. A range of geochemical signatures in oceanic eclogites have been studied to unravel the fluid-rock interaction processes. A key tracer is the trace-element boron and its isotope ratio (11B/10B) in oceanic eclogites with its great potential for quantifying mass transfer processes at convergent margins. Current models predict a strong decrease of δ11B values in the subducting crust with progressive dehydration to values much below that of the depleted mantle (appr. -7 ‰).

We have analyzed elemental abundances and boron isotopic compositions of oceanic metamorphic rocks, from Zambezi Belt, Cabo Ortegal complex, Raspas Complex, Syros Island, and Tian Shan. Whole-rock B/Pr ratios were used to quantify the progress of dehydration. The boron isotopic composition of almost all samples (approximately -10 to +5 ‰) ranges from δ11B values close to that of fresh MORB to that of typical altered oceanic crust. Also, the sample set shows no correlation between δ11B values and B/Pr, as would be expected from current theoretical models. Our results, thus, demonstrate that B isotopic fractionation in subducted oceanic crust is much smaller than predicted. We suggest that this discrepancy can be resolved by accepting high pH values in high-pressure hydrous fluids, which show a much smaller boron isotope fractionation in equilibrium with B-bearing silicates.



4:15pm - 4:30pm
Topics: 3.22 From the ocean floor to the deep mantle and the arc: Element cycling through subduction zones and in orogens

Fluid Release from a Dehydrating Serpentinite by Reactive Porosity Waves

K. Huber1, L. Khakimova2, J. C. Vrijmoed1, Y. Y. Podladchikov2, T. John1

1Freie Universität Berlin, Germany; 2Université de Lausanne, Switzerland

Dehydration of oceanic lithosphere during subduction is a key process in the Earth's deep volatile cycle. Field observations and studies of obducted meta-serpentinites that underwent dehydration at depth often show an interconnected, channelized vein network that formed during dehydration and served as pathway for fluid release from the dehydrating rock. Previous studies show that chemical heterogeneities in the bulk-rock composition lead to channelization of fluid flow from the onset of the dehydration process and how subsequent reactive fluid flow in the porous network causes further dehydration and channelization. On larger scales, fluid release from the rock is governed by mechanical processes such as porosity waves. While the micro- and meso-scale have been studied so far, this large-scale fluid release mechanism has not yet been explored for dehydrating serpentinite.

Here, we present a model for reactive porosity waves that investigates the large-scale fluid release from a dehydrating serpentinite. The model combines viscous rheology with the transport of dissolved silica in the fluid which has been shown to be a key metasomatic agent in the dehydration process. As input for our model, we use a multi-scale dataset of fully hydrated serpentinite from an ophiolite taken as representative for serpentinized oceanic lithosphere entering a subduction zone. We use the data to explore the formation of the vein network during dehydration and the behavior during large-scale fluid escape by reactive porosity waves.



4:30pm - 4:45pm
Topics: 3.22 From the ocean floor to the deep mantle and the arc: Element cycling through subduction zones and in orogens

From dry to drenched: variability of H2O contents in rutile from subducted rocks using quantitative in-situ FTIR spectroscopy and mapping

Mona Lueder, Renée Tamblyn, Jörg Hermann

Institute for Geology, University of Bern, Switzerland

Rutile is potentially very important for the transport of water during subduction metamorphism after the breakdown of hydrous phases, as it is one of the most hydrous nominally anhydrous minerals (up to several 1000 μg/g H2O) and commonly occurs in a variety of lithologies and P-T conditions across subduction zones.

We present results from quantitative in-situ Fourier Transform Infrared (FTIR) spectroscopy of rutile from different subduction settings (P-T, lithology, geothermal gradients) and high-resolution FTIR mapping to evaluate the variability of H2O contents in rutile and retention of H+.

Observed H2O contents are highly variable. Granulite facies rutile have low H2O contents (<150 μg/g) with high-P granulites showing up to ~400 μg/g H2O. The highest average H2O contents were observed in low-T eclogite facies rutile (500–1700 μg/g). Amphibolite- and high-T – high-P eclogite facies rutile has intermediate H2O contents (~200–400 μg/g). Rutile from UHP shows greatly varying H2O contents (<10–700 μg/g).

FTIR maps of high-P granulite-, high-T – high-P eclogite facies and UHP rutile show evidence for diffusive H+ loss, while low-T eclogite- and amphibolite facies rutile are homogeneous or show growth zoning and thus retain their original H2O contents. Therefore, the typically variable and lower H2O contents at higher P-T conditions result from H+ loss at temperatures above ~650–700 °C.

Generally, H2O contents are distinctive for specific subduction zone conditions, especially when coupled with Zr-in-rutile thermometry and trace-element geochemistry, e.g. high H2O contents above 500 μg/g coupled with Zr contents below 200 μg/g indicate cold subduction geotherms.



4:45pm - 5:00pm
Topics: 3.22 From the ocean floor to the deep mantle and the arc: Element cycling through subduction zones and in orogens

Efficiency and depth of H2O recycling from a modelling perspective

Sara Vulpius, Falco Menne, Lena Noack, Oliver Henke-Seemann, Enrique Sanchis Melchor

Freie Universität Berlin, Germany

The recycling of volatiles like H2O from the surface into the interior is critical as it influences the physical and chemical properties of the mantle. One of the essential effects H2O has on the mantle is the reduction of the solidus temperature, as this can trigger partial melting. On the one hand, the process of partial melting is vital for arc and ore deposit formation. On the other hand, it is thought to be a requirement for the generation of the continental crust.

Even though intensive work has been done on investigating the stability fields of hydrous phases experimentally and thermodynamically depending on pressure, temperature, and composition, it is still debated to which depths and in which quantities H2O can be recycled. However, the parameters influencing the mineral stability and break-down (e.g., pressure, temperature, composition, oxygen fugacity) change constantly during the recycling process. To include these changes, global convection models are required which take the varying conditions over time into account. While numerous studies exist, that model the subduction process itself, the recycling of H2O is not considered to date in most of the simulations, or strongly simplified models are applied.

We model the quantity of H2O that can be recycled as well as the depth to which the recycling is possible. For this purpose, we test individual parameters affecting the H2O recycling and dehydration from the subducting slab. To benchmark our simulations, we compare our results with seismological observations of the Pacific plate subducting beneath northeast Japan.

 
4:00pm - 5:30pm3.13 Identifying tectonics and climatic signals in deep-time: challenges and opportunities
Location: Wiwi 101
Session Chair: Guido Meinhold, TU Bergakademie Freiberg
Session Chair: Luca Caracciolo, Friedrich-Alexander Universität
 
4:00pm - 4:30pm
Invited Session Keynote
Topics: 3.13 Identifying tectonics and climatic signals in deep-time: challenges and opportunities

Pre-Cenozoic paleoclimate responses to astronomical forcing

David De Vleeschouwer1, Lawrence M.E. Percival2, Nina Wichern1, Sietske J. Batenburg3

1Institute of Geology and Palaeontology, Corrensstr. 24, 48149 Münster, University of Münster, Germany; 2Analytical, environmental and Geochemistry, Pleinlaan 2, 1050 Brussels, Vrije Universiteit Brussel, Belgium; 3Faculty of Earth Sciences, Martí I Franqués, 08028 Barcelona, University of Barcelona, Spain

Astronomical insolation forcing is now well-established as the underlying metronome of Quaternary ice ages and Cenozoic climate carbon-cycle feedback mechanisms. However, its effects on earlier Eras (Mesozoic, Paleozoic, and pre-Cambrian) are less understood. In this presentation, I will evaluate various pre-Cenozoic modes of response to astronomical forcing, and provide an overview of the Earth System components that were particularly sensitive to astronomical forcing under evolving boundary conditions. Subsequently, the role of astronomical forcing in pacing the global carbon cycle in the Devonian warmhouse and Cretaceous hothouse worlds is discussed. Both periods are characterized by recurrent ocean anoxia and remarkably similar hypotheses exist regarding how astronomical forcing could have amplified a nutrient surplus (from chemical weathering and volcanism, respectively) to tip the ocean system into anoxia. The Triassic-Jurassic boundary cyclostratigraphy illustrates the importance of precession-scale time-control to understand feedback mechanisms and cause-and-effect chains at a resolution that is relevant for making analogies with the present-day. Finally, this presentation provides an outlook on the need for a coordinated approach, using so-called astrochronozones, to establish a fully astronomically-calibrated timescale for the Phanerozoic. Overall, I will highlight the need for a more comprehensive understanding of the role of astronomical insolation forcing in shaping Earth's climate over geologic time.



4:30pm - 4:45pm
Topics: 3.13 Identifying tectonics and climatic signals in deep-time: challenges and opportunities

A hot, hydrothermally-fed microbial tidal flat in the Paleoarchean Moodies Group, Barberton Greenstone Belt, South Africa?

Hannes Stengel, Christoph Heubeck

Friedrich-Schiller Universität Jena, Germany

Sandy alluvial-, deltaic-, and tidal-facies sediments of the Paleoarchean Moodies Group (ca. 3,220 Ma) are preserved several km thick in the central Barberton Greenstone Belt, interspersed with diverse units representing substantial mafic to intermediate (sub-)volcanism. Densely biolaminated sandstones feature common, up to 6 m high fluid-escape structures which fed small sand volcanoes during prolonged and/or recurring discharge of gases, liquids, and solids. The to-date highest documented concentration of fluid-escape structures occurs in a single, largely silicified unit of tidal-facies sandstones ca. 150 m thick, traceable along strike for ca. 14 km and located stratigraphically ca. 1 km above the Lomati River Sill, a 15 km long mafic sill of Moodies intrusive age. Fluid-escape conduits are filled by sand, sericitic clay and fine-grained organic matter. Semiquantitative XRF scanning of several slabbed fluid-escape structures indicates that conduits are enriched in Fe, Cr, Ti, and Mg in comparison to the mean composition of adjacent beds, suggesting that fluid-escape structures may not only have formed due to overpressure build-up from decaying microbial mats in the shallow subsurface but also resulting from release of hydrothermal fluids generated in a thermal aureole above the cooling sill. This inference is also supported by sediment textures characteristic of argillaceous and sericitic alteration, Raman temperatures ca. 50 - 100°C above the regional maximum metamorphic temperature of 320 - 370°C, and associated peperites nearby. Surficial hydrothermal activity in the tidal zone would have likely boosted microbial growth. Surficial pre-compaction carbonation and silicification greatly facilitated the preservation of delicate microbial mats.



4:45pm - 5:00pm
Topics: 3.13 Identifying tectonics and climatic signals in deep-time: challenges and opportunities

Expressions of Early Silurian climate changes in the stratigraphic record of Baltica and South China

Oliver Lehnert1,3,7, Guido Meinhold2, Michael Joachimski1, Guanzhou Yan3,4, Mikael Calner5, Peep Männik6, Jiri Frýda7, Fangyi Gong3,4, Rongchang Wu3,4

1GeoZentrum Nordbayern, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Schloßgarten 5, D-91054 Erlangen, Germany; 2TU Bergakademie Freiberg, Institut für Geologie, Bernhard-von-Cotta-Straße 2, D-09599 Freiberg, Germany; 3State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology & Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China; 4Center for Excellence in Life & Palaeoenvironment, Chinese Academy of Sciences, Nanjing 210008, China; 5Department of Geology, Lund University, Sölvegatan 12, SE-223 62 Lund, Sweden; 6Tallinn University of Technology, Institute of Geology, Ehitajate tee 5, 19086 Tallinn, Estonia; 7Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 165 21, Praha 6 – Suchdol, Czech Republic

The Silurian record in the Siljan crater, Europe’s largest impact structure, in the succession at Baizitian (Sichuan Province) in South China, in other Swedish and Estonian sections, together with records from Laurentia and high latitude peri-Gondwana imply a series of glacial events during the Early Silurian. The associated climate shifts are expressed in stratigraphic sections as δ18Oapatite anomalies and subaerially exposed sequence boundaries with associated palaeokarst in the tropics and subtropics. During the continuing icehouse after the Hirnantian glacial maximum several stratigraphic gaps developed in the basal Silurian in many parts of the world due to extremely low sea levels, erosion, and first onlaps during deglaciations much later in Silurian times.

Our Telychian to Sheinwoodian chemostratigraphic data include several prominent excursions, such as the pronounced Manitowoc Carbon Isotope Excursion (Manitowoc CIE, ‘Manitowoc Excursion’), spanning the upper Pterospathodus eopennatus Zone and the lower Pterospathodus amorphognathoides amorphognathoides Superzone. Well-bracketed by conodont biostratigraphy, the Manitowoc CIE is an essential tie-point for a detailed correlation between the Baizitian succession in South China and the Telychian strata of Baltica and Laurentia.

Here we focus on the Early Silurian climate development spanning the Telychian Valgu glaciation (more widely recognized than older glacials during the Aeronian), the Manitowoc Icehouse including two short-term glacial events and the late Telychian Glaciation (LTG), , and the Sheinwoodian glaciation reflected by the Sheinwoodian Oxygen Isotope Excursion (SOIE) following directly after the maximum δ13C values of the widely known Early Sheinwoodian Carbon Isotope Excursion (ESCIE).



5:15pm - 5:30pm
Topics: 3.13 Identifying tectonics and climatic signals in deep-time: challenges and opportunities

Detrital garnet petrology challenges Paleoproterozoic ultrahigh-pressure metamorphism in western Greenland

Jan Schönig1, Carsten Benner1, Guido Meinhold2, Hilmar von Eynatten1, N. Keno Lünsdorf1

1Georg-August-University Göttingen, Germany; 2TU Bergakademie Freiberg, Germany

Modern-style plate tectonics is characterized by the global operation of deep and cold subduction involving ultrahigh-pressure and blueschist-facies metamorphism. This is a common process since the Neoproterozoic, but a couple of studies indicate similar processes have been active in the Paleoproterozoic, at least on the local scale. Particularly conspicuous are extreme ultrahigh-pressure conditions of ~7 GPa at thermal gradients <150°C/GPa proposed for metamorphic rocks of the Nordre Strømfjord shear zone in the western part of the Paleoproterozoic Nagssugtoqidian Orogen of Greenland (Glassley et al., 2014). By acquiring a large dataset of heavy minerals (n = 52,130) and garnet major-element composition integrated with mineral inclusion analysis (n = 2,669) from modern sands representing fresh and naturally mixed erosional material from the metamorphic rocks, we here intensely screened the area for potential occurrences of ultrahigh-pressure rocks and put constraints on the metamorphic evolution. Apart from the absence of any indications pointing to ultrahigh-pressure and low-temperature/high-pressure metamorphism, the results are well in accordance with a common Paleoproterozoic subduction−collision metamorphic evolution along a Barrovian-type intermediate temperature/pressure gradient with a pressure peak at the amphibolite−granulite−eclogite-facies transition and a temperature peak at medium- to high-pressure granulite-facies conditions. This is in strong contrast to the proposed ultrahigh-pressure conditions and low geothermal gradients, and challenges the existence of a Paleoproterozoic modern-style plate-tectonic regime in western Greenland.



5:30pm - 5:45pm
Topics: 3.13 Identifying tectonics and climatic signals in deep-time: challenges and opportunities

Collecting ‘Big’-data in sedimentary provenance analysis: An optimized workflow from sample preparation to analysis

Nils Keno Lünsdorf1, Jan Ontje Lünsdorf2, Gábor Újvári3, Lukas Wolfram4, Adrian Hobrecht4, Lothar Laake4, Hilmar von Eynatten1

1Georg-August University Göttingen, Geoscience Centre, Department of Sedimentology and Environmental Geology, Göttingen, Germany; 2Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Institute of Networked Energy Systems, Oldenburg, Germany; 3Centre for Astronomy and Earth Sciences, Institute for Geological and Geochemical Research, Eötvös Loránd Research Network, Budapest, Hungary; 4Georg-August University Göttingen, Central Workshop of the Geoscience Centre, Göttingen, Germany

For a robust interpretation in sedimentary provenance analysis studies (SPA) a combination of multiple methods is usually applied to a selected number of samples. To circumvent effects that perturb the provenance signal (e.g. hydraulic sorting) information on radiometric age, chemical composition and mineralogy is collected for mineral varieties usually by means of laser ablation inductively coupled mass spectrometry (LA-ICPMS), electron probe microanalyzer (EPMA), Raman micro-spectroscopy and polarized optical microscopy.

These methods have become increasingly efficient and allow for rapid analysis of statistically relevant numbers of samples which is fundamental to SPA. However, routine combination of these methods on the same grains is rarely realized and sample preparation quickly becomes a bottleneck when sample numbers are significantly increased. The latter is especially important to detect subtle variations in deposits due to processes operating on centennial to millennial time scales such as rapid climatic variability.

Here we present a workflow that is optimized for high throughput of silt to sand-sized sedimentary samples, which allows routine combination of optical microscopy, Raman micro-spectroscopy, EPMA and LA-ICPMS by means of machine learning methods. Due to the high degree of automatization our workflow enables to access sedimentary archives at high spatial and/or temporal resolution and will provide, depending on combined methods, single-grain datasets that contain information on grain-size, shape, roundness, color, mineralogy, degree of metamictization, chemical composition, trace element composition and radiometric age. We demonstrate innovative approaches in the relevant sample preparation steps and showcase data of several loess profiles highlighting the feasibility of our workflow.

 
4:00pm - 5:30pm1.20 Resource management tools – as a knowledge base for the availability of raw materials and for decision-making
Location: Wiwi 104
Session Chair: Antje Wittenberg, Federal Institute for Geosciences and Natural Resources (BGR)
Session Chair: Soraya Heuss-Aßbichler, University of Munich (LMU)
 
4:00pm - 4:30pm
Invited Session Keynote
Topics: 1.20 Resource management tools – as a knowledge base for the availability of raw materials and for decision-making

From boring needs to cool instruments. – Can codes and standards assist to ensure fair, responsible and legal mining?

Christian Masurenko

ECTerra GEO Consult GBR, Germany

Worldwide 80-100 million people are involved in small-scale mining, another 4 million people in "normal" mining in order to survive and to gain income for their families. Many strategic minerals, such as Coltan, Cobalt, etc., are shipped to Europe from small-scale mining. Materials from legal mining mix with illegal operations and disappear undetected in refineries. Responsible, legal, and fair mining can only emerge if we progress with transformation in this sector. A rethinking of ethical and moral principles. But is that even possible? Yes, it is achievable! When governments, mine owners, small-scale miners and social communities come together and are more interested in long-term profits than in "quick & dirty money". The standards for responsible mining already exist. OECD, IFC, UNFC and others have already developed and framed these standards. Only their practice in the field and the implementation of these standards in the real world remains difficult. Our supply chains often start right in the bush in the hinterland of many developing countries. This is where people want to earn money through honest and fair work. Communities want to profit from the "exploitation" of their natural resources. Governments must be able to participate in the sales & exports and monitor them. Environmental protection and human rights are the highest good and must be introduced and always respected. This can only be achieved through a very lengthy process of training and further education of all those involved. Mining standards help us to monitor and evaluate progresses. Based on a feasibility study in Ni mining in South America, fluorspar mining in Germany and small-scale mining for tantalum in Liberia, we discuss the necessary transformations in the raw materials sector.



4:30pm - 4:45pm
Topics: 1.20 Resource management tools – as a knowledge base for the availability of raw materials and for decision-making

Promoting Sustainability through Inclusive Resource Management: The Role of UNFC and Intergenerational Action

Bianca Derya Neumann, Ghadi Sabra, Jodi-Ann Wang, Yuhan Zheng

UNECE Resource Management Young Member Group (RMYMG), Germany

The promotion of accessible knowledge and better understanding of raw materials extraction and management is a crucial step towards ensuring sustainable resource management across industries and nations. Intergenerational equity can only be achieved through the inclusion of public stakeholders, including the youth, in decision-making processes and implementation of standards and practices in the industry.

Resource classification tools like CRIRSCO dominated the minerals industry in the past, providing information mainly accessible to geoscientists trained to interpret the assessments and investors. But as the public is an important stakeholder of the global environment, it is important to create an all-inclusive system that can be used by everyone. Thus, standards that cater to investors only do not serve the broader purpose of promoting sustainable resource management. The UNFC classification and UNRM provide easily digestible information that allows non-experts to compare national resources, their implications on the economy, society, and the environment, that, unlike other standards, don’t vary from industry to industry and country to country. However, many questions about the implementation of UNFC are still to be answered. How do we strengthen the UNFC to equitably involve non-experts and future generations from various sectors and industries? And how can a policy implementation, that ensures environmental, social and intergenerational equity be ensured? This proposed talk combines perspectives of industry, government, academia, and NGOs, and provides a rounded discussion on how we demystify, heighten social awareness, and encourage intergenerational action around the UNFC and towards sustainable resource management by and for all.



4:45pm - 5:00pm
Topics: 1.20 Resource management tools – as a knowledge base for the availability of raw materials and for decision-making

Developing an EU International Centre of Excellence on Sustainable Resource Management to support UNRMS

Meta Dobnikar1, Snježana Miletić1, Zoltán Horváth2

1Geological Survey of Slovenia, Slovenia; 2Supervisory Authority of Regulatory Affairs

Sustainable use of mineral resources that we need for energy storage, power generation and the transition to climate neutrality, and which is at the same time more efficient and integrated, can be achieved by orchestrated activities to harmonise and careful manage data on reserves and resources. This makes an opportunity to build on EU level mineral intelligence by developing a capacity building and knowledge centre in support to the United Nations Resource Management System (UNRMS). UNRMS is represented by the principles and requirements on sustainable resource management, set by the United Nations Economic Commission for Europe (UNECE).

On that purpose the Horizon Europe´s Coordination and Support Action acronymed GSEU is establishing the Geological Service for Europe, which will include an EU International Centre of Excellence on Sustainable Resource Management (EU ICE SRM). The objective of the EU ICE SRM will be promotion and capacity building on the United Nations Framework Classification for Resources (UNFC) - an international scheme for the classification and management of energy, mineral and raw material resources (UNECE, 2023) that takes into account the degree of confidence, technical feasibility and social-economic-environmental aspects of a project.

The EU ICE SRM will thus support UNRMS by capacity building and promotion of the resources needed to accomplish the 2030 Agenda for Sustainable Development (UNECE, 2020). It will operate as a network of partners and experts to assist the decision makers and key stakeholders in resource management.

References:

UNECE, 2020: Criteria for ICE-SRM Designation

https://unece.org/fileadmin/DAM/energy/se/pdfs/UNFC/ICE-SRM/20200925_EGRM-11-2020-INF3_ICE.SRM_Criteria___ToR_Final.pdf

UNECE, 2023: What is UNFC? https://unece.org/sites/default/files/2023-02/What-is-UNFC_E.pdf



5:00pm - 5:15pm
Topics: 1.20 Resource management tools – as a knowledge base for the availability of raw materials and for decision-making

A Novel Web-tool for the Assessment of Materials Recovery and Recycling Projects Aligned with UNFC

Iman Dorri, Bhagya Jayasinghe, Alireza Sobouti, Soraya Heuss-Aßbichler

Ludwig-Maximilians-Universität München (LMU), Department of Earth and Environmental Sciences, Germany

The current challenges in our society regarding digital, energy, and circular economy transition have made the recycling and recovery of materials from waste streams a hot topic since they have the potential to provide part of the materials required to meet the challenges. Evaluating the sustainability of a project is also crucial, which usually involves a number of requirements for the project. In this regard, the classification of projects is key to the development of secondary raw materials (SRMs) recovery and recycling projects, including their proper management. The United Nations Framework Classification for Resources (UNFC) is a unique tool to assess all types of resources on the same principle notably projects related to the supply of Critical Raw Materials and SRMs from primary and anthropogenic resources. It considers the level of confidence in the quantity of products obtained, their technical feasibility, and their environmental-social-economic viability. Hence, it can be used as a decision-support tool on company, regional, and national levels.

This paper presents a web-based tool developed for the assessment of SRMs to determine, among other things, the maturity level of SRM recovery projects in accordance with the UNFC. The development process of the web-based tool will be discussed, including its design, features, and functionalities. An example is provided to show how the tool can be used to assess different types of secondary raw materials, highlighting its potential benefits for the circular economy.



5:15pm - 5:30pm
Topics: 1.20 Resource management tools – as a knowledge base for the availability of raw materials and for decision-making

UNFC – a tool the scientific community should be aware of

Antje Wittenberg1, Sören Henning1, Jochen Kolb2

1Federal Institute for Geosciences and Natural Resources (BGR), Germany; 2Karlsruhe Institute of Technology (KIT), Germany

Fieldwork, sampling and analysis are tasks that most geoscientists enjoy, whether they are aspiring young scientists or experienced field geologists. Some of the activities arouse curious interest others are viewed with scepticism. Yet, what they all have in common is that good communication is part of successful work. Hence, an open and transparent discourse with non-scientists, is of importance as it is for mutual communication among fellow scientists, among and across disciplines.

Natural resources are a valuable asset, so the possibilities, risks, opportunities and challenges associated with projects to explore and use them should be made equally known to all interested parties. The United Nations has developed a tool (UNFC) that can help with communication in order to achieve mutual understanding in the context of resource management.

Furthermore, in its draft legislation on critical raw materials (CRM), the European Commission has proposed to use the UNFC as a mandatory tool in reporting on mineral resources in the EU and in European and national research programmes. EIT Raw Materials - as one of Europes´ largest project promoters - is already encouraged to assess the proposals against the UNFC concept.

Due to the worldwide high demand for CRM, increased exploration activities currently also stepped up in Germany. These projects are at different stages of exploration and development maturity. A unified classification via UNFC could help to support the regional sustainable raw material supply.

This contribution aims to raise awareness of the UNFC concept and improve understanding of its application.

 
4:00pm - 5:30pm3.12-2 Past climates and environments inform our future
Location: Wiwi 104a
Session Chair: Cécile Blanchet, GFZ Potsdam
Session Chair: Stefanie Kaboth-Bahr, Free University Berlin
 
4:00pm - 4:15pm
Topics: 3.12 Past climates and environments inform our future

New insights into Early Cretaceous continental environments and climate based on lignite-bearing strata from central Mongolia

Fritz-Lukas Stoepke1, Ralf Littke2, Laura Zieger2, Hitoshi Hasegawa3, Niiden Ichinnorov4, Ulrich Heimhofer1

1Leibniz University Hannover, Germany; 2RWTH Aachen University, Germany; 3Kochi University, Japan; 4Mongolian Academy of Sciences, Mongolia

The late Early Cretaceous (121.4 to 100.5 Ma) was characterized by a gradual warming trend superimposed on an already warm greenhouse climate. Whereas the evolution of ocean temperatures during this time interval is relatively well constrained, information on the response of continental interiors to such climatic extremes is limited. Here we report new data from the continental Choir-Nyalga Basin of central Mongolia, which contains thick, lignite-rich successions (Khukhteeg Fm.) bearing an exceptionally well-preserved fossil flora of various pine and redwood species as well as representatives of extinct seed plant lineages. The continuous and often long-lasting accumulation of plant remains results in continental high-resolution archives documenting the palaeoecological conditions prevailing during bog growth.

In order to reconstruct the palaeoenvironmental conditions, a combined approach including brGDGT-based palaeothermometry, coal petrology and palynology is applied, complemented by geochemical measurements (TOC, TS, δ13Corg). Due to the limited biostratigraphic resolution of the continental Khukhteeg Fm., stratigraphic trends in δ13Corg will be applied for local and super-regional chemostratigraphic correlation. The carbon isotopic composition of the land plant-derived organic matter shows pronounced stratigraphic fluctuations and varies between -20.8 ‰ to -24.4 ‰ (average: -22.4 ‰). The brGDGT data represent the oldest analyses obtained from lignites so far. The new data indicate that the climatic conditions in central paleo-Asia (paleolatitude of ~38°N) during the late Early Cretaceous were characterised by high mean annual air temperatures (ranging between 8 ± 3°C and 10 ± 4°C).



4:15pm - 4:30pm
Topics: 3.12 Past climates and environments inform our future

New insights into hyperthermal events during the late Paleocene to early Eocene

Bryan Niederbockstruck1, Heather Jones1, Kazutaka Yasukawa2, Erika Tanaka3,4, Isabella Raffi5, Thomas Westerhold1, Ursula Röhl1

1MARUM - Center for Marine Environmental Sciences, University of Bremen, Germany; 2University of Tokyo; 3Kochi University; 4Chiba Institute of Technology; 5Dipartimento di Ingegneria e Geologia, Universita’ degli Studi “G. d’Annunzio” di Chieti-Pescara

The late Paleocene and early Eocene climate was punctuated by several warming events known as hyperthermals. These events reflect perturbations in the carbon cycle, identified by the negative carbon isotope excursions, including the prominent Paleocene-Eocene Thermal Maximum. Under the high carbon emission scenario of RCP8.5, the climate is predicted to most closely resemble early Eocene conditions within the next hundred years, making it a promising analog to study the possible long-term environmental changes that we have to face in the near future. High-resolution geochemical records from the Atlantic and Pacific provide astronomically calibrated age models of the early Paleogene. However, these sites are located in the equatorial- to subequatorial regions, so the high-latitude climate changes of the early Paleogene still remain elusive. IODP Expedition 378 recovered new Paleogene sediments at Site U1553 in the high-latitude Southwest Pacific.

Here, we present a novel late Paleocene to early Eocene age model spanning ~7 million years, which will be essential for future paleoceanographic studies of this site. To construct the age model, we used a combined chemostratigraphic and biostratigraphic approach. Our results show that the shape and pattern of the U1553 bulk sediment δ13C record generally match the orbitally-tuned records, which is reflective of a global trend. However, the nannofossil events at site U1553 exhibit a striking delay compared to lower latitude sites, suggesting that these commonly-used datums are not applicable at the high latitudes.



4:30pm - 4:45pm
Topics: 3.12 Past climates and environments inform our future

Environmental change at the Mid-Eocene Climate Optimum in Central Asia and potential relations with Eurasian paleoecological dispersals

Guillaume Dupont-Nivet1,2, Silke Voigt3, Alina Seufert3, Erwin Appel4, Saida Niglatova5, Nariman Jamikeshev1

1CNRS - université de rennes, France; 2GFZ Potsdam; 3Frankfurt university; 4Tuebingen university; 5Saptayev institute of geology, Kazakhstan

limatic optima and hyperthermals of the Paleogene period (66-34 Ma) open windows into the past to explore the Earth System under extreme conditions, beyond several tipping points. During this period Central Asia was intensely hot and arid and offered only a few corridors between Asian and European ecosystems that enabled significant dispersal events such as the "Grande Coupure". These events may have beentriggered by climatic and/or paleogeographical events including the fluctuations of the proto-Paratethysepicontinental sea and its progressive retreat. To date, it has been difficult to disentangle these various forcing factors.Sedimentary sections and associated climate tracers in this region and period are notoriously rare, and existing records suffer from poor age control that precludes robust correlations. We present here a high-resolution magnetostratigraphic dating of integrated environmental proxies from deposits of the Ili Basin, Kazakhstan, bearing rare Eocene mammal fossils. Preliminary results suggest the section encompasses a significantly wetter phase that can be precisely correlated to the Middle Eocene Climate Optimum, a globally recognized hyperthermal expressed by various extreme climate events from 40.5 to 40.1 Ma. In the studied Ili Basin record, Mammal fossils are reported to come precisely from this wet interval. This singular concentration of evidence suggests the MECO may have promoted Eurasian dispersal, however, further climate modelling and proxy data are required to identify potential controlling mechanisms.



4:45pm - 5:00pm
Topics: 3.12 Past climates and environments inform our future

Post-glacial climate amelioration recorded in the early Permian Aramac Coal Measures (Galilee Basin, Australia)

Alexander Thomas Wheeler1, Ulrich Heimhofer1, Joan Sharon Esterle2, Ralf Littke3, Laura Zieger3

1Institute for Geology, Leibniz University Hannover, Callinstraße 30, D-30167 Hannover, Germany; 2School of Earth and Environmental Sciences, The University of Queensland, QLD 4072, Australia; 3Energy and Mineral Resources Group (EMR), Institute of Geology and Geochemistry of Petroleum and Coal, Lochnerstr. 4-20, RWTH Aachen University, 52056 Aachen, Germany

The end of the Late Palaeozoic Ice Age (LPIA) was characterized by the development of widespread peat-forming mires across Gondwana concurrently with the evolution of the Glossopteris­-flora. The Aramac Coal Measures in the Galilee Basin of Australia represent some of the early phase of humic peat formation following the deglaciation in an ameliorating climate. This work aims to examine two boreholes using a multidisciplinary approach involving palynology, coal petrology, carbon isotope geochemistry and biomarkers to reconstruct the climate, environment and floras of this post-glacial period.

Palynostratigraphy suggests a late Artinskian to early Kungurian age for the Aramac Coal Measures separated from the overlying JK seams by an unconformity. Small-scale sedimentary dykes and cryostructured palaeosols suggest the peats would have formed under permafrost conditions. Palynological assemblages display a typical mix of early Permian elements and remnants of the Carboniferous floras with striate bisaccate pollen representing glossopterids, monosaccate pollen representing cordaitaleans, and spores representing herbaceous ferns, lycopsids and horsetails. Maceral analysis of the coals show high inertinite values, which, along with pristane/phytane ratios indicate an oxidative environment in which the peats were influenced by fire and/or fungi and bacteria. Stable carbon isotope values are typical for terrestrial environments (-22‰ to -26‰) but show an apparent cyclicity that may be related to climatic fluctuations following the end of the glaciation. This indicates the rise of the Glossopteris-flora was a gradual process which may have been influenced by warm and cool climatic phases well into the Permian.

 
4:00pm - 5:30pm2.06-2 Interior, surface and atmosphere processes on rocky worlds
Location: Wiwi 105
Session Chair: Solmaz Adeli, DLR
 
4:00pm - 4:30pm
Invited Session Keynote
Topics: 2.06 Interior, surface and atmosphere processes on rocky worlds

Surface processes on the Moon, Mars and the Earth

Giulia Magnarini

Natural History Museum, London, United Kingdom

Planetary surfaces hold evidence of past geological processes through the geomorphological record of landforms. Fast erosion rates, active tectonics, and a thick atmosphere contribute to partial or total loss of the terrestrial record, therefore leading to the misinterpretation and underestimation of the geological processes that formed it. Well-preserved extraterrestrial landforms, coupled with high resolution imagery, can compensate for the terrestrial missing geomorphological information. On the other hand, on Earth, we have direct access to landforms. Field observations are vital to gain insights into the mechanisms involved and into the environmental and climatic conditions in which landforms form. Therefore, the combination of terrestrial and planetary observations can be very effective in better understanding geological processes across the Solar System.

This talk will focus on long runout landslides and impact craters. I will discuss: a) the importance of comparative planetary geology in studying long runout landslides on Mars and Earth, in the attempt to understand their emplacement mechanisms and the link with climatic conditions; b) present day impact events on the Moon and the implications for Solar System chronology and impact flux rate.



4:30pm - 4:45pm
Topics: 2.06 Interior, surface and atmosphere processes on rocky worlds

Formation and development of polygonal soils in the hyper-arid Atacama Desert and their relevance for Mars.

Christof Sager1, Alessandro Airo1, Felix L. Arens2, Dirk Schulze-Makuch2,3,4,5

1Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, 10115 Berlin, Germany; 2Astrobiology Research Group, Zentrum für Astronomie und Astrophysik, Technische Universität Berlin, 10623 Berlin, Germany; 3Section Geomicrobiology, German Research Centre for Geosciences (GFZ), 14473 Potsdam, Germany; 4Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), 12587 Stechlin, Germany; 5School of the Environment, Washington State University, Pullman, WA 99164, USA

Polygonal networks occur on various terrestrial and extraterrestrial surfaces holding valuable information on the pedological and climatological conditions under which they develop. However, in contrast to their periglacial counterparts, the information that polygons in the hyper-arid Atacama Desert can provide is little understood. To gain insights into their geometrical and geochemical build-up, we performed a morphometric terrain characterization in combination with geochemical and sedimentological analysis on four polygonal networks in the Yungay area of the Atacama Desert. The polygons are composed of siliciclastic sediment that is mainly cemented by sulfates in ~0–50 cm depth and by nitrates and chlorides in ~50–100 cm depth while being separated by about 1 m deep, salt-poor and V-shaped sand wedges. The high salt content (>60 wt%) and high surface temperature variations make a thermal contraction origin likely. The low clay content (~2 wt%) makes an exclusive desiccation origin less relevant but a formation based on dehydration of sulfates remains conceivable. Morphometric data indicate a link between topography and polygon geometry, as the flat-centered polygons (mean size ~4 m) are aligned either in slope direction or perpendicular to it, while being more elongated on steeper slopes. Erosion of these networks is mainly eolian-driven, but we also find signs for aqueous resurfacing of microtopography by fog and minimal rainwater infiltration. Our findings provide a basis for future polygon research in hyper-arid environments, such as Mars, while allowing for the use of polygons as environmental proxies in the Atacama Desert that indicating saline soils and hyper-arid conditions.



4:45pm - 5:00pm
Topics: 2.06 Interior, surface and atmosphere processes on rocky worlds

Climate dynamics plays a key role in determining the Snowball bifurcation point on Earth

Georg Feulner1, Mona Bukenberger1,2, Stefan Petri1

1PIK, Germany; 2ETH Zurich, Switzerland

One of the limits of planetary habitability of Earth and other water-rich planets relates to the instability with respect to global glaciation, a fundamental property of the climate system caused by the positive ice-albedo feedback. Due to the steady increase in solar luminosity, the atmospheric concentration of carbon dioxide (CO2) at which this Snowball bifurcation occurs evolves over time. Earlier studies on the limit of global glaciation are based on investigations with very simple climate models for Earth’s entire history or studies of individual time slices carried out with a variety of more complex models and for different boundary conditions, making comparisons difficult. Here we use a relatively fast coupled climate model of intermediate complexity to trace the Snowball bifurcation of an aquaplanet through Earth’s history in one consistent modelling framework. We find that the critical CO2 concentration decreases more or less logarithmically with increasing solar luminosity until about 1 billion years ago, but drops faster in more recent times. Furthermore, there is a fundamental shift in the dynamics of the critical state about 1.8 billion years ago, driven by the interplay of wind-driven sea-ice dynamics and the surface energy balance. These results highlight once again the importance of climate dynamics for investigations of planetary habitability.



5:00pm - 5:15pm
Topics: 2.06 Interior, surface and atmosphere processes on rocky worlds

Long-term changes of Earth's internal magnetic field and their effects on the shielding and cosmogenic nuclides

Sanja Panovska1, Monika Korte1, Ilya Usoskin2,3

1GFZ German Research Centre for Geosciences, Helmholtz Centre Potsdam, Germany; 2Space Physics and Astronomy Research Unit, University of Oulu, Finland; 3Sodankylä Geophysical Observatory, University of Oulu, Finland

The Earth’s magnetic field shields our planet against highly energetic particles from the Sun and outer space. Over geological times, the time-varying geomagnetic field exhibited periods of dramatic changes, both in intensity and direction. Recent data compilations of paleomagnetic records enable us to model the long-term, global evolution of the geomagnetic field and better understand the internal dynamics and underlying phenomena. On the other hand, the spatial and temporal changes influence the shielding and cosmogenic nuclide production rates. In general, the higher the field intensity, the larger the shielding and the fewer cosmogenic nuclides are produced in the atmosphere.

We cover the evolution of the geomagnetic field over the past 100 000 years by presenting characteristics found to be robust in available global models. The period includes a few geomagnetic excursions, including the Laschamps excursion 41 000 years ago – when the intensity was globally very low, and the field had a complex, multipolar structure. Several properties of and estimates based on the models will be discussed, including the field morphology at the core-mantle boundary and Earth’s surface, global cutoff rigidity variations, impact area, global cosmic ray flux, and production rates of different cosmogenic nuclides. The latter results from the models are validated through comparison with actual measurements from ice and marine cores.

 
4:00pm - 5:30pm4.10-3 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?
Location: Wiwi 107
Session Chair: Sylke Hlawatsch, Richard Hallmann Schule
Session Chair: Dirk Felzmann, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau
 
4:00pm - 4:15pm
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?

EGU Geosciences Education Field Officers: the assessment of the programme

Gina P. Correia1,2, Sylke Hlawatsch3, Anna Anglisano Roca2,4, Hélder Pereira2,5, Jean-Luc Berenguer Berenguer2,6

1Centre for Earth and Space Research of the University of Coimbra (CITEUC), Coimbra, Portugal.; 2European Geoscience Union - Education Committee (EGU-EC); 3Richard-Hallmann-Schule, Trappenkamp, Germany; 4Spanish Earth Science Teachers Association (AEPECT), Spain.; 5Escola Secundária de Loulé, Loulé, Portugal; 6GEOAZUR Education & Outreach, Université Côte d'Azur, France

With the main goal of supporting geosciences education in Europe and beyond, the European Geosciences Union (EGU) Education Committee (EC) launched and support the Geoscience Education Field Officers (GEFO) programme. A GEFO is a teacher trainer that promotes hands-on workshops to geoscience teachers and pre-service teachers, from primary to secondary school, in his own country. Since 2019, a network of 11 EGU GEFO are working, initially with members from France, Italy, Portugal, and Spain, later reinforced, in May 2022, with GEFO from Albania, Estonia, Germany, Greece, Romania, Turkey, and the United Kingdom. Beyond Europe GEFO programme is established in eight countries (Burkina Faso, Chile, Colombia India, Malaysia, Morocco, Togo) and is supported by the International Union of Geological Sciences Commission on Geoscience Education (IUGS-COGE). Indicators as: a) number of workshops held, attending participants, and locations; b) workshop contents; c) teachers’ conferences attended and abstracts/papers published by GEFO about their activity; d) and an evaluation form provided to attending participants that allows to make a sample characterisation (teacher education establishments involved, gender, role, teaching years, professional position, school level, taught subjects) and appreciation of the interest of the workshops, have been used to assess the progress of the programme. The evaluation form was adapted from one used by the Earth Science Education Unit (University of Keele, UK). The assessment has brought some challenges particularly related to the application of the same evaluation form in different national educational systems/curricula, and with the encouragement of attends to fill in the form.



4:15pm - 4:30pm
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?

EGU Geoscience Education Field Officer (GEFO) initiative in Germany – results of the first year of activity

Sylke Hlawatsch

Richard-Hallmann-Schule Trappenkamp, Germany

Geoscientists know that their scientific understanding of the Earth as a system is important for the sustainable development of planet Earth. In Germany they expressed their concern about the state of geoscience education in 1996 (Leipziger Erklärung) and in 2023 (Positionspapier der GEOUNION und des Dachverbandes der Geowissenschaften). Explicit geoscience education expertise is still lacking at all levels of the educational system: education research at the universities, teacher training, professional development of teachers, syllabus commissions.

In 2019 the European Geoscience Union - Education Commission (EGU-EC) launched an initiative by appointing Geoscience Education Field Officers (GEFO) to support science and geography teachers that are interested in teaching geosciences. The GEFO are trained to offer in service and pre service teacher training according the teacher training method developed by the Earth Science Education Unit originally based at Keele University (UK). It provides interactive hands-on workshops and access to a wealth of teaching resources that are freely available through a website. The workshops are evaluated by an online questionnaire. (Correia et al. 2020).

In 2022 the EGU-EC appointed a GEFO for Germany. Measures of cooperation have been established and first workshops conducted. Cooperation partners as well as German teachers show a high level of interest in the workshops. The workshop schedule will be explained and first evaluation results presented.

Source:

Correia, G. P. et al. (2020) Geoscience Education Field Officer international programme – the first year of activity (May 2019 – April 2020). ASE International. 10. 11-21.



4:30pm - 4:45pm
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?

Earth system science in schools: Teaching geoscientific content with the help of instructional videos

Martin Meschede

Universität Greifswald, Germany

There is an urgent need to include Earth systems sciences (ESS) in the school curricula in order to enable the next generation to understand that the Earth is a dynamic system and its global problems such as climate change or the sustainable use of georesources as discussed by the 2022 report of the Leopoldina, the German National Academy of Sciences.

Right now, geosciences are not explicit part of the German school curriculum. Basic knowledge of the earth sciences is currently only taught in geography classes and occasionally in physics, chemistry and biology classes. But geography and all science teachers do not receive qualified training in Earth system sciences as part of their studies. While they rely on textbooks for their teaching, geoscientific texts and illustrations in many textbooks currently used in schools contain errors, especially concerning the dynamic of the solid Earth.

The German Geological Society (DGGV) currently develops a series of about 10 minutes long educational videos with text and figures on the Earth system on its website, in which basic geoscientific knowledge is conveyed. The videos are aimed specifically at teachers in schools, but also at students and interested laypeople. First tests in school education settings by individual teachers have revealed that they are a useful and welcome aid for teachers in their classrooms.



4:45pm - 5:00pm
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?

GEOWiki@LMU - behind the scenes

Donjá Aßbichler1, Daniel Schmid1, Carolin Otte1, Elina Bauer1, Natalie Diesner1, Leonard von Ehr1, Paul Herwegh1, Philipp Kessler1, Leon Koß1, Phil Lavorel1, Alina Piller1, Andrea Schmid2, Wolfgang Stoiber1, Malte Junge3, Eileen Eckmeier4

1Ludwig-Maximilians-Universität München, Germany; 2Technische Universität München, Germany; 3Mineralogical State Collection (SNSB-MSM), Germany; 4Christian-Albrechts-Universität zu Kiel, Germany

GEOWiki@LMU is more than just a visible website on the Internet. Various different activities are going on behind the scenes. All students, from the first semester up to advanced classes, independent from their thematic specialization have the opportunity to enhance their knowledge in research areas of their choice and even to conduct their own research as part of the GEOWiki-Team.

One outstanding example is the StudForschung program of the LMU, where contents for the new branch GEOWiki@Schule were developed. We are happy to announce that also student teachers work together with their colleagues from geoscience to develop the course. Together they gain insights into geoscientific topics and methods and get prepared for their future teaching activities. In addition, the content developed together with the instructions can be applied by the teachers and pupils promoting the knowledge in geosciences in different school subjects.

We work with a variety of tools to realize our own ideas and bring them into practice. The website of the GEOWiki@LMU is meanwhile very broad: in addition to the classic webpages we offer an OPEN-VHB course to teach geoscientific content. The interdisciplinary team developed a wide variety of content, which are always interlinked. Our didactic goal is to learn with fun and motivation independent whether you are a user of the website or active developer of the content. We invested an immeasurable amount of heart and soul in this project and we are excited to continue the journey of education.

 
4:00pm - 5:30pm4.03-2 Open Science and Data – challenges, opportunities and best practices
Location: Wiwi 108
Session Chair: Jürgen Grötsch, Friedrich-Alexander University of Erlangen, Germany
Session Chair: Kirsten Elger, GFZ German Research Centre for Geosciences
 
4:00pm - 4:15pm
Topics: 4.03 Open Science and Data – challenges, opportunities and best practices

FID GEO: library-based services that help establish Open Science practices.

Melanie Lorenz1, Malte Semmler2, Kirsten Elger1

1GFZ German Research Centre for Geosciences, Germany; 2Göttingen State and University Library

In the context of Open Science, data are just one, albeit important, part of the chain of scientific outputs, ranging from samples, to data, software, and research articles. The Specialized Information Service for Geosciences FID GEO has adopted this holistic view and considers the areas of text and data publications as two complementary components of Open Science.

Since 2016, FID GEO is offering information and publication services for the geoscientific community and is increasingly acknowledged as a competence center for the transformation of the publication culture in the geosciences. FID GEO’s services focus on electronic publishing of texts and research data, as well as digitization through the participating repositories GEO-LEOe-docs, hosted at the Göttingen State and University library (SUB), and GFZ Data Services, hosted at the GFZ German Research Centre for Geosciences, but also a comprehensive consulting portfolio.

FID GEO’s services were developed with the active participation of the geoscience community. The website, social media accounts and our newsletter are tools for actively connecting with the community. Informations on practical aspects of Open Science practices are regularly published in the journal “GMIT – Geowissenschaftliche Mitteilungen”, on the website and partner websites (e.g. forschungsdaten.info). Workshops and talks are successful tools to enable discussions, to address questions or uncertainties directly and to provide the appropriate framework to address specific requirements of individual research groups. FID GEO collaborates with strategic (inter)national initiatives (like NFDI4Earth), with several German Geosciences societies and other library-related projects to ensure the ongoing successful shift towards Open Science practices.



4:15pm - 4:30pm
Topics: 4.03 Open Science and Data – challenges, opportunities and best practices

Promoting FAIR and open data publication at the Department of Earth Sciences, Freie Universität Berlin

Andreas Hübner, Heinz-Alexander Fütterer

Freie Universität Berlin, Germany

The Department of Earth Sciences at Freie Universität Berlin has recently established a concept and workflow for the promotion of research data and its publishing. The project, funded with seed money from central university administration, was developed in close cooperation with the research data management (RDM) team of the university library.

A key element in the project is the RDM-team proactively advertising support for data publishing to researchers of the department. This offer is very well received by the researchers, as they are often willing to publish data, but lack time as well as knowledge of best practice in data publication. Several data publishing projects have been kicked-off this way.

Another thrust of the project is to feature data publications on the department´s website. This fosters the recognition of data publications as important resarch output of the scientists of the Department of Earth Sciences. The data are presented on the website in an easily accessible and understandable context, to makes them available to potenially new user groups like lay persons, citizen scientists, or pupils. Before published on the website, researchers are asked by the RDM-team to proof-read short descriptive drafts about their data publications, and this opens up a great opportunity for researchers to engage with data publication specialists about best practices and standards of „FAIR and open“ data practices.

This project facilitates cultural change towards FAIR and open data publication at an university department and may be used as a blueprint for departments in other universities and research institutions.



4:30pm - 4:45pm
Topics: 4.03 Open Science and Data – challenges, opportunities and best practices

GEOTHERMAL FAVORABILITY MAPS FOR THE MEMBER COUNTRIES OF THE SICA REGION: A MAP OF OPPORTUNITIES

Karla María Alvarenga Zaldívar, Alejandra Tatiana Menjívar Menjívar

Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ)

The Geothermal Heat Utilization in Industrial Processes in SICA Member Countries (GEO II) project, implemented by the Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH on behalf of the German Federal Ministry for Economic Cooperation and Development (BMZ) for SICA, proposes a methodology for the elaboration of geothermal favorability maps for the member countries of the Central American Integration System (SICA). The methodology is a spatial analysis tool, based on a simple weighted overlay model that assigns a favorability index in the range of 0 to 10, with the objective of locating suitable sites to initiate the geothermal exploration stage. It considers geoscientific evidence defined as input criteria of the model, assuming that they indicate the probable presence of volcanic geothermal systems typical of the region. It is performed in Geographic Information Systems (GIS): QGIS and ArcGIS, through the stages: definition, derivation, transformation, and superposition. The model combines the transformed data, applying a weighted overlay to the geological, geochemical, and geophysical criteria, resulting in a raster surface that represents the suitability index, indicating the geothermal favorability for each country, allowing a comparison between them according to their variation in the input criteria.

Finally, an analysis stage, based on the comparison of the favorability map with the location of geothermal projects in the region to ensure that the result is a starting point for the identification of favorable areas in the exploration stage for the development of geothermal projects through a platform and database accessible at the regional scale of SICA.



4:45pm - 5:00pm
Topics: 4.03 Open Science and Data – challenges, opportunities and best practices

Automatic classification of benthic foraminifera for biomonitoring studies

Tobias Walla1,2, Christine Barras2, Emmanuelle Geslin2, Louis Lanoy2, Jean-Charles Mazur3, Camille Godbillot3, Ross Marchant3, Thibault de Garidel-Thoron3

1Institute of Geosciences, University of Bonn, Bonn, Germany; 2Université d'Angers, Nantes Université, Le Mans Université, CNRS, Laboratoire de Planétologie et Géosciences, LPG UMR 6112, 49000 Angers, France; 3CEREGE, Aix-Marseille Université, CNRS, IRD, INRAe, Technopôle de l'Arbois BP80, 13545 Aix-en-Provence, France

Living benthic foraminifera are used as environmental proxies to evaluate the quality of marine ecosystems. This evaluation is usually based on diversity indices and/or on a group of indicative species with specific ecological requirements (tolerant to sensitive species). For this purpose, sorting and identification of living benthic foraminifera are needed which is time-consuming and requires taxonomical expert knowledge. In this study, we present an approach to automatically identify living (Rose Bengal stained) benthic foraminifera using the "ParticleTrieur" software (Marchant et al. 2020) and test its applicability for biomonitoring purposes. Samples from the intertidal mudflat of the Atlantic coast and the French Mediterranean coast were photographed by an automated machine consisting of a 3D printer moving in X, Y, and Z space and a camera connected to an objective with a ring light. Focus stacked images were always taken with the same exposure, stack height, and stack step. Through initial manual segmentation in the "Computer Vision Annotation Tool" (CVAT) and later training in the segmentation by artificial intelligence, living benthic foraminifera are cropped as individual images from full-field images. Using "ParticleTrieur", foraminifera images are manually labelled at the species level and a model is trained to automatically classify future images of interest. Convolutional Neural Network training is performed using Tensorflow libraries. The trained models will be applied to unclassified datasets to compare human and artificial intelligence classification concerning different ecological indices in both contrasted study areas.



5:00pm - 5:15pm
Topics: 4.03 Open Science and Data – challenges, opportunities and best practices

Applied Metadata - The Helmholtz Metadata Collaboration HMC

Andrea Pörsch1, Emanuel Söding2, Kirsten Elger3

1Helmholtz Metadata Collaboration (HMC) at GFZ German Research Centre for Geosciences, Potsdam, Germany; 2Helmholtz Metadata Collaboration (HMC) at GEOMAR Helmholtz Zentrum für Ozeanforschung, Kiel, Germany; 3GFZ German Research Centre for Geosciences, Potsdam, Germany

Metadata, i.e. 'data about data', are fundamental for making research data findable, usable and understandable by researchers and all interested parties now and in the future. Moreover, with the advent of new, data-driven technologies and instrumentation leading to constantly increasing data volumes, and scientific research becoming increasingly interdisciplinary, research data has to be inseparably linked to standardized, machine readable and complete metadata in order to foster data reuse and reproducibility of research results, e.g. by provenance metadata. Only by supporting standards and tools for metadata handling, interoperability with national and international research data infrastructures can be ensured.

The mission of the Helmholtz Metadata Collaboration (HMC, https://helmholtz-metadaten.de/en) is to facilitate the discovery, access, machine readability, and reuse of research data of the Helmholtz Association. Concepts and services are developed and established, allowing the enrichment of research data with standardized metadata in the various phases of their creation. The aim of HMC is to co-ordinate these services with the national and international scientific community in order to establish widely accepted practices in the handling of research data.

In this presentation we will introduce to the current HMC activities and outcome: working groups, recommendations on specific metadata elements (e.g. different persistent identifiers), and standards for sharing metadata and tools to do so. Both activities, our discussion and jointly agreed recommendations take place on a "Community Platform" website that is currently being developed.



5:15pm - 5:30pm
Topics: 4.03 Open Science and Data – challenges, opportunities and best practices

Harmonizing the use of PIDs in data repositories - What do we need to consider?

Emanuel Söding1, Andrea Pörsch2

1GEOMAR Helmholtz Zentrum für Ozeanforschung, Germany; 2Deutsches GeoForschungsZentrum GFZ

Persistent identifiers (PIDs) are an integral element of the FAIR principles (Wilkinson et al. 2016) as they are recommended to refer to data sets and metadata. They are, however, also considered to be used to refer to other data entities, like people, organizations, projects, laboratories, repositories, publications, vocabularies, samples, instruments, licenses, methods and others. Consistently integrating these PIDs into data infrastructures can create a high level of interoperability allowing to build connections between data sets from different repositories according to common meta information.

For developers and maintainers of repositories it is very difficult to decide, which PID systems to integrate, and how to implement the PIDs into the repositories metadata schema. Many decisions have to be made, e.g. where is the reference information, in my repositories metadata or the PID metadata? Who is responsible for a PID record, who registers is and who maintains it, in case the meta-information changes?

In this presentation we will shed some light on selected PID systems we recommend to use within the Helmholtz Association, and how we envision to solve some of the mentioned challenges. We develop and outline procedures to implement PIDs in a harmonized way, in order to achieve a level of interoperability across data infrastructures, based on metadata of commonly referenced PIDs.

 
5:30pm - 6:30pmPoster social - Themes: 1.05 | 1.06 | 1.10 | 1.13 | 1.14 | 1.15 | 1.20 | 1.31 | 3.05 | 3.10 | 3.12 | 3.13 | 3.14 | 3.21 | 3.22 | 3.23 | 3.25 | 3.29 | 4.03 | 4.07 | 4.11
Location: Foyer (Henry Ford Building)
 
Wed: 1
Topics: 1.05 Aquifer thermal energy storage (ATES): Potential, technologies and geoscientific challenges for a sustainable energy transition

KONATES - Design and pilot plant operation for the use of contaminated aquifers for energy management with ATES plants

Diana Altendorf1, Ahmed Abdelsamad1, Matteo Bauckholt1, Anett Georgi1, Nina-Sophie Keller1, Ralf Köber2, Katrin Mackenzie1, Carsten Vogt1, Ulrike Werban1, Holger Weiß1

1Helmholtz-Zentrum für Umweltforschung - UFZ Leipzig, Germany; 2Christian-Albrechts-Universität zu Kiel, Germany

A pilot plant for an aquifer thermal energy storage (ATES) system in a contaminated aquifer is under construction at the scientific park of Leipzig. The research at this pilot plant is focused on developing and testing technologies to simultaneously store energy from shallow aquifers through an ATES system and remediate the contaminated aquifer.

For this purpose, investigations will be conducted in an approximately 10-meter-deep sandy/gravelly aquifer which is contaminated with chlorinated volatile organic compounds (Cl-VOCs). The main contaminants are trichloroethene (TCE, up to 6.0 mg/l) and cis-dichloroethene (cis-DCE, up to 0.4 mg/l).

With a two-well system that runs cyclically, the proposed ATES system will inject up to 80 °C heated water. This has a greater impact on the chemical composition of the groundwater than ATES systems that operate at lower temperatures. A previous field project revealed a considerable change in hydrogeochemistry and the microbiological community at temperatures of 45 °C and 60 °C.

As a result, this study investigates the hydrochemical and biological interactions that occur in the extraction and injection wells, the thermally affected aquifer as well as in the aboveground system. Cl-VOCs will be removed from groundwater using an on-site regenerable zeolite absorber (Fe-zeolite) and in situ degradation with persulphate.

Furthermore, these investigations will be supported by stable isotope biochemical and abiotic migration investigations of Cl-VOCs as well as microbiological and geochemical analyses including trace elements. It is anticipated to enhance the carbon footprint of urban energy management by the ATES operation, including groundwater remediation.



Wed: 2
Topics: 1.05 Aquifer thermal energy storage (ATES): Potential, technologies and geoscientific challenges for a sustainable energy transition

Applying coupled numerical model in the design of ATES facility in a contaminated urban environment

Maximilian Dörnbrack1, Chaofan Chen2, Holger Weiß1, Haibing Shao1

1Helmholtz-Zentrum für Umweltforschung GmbH - UFZ; 2Technische Universität Bergakademie Freiberg

Within the KONATES project, an Aquifer Thermal Energy Storage (ATES) system is planned in the scientific park of Leipzig, where the groundwater is contaminated with chlorinated volatile organic compounds (Cl-VOCs). Supported by the SpeicherCity project, corresponding numerical model is being further developed and applied to study the environmental impact of ATES operation.

From the regulatory perspective, the operation of ATES system in the urban area should not induce temperature changes beyond a few degrees Celsius at the boundary of the properties. The challenge faced in the KONATES project is that this temperature limit will be quickly exceeded, as the injection temperature is planned to be ca. 80°C. This requires a careful planning on the timing, duration, and location of the injection, as well as the pumping rate.

To satisfy the regulatory requirements and facilitate the understanding of such impacts, a 3D numerical model has been constructed, simulating both hydraulic and heat transport process in the aquifer. The model is capable of predicting the propagation of the thermal plume in response to different design of injection temperature and flow rate. Due to the high groundwater velocity, it shows that at a pumping rate of 600 l/h, injection can only be carried out for 12 days continuously without increasing the groundwater temperature more than 2°C at the boundary.

The next step of model development is to include feature that reflects the elevated mobility of the Cl-VOCs, which is relevant to the quantification of extracted contamination in the surface treatment facility.



Wed: 3
Topics: 1.05 Aquifer thermal energy storage (ATES): Potential, technologies and geoscientific challenges for a sustainable energy transition

Biogeochemical processes in saline siliciclastic aquifers due to Aquifer thermal energy storage

Tatjana Kliwer1, Martin Gitter1, Ferry Schiperski1, Julia Mitzscherling2, Thomas Neumann1

11) Technische Universität Berlin, Department of Applied Geosciences, Applied Geochemistry, 10587 Berlin, Germany; 22) GFZ German Research Centre for Geosciences, Section Geomicrobiology, 14473 Potsdam, Germany

Aquifer Thermal Energy Storage (ATES) is a highly promising technology for storing excess energy due to its high storage capacity and small surface footprint. Despite its numerous advantages, planning, approval, and application are not yet widespread in Germany. Mineral precipitation and biofilm formation can lead to clogging of wells and aquifers. In addition, changes in the physico-chemical conditions may trigger the mobilization of toxic trace elements such as arsenic. The BMBF-funded joint project UnClog-ATES aims to investigate biogeochemical processes in the subsurface that may reduce the efficiency and long-term performance of ATES systems.

Sterile and non-sterile flow-through experiments are conducted under anoxic conditions, using both siliciclastic sediments and groundwater from a potentially ATES-suitable saline aquifer in Berlin. Through laboratory studies, the project investigates the effects of temperature changes, variations, and temporary oxygen input, and analyzes changes in the chemistry, mineralogy, and microbial community of both the groundwater and aquifer. Numerical models, including reactive transport and batch models, are developed using PHREEQC. Sensitivity analyses aid in the calibration and validation of models. They provide valuable insights into the geochemical behavior of the aquifer system and its response to different scenarios or conditions, by identifying the most influential parameters. Another key objective is to determine biogeochemical indicators that can be used to forecast clogging and define practical countermeasures to prevent or mitigate adverse effects in the aquifer.

Here we present our experimental setup and first modeling results for an ATES-suitable formation located in Berlin, Germany.



Wed: 4
Topics: 1.05 Aquifer thermal energy storage (ATES): Potential, technologies and geoscientific challenges for a sustainable energy transition

Microbial diversity and metabolic potential in siliciclastic ATES horizons

Julia Mitzscherling1, Lioba Virchow2, Martin Gitter3, Armando Alibrandi1, Simona Regenspurg2, Jens Kallmeyer1, Dirk Wagner1,4

1GFZ German Research Centre for Geosciences, Section Geomicrobiology, 14473 Potsdam, Germany; 2GFZ German Research Centre for Geosciences, Section Geoenergy, 14473 Potsdam, Germany; 3Technische Universität Berlin, Department of Applied Geosciences, Applied Geochemistry, 10587 Berlin, Germany; 4University of Potsdam, Institute for Geosciences, 14476 Potsdam, Germany

Microbial processes such as biofilm formation (clogging) and mineral precipitation (scaling) can affect the effectiveness of ATES systems. They can reduce the permeability of potential reservoirs and compromise the efficiency of ATES facilities on the long term. In addition, microbial processes can influence dynamics of toxic trace elements in the subsurface e.g. by releasing arsenic through iron mineral dissolution. Hence, it is crucial to identify microbial key players and metabolic processes to estimate the microbial impact on ATES and the clogging potential.

Here, we analyze the microbial abundance, community composition and their functional potential in relation to the thermo-hydrogeochemical conditions of bulk sediment and formation water of a Mesozoic sandstone aquifer of the North German Basin. The study focusses on the application of DNA-based approaches such as qPCR, high throughput sequencing and metagenomics. Bulk sediments and fluids were obtained from Jurassic sandstone in Berlin, Adlershof from a depth of 200-450 m.

The aquifer is characterized by an in-situ temperature of 17-22°C, Na and Cl dominated fluids (TDS ~20 g L-1) and DOC including acetate (~3.5 mg L-1), propionate and valerate. First results show that the fluid microbial community is adapted to saline and alkaline conditions. The community is highly dominated by the two taxa Alkaliflexus and Defluviitaleaceae UCG-011, but also contains sulfate reducing bacteria.

Results of this study together with a flow-through experiment analyzing geochemical, hydrochemical, mineralogical and microbiological processes under different conditions typical for ATES, will help to develop prediction tools for potential system operational failures and appropriate countermeasures.



Wed: 5
Topics: 1.05 Aquifer thermal energy storage (ATES): Potential, technologies and geoscientific challenges for a sustainable energy transition

Renaissance of a ground foundation absorber: Efficient building climate control using model-based operational optimization

Felix Schumann1, Maximilian Friebe2

1FG Ingenieurgeologie, Technische Universität Berlin, Germany; 2Hermann-Rietschel-Institut, Technische Universität Berlin, Germany

The energy concept for the VW library in Berlin, which was built in 2004, centers on a ground foundation absorber (GFA) that uses concrete core temperature control to freely cool the building in the summer and cover the building's base heating load in the winter via a heat pump. Due to unexpectedly high subsurface temperatures beneath the building, as well as difficulties in controlling the concrete core temperature control system, the GFA has been largely decommissioned in recent years. The goal of this research is to work with building engineers and engineering geologists to determine the cause of the elevated temperatures and to transition the GFA to optimized seasonal operation. To this end, detailed thermal models were created for the building and the subsurface, validated with measured data, and coupling approaches between the models were investigated. This should ensure a better evaluation of the interaction between the subsurface and the building during operation. Model-based parameter studies will then be used to determine an optimally adjusted operation of the GFA. In addition, the temperature development of the subsurface of the study area will be investigated to ensure sustainable operation. Optimized reactivation of the GFA shows significant ecological and economic potential with annual savings of 15% of the building's CO2 emissions and €23,000 in energy costs compared to the current building operation. The developed adjustments to the operating and control parameters will be tested and monitored in the building during the coming heating periods.



Wed: 6
Topics: 1.05 Aquifer thermal energy storage (ATES): Potential, technologies and geoscientific challenges for a sustainable energy transition

Geothermal energy as a stepstone for a zero-emission university campus

Felix Schumann1, Hannes Hofmann3,4, Maximilian Friebe2, Guido Blöcher3,5, Tomás Fernandez-Steeger1

1FG Ingenieurgeologie, Technische Universität Berlin, Germany; 2Hermann-Rietschel-Institut, Technische Universität Berlin, Germany; 3Geoforschungszentrum Potsdam; 4FG Reservoir Engineering Technische Universität Berlin, Germany; 5TU Berlin Institut f. Angewandte Geowissenschaften

The University Campus Charlottenburg/Berlin will be used as an example to show how geothermal energy can make a decisive contribution to a climate-neutral university campus. In combination with heat pumps, geothermal energy offers the possibility of a secure heat supply for the campus, which is in the process of transformation. The investigation addresses the geological horizons Muschelkalk and Buntsandstein at depths of 900 - 1250 m. Temperatures of 45 - 63°C and an extraction capacity of 1.2 to 4.7 MW are expected. Depending on the outside temperatures, direct use for heat supply can take place. The ongoing renovation process on campus significantly increases the direct use potential of geothermal energy. In the retrofitted state, the maximum supply temperature drops to 60°C with an outside temperature of -10°C. This demonstrates that the geothermal use of the underground can provide a reliable heat source for the transformation process on campus or in city quarters in general. An essential aspect of this utilization is the redesign of the heating network to allow a differentiated supply of buildings with different temperature levels. The example of the location's south campus shows that the use of geothermal energy enables a CO2 savings potential of up to 64%. In addition, the use of geothermal energy for cooling supply via ad- and absorption chillers is investigated. This approach opens up new perspectives for the holistic use of geothermal energy and helps to increase efficiency and conserve resources in campus operations.



Wed: 7
Topics: 1.05 Aquifer thermal energy storage (ATES): Potential, technologies and geoscientific challenges for a sustainable energy transition

Assessment of hydrogeochemical processes in two potential HT-ATES reservoirs in Berlin using core analysis, laboratory experiments and geochemical modelling

Lioba Virchow, Simona Regenspurg, Ali Saadat

Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Germany

While the share of renewable energy in the electricity sector is steadily increasing, it has stagnated in the heat supply, despite the fact that in Berlin, for example, more than 40 % of the CO2 emissions are caused by the heating sector. Due to its ability to store large volumes in the underground while at the same time taking up little space on the surface, HT-ATES is particularly well suited for use in urban areas and can therefore contribute to the reduction of CO2 emissions. However, clogging of aquifer pores thus reducing the permeability, corrosion and mobilization of trace elements may be undesirable effects of HT-ATES.
Here, the Triassic limestones and the Jurassic sandstones were investigated as part of two Berlin ATES studies with the aim of (a) simulating the effect of HT-ATES operation on the carbonate aquifer by geochemical modelling, (b) identifying reactive mineral phases by systematic elemental analysis using a handheld XRF and (c) estimating the permeability and mobilization processes by column and batch experiments at elevated temperatures.
The results show that rapid analysis of drill cores at the drilling site provides important information on the presence of reactive mineral phases such as iron minerals, clay and carbonate content, and can therefore assist in filter placement. The mobilization of organic matter and trace elements has been observed in laboratory tests with siliciclastic sediments. The simulation of the HT-ATES operation in the saline carbonate aquifer, on the other hand, indicated carbonate precipitation due to temperature increase and degassing.



Wed: 8
Topics: 1.06 Deep geothermal resources and projects

Decimeter-scale hydraulic testing of pre-existing fractures (HTPF) under anisotropic stress conditions. Part 1: Experimental setup

Alexander Cadmus1, Julian Osten2, Mohammadreza Jalali2, Raul Fuentes1, Florian Amann2,3

1Chair of Geotechnical Engineering and Institute of Geomechanics and Underground Technology, RWTH Aachen University, Germany; 2Lehrstuhl für Ingenieurgeologie und Hydrogeologie, RWTH Aachen University, Germany; 3Fraunhofer Research Institution for Energy Infrastructures and Geothermal Systems IEG, Aachen, Germany

Sustainable development of enhanced geothermal systems (EGS) requires a comprehensive understanding of the in-situ stress conditions. Among several techniques developed in the last decades, Hydraulic Testing of Pre-existing Fractures (HTPF) is a common practice to quantify the normal stress acting on hydraulically isolated fractures. To better understand the hydromechanical coupled mechanisms involved during HTPF as well as validation of HTPF analysis methods, a decimeter-scale true triaxial testing (TTT) apparatus was utilized that allows HTPF measurements on fracture planes under anisotropic stress conditions.

This work is primarily focusing on the experimental setup, calibration, and boundary conditions of the TTT apparatus. The apparatus contains three sets of oil-filled flat-jacks, which independently control the stress boundary conditions in the (horizontal) x, y, and (vertical) z directions. Contained within a steel frame, the flat-jacks exert pressures onto loading plates, which transfer and distribute pressure onto the sample’s surfaces. The 30*30*45cm cuboidal granite sample contains a vertical saw cut fracture, oriented 45° in respect to the x and y axis. Boreholes, drilled through the sample to the fracture surface, allow high-pressure fluid injection and monitoring of the fracture fluid pressure. Thirty-two acoustic emission sensors, mounted in the loading plates, allow for active and passive seismic measurement. The deformation of the rock sample is captured by 16 linear variable differential transformer (LVDT) displacement sensors mounted externally to the loading plates. The test procedure and preliminary results of the HTPF tests can be found in Osten et al. (2023; this conference).



Wed: 9
Topics: 1.06 Deep geothermal resources and projects

Analysis of surface karst phenomena in Devonian carbonates in North Rhine-Westphalia – context to geothermal exploration

Manfred Heinelt1, Mathias Mueller2, Adrian Immenhauser2

1Fraunhofer IEG, Germany; 2Ruhr-University Bochum

The deep geothermal reservoir potential in North Rhine-Westphalia was assessed in Devonian carbonates (Massenkalk) in the Steltenberg Quarry in Western Germany. The karstification phenomena of the carbonates were recorded utilising drone images in the quarry. Rocks at the karst chutes were examined by polarisation- and cathodoluminescence microscopy regarding karstification phenomena and carbonate cements. X-ray diffraction and inductively coupled plasma analyses were carried out to gain mineralogical information about different carbonate phases in various samples. Carbon and oxygen isotopes were analysed to understand the formation conditions of the carbonates. The examined rocks at the karstification structures show that the host rock (Massenkalk) has average marine δ13Cmean values of 3.7 ‰ VPDB and -4.7 ‰ VPDB for δ18Omean. At the karstification surfaces and leaching zones, the isotope analyses revealed values of meteoric overprinting in the form of increasingly more negative δ13C values down to -8.5 ‰ VPDB and -5.9 ‰ VPDB for δ18O. These changes in the formation conditions are strengthened by cathodoluminescence results. The narrowing of karstification observed by drone with increasing depth in the quarry walls and the siliciclastic sediments in these structures indicate near-surface karstification. These dissolution structures have presumably developed in cracks caused by tectonism. It can be assumed that karstification at greater depths is also possible due to fault associations, which could be caused not only by meteoric waters but deep hydrothermal CO2-bearing fluids



Wed: 10
Topics: 1.06 Deep geothermal resources and projects

Analogue studies for potential geothermal reservoirs in the Ruhr district, Germany: What can we expect?

Felix Jagert1, Adrian Immenhauser2,1, Stefan Wohnlich2

1Fraunhofer IEG, Germany; 2Ruhr-University Bochum, Germany

Deep geothermal power plants are baseload-capable and can serve as substitutes for fossil fuel power plants. In the Ruhr region of Germany, a densely populated area with high energy demand, potential deep geothermal reservoirs have been limited to a few sedimentary layers, specifically Carboniferous and Devonian strata. These reservoirs have not been explored with hydraulic field studies for geothermal purposes so far. Deep boreholes for geothermal research are non-existent, so shallow boreholes provide an analogue for evaluating the potential of deep reservoirs.

For this study, a naturally-fractured Carboniferous sandstone and a karstic dolomitic limestone reservoir of the Devonian were investigated using geophysical borehole measurements, hydraulic and hydrochemical experiments, and acoustic/optical televiewer recordings.

The sandstone formation (investigated depth: 20 – 305 m) showed a low hydraulic conductivity, and it is probably necessary to drill into fault zones or to enhance the permeability via stimulation in future geothermal projects. Chemical enhancement of permeability was attempted using CO2 to dissolve carbonate fillings in fractures, but further research is needed to evaluate the effectiveness of this method.

The dolomitic limestone formation (investigated depth: 10 – 224 m) exhibits exceptional permeability due to enlarged fractures, cavities and vuggy porosity resulting from karstic processes, making it a promising reservoir overall. However, further confirmation is required at reservoir depths (e.g. 2500 – 4000 m).

In summary, deeper geothermal reservoirs in the Ruhr region have not been explored enough so far, and further field studies are necessary to evaluate their potential for geothermal energy production.



Wed: 11
Topics: 1.06 Deep geothermal resources and projects

Estimation of shallow groundwater temperatures in Saxony-Anhalt, Germany

Maximilian Noethen, Hannes Hemmerle, Laura Meyer, Peter Bayer

Martin Luther University of Halle-Wittenberg, Applied Geology, Halle, Germany

Groundwater temperatures (GWTs) vary based on the local geothermal heat flux, the energy budget at the surface, and land cover. With subsurface temperature data being scarce, standard techniques for the spatial interpolation often produce unrealistic representation of shallow GWT. It has been shown that utilizing remote sensing data can reproduce shallow GWT at an error of roughly 1 K. In our contribution, we apply such a technique to the state of Saxony-Anhalt, Germany. The estimation is trained and validated with a set of over 600 observation wells. The data used comprises data from the Landesbetrieb für Hochwasserschutz und Wasserwirtschaft Sachsen-Anhalt (LHW) as well as own monitoring campaigns for the cities of Magdeburg, Halle (Saale), and Dessau. Together with different satellite datasets, such as land surface temperature and building density, we use this measured GWT data to derive spatially resolved estimated GWTs (eGWT) for Saxony-Anhalt. The measured and estimated GWTs are then correlated to the land cover at the location. Thus, this study aims to (1) present measured GWT and eGWT distribution for Saxony-Anhalt, (2) assess the application of satellite data for estimating shallow GWT, and (3) research the correlation between GWT/eGWT and land cover.



Wed: 12
Topics: 1.06 Deep geothermal resources and projects

Decimeter-scale hydraulic testing of pre-existing Fractures (HTPF) under anisotropic stress conditions. Part 2: Test procedure and results

Julian Osten1, Alexander Cadmus2, Mohammadreza Jalali1, Raul Fuentes2, Florian Amann1,3

1Chair of Engineering Geology and Hydrogeology, RWTH Aachen University, Germany; 2Chair of Geotechnical Engineering and Institute of Geomechanics and Underground Technology, RWTH Aachen University, Germany; 3Fraunhofer Research Institution for Energy Infrastructures and Geothermal Systems IEG, Aachen, Germany

To extract heat from tight deep subsurface formations, hydraulic stimulation is used to create efficient heat exchangers in the context of enhanced geothermal systems (EGS). Successful geothermal reservoir initiation requires detailed characterization of the regional in-situ stress field and local stress field variations of heterogeneous, i.e. fractured and faulted rock masses, which is often achieved by hydraulic fracturing (HT) and hydraulic testing of pre-existing fractures (HTPF).

To further develop and validate these field-scale in-situ stress determination techniques, decimeter laboratory scale HTPF tests into saw-cut and polished fracture planes are performed in a true triaxial testing apparatus (see Cadmus et al. 2023, this conference for details). Tests are carried out under various anisotropic stress boundary conditions to analyze normal opening and shear behavior. Results of two rock samples with different fracture roughness are analyzed and compared in terms of the injection pressure and flow rate evolution, shear displacement and acoustic emissions. The results indicate that both shear displacement and hydraulic jacking initiate as the injection pressure exceeds the fracture normal stress, which is attributed to heterogeneous fluid pressure distribution in the fracture plane. Future experiments on a fracture surface of intermediate roughness with additional observation boreholes aim to further assess the effects of fluid pressure distribution and fracture plane roughness in the context of stress measurement and induced seismicity.



Wed: 13
Topics: 1.06 Deep geothermal resources and projects

Machine learning aided 3D modeling of Buntsandstein Formations for potential analysis of hydrothermal systems

Sebastian Weinert, Michael Göthel, Jasmin Pikelke, Andreas Simon, Thomas Höding

Landesamt für Bergbau, Geologie und Rohstoffe Brandenburg, Germany

Hydrothermal systems offer significant potential for green energy and heat production. The Buntsandstein Formations provide aquifers that are applicable for hydrothermal heat (or power) production. The Geological Survey of Brandenburg (LBGR) will improve its data base on Middle Buntsandstein aquifers using machine learning algorithms on archived exploration data.

Data stored in the archive of the LBGR contains drilling information for some 200 boreholes penetrating the Buntsandstein Subgroup. The LBGR has access to some thousand 2D seismic profiles from exploration surveys, typically reaching the Zechstein Group or the deeper-lying sandstone aquifers in the Upper Rotliegend Subgroups.

Drilling logs such as gamma ray or density logs provide valuable information for stratification and petrophysical rock property analysis. Available drilling logs will be digitized, and machine learning algorithms will be trained on exemplary data sets such as drilling E Hr 1/68. Machine learning algorithms will help to stratify the Buntsandstein sections of the available drillings. The stratification based on machine learning is further validated on newly interpreted seismic and drilling results, such as the cores stored at the drilling core and sample archive of the LBGR. The base will be in consideration of depositional gaps and tectonics. Also, a well-to-seismic-tie is performed at selected locations, and synthetic seismic profiles are generated.

If possible, seismic lines are (semi-)automatically evaluated to identify Hardegsen, Detfurth, and Volpriehausen Formations. Interpretation results are integrated in a 3D-geological model to build a regional-scaled Buntsandstein model of Brandenburg, allowing parameterization and calculation of reservoir temperature or heat in place.



Wed: 14
Topics: 1.06 Deep geothermal resources and projects

Green-field exploration strategy for de-risking geothermal projects in the Aachen-Weisweiler area, Germany – The “Field Scale Laboratory for Deep Geothermal Energy Rhineland” Project

Florian Wellmann1,2, Oliver Ritzmann1, Michael Kettermann1, Jan Niederau1, Kira Aßhoff1, Alexander Jüstel1,3, Frank Strozyk1, Thomas Reinsch1, Rolf Bracke1,4

1Fraunhofer IEG, Fraunhofer Research Institution for Energy Infrastructures and Geothermal Systems IEG, Kockerellstraße 17, 52062 Aachen, Germany; 2Institute for Computational Geoscience, Geothermics and Reservoir Geophysics, RWTH Aachen University, Mathieustraße 30, 52074 Aachen, Germany; 3Geological Institute, RWTH Aachen University, Wüllnerstraße 2, 52072 Aachen, Germany; 4Chair of Geothermal Energy Systems, Faculty of Mechanical Engineering, Ruhr University Bochum, 44801 Bochum, Germany

The subsurface of the Aachen-Weisweiler area with its Carboniferous and Devonian carbonates is a green-field target location for testing and developing deep geothermal energy systems in North Rhine-Westphalia, Germany. Despite subsurface mining, surface mapping and isolated deep exploration wells and crustal seismic data, only sparse information on the deeper structures (down to 4,000 m), the spatial distribution of the reservoirs and reservoir properties has so far been recorded and/or published. Therefore, the complex structures of the faulted and folded Paleozoic layers remain unknown requiring further investigations. With the “Field Scale Laboratory for Deep Geothermal Energy Rhineland”, we aim to characterize the subsurface of the Aachen-Weisweiler area including its structural uncertainties, to quantify the reservoir properties of the carbonates and their associated parametric uncertainties to better describe the geological risk in exploring the reservoirs. Firstly, we constrain a geological model based on the publicly available surface and subsurface data and quantify its structural uncertainties. The model and the uncertainties are revised after the integration of vintage and newly acquired seismic data. Planned deep exploration wells will provide further constraints for the structural model but also deliver in-situ measurements of reservoir properties and geomechanical properties for subsequent thermo-hydraulic-mechanical modeling. The investigations contribute to the characterization of the potential geothermal reservoirs in this region, aid in the exploitation of the reservoirs, finding drilling locations for wells, and expand geological knowledge of the carbonates from other regions into Germany, hence, de-risking the geothermal plays in the Aachen-Weisweiler area.



Wed: 15
Topics: 1.07 Understanding reactions and transport in porous, fractured, and tight media - from field work to rock analytics and predictive modelling

Mineralogical and geochemical alterations in the Opalinus Clay and surrounding formations provide information about the long-term stability of this hydrogeochemical system

Marie Bonitz1,2, Theresa Hennig1, Anja M. Schleicher1,2, David Jaeggi3, Michael Kühn1,2

1GFZ German Research Centre for Geosciences, Germany; 2University of Potsdam, Germany; 3Federal Office of Topography swisstopo, Switzerland

The Opalinus Clay is the chosen host rock for the Swiss deep geological disposal of nuclear waste, and it is also investigated in Germany. For the long-term integrity of the disposal site, temporal and spatial stable geochemical conditions are essential. The identification of mineralogical and geochemical alterations in the Opalinus Clay and surrounding formations gives insights on their stability in the past, and thus enables an assessment for the future.

To detect the mobility of chemical elements and associated mineralogical changes, a 58 m long borehole was drilled at the Mont Terri Rock Laboratory (Switzerland). Drilling was conducted from the Opalinus Clay through the entire underlying Staffelegg Formation, which includes two water-bearing sections. The rock members and their transitions were characterised with a variety of analytical methods.

The results show that many trace elements are particularly enriched at the upper transitions of the water-bearing sections. At the top of the Rietheim Member (Posidonia Shale), this enrichment is accompanied by an increase in pyrite, which can be interpreted differently. On the one hand, the depositional conditions may have led to enhanced pyrite formation and the associated pyritization of trace metals. On the other hand, the overlying rock layers could have acted as cap rock for mobile elements in the pore water, leading to the observed accumulations. Consequently, to distinguish between depositional or diagenetic and alteration or mobilisation features is crucial for the interpretation of the analytical results in order to assess the long-term stability of Opalinus Clay and surrounding formations.



Wed: 16
Topics: 1.07 Understanding reactions and transport in porous, fractured, and tight media - from field work to rock analytics and predictive modelling

Fracture permeability evolution as a result of long-term geochemical granite alteration in geothermal systems: A combined experiment and modelling approach

Nick Harpers1, Niko Kampman2, Jim Buckman1, Hannah Menke1, Julien Maes1, Andreas Busch1

1Heriot-Watt-University, United Kingdom; 2Nuclear Waste Services, United Kingdom

Geothermal systems in crystalline basement rocks require fractures and faults to allow economic heat production. Sufficient permeability of these flow paths is vital and affects the lifetime of such systems. As fluids are produced and reinjected, the resulting flow, fluid mixing as well as related pressure and temperature changes affect the geochemical equilibria between fluids and host rock. Disequilibria of fluids and rock then potentially drive geochemical alteration (e.g., dissolution, precipitation, illitisation). Such changes can affect the hydraulic properties of the major flow paths of the fault zones. Cornwall in SW England hosts several granitic plutons that are subject of current geothermal projects (United Downs Deep Geothermal Power and Eden Projects). These projects target fault zones in crystalline rock as pathways for fluid flow.

To study the effects of geochemical alterations on fracture permeability in granites, we conducted a series of long-term reactive transport experiments in our unique flow-through reactor setup. Carnmenellis granite samples from central Cornwall have been collected of which small, artificially fractured plugs (15 mm length, 10 mm width) and powders (< 125 μm grain size) were prepared. We injected water with different fluid composition, representing brines encountered around geothermal systems, into the fractured granite plugs and pulverized gouges at 80 °C and 20 MPa confining pressure. The development of sample permeability and effluent composition are analysed. CT-scans are used to analyse changes in fracture and gouge structure. To complement the experiments, we model our system with GeoChemFoam [Maes and Menke, 2021], an OpenFOAM-based reactive-transport modelling code.



Wed: 17
Topics: 1.07 Understanding reactions and transport in porous, fractured, and tight media - from field work to rock analytics and predictive modelling

Simulation of neptunium migration as a function of redox conditions and clay mineralogy

Majedeh Sayahi1,2, Theresa Hennig1, Vinzenz Brendler3, Michael Kühn1,2

1GFZ German Research Centre for Geosciences, Fluid Systems Modelling, Potsdam, Germany; 2University of Potsdam, Institute of Geosciences, Potsdam, Germany; 3Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Resource Ecology, Dresden, Germany

Migration of neptunium, i.e. 237Np, a minor component of high-level nuclear waste, is in focus regarding the safety of nuclear waste disposal sites due to its long half-life and radiotoxicity. Opalinus Clay, the preferred host rock in Switzerland and also an option in Germany, is regarded as a reference formation with diffusion as the dominant transport process additionally retarded by sorption. One-dimensional diffusion simulations are conducted with PHREEQC to quantify neptunium migration. Sorption on clay minerals is integrated using surface complexation models. Numerical simulations are based on two diffusion experiments with the same setup, but one order of magnitude difference in transport parameters attributed to the core samples which stem from different rock facies. In the laboratory experiments, Np(V) was applied via a synthetic oxygen free pore water with neutral pH. The redox conditions are controlled by pyrite, while the pH of the system is buffered by calcite. The experiment of Fröhlich et al. (Radiochimca Acta, 2013, 101, 553-560) defined the numerical setup applied to the experiment of Wu et al. (Environmental Science & Technology, 2009, 43, 6567-6571). Our results indicate that neptunium migration is mainly controlled by pyrite oxidation and the associated reduction of Np(V) to Np(IV), while clay mineral quantities have only a minor impact. Since neptunium speciation and hence migration is very sensitive to oxidation and reduction reactions, redox conditions need to be accurately controlled and monitored in the laboratory if transport parameters are determined to be applied in the context of safety assessments.



Wed: 18
Topics: 1.10 Lithiumresources

PHREEQC modeling approaches for characterizing lithium release from rock during geothermal plant operation

Felix Jagert1, Felix Coenen2, Max Berndsen1, Katharina Alms1

1Fraunhofer IEG, Germany; 2Ruhr-University Bochum (RUB)

The poster presents the framework of the modeling part of the BMWi-funded project "Li-Fluids" (grant number: 03EE4034A). It introduces PHREEQC modeling approaches for simulating lithium-bearing minerals in geothermal reservoirs. By integrating lithium sources into PHREEQC, the release of lithium can be simulated. Additionally, a 1D dual-porosity approach is used to define reservoirs and calculate time-dependent depletion.

However, there are challenges. The accurate calculation of brines requires the Pitzer approach, which is limited in the number of minerals considered and does not include aluminum. Li-Mica, a modified form of K-Mica, appears to be an important primary source of lithium in the host rock. To address these limitations, other databases like the SIT database can be extended to include lithium-bearing aluminum silicates.

Saturation experiments were conducted up to 200°C using pure H2O, approximating the observed Li+ concentrations from gold capsule experiments conducted by the project partner BGR. These concentrations ranged from a few mg/l Li+. Since Al3+ is necessary for calculating the saturation indices of Li+-bearing aluminum silicates, the use of pure H2O was necessary to combine the BGR's laboratory experiments with PHREEQC's capabilities.

The next step involves implementing reservoir properties and developing an approach for modeling transport using concentrated saline waters frequently encountered in deep sedimentary basins in Germany. Van Genuchten's (1985) approach, which incorporates dual porosity similar to sedimentary rocks, will be utilized in PHREEQC. This hydraulic extension, combined with deep saline waters (e.g., the North German Basin), facilitates the extrapolation of findings from pure water experiments to a quasi-reservoir.



Wed: 19
Topics: 1.10 Lithiumresources

Upper Rhine Graben: Deciphering a geothermal fluid system and its raw material potential

Michèle Jungmann1,2, Benjamin F. Walter1,2, Elisabeth Eiche1,2, Jochen Kolb1,2

1Chair of Geochemistry and Economic Geology, Institute of Applied Geosciences, Karlsruhe Institute of Technology, Karlsruhe, Germany; 2Laboratory for Environmental and Raw Materials Analysis, Institute of Applied Geosciences, Karlsruhe Institute of Technology, Karlsruhe, Germany

In the context of the energy and mobility transition, operators of geothermal power plants and associated industries spotlight the potential to combine the production of sustainable energy with the extraction of strategic raw materials (SRM) (e.g., lithium) from geothermal fluids. Brine mining of SRM requires a comprehensive understanding of the related geothermal fluid system.

In southwest Germany, the Upper Rhine Graben (URG) represents a reservoir with great geothermal and SRM potential (thermal gradient up to 120°C/km; Li ~170mg/L). Data about the reservoir rocks and the thermal fluid at different depths is provided by ~1300 oil and geothermal wells as well as thermal water wells. Chemical data of sampled fluids indicate variations in the trace element distribution that are related to the Cl/Br-ratio, and trends of stable isotope systematics of the water.

The results show that in the northern URG evaporites are dissolved (Cl/Br>1200), while in the central URG the thermal waters have almost seawater composition (Cl/Br=290). Independent of the Cl/Br ratio, Li concentrations in the thermal waters vary between 3-43 mg/L. At nearly the same Cl/Br ratio of ~300 the geothermal fluids have ~170 mg/L Li. Stable isotope systematics imply that all thermal fluids have a meteoric component. The results indicate a modification of the fluid chemistry through time and depth, resulting from fluid mixing and water-rock interaction with various reservoir rocks. To investigate the fluid evolution, additional element tracers to determine the origin and raw material potential of Li and other trace elements, are established.



Wed: 20
Topics: 1.10 Lithiumresources

Petalite – The Underdog in the Lithium Business?

Nico Kropp1,2, Gregor Borg1,2

1Martin Luther University Halle-Wittenberg, Germany; 2ITEL-Deutsches Lithiuminstitut GmbH, Germany

Petalite was the first mineral in which lithium was detected, but its economic importance is less than that of the lithium-rich spodumene. Both minerals occur in pegmatitic deposits (LCT pegmatites), which were explored in the past mainly for tin and tantalum. Nowadays, lithium-bearing minerals are the focus of mining. Although both minerals are similar in the processing and extraction of lithium, their mineralogical properties differ. Through roasting, petalite undergoes a phase transformation to β-spodumene, producing quartz as an excess. Subsequently, the roasted material can be fed into the established converter process to produce lithium hydroxide or lithium carbonate.

In order to cover the increasing demand for lithium for use in lithium-ion batteries as a contribution to the energy transition and the associated turn away from fossil fuels, investments in mining projects away from the particularly lucrative spodumene pegmatites are necessary. Petalite is one such alternative.

Using petalite deposits in Namibia as an example, we will show whether it is possible to determine the mine of origin based on mineralogical and geochemical properties to contribute to possible lithium fingerprinting as proof of origin. The approach is based on the combination of different analytical methods, such as EDX, electron microprobe and trace element distribution using ICP-MS. Lithium fingerprinting can then be used as a tool for material-based control of ESG criteria upstream in the lithium value chain.



Wed: 21
Topics: 1.10 Lithiumresources

Maximizing Geothermal Resources: Innovative Lithium Extraction for Energy Transition and Reduced Dependency in the EU.

Detlev Rettenmaier, Roman Zorn, Elodie Jeandel

EIfER Europäisches Institut für Energieforschung, Germany

Lithium is a critical raw material for the EU, being strategic for the energy transition, especially for battery production. Solutions are needed to reduce the EU dependency on the whole value chain and the geopolitical risks associated with the growing Li demand in a concentrated market. The deep geothermal reservoir in the Upper Rhine Graben (URG) along the German-French border not only show good conditions for direct energetic use but also high Li contents (160-200 mg/L). In this context, the deep geothermal reservoir has generally very similar geothermal and hydrochemical characteristics. An innovative lithium extraction process developed on Argentine brines by ERAMET and IFPEN was therefore installed directly on an extraction unit at the reinjection branch of an existing geothermal plant in the ORG. In the course of pilot-scale tests, the possibility of extracting lithium from geothermal brine was demonstrated in early 2021 in collaboration with Electricité de Strasbourg in the frame of the EUGELI project.
The extent to which lithium extraction can maximize the utilization of geothermal resources by combining lithium extraction with electricity and/or heat production via a single well will be shown in this poster presentation at an economic sensitivity assessment by evaluating the various key parameters and then subjecting them to a specific variation. Ultimately, this combined use of geothermal resources at an existing facility will demonstrate the extent to which environmental and social impacts can be avoided compared to conventional mining, or conventional brine lithium production.



Wed: 22
Topics: 1.13 Site selection for a nuclear waste repository – Data acquisition, host rock characterisation and analogue studies

3D basin modeling of the Hils Syncline, Germany: reconstruction of burial and thermal history and evaluation of their influence on the present-day petrophysical properties of potential host rocks for nuclear waste storage

Leidy Castro-Vera1,2, Ralf Littke1, Sebastian Amberg1

1Energy and Mineral Resources Group (EMR), Institute of Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University; 2Grupo de investigación en Ciencias de la Tierra y Energía, Amonite SAS

The Hils Syncline is located in the south of the Lower Saxony Basin, Lower Cretaceous and Jurassic rocks crop out in its center. The Cretaceous and Jurassic sedimentary sequences in northern and southern Germany are known to be largely composed of clay-rich shales suitable for nuclear waste storage. Highly variable thermal maturity increasing towards the northwest characterizes the Hils Syncline, which makes it a natural laboratory to study the effects of burial and thermal maturation on petrophysical properties of shales at different levels of thermal maturation, which is our focus.

We reconstructed the burial and thermal history of the Hils Syncline resulting from a 3D-thermally-calibrated numerical model to better understand its geodynamic evolution, constrain maximum paleo-depths, –temperatures and erosion amounts, and evaluate their influence on the present-day petrophysical properties of Cretaceous and Jurassic units.

The basin experienced continuous subsidence interrupted by the Upper Cretaceous major phase of erosion. During the latest Early Cretaceous, deepest burial and maximum temperatures of Jurassic and Cretaceous rocks occurred showing an increasing northward trend. These units' porosity and vertical permeability decreased while the vertical thermal conductivity increased during burial. The Late Cretaceous inversion caused severe uplift and erosion that was stronger towards the northwest where up to 3,200 m of sediment was eroded compared to only about 1,200 m in the south. The petrophysical properties were not affected by the inversion according to the model. Calibration is currently performed based on new cores of Pliensbachian shales; thus, model results and experimental data will be compared.



Wed: 23
Topics: 1.13 Site selection for a nuclear waste repository – Data acquisition, host rock characterisation and analogue studies

NMR-Relaxometry – a new, reliable and non-destructive method to estimate the fluid content in rock salt

Raphael Dlugosch, Michael Mertineit, Michael Schramm, Stephan Kaufhold, Lisa Richter

Federal Institute for Geosciences and Natural Resources, Germany

In the context of the site selection procedure for a high-level radioactive waste repository in Germany, the fluid content in salt rocks is an important parameter to evaluate their barrier properties (i.e. gas formation potential and fluid pathways). Moreover, it can affect hydraulic conductivity, heat resistance, rock mechanical properties and it can be used for the spatial characterisation of the host rock. Fluids in rock salt (halite) are typically present in small, unconnected inclusions located within crystals or arranged along crystal boundaries and fissures, and can consist of brine, minor amounts of gases and hydrocarbons. When estimating the fluid content of rock salt, the main challenges are the low fluid content, the low permeability of the bulk rock preventing fluid extraction and the spatial heterogeneous fluid distribution. In summary, the measurements are time intensive and the results are highly dependent on the sample selection and preparation.

Nuclear magnetic relaxation (NMR) relaxometry is an established petrophysical method for a non-invasive characterisation of hydrocarbon host rocks and its fluids but it has not been used for rock salt so far. We present first results obtained from steeply inclined Zechstein rock salt (z2HS2) and compare them with a water content estimated by an extensive grinding of the salt samples in dried acetone and a subsequent analysis of the extracted fluids using infrared-spectroscopy. First results show, that NMR has promising features including a low limit of detection, non-destructive and quick measurements, no need for extensive sample preparations, and averaging over a large sample volume.



Wed: 24
Topics: 1.13 Site selection for a nuclear waste repository – Data acquisition, host rock characterisation and analogue studies

Experimental investigation of gas diffusion in claystones: The potential of gas uptake measurements as a means to assess diffusivity in water saturated porous media

Saeed Khajooie, Garri Gaus

Institute of Geology and Geochemistry of Petroleum and Coal, Energy and Mineral Resources Group (EMR),RWTH Aachen University, Germany

This study investigates sealing properties of Jurassic claystones, specifically Lias and Dogger mudstones of the Lower Saxony Basin, in the context of the disposal of high-level radioactive waste. Within the repository, the occurrence of various mechanisms such as corrosion, radiolysis, and microbial degradation may lead to generation of gases including hydrogen, methane and carbon dioxide. It has been reported through experimental studies that claystones possess hydraulic conductivities ranging from 10-12 to 10-15 m/s, indicating that the primary mechanism to dissipate the generated gases away from the repository is diffusive transport. Excessively high diffusion coefficients may compromise seal integrity, while overly low diffusion coefficients could result in localized overpressure zones, free gas formation, and interconnected gas transport pathways. Therefore, it is imperative to conduct a comprehensive investigation of gas diffusion in the context of nuclear waste disposal.

In the present study we assess the use of the pressure decay technique to measure gas diffusivity through water-saturated claystones. The experimental approach involved conducting radial gas diffusion into the pore space of core plugs that were sealed at both ends. Gas diffusivity was determined using a mathematical model that couples the analytical solution of the diffusion equation with the real gas law. Experiments were conducted on deionized water and water-saturated Boom Clay to determine hydrogen and methane diffusion coefficients, and the results are highly consistent with literature data obtained from other techniques. Currently, the measurement of hydrogen, carbon dioxide, and methane diffusion coefficients through water-saturated Lias and Dogger rock specimens is underway.



Wed: 25
Topics: 1.13 Site selection for a nuclear waste repository – Data acquisition, host rock characterisation and analogue studies

Compositional-structural characterization of the Opalinus Clay: New data from core samples from the Mont Terri URL, Switzerland

Tilo Kneuker1, Reiner Dohrmann1, Kristian Ufer1, David Jaeggi2, Lukas Pollok1, Thomas Mann1, Bernhard Schuck1

1Federal Institute for Geosciences and Natural Resources (BGR), 30655 Hannover, Germany; 2Federal Office of Topography (swisstopo), 3084 Wabern, Switzerland

Middle Jurassic Opalinus Clay (OPA) is considered as host rock for the disposal of heat-generating high-level radioactive waste. For the present study, samples from the Mont Terri rock laboratory (Switzerland) were analyzed using sedimentological, mineralogical and geochemical methods. Thereby, the ordering of irregular illite-smectite interstratified clay minerals (I-S) was of particular interest as it is responsible for sorption of radionuclides and swelling properties.

Results support the classification of OPA into five main facies instead of the well-established threefold division, and further into six subfacies. The clay fraction present in the samples varies according to these facies, consistent with variations in cation exchange capacity. X-ray diffraction analyses of this < 2 µm fraction revealed a homogenous composition of the main constituents, namely R1-ordered I-S, illite and kaolinite. Crystal-structure based Rietveld refinement indicates strong similarities in the nature of disorder of the interstratified illite-smectite minerals. In all facies and subfacies the amount of illitic layers in the I-S varies from 73 - 85 % for all refinements and ordering types. Collectively, results point to (1) a homogenous overprint of the clay assemblage during burial and/or (2) a uniform siliciclastic sedimentary supply throughout the sedimentation period of the OPA.

This uniformity will facilitate the calibration of mineralogical models and the extrapolation of geophysical logging data where no data is available. However, the transferability of these calibrations to both other OPA locations and claystone formations should be critically examined.



Wed: 26
Topics: 1.13 Site selection for a nuclear waste repository – Data acquisition, host rock characterisation and analogue studies

Geoscientific Characterisation of Sub-areas as Part of the German ‘Repository Site Selection Act‘

Dorothea Reyer, Nadine Schöner

Bundesgesellschaft für Endlagerung mbH, Germany

According to the ‘Repository Site Selection Act’ (Standortauswahlgesetz – StandAG), the German site selection procedure is an iterative process and consists of three phases with increasing levels of detail in which the assessed area is continuously reduced during the process. Starting with an empty, so-called ‘white map of Germany’, BGE (implementer of the German site selection procedure) completed Step 1 of Phase I in September 2020 with the submission of the Sub-areas Interim Report (BGE 2020). In the report, BGE identified 90 individual sub-areas (in claystone, rock salt and crystalline rock), where favourable geological conditions for the safe disposal of high-level radioactive waste can be expected.

In Step 2 of Phase I, BGE aims to localise siting regions within the 90 sub-areas by applying preliminary safety assessments and other scientific criteria. Within the preliminary safety assessments, subsurface data are interpreted and the results documented. The workflow comprises the detailed characterisation and interpretation with focus on the host rock formation that acts as the main geological barrier, but also considers the surrounding rock formations.

This contribution describes some of the compulsory geoscientific interpretation steps (e.g. well log interpretation, subsurface modelling) that are required during the preliminary safety assessments, focusing on sub-areas with flat bedded rock salt. The assessment of the spatial geometry of potential barrier rocks as well as the interpretation of their internal configuration (e.g. facies) and the understanding of relevant geological processes affecting the safety of a potential repository site are important characteristics.



Wed: 27
Topics: 1.13 Site selection for a nuclear waste repository – Data acquisition, host rock characterisation and analogue studies

Identifying the composition of hydrocarbon inclusions in rock salt

Lisa Richter, Michael Mertineit, Michael Schramm

Federal Institute for Geosciences and Natural Resources, Germany

Rock salt is one of the three potential host rocks for the final repository for high-level radioactive waste in Germany. For the site selection procedure and for safety assessments, the content and composition of trapped fluids can be crucial to evaluate the potential of gas formation. Certain salt formations in northern Germany are known to contain gases and hydrocarbons as fluid inclusions. Fluid inclusion studies can provide information on their composition or temperature- and pressure conditions of fluid migration. Investigating individual fluid inclusion assemblages has certain advantages compared to bulk analyses: (1) the possibility to differentiate between different fluid sources and/or (2) the reconstruction of a complex fluid history. Among the suitable methods for the analyses of the fluid inclusion composition is Raman spectroscopy. Here we used a Renishaw inVia QONTOR Raman spectrometer attached to a Leica microscope (DM3000) equipped with a 100x objective and a 532 nm laser. Raman spectra were obtained with a 2400 grating, at ~5 mW, 180–240 s acquisition time and 2 accumulations in the spectral range of 300–4000 cm-1. The analyses of the hydrocarbon phase show peaks at ~940, at 2500–2700 and 2900–3100 cm-1 indicating C-H stretching modes, potentially of alkanes and their derivatives (Dollish et al., 1974; Orange et al. 1996).



Wed: 28
Topics: 1.13 Site selection for a nuclear waste repository – Data acquisition, host rock characterisation and analogue studies

A promising sequence stratigraphic approach to identify potential siting regions in claystone formations

Bernhard Schuck1, Thomas Mann1, Jochen Erbacher1, André Bornemann1, Tilo Kneuker1, Géraldine Zimmerli2, Lukas Pollok1

1Federal Institute for Geosciences and Natural Resources (BGR), Hannover, 30655, Germany; 2Department of Geosciences, University of Fribourg, 1700 Fribourg, Switzerland

The selection procedure to identify the site “best possible” to host Germany’s repository for the final disposal of its high activity nuclear waste considers claystone, rock salt and crystalline rock as potential host rocks. Preliminary considerations estimate the area required for a claystone-hosted repository to be 10 km2. There are nine “sub-areas” (i. e. areas with conditions expected to be favourable for the safe final disposal of high activity nuclear waste) having claystone formations as potential host rock. Their sizes range between 943 and 62,885 km2, which is roughly 90 to 6000 times the size considered necessary for a claystone-hosted repository. Consequently, reducing sub-area size sophisticatedly constitutes a major challenge to the site selection procedure.

The project SEPIA aims to apply a sequence stratigraphic approach to characterize and correlate barrier properties of Aalenian rock formations, namely the Opalinus Clay (OPA), in Southern Germany. Therefore, four drillcores constituting an approx. 330 km long transect have been acquired to derive the spatial distribution of clay-rich and -poor horizons across the sedimentary basin, eventually leading to a paleofacies map. In addition, correlation with results from similar investigations in Switzerland adds another 100 km to the transect. This will allow assessing to which degree results from the OPA characterization carried out in the Swiss site selection procedure can be transferred to Southern Germany. Overall, the approach used in SEPIA appears to be a promising one to identify potential siting regions of reasonable size out of the large sub-areas for detailed exploration.



Wed: 29
Topics: 1.13 Site selection for a nuclear waste repository – Data acquisition, host rock characterisation and analogue studies

The influence of burial and temperature history on hydraulic and hydro-mechanical properties of a Lower Jurassic (Pliensbachian) clay rock formation – First results of the MATURITY project

Lisa Winhausen1, Florian Amann1,2, Raphael Burchartz1, Jochen Erbacher3, Garri Gaus4, Sebastian Grohmann4, Mohammadreza Jalali1, Ralf Littke4, Ivan Luna1

1Department of Engineering Geology, RWTH Aachen, Germany; 2Fraunhofer Research Institution for Energy Infrastructures and Geothermal Systems, Aachen; 3Federal Institute for Geosciences and Natural Resources (BGR), Hanover; 4Institute of Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University

The characterization of potential host rocks for the final disposal of high-level radioactive waste is of great importance in the site selection procedure. For clay-rich host rocks, hydraulic and geomechanical characteristics often depend on the burial history determining the maximum effective stress and temperature (i.e., maturity), and the associated compaction as well as transformations during diagenesis. Therefore, the direct transferability of host rock properties between different regional-geological sites is challenging and requires detailed quantitative knowledge about host rock property variations at different maturity levels.

We present the first results of the “Maturity” research project that deals with a Lower Jurassic clay rock via field and laboratory investigations. The target formation of Pliensbachian age (182–190 Ma) is located in the Lower Saxony Hils Syncline and the neighboring Sack Syncline. Whereas the mineralogical composition can be considered similar, the clay rock is characterized by a large thermal maturation gradient over a relatively short lateral distance. The project involves shallow core drillings at five locations along the sequence of changing maturities and an extensive testing program. We explore the influence of thermal maturity on the i) hydraulic rock mass properties using in-situ single-hole and cross-hole hydraulic tests within fixed packer intervals, and ii) petrophysical and hydromechanical properties by conducting a variety of laboratory tests on core material. In this contribution, we present preliminary results of our field and lab testing campaigns including thermal maturity-dependent hydraulic rock mass and geochemical characteristics as well as porosity and mechanical strength determinations of the clay rock.



Wed: 30
Topics: 1.13 Site selection for a nuclear waste repository – Data acquisition, host rock characterisation and analogue studies

Finding opportunities in the uncertainties of geomechanical-numerical models

Moritz Ziegler1, Oliver Heidbach1,2, Karsten Reiter3, Mojtaba Rajabi4

1Helmholtz Zentrum Potsdam, Deutsches GeoForschungsZentrum GFZ, 14473 Potsdam, Germany; 2Institute of Applied Geosciences, TU Berlin, 10587 Berlin, Germany; 3Institute of Applied Geosciences, TU Darmstadt, 64287 Darmstadt, Germany; 4School of Earth and Environmental Sciences, The University of Queensland, St Lucia, QLD, 4072, Australia

The numerical modelling of the in-situ stress state is commonly performed for reservoir management or subsurface applications such as nuclear waste repositories. Modelling is required due to the sparsity of available stress magnitude data records in addition to the uncertain underground structures and heterogeneous material properties. Even though, geomechanical models provide an increase in confidence and allow an interpretation of the in-situ stress state, the associated uncertainties are very high.

We present an approach where, instead of just one model scenario that is a best fit to all available data (but necessarily has a poor fit to some data records), a wide range of model scenarios that each satisfies at least one data record perfectly is estimated. Then, additional indirect data on the stress state or other manifestations are added in order to assess the predictive quality of each model scenario. These can be for example Formation Integrity Tests or Borehole Breakouts. While model scenarios that have a good agreement with indirect data are preferred, those that are largely in contradiction are neglected.

Eventually, this approach can be used to increase the knowledge on the subsurface. Of all things, remaining contradictions help to identify anomalies or geographical and lithological areas where the model is not representative (yet). This allows to improve and evolve the model in a data-based way not only based on geomechanics. Thus, adding uncertainties and further indirect data to the standard toolbox empowers the significance of a model.



Wed: 31
Topics: 1.14 Secondary raw materials: Geoscientific approaches to enable a circular economy

Towards a geochemical approach to guide hydrothermal REE recovery from NdFeB magnets

Fabrice Brunet1, Hugues Cabane2, Simona Denti1, Sophie Rivoirard3

1ISTerre - Univ. Grenoble Alpes, CNRS, France; 2Cristal Innov, Parc d’activités Alpespace, France; 3Institut Néel, Univ. Grenoble Alpes, CNRS, France

The NdFeB magnet world demand has doubled since 2005 to reach above 120 kton in 2020 [1]. The growing demand for REEs prompts their recycling. Sintered NdFeB permanent magnets are usually composed of above 20 wt.% Nd and a few wt.% of Pr and Dy. There are two main recycling ways for REE-based magnets. In the “short-loop process”, the main alloy is maintained in the valorized magnets, meaning that the microstructure and magnetic properties directly arise from the end-of-life product. In the “long loop” recycling process, one tries to extract the REEs from the alloy, which is the purpose of the present work.

The chemical separation of REEs from each other is difficult due to the similarity of their chemical properties. Following the encouraging results obtained by [2] in recovering REEs from NdFeB by hydrothermal treatment, we developed a geochemical approach of aqueous fluid – REE-compounds interactions based on the use PHREEQC software with the implementation of relevant REE-phases in the database. The database is tested against hydrothermal experiments on NdFeB powders with in-situ solution sampling. When reacted at 250°C and 100 bar, NdFeB powders transform into Nd(OH)2, magnetite and Nd-borates along with large amounts of H2. The low Nd solubility measured in the experiment is likely controlled by Nd-borates. The database will allow to investigate the effect of chlorine or CO2 on the REE behaviour.

[1] Yang, Y. et al. (2017). J. Sustain. Metall., 3, 122-149.

[2] Maât, N. et al. ACS Sustain. Chem. Eng., 4, 6455-6462.



Wed: 32
Topics: 1.14 Secondary raw materials: Geoscientific approaches to enable a circular economy

Development of a routine method for the chemical and mineralogical characterization of Li- and Mn-containing slags from the recycling of NMC-type lithium-ion batteries (LIBs)

Marko Ranneberg, Torsten Graupner

Federal Institute for Geosciences and Natural Resources (BGR), Germany

In the BMBF-funded project PyroLith, a methodical approach for the recovery of Li from NMC type LIB via a combined pyro- and hydrometallurgical process route is being developed. For this purpose, the cooling conditions and the chemical composition of the battery slags are optimized in the pyrometallurgical process step so that the whole Li content of the melt is enriched in the artificial, Li-rich compound lithium aluminate (γ-LiAlO2). After comminution of the slags, the γ-LiAlO2 is separated from the largely silicate slag matrix by flotation. The lithium is then leached out by hydrometallurgical processes and recovered as Li2CO3.

In order to achieve the project goal, extensive chemical and mineralogical analyses of the process samples are required, which are carried out as part of a method development at BGR. Because Li cannot be directly measured by conventional wavelength- and energy-dispersive X-ray spectroscopic investigation procedures, and amorphous components are only given as a sum in X-ray diffraction analysis, the use of several complementary analytical methods for sample characterization is necessary.

In the work presented here, it is briefly outlined how a Li- and Mn-rich slag from the simplified battery slag system Al2O3-SiO2-CaO-MnO-Li2O can be fully characterized chemically and mineralogically using QXRD, SEM-MLA, EPMA, XRF and ICP-MS. Furthermore, a rapid analytical tool based on UVC radiation or alternatively on µEDXRF is presented to determine distribution, crystal size, crystal morphology and relative content of the target phase γ-LiAlO2 in the slags within a few seconds (UVC radiation) or within 3 hours (µEDXRF).



Wed: 33
Topics: 1.15 Mineralogy of complex ore deposits – from exploration to ore processing

Mechanisms of Paleoproterozoic critical metal (Ge, Bi, Te) mobilisation in the Black Angel district, West Greenland

Michael Eigler, Jochen Kolb, Benjamin Walter

Karlsruhe Institute of Technology, Germany

Zn-Pb deposits are host to a large proportion of worldwide resources of Ge and other critical metals. The Black Angel district in central West Greenland hosts several Zn-Pb occurrences, including the historic Black Angel mine, South Lakes and Kangerluarsuk, that show a previously unrecognized endowment of Ge and Bi (± Te) respectively. The carbonate-hosted MVT deposits at Black Angel and South Lakes show strong deformation and associated ore remobilisation at Upper Greenschist facies conditions (ca. 470°C), as indicated by graphite thermometry. Germanium occurs in tectonised and remobilised ore in the form of briartite, which is hosted in sphalerite and galena matrix. We studied how rock deformation and related remobilisation processes in these ore bodies lead to the redistribution of Ge and formation of briartite. Germanium was most likely exsolved from sphalerite as nanoinclusions of briartite during recrystallisation. Subsequent solid-state and fluid-assisted processes lead to formation of micrometre sized grains of briartite in sphalerite matrix, as well as up to millimetre-sized briartite aggregates. However, the nearby clastic-hosted SEDEX deposit at Kangerluarsuk shows native bismuth and tellurides hosted with galena, and no briartite or other Ge enrichment. Thus, two contrasting Zn-Pb systems with a different critical metal endowment are in close proximity to one another.



Wed: 34
Topics: 1.15 Mineralogy of complex ore deposits – from exploration to ore processing

Biohydrometallurgy for Cobalt and Nickel recovery from laterites: project BioProLat

Stefanie Hetz1, Srdjan Stankovic1, Mirko Martin2, Frank Haubrich2, Simon Goldmann1, Herwig Marbler1, Reiner Neumann3, José Luciano Stropper4, Axel Schippers1

1Federal Institute for Geosciences and Natural Resources (BGR), Germany; 2G.E.O.S. Ingenieurgesellschaft mbH, Schwarze Kiefern 2, 09633 Halsbrücke, Germany; 3Centro de Tecnologia Mineral, Avenida Pedro Calmon, 900, 21941-908 Rio de Janeiro, Brazil; 4Companhia de Pesquisa de Recursos Minerais, Rua Banco de Província 105, Santa Tereza 90840-030 Porto Alegre, Brazil

Laterite ore deposits in Brazil and other tropical countries contain approximately 70% of the world’s Ni and Co resources. High energy and/or reagent costs, accompanied by expensive equipment costs, are generally incurred when recovering Ni and Co via pyrometallurgy or high pressure acid leaching. Considering economic efficiency, the development of an integrated low-energy and environmentally benign biohydrometallurgical process for the recovery of these metals from laterite ores in Brazil is the aim of the German-Brazilian project BioProLat. Several acidophilic bacteria are able to use sulfur (S) as electron donor and couple the oxidation of S to the reduction of ferric iron, and are thereby capable of reducing the insoluble metal compounds to a water-soluble form. During this process sulfuric acid is generated, providing the acidic conditions that are needed to keep iron and other metals soluble. Stirred-tank bioreactor and percolation column laboratory experiments were used to optimize parameters including pH, temperature, aeration and a most suitable bacterial consortium for the bioleaching of Ni and Co. Stirred-tank laterite bioleaching at a start pH 1.5 under aerobic conditions with a consortium of different Acidithiobacillus thiooxidans strains resulted after 15 days in maximal 83 % extraction for both, Co and Ni, for 10 % (w/v) pulp density of a laterite sample from Barro Alto mine, Brazil. Eventually, the optimized process will be upscaled and reach pilot scale, transforming unexploited ores and limonite stockpiles into valuable resources, unlocking new reserves of raw materials through increasing recovery of metals from existing mines.



Wed: 35
Topics: 1.15 Mineralogy of complex ore deposits – from exploration to ore processing

Impact of erratic and constant fluid flow on epithermal ore formation via numerical modelling

Maximilian Korges1, Philipp Weis2

1University of Potsdam, Germany; 2GFZ German Research Centre for Geosciences

Epithermal ore deposits are important resources for various precious (e.g. Au, Ag) and base (e.g. Cu, Pb, Zn) metals. They form within the uppermost 1.5 km of Earth's crust by circulation of hydrothermal fluids through fractured and porous rocks in geothermal and volcanic systems. Many hydrothermal veins in epithermal deposits show evidence for pulsed ore formation events with high metal contents limited to distinct growth zones. As a particularly efficient mechanism for metal enrichment to economic grades, transport and precipitation of precious metals has been proposed to occur by isochemical contraction of a magmatic vapor phase from an underlying magmatic-hydrothermal system, where fluids can phase separate, followed by a second phase-separation event of near-surface boiling. Numerical models can provide unique insights into the temporal and spatial relationships of ore-forming processes. We use a model for magma reservoir growth to investigate the impact of sill injection rates on the hydrothermal system. The simulations with more episodic, low injection rates (<1.3 x10-3 km³/y) result in a highly variable fluid plume which allows almost pure magmatic fluids to migrate to shallower and cooler regions, where they can phase separate and potentially form epithermal ore deposits. The modelling results point towards a relatively short time span of potential ore formation of a few thousands of years until the magmatic fluid plume retreats. Long-lived magma reservoirs which are forming at higher injection rates hamper the formation of high-grade epithermal deposits, but are more favourable for high-grade porphyry Cu deposits.



Wed: 36
Topics: 1.15 Mineralogy of complex ore deposits – from exploration to ore processing

Mineralogical and geochemical investigations on lamprophyric intrusions of the Gottesberg Sn-(W) greisen deposit, Vogtland, Germany

Ferdinand Martens1, Thomas Seifert1, Eric Hohlfeld2, Sabine Gilbricht1

1TU Bergakademie Freiberg, Germany; 2Saxore Bergbau GmbH, Germany

The Erzgebirge-Vogtland metallogenic province covers a wide variety of tin mineralization (greisen-, vein- and skarn-type) and represents one of the classic Sn regions in the world. The Gottesberg Sn(-W) greisen deposit is located on the western rim of the Eibenstock granite pluton. The multistage Sn mineralization of Gottesberg is closely spatial and temporal related to multiphase intrusions of subvolcanics and brecciation, controlled by a crosscutting area of major deep fault zones. For this work, lamprophyric dikes from latest drill core of Saxore Bergbau GmbH were sampled. Microscopic investigations were supplemented by the method of MLA (Mineral Liberation Analysis). Geochemical analyses of major and trace elements were performed. Previous work focused primarily on the Gottesberg Subvolcanic Suite (rhyolites and microgranites) whereby this work provides the first modern study of lamprophyres from the deposit and their age relationship to other magmatic events and the Sn(-W) mineralization. The porphyritic lamprophyres occur in dikes up to 3.5 m thick, carry xenocrysts of the granite, microgranite and rhyolite, and are partly strongly altered. Amphiboles were replaced by biotite. In the contact with the granite, the dikes form a chilled margin consisting mainly of biotite. Alteration phenomena on the groundmass and xenocrysts were studied. Cassiterite-quartz-sulfide veinlets and enclaves of granite and rhyolite in lamprophyric dikes provide information on the age position of the rocks. Overprinted lamprophyres show Sn and Rb contents >1,000 ppm and F contents up to 1.10 wt.%. Lamprophyre samples with high Zn contents (2.090-3640 ppm) show relatively high In contents (5-15 ppm).



Wed: 37
Topics: 1.15 Mineralogy of complex ore deposits – from exploration to ore processing

Experimental determination of boron isotope fractionation between silicate melts and hydrous fluids, with application to understanding magmatic-hydrothermal ore genesis

Jakob Heinrich Rauscher1,2, Bernd Wunder1, Max Wilke2, Robert Trumbull1, Sandro Jahn3, Melanie Jutta Sieber2, Julie Michaud4, Florian Pohl4, Maria Rosa Scicchitano1, Michael Fechtelkord5, Oona Appelt1

1GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Germany; 2University of Potsdam, Karl-Liebknecht-Str.24-25, 14476 Potsdam-Golm; 3University of Cologne, Zülpicher Str. 49b, 50674 Köln; 4University of Hannover, Callinstraße 3, 30167 Hannover; 5University of Bochum, Universitätsstraße 150, 44780 Bochum

The magmatic-hydrothermal transition is an important but poorly-understood process in the formation of Sn-W, Nb-Ta and Li deposits associated with evolved granites and pegmatites. Theory predicts that boron isotopes will fractionate between magma and fluid, so the magmatic-hydrothermal transition may be recorded in the borosilicate mineral tourmaline, which is widespread and common in these kinds of deposits. The key information needed to interpret the tourmaline record is the B-isotope fractionation between granitic melts and the fluids derived from them but former experimental studies on B-isotope fractionation between the relevant phases are not in agreement (e.g. Kowalski and Wunder, 2018, Maner and London, 2018).

This study fills this gap by an experimental, multivariant approach. We synthesized a glass of haplogranitic composition (Ab40Or25Qtz35) and produced variants of water content (0, 4 and 6 wt%), aluminum saturation (ASI 0.7, 1, 1.3) and boron concentration (2 and 5 wt%). For each composition we determined the coordination environment of B in the glass and the fractionation of B isotopes between the respective melt and aqueous fluid at near-solidus temperature. The first part of the study was the chemical characterization and analysis of B coordination in the glasses. The NMR analysis of 11B indicates that the coordination of 11B is dominantly trigonal in all glasses, but there is an increase of tetrahedral coordination with increasing boron concentration and water content. Fluid-melt fractionation experiments are ongoing and first results will be presented.



Wed: 38
Topics: 1.20 Resource management tools – as a knowledge base for the availability of raw materials and for decision-making

Ohmgebirge Potash Deposit – Confirmation Drilling & Mineral Resource Update

Sabine van der Klauw, Ricarda Hanemann

Südharz Kali GmbH, Germany

South Harz Potash Limited (SHP) is a publicly listed company on the Australian Securities Exchange (ASX). Through its wholly-owned subsidiary Südharz Kali GmbH, the Company holds the Ohmgebirge mining licence in the north-western part of the Thuringian Basin, a region with more than 100 years of history of mining Permian potash deposits.

Based on the available historical exploration data, the potash resource at the Ohmgebirge was categorised by Micon International Co Limited in 2019 as an Inferred Mineral Resource in accordance with the guidelines of the Australasian JORC Code (2012).

In order to increase the level of geological knowledge and the confidence in the existing drill hole and assay database and to advance the project, two confirmation holes were drilled in 2022. The successful drilling demonstrated a good comparability of lithostratigraphic, mineralogical and geochemical data with the historic exploration data. Combining the existing and new data sets, the geological model has been updated, allowing an upgrade of a substantial proportion of the Ohmgebirge Mineral Resource estimate from the Inferred to the Indicated classification.

Currently, SHP is collaborating with experienced consultants to prepare a feasibility study which will consider all relevant technical, economic, social and environmental aspects of the project in order to transform the Mineral Resource to a Mineral Reserve according to JORC (2012). To increase awareness of the importance of mining local raw materials, we communicate transparently and regularly with the regional public and all stakeholders on our project advancements.



Wed: 39
Topics: 1.20 Resource management tools – as a knowledge base for the availability of raw materials and for decision-making

Aluminium is Now Critical – Enabling UNFC-Compliant Classification for a German Aluminium Scrap Recovery Project

Marina von Vietinghoff-Scheel1, Nathalie Korf1, Thorsten Greb2, Vera Susanne Rotter1

1Technische Universität Berlin, Chair of Circular Economy and Recycling Technology, Berlin, Germany; 2ALBA Europe Holding plc & Co. KG, Berlin, Germany

The United Nations Framework Classification for Resources (UNFC) is an assessment tool for mineral resource endowments, originally developed for side-projects concerning geogenic resources, such as mines. Given the integration of UNFC into the Critical Raw Material Act, it is crucial to develop a standardized classification method for secondary raw materials. However, the current framework lacks concrete guidance and primarily relies on mining sector definitions. This leads to the inconsistent use of various factors and methods in case studies, resulting in diminished comparability. To understand the requirements and challenges of the application on secondary raw material projects and address the recent assessment of aluminium as critical, a pioneering case study is conducted on a novel aluminium sorting plant using laser-induced-breakdown-spectroscopy to enable alloy specific sorting of old scrap.

The UNFC assessment bases on three criteria: "Environmental-Socio-Economic Viability," "Technical Feasibility," and "Degree of Confidence in the Estimate”. In this study the criteria are evaluated with newly developed and existing factors such as quantity, quality, supply continuity, technology, infrastructure, and socio-economic, legal and environmental aspects, using assessment methods like technology readiness level and material flow analysis. This results in a concrete guidance covering data demand, data sources and assessment tools.

The study's results will highlight the distinct requirements that differ from those of the mining sector and contribute to the development of a modified methodology. These advancements aim to enhance the applicability of UNFC, enabling comprehensive evaluations of different types of resources and projects and promoting informed decision-making towards a circular economy.



Wed: 40
Topics: 1.31 Bergbau in Deutschland

The Working Group on Mining Consequences of the DGGV e. V.

Henny Gerschel1, Katrin Kleeberg2

1TU Bergakademie Freiberg, Germany; 2Oberschöna

With its long mining history, Germany is a country with an important tradition in the field of mining science. The "Working Group on Geoscientific Aspects in Mining Areas" has been dealing with the remnants of mining and the resulting subsequent uses since it was founded in 1995. The task of the working group is to bring together geoscientists and other experts from the mining industry, from mining and geology-related administrative departments and research institutions for an interdisciplinary exchange of ideas and experience.

The first meeting of the Working Group on Mining Consequences took place in Upper Lusatia on the landscapes resulting from lignite mining. The thematic range of further events expanded to include ore, salt, uranium, hard coal and earths and stone mining, oil and natural gas extraction, and the search for a final repository for radioactive waste.

The meetings of the working group combine theory and application in a very practical and illustrative way. Thematically diverse technical presentations and a full-day excursion to geological outcrops, historical or operating mining facilities and post-montane landscapes are the basis for intensive exchange among the participants.

In 2023, the Working Group on Mining Consequences looks back on 51 successful meetings in different mining regions of Germany, attended by about 5,000 professional colleagues from the geo- and mining sector, nature and geotope conservation, geoparks and many other disciplines. A conference volume with excursion guide is published for each meeting in the EDGG series.



Wed: 41
Topics: 1.31 Bergbau in Deutschland

Slope Stability Challenges in Repurposing Abandoned Coal Mine Pit for Hybrid Pump Hydropower Storage

Ershad Ud Dowlah Pahlowan

Technische Universität Berlin, Germany

The transition towards renewable energy sources has led to a growing need for effective energy storage systems to ensure a stable and reliable power supply. Solar and wind power, although abundant, are intermittent, causing fluctuations in electricity generation. To mitigate this issue, energy storage solutions are required to store surplus energy during periods of low demand and release it during times of high demand. This research focuses on repurposing abandoned open pit coal mines as Hybrid Pump Hydropower Storage (HPHS) systems, where the mine pit functions as the lower reservoir.

The stability of the slopes in these repurposed mines is a critical factor for the successful implementation of HPHS. The presence of water in the lower reservoir and the potential inflow of groundwater play significant roles in determining slope stability. An analytical and numerical model has been developed to assess the slope stability in the selected mines for HPHS operations. Various factors, including fluctuating groundwater levels, reservoir filling levels, and different loading conditions, have been considered in the analysis.

The findings of this study contribute to a better understanding of the impact of these factors on slope stability in HPHS applications.



Wed: 42
Topics: 1.31 Bergbau in Deutschland

Der Sprung über den Harz - Ersterkundung auf Kalisalze im Südharz-Revier vor 135 Jahren

Andreas Johann Jockel, Henry Andreas Michael Rauche

ERCOSPLAN Ingenieurgesellschaft Geotechnik und Bergbau mbH, Germany

Nachdem die Kalidüngemittelproduktion in den 1860er Jahren in Staßfurt, im nördlichen Harzvorland, ihre weltweite Premiere erlebte, sich zunächst auf das sogenannte Nordharz-Kalirevier beschränkte, begann auf Betreiben des preußischen Bergbeamten Pinno - und entgegen der damaligen akademischen Lehrmeinung Ochsenius’ - schon in den 1880er Jahren die Erkundung der südlich des Harzes gelegenen Kalivorkommen. Die erste Bohrung Hochstedt wurde westlich Nordhausen bei Günzerode platziert und im November 1888 eingestellt ohne Kalisalze erreicht zu haben. Die zweite Bohrung bei Kehmstedt traf im Juli 1889 ein 63m mächtiges Kalisalzlager an. Bis November 1897 folgten weitere 64 Erkundungsbohrungen in über 50 Gemarkungen bis das erste - vom Preußischen Staat finanzierte - Bohrprogramm im November 1897 mit dem Nachweis der großflächigen Verbreitung bauwürdiger Hartsalz- und Carnallitit-Vorräte erfolgreich abgeschlossen wurde.

Bereits kurze Zeit nach der ersten fündigen Kalibohrung im preußischen Hoheitsgebiet des Südharz-Revieres startete auch die erste privatrechtliche Kapitalgesellschaft die Bohrerkundung auf Kalisalze im August 1891 bei Jecha, Fürstentum Schwarzburg-Sondershausen. Die Bohrung erreichte in 626,20m Teufe ein über 12m mächtiges Carnallitit-Lager, was für den Markscheider, Bergbauunternehmer und Brauereibesitzer Brügmann aus Dortmund als hinreichender Bauwürdigkeitsnachweis genügte, so dass bereits im Mai 1893 mit dem Teufen des ersten Kalischachtes im Südharz-Revier begonnen wurde. Die bergmännische Gewinnung der Kalisalze begann ab 1896 auf dem nach ihm benannten Brügmann-Schacht der Gewerkschaft "Glückauf" in Sondershausen, worauf rasch weitere Bergwerke folgten. Bereits 1914 verfügte das Südharz-Revier über 33 Schächte, zum Jahreswechsel 1924/25 waren es bereits 50 vollendete Schachtanlagen mehrerer Kaligesellschaften, die in der Folgezeit verschiedene, auch staatlich gelenkte Konsolidationen und Stilllegungen erfuhren.



Wed: 43
Topics: 1.31 Bergbau in Deutschland

Das jüngste Kapitel in der Erkundungsgeschichte auf Kalisalze im Südharz-Revier: Bergwerkseigentum Ohmgebirge der Südharz Kali GmbH

Sabine van der Klauw1, Ricarda Hanemann1, Stephan Pfeifer2, Christian Fritze2, Marie-Luise Richter2, Liz de Klerk3, Andreas Jockel2

1Südharz Kali GmbH, Germany; 2Ercosplan Ingenieurgesellschaft Geotechnik und Bergbau mbH; 3Micon International Co Limited

Die Südharz Kali GmbH, eine 100%ige Tochtergesellschaft der South Harz Potash Ltd., eine in Australien gelistete Aktiengesellschaft, hat 2017 das Bergwerkseigentum (BWE) Ohmgebirge erworben und beabsichtigt dort die Gewinnung von Kalisalzen. Das BWE Ohmgebirge grenzt im SW bzw. W an die Grubenfelder der ehemaligen Kalibergwerke Bischofferode und Sollstedt. Dort wurden bereits Ende des 19./Anfang des 20. Jahrhunderts, zwischen 1956 und 1965 und in den 1980er Jahren in mehreren staatlich finanzierten Erkundungskampagnen wirtschaftlich interessante Kalisalzvorräte nachgewiesen. In den Jahren 2017 und 2019 erfolgte zunächst die Neubewertung dieser historischen Erkundungsdaten. 2022 wurden zwei neue Tiefbohrungen abgeteuft, durch die die Resultate unmittelbar benachbarter historischer Bohrungen aus den Jahren 1906 und 1983 bestätigt wurden.
Im Posterbeitrag werden die Erkundungsstrategie und die Resultate der jüngsten Bohrerkundung im Südharz-Kalirevier vorgestellt.



Wed: 45
Topics: 3.05 „Geomorphology and Sedimentology Beyond Boundaries“ - towards integrating geomorphology and sedimentary system science

A Quaternary fluvial sequence tells the story of a drainage reorganization

Elhanan Harel1, Liran Goren1, Eitan Shelef2, Onn Crouvi3, Naomi Porat3, Hanan Ginat4

1Department of Earth and Environmental Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.; 2Geology and Environmental Science, University of Pittsburgh, 4107 O'Hara Street, Pittsburgh, Pennsylvania 15260- 3332, United States; 3Geological Survey of Israel, Yesha'yahu Leibowitz 32, Jerusalem 9692100, Israel.; 4The Dead-Sea and Arava Science Center, Tamar Regional council Dead-Sea mobile post 86910, Tamar Regional council, Israel.

Field observations across the globe show that drainage reversal toward a cliff is a common type of drainage reorganization. Drainage reversal occurs when a channel reverses its flow direction by 180 degrees while exploiting its antecedent valley. In these settings, fluvial deposits of the antecedent, pre-reversal drainage potentially record valuable information about the process of drainage reorganization. However, such fluvial deposits are rare because they are typically eroded by the reversed channels.

We present a spectacular case of a reversed channel in the Negev desert, Israel, that forms a narrow canyon with several-meters high vertical walls exposing a sequence of fluvial deposits that reflect the reversal process. At the base of the sequence, a <1 m thick conglomerate layer is characterized by clast imbrication consistent with the westward flow direction of the antecedent drainage. Overlying the conglomerate, reddish fine-grained sediments (~1-2 m thick) indicate a decrease in flow energy, reflecting the reversal of the flow toward the current eastward flow direction. Paleosols and scattered calcite nodules within the sediment imply phases of soil development, most likely during a more humid climate than today. The uppermost layer (<1 m thick) consists of sediments of alluvial fans fed from the neighboring hillslopes, that play a key role in the development of the reversed channel through their avulsion cycling. Using geomorphic mapping based on high-resolution DEMs and preliminary dating results, we propose a holistic approach for better understanding the relationships between sedimentary systems, climate changes, and erosional processes in landscapes experiencing drainage reorganization.



Wed: 46
Topics: 3.05 „Geomorphology and Sedimentology Beyond Boundaries“ - towards integrating geomorphology and sedimentary system science

Modeling in Landlab: Long-Profile Evolution of Transport-Limited Gravel- and Sand-Bed Rivers

Behiye Nilay Iscen1,2, Jeffrey Kwang1,2, Andrew Wickert1,2,3

1Department of Earth & Environmental Sciences, University of Minnesota Twin Cities, Minneapolis, MN, USA; 2Saint Anthony Falls Laboratory, University of Minnesota Twin Cities, Minneapolis, MN, USA; 3The GFZ German Research Centre for Geosciences, Potsdam, Germany

Alluvial river adjustment occurs in response to altered sediment and water inputs, driven by both natural and anthropogenic climate change, changes in land use and/or land cover, and/or imposed by tectonic boundary conditions. This river response is ultimately reflected in the geometry of the bankfull channel, the planform characteristics of the river, and the longitudinal profiles of the mainstem river and its tributaries. This study utilizes analyses of river longitudinal profiles and provides a powerful tool to detect the change and extend it to long-term landscape evolution. Wickert and Schildgen (2019) developed the model, GRLP, to compute transient and steady-state solutions for the long-profile evolution of transport-limited gravel-bed rivers with self-forming channel-width adjustments. Following an analogous approach to that taken by Wickert and Schildgen (2019) and linking sediment transport and river morphodynamics, we developed a model describing the long-profile evolution of a transport-limited sand-bed river. This sand-bed model allows for planform adjustments as a function of excess shear stress (following Parker, 1978, and Dunne et al., 2018) thereby linearizing the sediment-transport response to changing river discharge. Ultimately, the resultant equations suggest a diffusive form for sand-bed river long-profile form and evolution. Both models were further built to work with the Landlab component library. Here, with these Landlab compatible models, we further present examples of sand- and gravel-bed river long-profiles under a variety of water- and sediment-supply boundary conditions, and present the transition into models of linked tributaries reproducing river-network evolution over both human and geological time scales.



Wed: 47
Topics: 3.05 „Geomorphology and Sedimentology Beyond Boundaries“ - towards integrating geomorphology and sedimentary system science

A process-based model for fluvial valley width

Jens Martin Turowski1, Aaron Bufe1,2, Stefanie Tofelde3

1GFZ German Research Center for Geosciences, Germany; 2Ludwig Maximilian University Munich, Germany; 3University of Potsdam, Germany

The width of fluvial valley-floors is a key parameter to quantifying the morphology of mountain regions. Valley-floor width is relevant to diverse fields including sedimentology, fluvial geomorphology, and archaeology. The width of valleys has been argued to depend on climatic and tectonic conditions, on the hydraulics and hydrology of the river channel that forms the valley, and on sediment supply from valley walls. Yet, so far, a physically-based model that can be used to predict valley width is lacking. Here, we derive such a model and test it against three different datasets. The model applies to valleys that are carved by a river migrating across the valley floor, and includes the effects of uplift and lateral hillslope sediment supply. Valley width is controlled mainly by the mobility-uplift number, which is the ratio between lateral channel mobility and uplift rate. At high values of the mobility-uplift number, the valley evolves to the channel-belt width, which is the width of the area actively reworked by the river in an unconfined setting. At low values of the mobility-uplift number, valley width corresponds to channel width. Between these limits, valley width is linked to the mobility-uplift number by a logarithmic function. We compare the model to independent data sets of valleys in experimental and natural uplifting landscapes and show that it closely predicts the first-order relationship between valley width and the mobility-uplift number.



Wed: 48
Topics: 3.05 „Geomorphology and Sedimentology Beyond Boundaries“ - towards integrating geomorphology and sedimentary system science

Control of valley width on the flank erosion rate: measure of erosion rates of Andean and French fluvial valleys by using 10-Be and 26-Al

Chloé VALENTI1, Sébastien CARRETIER1, Vincent REGARD1, Sandrine CHOY1, Vincent GODARD2, Frédéric CHRISTOPHOUL1, Willem VIVEEN3

1Géosciences Environnement Toulouse, France; 2Centre Européen de Recherche et d'Enseignement en Géosciences de l'Environnement, France; 3Pontificia Universidad Católica del Perú, Peru

Any keen observer has noticed that valleys show a large variability in their shapes, explained by the incision and widening processes. However, valley widening processes and rate are still poorly documented while valley evolution has a key role in geomorphological processes (contribution to the formation of abrasion terraces and establishment of ecosystems) and global geochemical cycles (increase of carbon storage in wide valley and buffering sediment fluxes transported to the oceans). Given these issues, it is becoming truly necessary to better understand valley widening rate and its controls.

For that, we focused on several river valleys (in the Arequipa Province, Peru, and in the plateau of Valensole, France) and we have used and further developed the approach tested in northern Chile by Zavala et al. (2021). We collected samples from valley flanks to measure the millennial erosion rates, by using in-situ produced Beryllium-10 and Aluminium-26, and analysed 10-Be and 26-Al concentrations to estimate the local valley flank erosion rate.

We also extracted different factors that may control widening rate (valley width, slope of flanks and valley floors, incision and drainage area, etc) in order to compare these factors to 10-Be and 26-Al concentrations. Our preliminary results show comparable 10-Be concentrations along a single stretch of valley, except for several outliers, for different valleys in the Andes and France, indicating some robustness in the sampling method. These results are promising and will provide new answers, by integrating more metadata, about what controls the widening rate of valleys and how.



Wed: 49
Topics: 3.05 „Geomorphology and Sedimentology Beyond Boundaries“ - towards integrating geomorphology and sedimentary system science

Morphology and depositional architecture of supercritical alluvial fans: control by autogenic processes or high-frequency climatic oscillations?

Jutta Winsemann1, Tim Hartmann1, Lang Jörg1, Fälber Runa1, Lauer Tobias2

1Leibniz Universität Hannover, Germany; 2Universität Tübingen, Germany

The depositional architecture and geomorphology of alluvial fans that have evolved in response to similar regional environmental conditions can differ strongly, implying that autogenic processes may play an important role and lead to similar cycles of fan aggradation and incision that may be difficult to be distinguished from the effects of tectonics or climate change. Here we present new data from two different Late Pleistocene (33-18 ka) alluvial fan systems in northern Germany. These fans formed under similar climatic and tectonic conditions, but differ in size, type, and drainage area allowing to estimate the role of climate and autogenic controls on flow processes, facies architecture, and fan-stacking patterns.

Sand-rich, sheetflood-dominated fans are related to larger, low-gradient fan catchments. Steep depositional fan slopes (5°-17°) favored supercritical flow conditions. Steep, dip-slope catchments enhanced stream gradients and promoted the transport of coarser-grained sediments. These fans have lower gradient slopes (2-6°) and are dominated by channelized flows, alternating with periods of unconfined sheetfloods. Fan onset and aggradation occurred in response to climate change at the end of MIS 3. Meter-scale coarsening-upward successions are characterized by sandy sheetflood deposits at the base and overlain by multilateral or smaller single-story gravelly channel fills are related to high-frequency climatic fluctuations or seasonal fluctuations in water and sediment supply. In contrast, the recurrent pattern of multistorey, multilateral, and single-storey channel bodies with a lateral offset to vertical stacking pattern most probably was controlled by autogenic switch in an avulsion-dominated system.



Wed: 51
Topics: 3.12 Past climates and environments inform our future

Identifying the seasonal variability of the isotopic composition of seawater by combined stable oxygen and dual clumped isotopes in marine bivalves

Jorit F. Kniest1, Amelia Davies1, Jonathan A. Todd2, Jens Fiebig1, Jacek Raddatz1

1Goethe-University, Frankfurt a.M., Germany; 2The Natural History Museum, London, UK

Reconstructing sea water temperatures from carbonate derived δ18OC is a widely used approach in paleo-environmental studies. However, converting δ18OC to water temperatures requires information about the isotopic composition of the sea water (δ18OSW), which usually can only be estimated for paleo-environments. Especially in shallow marine settings δ18OSW can potentially be altered by a strong seasonal variability of fresh water supply. Dual clumped isotopes (Δ4748) can be employed to determine seawater temperatures independent of δ18OSW, as isotopic clumping is independent of the bulk isotopic composition of seawater.

In the current study we aim to resolve the seasonal variability of δ18OSW by the combined measurement of δ18OC and dual clumped isotopes (Δ4748) in Eocene bivalve shells (Venericor planicosta) from the Paris Basin. To determine seasonal variations and to detect annual extrema, δ18OC was measured along the shell. Based on the δ18OC record, annual extrema were resampled for dual clumped analysis.

The analysed bivalve revealed a pronounced seven-year seasonal cycle in δ18OC, yielding an average annual amplitude of 2.5‰. Translating this seasonal range to sea water temperatures, applying a constant δ18OSW, results in an annual temperature amplitude of ~11°C. The dual clumped isotope measurements, however, point to a more damped seasonal temperature range (~4°C) and a variable δ18OSW with a seasonal difference of ~1‰.

The Δ4748-based seasonal temperature amplitude agrees with an Eocene warm-house climate and a considered weaker latitudinal thermal gradient. Reconstructed δ18OSW exhibits high seasonal variability, indicating the periodic influx of isotopically lighter fresh water into the Paris Basin.



Wed: 53
Topics: 3.12 Past climates and environments inform our future

Great Blue Hole: a sedimentological archive of tropical cyclone frequency covering the Holocene at annual resolution

Dominik Schmitt1, Eberhard Gischler1, Martin Melles2, Hermann Behling3, Lyudmila Shumilovskikh3, Flavio S. Anselmetti4, Hendrik Vogel4, Jörn Peckmann5, Daniel Birgel5

1Institut für Geowissenschaften, Johann Wolfgang Goethe-Universität, Frankfurt, Germany; 2Institut für Geologie und Mineralogie, Universität zu Köln, Germany; 3Albrecht-von-Haller-Institut für Pflanzenwissenschaften, Abteilung Palynologie und Klimadynamik, Georg-August-Universität Göttingen, Germany; 4Institut für Geologie & Oeschger Centre for Climate Change Research, Universität Bern, Switzerland; 5Institut für Geologie, Zentrum für Erdsystemforschung und Nachhaltigkeit, Universität Hamburg, Germany

Sedimentary archives from marine sinkholes enable long-term reconstructions of past storm activity. In the last years, numerous cyclone-frequency reconstructions have been obtained from sediment cores collected in blue holes located in the circum-Caribbean region. Such structures work as sediment traps for allochthonous particles, mobilized through storm waves and surges from adjacent areas by passing cyclones. The 320 m wide and 125 m deep Great Blue Hole (Lighthouse Reef, Belize) is an outstanding cyclone-frequency archive worth exploring due to anoxic bottom-water conditions and the opportunity to recover annual deposits spanning the Holocene interglacial and even parts of the late Pleistocene. In June 2022, a 30-m-long sediment core (BH8) was extracted from the sinkhole and dated to 12.5 ka BP at its base. Sedimentological and palynological analyses point to an initial cenote-like setting that experienced a rising marine influence starting around 7.2 ka BP, which led to brackish and restricted marine conditions until 5.7 ka BP. Afterwards, full marine conditions have persisted in the Great Blue Hole to present day. Our sediment-core analysis resulted in a 12000-years-long paleoenvironmental reconstruction at annual resolution. Several warm climate periods of this timeline represent past equivalents for the current situation of rising ocean temperatures. In the SW Caribbean, cyclone frequency changed from a rather variable and less active stage (12.5-3.5 ka BP) to a more stable and active state (3,5-0 ka BP). This bipartite pattern is surprisingly best explained by latitudinal changes of the Intertropical Convergence Zone (ITCZ) from a northern towards a southern location.



Wed: 54
Topics: 3.12 Past climates and environments inform our future

Geology of the Layla Lakes: An exceptional lake formation history in Central Saudi Arabia

Anastasiya Oepen1, Jens Hornung1, Nils Michelsen1, Susanne Lindauer2, Matthias Hinderer1

1Technical University of Darmstadt, Germany; 2Curt-Engelhorn-Centre Archaeometry, Mannheim, Germany

The Layla Lakes (300 km S Riyadh) had been fed by fossil groundwater until they dried up in the 1990s due to agricultural water abstraction, revealing a series of 22 sinkholes. At their walls, well stratified to laminated sediments became exposed, unlocking a hitherto unexplored paleoenvironmental and paleoclimatic archive in the center of the Arabian Peninsula.

In November 2022, sedimentary logs were recorded, including on-site spectral gamma-ray and magnetic susceptibility measurements. From four sinkholes, >600 samples were taken to unravel the geochronological, mineralogical, geochemical, and palynological evolution of the lakes at high resolution. Lithofacies analysis shows changes between laminated lake sediments and weakly stratified sebkha deposits composed of sulfates (gypsum, anhydrite), carbonates, siliciclastic components, and bioclastic remains (shells, chironomidae tubes).

Initial radiocarbon dating indicates that the laminated lake sediments comprise a time interval from recent to 300 a A.D., suggesting at least partly varve-type sediments. The sebkha facies with short lacustrine intervals covers the entire Holocene. Different sections can be stacked together by high-resolution 3D-models, generated from a drone survey (cooperation with KAUST, Saudi Arabia). Based on field observations and first data analysis, a multi-stage paleolake model is suggested: Triggered by faults in the underlying Lower Jurassic Hith, anhydrite converts into gypsum, forming a topographic bulge and a sebkha environment. During fall of the groundwater level, sinkholes collapsed in its center due to phreatic dissolution, forming the groundwater-fed lakes. All sections show a pronounced cyclicity which will be further analyzed by high-resolution multi-proxy analyses.



Wed: 55
Topics: 3.12 Past climates and environments inform our future

Effect of global warming on the frequency and intensity of tropical cyclones: an Early Jurassic perspective

François-Nicolas Krencker1, Christian Zeeden2, Ulrich Heimhofer1

1Institute of Geology, Leibniz University Hannover, Germany; 2Leibniz Institute of Applied Geophysiccs (LIAG), Hannover, Germany

Anthropogenic warming is predicted to increase the frequency and intensity of tropical cyclones, leading to severe damage and loss of life. However, projections based on historical observations are limited due to the lack of longer-term and spatially-resolved data. Here, we use the Toarcian Oceanic Anoxic Event (T-OAE) as a case study to investigate the link between tropical cyclone patterns and climate change. The T-OAE is a well-studied example of intense global warming and environmental change in Earth's history, characterized by a 7°C increase in sea-surface temperature and the common occurrence of tropical cyclones recorded in sedimentary deposits.

We collected sedimentary outcrop data along a 60 km-long transect, comprising 10 detailed sections along the paleo continental shelf in the central High Atlas in Morocco. We used sedimentary characteristics such as grainsize, texture, sedimentary features, and ichnofossils to identify storm-generated strata in offshore to lower shoreface settings, and extract paleo-tropical cyclone parameters. To constrain the age model, we used a cyclostratigraphic approach based on magnetic susceptibility datasets. By comparing the results to pre- and post-T-OAE time intervals, we gained insights into the frequency and intensity of tropical cyclones during this event and how they may have been affected by climate warming.

Our study highlights the potential of outcrop data to extract past storminess characteristics and test current model predictions on tropical cyclone patterns. By improving our understanding of how climate change affects tropical cyclones, we can better prepare for and mitigate the damage caused by these extreme weather events.



Wed: 56
Topics: 3.12 Past climates and environments inform our future

The 8.2 ka event in the Dead Sea: tracking a high-latitude disturbance in the Mediterranean

Cécile Blanchet1, Assil Nwaigy2, Hana Jurikova3, Rik Tjallingii1, Michael Henehan4, Markus Schwab1, Achim Brauer1

1GFZ Potsdam, Germany; 2University of Potsdam; 3University of St Andrews; 4University of Bristol

The last deglaciation is an ideal time interval to investigate the effect of climatic and oceanic disturbances occurring at high latitude on the hydrological regimes of the Mediterranean Sea. In particular, a series of disruptions of the Atlantic Meridional Oceanic Circulation (AMOC) has punctuated the transition from glacial to interglacial conditions, with the so-called 8.2 ka event being the youngest one. After the publication of recent results showing the existence of instable climatic conditions in the Dead Sea during the Younger Dryas (Müller et al., 2022), we examine here the environmental record during the 8.2 ka event to illuminate the effects of the background climate (colder to warmer) on hydrological distrubances linked to AMOC disruptions. We performed a coupled limnological and geochemical analysis of sediments deposited in the deeper part of the Dead Sea (ICDP site 5017A), which showed the occurrence of repeated mass wasting deposits related to intense erosive activity in the watershed of the Dead Sea. Newly-acquired neodymium and strontium isotopes also show a rapid change in sediment provenance and a hiatus in outcrop sequences from western lake shores suggests a drop in lake level at that time (Migowski et al., 2006). Ongoing classification of mass wasting events and the integration of other well-dated regional records and paleoclimatic simulations will provide additional insights on the erosional processes operating at that time, as well as the climatic regimes associated.



Wed: 57
Topics: 3.13 Identifying tectonics and climatic signals in deep-time: challenges and opportunities

The DeepStor-1 exploration well

Jens Carsten Grimmer1, Florian Bauer2, Thomas Kohl3, Judith Bremer4, Eva Schill5

1Karlsruhe Institute of Technology (KIT), Germany; 2Karlsruhe Institute of Technology (KIT), Germany; 3Karlsruhe Institute of Technology (KIT), Germany; 4Karlsruhe Institute of Technology (KIT), Germany; 5Karlsruhe Institute of Technology (KIT), Germany

DeepStor-1 is the exploration well to the Helmholtz research infrastructure “DeepStor”. DeepStor focuses on the investigation of high-temperature heat storage marginal to the former oil-field “Leopoldshafen“. It is located about 10 km north of the city of Karlsruhe (Germany).

The DeepStor-1 well will probe marine to continental syn-rift sedimentary successions. It is planned to reach the Pechelbronn Group at 1‘460 m. Seismic investigation reveal a structurally undisturbed section that below 200 m depth covers the Landau, Bruchsal, Niederrödern and Froidefontaine Formations. Cores will be taken from the entire section below 820 m resolving about 6 Myr (about 26-32 Ma) of the Oligocene (about 23-34 Ma) and revealing an important geoarchive on regional and global signals, evolutionary trends of plate tectonics, paleolife, and paleoclimate. In addition to coring, the logging program is planned to include besides technical logging, a caliper-, self-potential-, temperature-, dual latero-, natural gamma spectrometry-, neutron-gamma porosity-, sonic-, elemental capture spectroscopy-, as well as image-logs in the sections 215-820 m as well as in the cored 820-1460 m section. Drilling of DeepStor-1 is planned between 2023 and 2024. Besides the interest of the Helmholtz Association in

  1. the characterization of the subsurface by logging and coring,
  2. the evaluation of the structural, hydraulic, and hydro-chemical set-up and the boundary conditions of the reservoir, and
  3. short and long-term testing of hydraulic and thermal performance of the reservoir,

the well offers opportunities for more fundamental investigations on the climatic and geological conditions during deposition of the reservoir rocks.



Wed: 58
Topics: 3.13 Identifying tectonics and climatic signals in deep-time: challenges and opportunities

Stromatolite-like structures within microbially laminated sandstones of the Paleoarchean Moodies Group, Barberton Greenstone Belt, South Africa

Christoph Heubeck1, Sebastian Reimann1, Martin Homann2

1Friedrich-Schiller Universität Jena, Germany; 2University College London, London, UK

We report abundant small calcareous mounds associated with fossilized kerogenous microbial mats in tidal-facies sandstones of the predominantly siliciclastic Moodies Group (ca. 3.22 Ga) of the Barberton Greenstone Belt (BGB), South Africa and Eswatini. Most of the bulbous, internally microlaminated mounds are several cm in diameter and formed at the sediment-water interface contemporaneous with sedimentation. They originally consisted of Fe-Mg-Mn carbonate which is now largely silicified; subtle internal compositional laminations are composed of organic matter and sericite. Their presence for >6 km along strike, their restriction to the inferred photic zone, and the internal structure suggest that mineral precipitation was induced by photosynthetic microorganisms. Similar calcareous mounds in this unit also occur within and on top of fluid-escape conduits, suggesting that carbonate precipitation may either have occurred abiogenically or involved chemotrophic metabolism(s) utilizing the oxidation of organic matter, methane, or hydrogen, the latter possibly generated by serpentinization of underlying ultramafic rocks. Alternatively or additionally, carbonate may have precipitated abiotically where heated subsurface fluids, sourced by the intrusion of a major Moodies-age sill, reached the tidal flats. In summary, precipitation mechanisms may have been variable; the calcareous mounds may represent “hybrid carbonates” that may have originated from the small-scale overlap of bioinduced and abiotic processes in space and time. Significantly, the widespread occurrence of these stromatolite-like structures in a fully siliciclastic, high-energy tidal setting broadens search criteria in the search for life on Mars while their possible hybrid origin challenges our ability to unambiguously identify a biogenic component.



Wed: 59
Topics: 3.13 Identifying tectonics and climatic signals in deep-time: challenges and opportunities

Genesis of thick, fine-grained calcite hardgrounds in the upper part of the Early to Late Cretaceous Natih Formation (Wadi Muaydin, Oman Mountains)

Frank Mattern1, Andreas Scharf1, Laura Galluccio2, Henk Droste3, Gianluca Frijia4

1Sultan Qaboos University, Oman; 22 Badley-Ashton, Winceby House, Winceby, Horncastle, Lincolnshire, LN9 6PB, United Kingdom; 33 University of Oxford, United Kingdom; 4University of Ferrara, Italy

We studied two fine-grained calcite hardgrounds (Hg1, Hg2) from the upper part of the Early to Late Cretaceous Natih Formation. Both hardgrounds occur in a 60-m-thick succession of limestones, comprising the Natih members C, B and the basal part of A. The hardgrounds of interest are positioned in the members C (Hg1) and B (Hg2) and typified by abundant borings of homogenous distribution, filled with dolomite. They occupy the upper part of a mudstone to wackestone bed (Hg1) and a wackestone bed (Hg2), respectively, above which the grain size increases. Field work, petrographic, microfacies and cathodoluminescence analyses, allowed us to shed light on the their unusual great thickness (75 and 100-120 cm, respectively) as the thicknesses of such fine-grained horizons may generally represent barriers for calcite-precipitating fluids. The logged section represents a protected/lagoonal environment with a relatively low sedimentation rate as indicated by the hardgrounds, peloidal limestones and bioturbation-related nodular bedding. The hardgrounds contain sponge spicules, which we did not encounter elsewhere. The two hardgrounds formed by minor sediment aggradation of locally produced mud-rich sediment, in which near-surface cementation was able to keep pace with aggradation. These conditions were met due to the Cretaceous calcite sea water composition, tropical climate, relatively low relative sedimentation rate and relative sea-level rise shifting the depocenter landward. Episodic sea-level rise was caused by regional plate convergence. Slab-pull and pulsed thrust-loading caused down-bending of the platform twice and formation of the two hardgrounds. Temporary down-bending events were followed by isostatic rebound.



Wed: 60
Topics: 3.13 Identifying tectonics and climatic signals in deep-time: challenges and opportunities

The mirror of a Late Ordovician post-glacial flooding - a conglomerate beachrock from the Tarim Basin

Qijian Li1, Lin Na1, Shenyang Yu2, Oliver Lehnert1,3, Axel Munnecke4, Yue Li1

1State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, East Beijing Road 39, 210008 Nanjing, China; 2School of Geography and Tourism, Qufu Normal University, Rizhao 276826, China; 3GeoZentrum Nordbayern, Krustendynamik, Department of Geography and Geosciences, FAU Erlangen-Nürnberg, Schlossgarten 5, D-91054 Erlangen, Germany; 4GeoZentrum Nordbayern, Paläoumwelt, Department of Geography and Geosciences, FAU Erlangen-Nürnberg, Löwenichstraße 28, D-91054 Erlangen, Germany

Understanding ancient climate changes is hampered by the inability to disentangle trends in continental ice volume from records of relative sea-level change. As a unique coastal deposit in tropical and subtropical regions, beachrock has been proved to be reliable for constraining the glacial meltwater signal and, thus, the total volume of land-based ice in the Quaternary. However, beachrock is rarely recognized in the fossil record due to (a) the 2-dimensional distribution of beach deposits, as opposed, for example, to extended platform sediments, and (b) the fact that specific environmental conditions are required in order to lithify sediments directly at the beach.

By combing the stratigraphic architecture with petrography of characteristic cements, we show the first Ordovician beachrock from the Tarim Block, northwestern China. According to biostratigraphic data, a middle Katian (Upper Ordovician) palaeokarst surface is capped by a carbonate conglomerate beachrock, indicating a significant late Katian relative sea-level rise.

These beachrocks can be correlated with the onlap on the widespread subaerial exposure surfaces during deglaciation and post-glacial sea level rise. They formed in northwestern Tarim Basin after a pronounced stratigraphical gap reflecting the expression of a Katian glacial. We suggest that the beachrock ‘fingerprinted’ a strong melt-water pulse in high latitudes after this short-lived glaciation, which until now did not receive much attention in the scientific literature.



Wed: 61
Topics: 3.14 Applied stratigraphy of Central European basins

News on the World’s Largest Ammonite, Parapuzosia (P.) Seppenradensis (Landois, 1895) together with a New Associated Stratotype Section and Point for the Base of the Campanian

Christina Ifrim

Staatliche Naturwissenschaftliche Sammlungen Bayerns, Germany

The world’s largest ammonite, Parapuzosia (P.) seppenradensis (Landois, 1895), has fascinated the world ever since the discovery in 1895 of a specimen measuring 1.74 metres (m) in diameter near Seppenrade in Westfalia, Germany. Subsequent findings of this taxon have been exceedingly rare and its systematic position has remained enigmatic. We have revised the historical specimens and documented abundant new material from England and Mexico. Our study (Ifrim et al., 2021) comprises 154 specimens of large (< 1 m diameter) to giant (> 1m diameter) Parapuzosia from the Santonian and lower Campanian, mostly with stratigraphical information. High-resolution integrated stratigraphy allows for precise trans-Atlantic correlation of these occurrences, and the Tepeyac section has become Associated Stratotype Section and Point for the base of the Campanian (Gale et al. 2023). It yields a rich macrofossil assemblage (Ifrim and Stinnesbeck, 2021) which is correlated to other parts of the world by the stable carbon isotope curve, and also to the successin of the German Münsterland Basin where the World's largest ammonite originates. The high- resolution correlation allows for further insight into the palaeobiology, evolution and dispersal of worlds largest ammonite.



Wed: 62
Topics: 3.14 Applied stratigraphy of Central European basins

Borehole Gressenich BK1: new insights into the early Mississippian Kohlenkalk Platform of the Aachen region, Germany

Sven Hartenfels, Martin Salamon, Oliver Heß

Geological Survey of North Rhine-Westphalia GD NRW, Germany

The early Mississippian of the Aachen region is characterized by a tropical shallow-water carbonate succession, the so-called Kohlenkalk Platform. Establishing a second phase of intensive carbonate production, it follows on the Givetian to Frasnian biostromal buildups around the southeastern edge of the London-Brabant Massif. The timing and patterns of the development of these Carboniferous carbonates were studied, based on drill core Gressenich BK1. It was sunk by the Geological Survey of North Rhine-Westphalia in the core of the Burgholz Syncline and reached a depth of 100 metres. The borehole is located in the Vygen/Gressenich Quarry, which exposed and strongly tectonized Devonian strata were previously investigated by Reißner (1990). In contrast to the nearby active Hastenrath Quarry, the Palaeozoic part of the succession shows an inverted stratification. As Holocene sediments comprise a thickness of 7.30 m within the drill core, subsequent Devonian sedimentary rocks (mostly reefal limestones) occur up to a depth of 27.00 m. Followed by 12.40 m of black shale of unclear stratigraphic age, possibly the Frasnian Matagne Shale, all formations and subformations of the drilled Kohlenkalk succession can be easily subdivided by lithostratigraphy. Considering the regional stratigraphic schemes in the Vesdre Massif of eastern Belgium and referring to the formal lithostratigraphic concept of Amler & Herbig (2006), these are the Vesdre and Terwagne formations. The latter contains the Hastenrath (= Vaughanites Oolith), Bärenstein, and Bernardshammer subformations. Unfortunately, conodonts are rare or absent. In the case of the Vaughanites Oolith, reworking processes cannot be ruled out.



Wed: 63
Topics: 3.14 Applied stratigraphy of Central European basins

Geochemical characterization of upper Berriasian to lower Turonian lithostratigraphic units from the Hanover area

André Bornemann1, Jochen Erbacher1,2, Martin Blumenberg1

1Bundesanstalt für Geowissenschaften und Rohstoffe, Germany; 2Landesamt für Bergbau, Energie und Geologie, Hannover, Germany

In northern Germany, Lower Cretaceous sediments are predominantly represented by CaCO3-poor mud- and siltstones of up to 2000 m thickness, which become more carbonate-rich during the Albian-Cenomanian transition and even chalkier in the upper Cenomanian. The sedimentary system can be simplified considered as bimodally controlled by carbonate and fine-grained siliciclastics; in addition, some lithostratigraphic units are characterized by a high organic carbon content (Hoheneggelsen Formation, Barremian-Lower Aptian; Hesseltal Formation, Cenomanian-Turonian).
We present a 1500-m-thick composite record of late Berriasian to middle Turonian age based on 14 drill cores and about 4500 samples. All cores and successions are located in the larger Hanover area, which represents the depocenter of the North German Lower Saxony Basin in early to mid-Cretaceous times. Beside a recently published long-term carbon-isotope stratigraphy, we generated high-resolution calcium carbonate and organic carbon data, which nicely trace the lithostratigraphic units on formation and on member level, allowing for a more detailed characterization for most of the units. Only the Albian-Cenomanian transition from the Peine to the Herbram Formation is less well developed in the geochemical data.



Wed: 64
Topics: 3.14 Applied stratigraphy of Central European basins

Integrated stratigraphy of the lower Danubian Cretaceous Group (lower Upper Cretaceous, southern Germany)

Niklas Metzner1, Birgit Niebuhr1, Thomas Pürner2, Markus Wilmsen1

1Senckenberg Naturhsitorische Sammlungen Dresden, Germany; 2Bayerisches Landesamt für Umwelt, Abt. 10 Geologischer Dienst, Marktredwitz, Germany

The Danubian Cretaceous Group (DCG; Bavaria, SE-Germany) represents the deposits of one of the most pronounced sea-level rises in the Phanerozoic. Integrated stratigraphy (litho-, sequence-, and chemostratigraphy) and (micro-) facies analysis of the Lower Cenomanian–Middle Turonian strata of the DCG based on new drill cores from the north of Regensburg and the Grub section in the Bodenwöhrer Senke provides new insights in the process linked to the early Late Cretaceous sea-level rise.

Unconformably overlying Jurassic carbonates or Variscan granites, the Cretaceous succession includes the Regensburg (Lower Cenomanian–Upper Cenomanian), Eibrunn (uppermost Cenomanian–lowermost Turonian), Winzerberg (Lower Turonian) and partly Kagerhöh and Roding (Middle Turonian) formations. All lithofacies is of marine origin and consists of glauconitic sandstones, argillaceous marlstones, silty-spiculitic wackestones to marlstones, fine-grained (marly) sandstones, glauconitites and bioclastic wackestones. Five Cenomanian–Turonian sequence boundaries and their corresponding depositional sequences have been identified. Their correlative nature on an intra-basinal scale and beyond suggests a eustatic control of the depositional processes. High-resolution carbon stable isotope-based chemostratigraphy through the Cenomanian to Lower Turonian considerably improves correlation to nearby sections and European reference sections in southern England and France. A nearly complete record of the Oceanic Anoxic Event 2 (OAE 2) allows a detailed stratigraphic calibration of the Cenomanian–Turonian boundary interval and provides new insides into the environmental processes associated with OAE 2 in the Danubian Cretaceous Basin, including the first proof of the Plenus Cold Event from the region.



Wed: 65
Topics: 3.14 Applied stratigraphy of Central European basins

Organo- and lithofacies variations of the Pliensbachian-Toarcian (Early Jurassic) sedimentary succession in the Hils Synline, Lower Saxony Basin: Implication on paleoenvironmental reconstruction

Linda Burnaz1, Sebastian Grohmann1, Jochen Erbacher2, Lukas Elzer3, Harald Strass3, Ralf Littke1

1Institute of Geology and Geochemistry of Petroleum and Coal, Energy and Mineral Resources Group (EMR), RWTH Aachen University, Aachen, Germany; 2Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Hanover, Germany; 3Institut für Geologie und Paläontologie, Westfälische Wilhelms-Universität Münster, Münster, Germany

The widespread deposition of Lower Toarcian (Early Jurassic) black shales throughout NW Europe has often been associated with a global oceanic anoxia event, the Toarcian Oceanic Anoxic Event (T-OAE). However, sedimentary variations within the European sub-basins suggest a significant influence of regional effects, arousing interest in investigating regional variations in the NW European basin system. At the Hils syncline (Lower Saxony Basin), black shales of the Posdionienschiefer Formation have been studied extensively in recent decades, mainly focusing on the effect of thermal maturation on organic-rich sediments. However, under- and overlaying organic-lean clay- and mudstones are sparsely studied in this region.

This study investigates a continuous profile of Upper Pliensbachian to Upper Toarcian/Lower Aalenian deposits by combining samples from two boreholes from the Hils syncline, Wickensen and BO2.0, to establish a regional model for the deposition of Lower Toarcian black shales in this region. Nearly 200 samples were analyzed using a multi-disciplinary approach, including X-Ray fluorescence, Corg isotopic composition, Rock-Eval pyrolysis, and biomarker analysis.

The geochemical results suggest that the development of anoxia was closely linked to sea level and associated water circulation variations. Upper Pliensbachian and lowermost Toarcian sediments were deposited under oxic conditions associated with increased terrestrial influx and a low sea level. The overlying black shales (falciferum zone) are characterized by prevailing anoxia and photic zone anoxia and decreased terrestrial input, indicating a sea level rise. For the overlying Upper Toarcian Jurensismergel shales, ongoing sea-level rise is suggested, promoting less restricted water circulation and dysoxic conditions.



Wed: 66
Topics: 3.14 Applied stratigraphy of Central European basins

The core section of HG 7025 Struppen-Siedlung: a new standard section for the facies transition zone of the Saxonian Cretaceous Basin (Lower Cenomanian–Upper Turonian, eastern Germany)

Melanie Melchisedech1, Markus Wilmsen2

1Senckenberg Naturhistorische Sammlungen Dresden, Germany; 2Senckenberg Naturhistorische Sammlungen Dresden, Germany

The sequence stratigraphic and facies analyses of the Lower Cenomanian to Upper Turonian core section HG 7025 provide a new standard section of the regional facies development and stratigraphic architecture in the so-called “Faziesübergangszone” (facies transition zone) of the Saxonian Cretaceous Basin. The section covers eight depositional sequences, divided by nine sequence-bounding sedimentary unconformities (SBs). The Lower Cenomanian depositional sequences DS Ce 1+2 and DS Ce 3 comprise the lower and upper fluvial Niederschöna Formation, separated by sequence boundary SB Ce 2. Above SB Ce 3, the Middle Cenomanian Wurmsandstein (DS Ce 4) displays the first marine influence in the succession. Intensifying this trend, the marine onlap continues during the early Late Cenomanian DS Ce 5, almost completely levelling the pre-existing paleo-topography. DS Ce 5 ends at SB Ce 5, representing a subaerial unconformity. Cenomanian marine onlap is completed by the plenus transgression during DS Ce-Tu 1, culminating in the lowermost Turonian Lohmgrund Horizon. The transition from Lower to Middle Turonian is marked by the regionally correlatable Bielatal Horizon of the Schmilka Formation (SB Tu 1). Both early Middle Turonian DS Tu 2 and Middle to early Late Turonian DS Tu 3 are defined by rapid sea-level rises and subsequent pronounced progradation phases. Separated by a subaerial unconformity (SB Tu 3), DS Tu 4 comprises a trans-/regressive cycle capped by SB Tu 4, marked by a sharp grain-size increase at the base of Sandstein c3. The Late Turonian DS Tu 5 is only represented by lowstand and early transgressive deposits.



Wed: 67
Topics: 3.14 Applied stratigraphy of Central European basins

The continental Hessenreuth Formation: syntectonic deposition during Late Cretaceous inversion (Danubian Cretaceous Group, Bavaria, Germany)

Birgit Niebuhr1, Thomas Pürner2, Annette E. Götz3, Frank Holzförster4, Markus Wilmsen1

1Senckenberg Naturhistorische Sammlungen Dresden, Germany; 2Bayerisches Landesamt für Umwelt, Marktredwitz, Germany; 3Geozentrum Hannover, Germany; 4GEO-Zentrum an der KTB, Windischeschenbach, Germany

The strata of the Danubian Cretaceous Group reflect dynamic depositional conditions in a peri-continental setting at the northern margin of the Alpine Tethys. From the Middle Turonian onwards, tectonic inversion along the Franconian Lineament started, reflected by the deposition of coarse-grained and extremely immature siliciclastics of the continental, more than 466 m thick Hessenreuth Formation, comprising the mid-Middle Turonian–Middle Coniacian depositional sequences DS Tu 3–Co 2. The composite section studied consists of successions cored by the deep Friedersreuth 10/1990 borehole as well as several shallow boreholes and outcrops. The >63 m thick Glashütte Member below 312 m ASL is characterized by beige-pink, conglomeratic sandstones alternating with thin brick-red, argillaceous-silty soil horizons. The Parkstein Member (312–390 m ASL) is dominated by several-meters-thick, partly inversely graded sandstone packages, interbedded by a few thin carbonaceous silt and clay beds with plant debris. The tripartite Friedersreuth Member (390–562 m ASL) starts with a cyclic conglomeratic-brecciform debris-flow unit, followed by a chaotic mud-flow unit, and is capped by predominantly fine-grained, plant-rich siliciclastics. The uppermost ca. 153 m constitutes the Hesserberg Member, i.e., mica-rich, coarse conglomerates that include meter-scale boulders. These alluvial subunits can be correlated to the mixed marginal marine / continental succession of the Bodenwöhrer Senke, ca. 60 km in the south, and the neritic deposits around Regensburg–Kelheim. Palynoassemblages are dominated by angiosperm pollen of the Normapolles group. Below 515 m ASL, the Turonian marker Complexiopollis christae occurs, while above 555 m ASL, Minorpollis minimus characterizes the Coniacian.



Wed: 68
Topics: 3.14 Applied stratigraphy of Central European basins

Lithostratigraphy in high-grade terrains – An approach for the classification of metamorphic rocks?

Sebastian Weber

Landesamt für Umwelt, Landwirtschaft und Geologie, Germany

A lithostratigraphic unit is a stratum or body of strata that conforms to the law of superposition and is defined based on lithic characteristics and stratigraphic position. The stratigraphic concept relies on the assumption that younger rocks are deposited on pre-existing rocks during earth's history, and that individual sedimentary layers of rather constant thickness expand laterally. This working hypothesis has been successfully applied in many sediment studies and the results have been presented on numerous geological maps. A stratigraphic approach is problematic in regional metamorphic series, since the primary stratigraphy is converted into tectonic layering during metamorphic overprint. Using the Saxon Granulite Massif as a case study, this contribution aims to demonstrate the difficulty in applying lithostratigraphic methods to high-grade metamorphic rocks. We provide a critical discussion of the arguments that favour a lithostratigraphic model for the Saxon Granulite Massif in the light of the state of the art literature. High-grade metamorphic rocks should be primarily characterized based on their macroscopic appearance and further investigated using geochronological, petrological and structural methods. Absolute age constraints can be derived from radiometric dating methods, however, it should be critically evaluated if these results reflect a protolith age, a metamorphic crystallisation age or an inherited age. Many metamorphic terrains are dominated by rocks of different ages and thus conventional principles of stratigraphy cannot be applied.



Wed: 69
Topics: 3.14 Applied stratigraphy of Central European basins

Late Triassic to Early Jurassic carbon isotope stratigraphy and organo-facies evolution in a basin-margin transect of the North German Basin

Wolfgang Ruebsam1, Matthias Franz2, Karsten Obst3, Jörg Ansorge4, Lorenz Schwark1

1University Kiel, Germany; 2Geowissenschaftliches Zentrum der Georg-August-Universität Göttingen; 3Landesamt für Umwelt, Naturschutz und Geologie (LUNG), Mecklenburg-Vorpommern; 4Institute of Geography and Geology, University of Greifswald

Profound climatic and environmental changes at variable timescales are documented throughout the Late Triassic to Early Jurassic (c. 210-170 Ma) and were linked to the emplacement of large igneous provinces, tectonic processes, as well as transient climate fluctuations. Climate and environmental change triggered bio- and geosphere evolution, and impacted on sedimentary archives of marine and terrestrial basins. Most severe environmental change events, involving global carbon cycle and ecosystem perturbations, occurred at Triassic-Jurassic boundary (TJB; c. 201 Ma) and during the early Toarcian Oceanic Anoxic Event (T-OAE, c. 182 Ma).

We here discuss the differential response of depositional settings and organo-facies towards secular and transient environmental change along a basin-margin transect of the NW European Epicontinental Seaway (North German Basin), an expanded and intensively structured shallow shelf sea.

Stable carbon isotope values (d13Corg) revealed diagnostic trends that allow the precise intercorrelation along the transect, as well as correlation with far-apart sites. The TJB and the T-OAE are indicated by prominent negative carbon isotope excursions.

Programmed pyrolysis data indicate spatio-temporal organo-facies trends that on a temporal scale occurred in response to changes in deposition, such as climate and sea level evolution, while spatial pattern reflect basin morphology and paleobathymetry. Marine organic matter is best preserved at anoxic basinal sites, while marginal settings received increased land plant contributions and/or experienced more intense oxic degradation of marine organic matter. Substantial TOC accumulations occurred only in association with the T-OAE during high sea level and were most continuous at basinal sites.



Wed: 71
Topics: 3.21 Tectonic Systems - TSK Open Session

An example of continuous plutonism during orogenesis - The emplacement of the Bassiès pluton in the central Pyrenees (SW-France)

Stephan Schnapperelle1, Michael Stipp1, Mandy Hofmann Zieger2, Johannes Zieger2, Ulf Linnemann2

1Martin-Luther-Universität Halle-Wittenberg, Germany; 2Senckenberg Naturhistorische Sammlungen Dresden, Abteilung Geochronologie, Germany

The Axial Zone of the Pyrenees represents a window into the Variscan evolution of the northern Gondwana margin. One enigma of this evolution is the origin of the many and large granitoid intrusions and gneiss domes as well as the timing of their emplacement and deformation.

New zircon U-Pb data using laser ablation ICP MS indicate that granitoid plutonism is an almost continuous process over the entire Variscan orogenesis between 360 and 285 Ma that can be statistically constrained and shown for a number of these intrusions and domes. The Bassiés pluton is a key example which shows the oldest Carboniferous intrusive units with ages of 350 - 340 Ma, followed by the main intrusion phase between 330 and 320 Ma including the magmatic peak of 321 Ma. Two further age clusters occur around 314 to 300 Ma and around 285 Ma in the early Permian.

The polyphase development and in-situ melt recycling of the granitoids can also be inferred from core-rim relationships of zircon grains. There are zircons with core and rim ages of 346 and 326 Ma or 330 and 305 Ma, respectively. According to these results, it is required to revisit the mechanisms of pluton emplacement over such a long time span as well as the definition of the emplacement age. The youngest age is clearly not the crystallization age of the pluton, but plutonism is a long-lasting process that affects the Variscan crust over tens of millions or years, i.e. during the entire orogeny.



Wed: 72
Topics: 3.21 Tectonic Systems - TSK Open Session

Late Mesozoic to Palaeogene cooling history of the Thuringian Forest basement high and its southern periphery (Central Germany) revealed by fission-track dating

Kamil Ustaszewski1, Manuel Thieme1, Fabian Jähne-Klingberg2

1Universität Jena, Germany; 2Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Hannover, Germany

We present new results from a fission track (FT) dating approach on zircon and apatite from the Thuringian Forest, a prominent fault-bounded basement high in central Germany, and its southwestern periphery exposing Mesozoic strata. Samples were collected from exposures of igneous rocks as well as from lower to upper Permian (Rotliegend) continental red beds and volcanics recovered from a borehole southwest of the Thuringian Forest. Apatite FT ages range between 86 and 70 Ma, suggesting rock uplift associated with a well-documented and regionally important phase of NNE–SSW-directed intraplate contraction, resulting in spatially homogeneous removal of c. 3 km of Upper Palaeozoic to Mesozoic rocks. No change in apatite FT ages was detected across the regional-scale Franconian Fault system at the southwestern margin of the Thuringian Forest. Additionally, apatite FT ages of borehole samples southwest of the Thuringian Forest from depths between 9.6 and 2.7 km range from 57 to 18 Ma, suggesting post-Late Cretaceous cooling of this peripheral region. Our data hence support recent models of a continued large-scale domal uplift of Central Germany without verifiable or detectable involvement of individual faults.



Wed: 73
Topics: 3.21 Tectonic Systems - TSK Open Session

Artificial clay mineral alignment during sedimentation and early compaction

Dustin Lang, Rebecca Kuehn, Rüdiger Kilian

Martin-Luther-University Halle, Germany

The formation of crystallographic preferred orientations (CPO/texture) in sediments is often attributed to rigid grain rotation of minerals and aggregates, plastic-brittle deformation and dissolution-precipitation processes. Especially, clay minerals have a large shape anisotropy due to their platy habit. Here, we present an experimental approach in order to quantitatively explore the influence of particle settling and subsequent compaction in an undisturbed, ideal environment.

A powder of idiomorphic kaolinite grains was mixed with a fine-ground, illite aggregates in mass proportions of 0, 30, 50, 70 and 100 % in artificial seawater. The sludges settled in 80 cm high tubes. For each composition three samples were produced: Sedimentation-only and two drained compaction experiments (30 and 60 vol-%), which were carried out in a mechanical press with uniaxial load up to 0.4 MPa and 4 - 8 MPa. The CPO of clay minerals was measured using high energy X-ray diffraction at beamline P07b at Deutsches Elektronen-Synchrotron (DESY) and pole figure data was directly extracted using single peak evaluation.

The results indicate that sedimentation alone, can yield a strong texture of the clay minerals. The increase in texture strength (TS) is decreased at higher applied loads. TS is linearly related to shortening and porosity reduction. The kaolinite TS is inversely correlated with texture-inhibiting illite aggregate content which hampers further particle rotation. It is interpreted that the initial stages of settling and early rigid body rotation during compaction are thus the most important processes in the formation of a CPO in clay rich sediments.



Wed: 74
Topics: 3.21 Tectonic Systems - TSK Open Session

Asymmetric river incision records the Quaternary uplift of the Rhenish Massif

Philipp Balling, Silvia Kolomaznik, Christoph Grützner, Kamil Ustaszewski

Friedrich-Schiller-Universität Jena, Germany

The topography of the Rhenish Massif is known to be affected by Late Cenozoic uplift. Recent GNSS studies imply surface uplift rates of up to 1 mm/a, likely controlled by a mantle plume beneath the Eifel. Studies on Rhine River terraces show that central parts of the Rhenish Massif have been uplifted by 140 to 250 m since 700-800 ka. These figures correspond to a very low long-term average uplift rate of 0.1-0.3 mm/a, which decrease to even lower rates towards the margins of the Rhenish Massif. There, conventional geomorphic analyses, such as KSN values, Chi-maps and basin asymmetries, show no evidence of vertical motions.

Field observations in several valleys of the Diemel river catchment in the northeastern Rhenish Massif show steeper west-facing topographic slopes compared with flatter east-facing slopes, suggesting asymmetric bedrock incision due to ongoing surface uplift. We analysed topographic river profiles on a regional scale in five catchments (Möhne, Alme, Ruhr, Diemel and Eder) using 1 m-resolution Lidar data to see whether they are affected by asymmetric river incision Our results show that only the S-N oriented streams cutting into lithologically heterogeneous rock formations show asymmetric incision. This pattern resulted from uplift and tilting of the Rhenish Massif towards the NE, causing differential erosion.

These preliminary results will be substantiated by a more regional study comprising the entire margin of the Rhenish Massif. We aim to investigate whether the slow vertical surface movements around the Eifel Plume could have led to asymmetric bedrock incision elsewhere, too.



Wed: 75
Topics: 3.21 Tectonic Systems - TSK Open Session

Fabric development in felsic granulites during multistage exhumation of the Saxonian Granulite Massive

Till Berndt, Rüdiger Kilian, Michael Stipp

Martin-Luther-Universität Halle-Wittenberg, Germany

Fabrics in the granulites of the Saxonian Granulite Massive (SGM) are interpreted to result from deformation related to early exhumation at deep crustal conditions, followed by subsequent shearing of the granulite roof against lower grade country rocks at retrograde conditions by top-SE shearing (e.g Reinhardt & Kleemann, 1994). For structural evidence and establishment of the rheological implications of such a multiphase deformation within the felsic granulites, detailed structural fieldwork and thin section scale microstructural analyses were carried out.

In the central SGM we observed a mylonitic foliation defined by interlayered quartz ribbons (20 vol.-%) and a homogeneous Qtz-Kfs-Pl-matrix that is transposed by a second mylonitic foliation towards the SE-rim, simultaneous with boudinage and proportion reduction of quartz ribbon (6 vol-%), and growth of biotite in the polyphase matrix. A NE-trending stretching lineation progressively rotates towards a SSE-trend. Quartz in the Qtz-Kfs-Pl-(Bt)-matrix generally has no CPO. Quartz ribbon’s (0001) CPOs change from two orthogonal, peripheral maxima to a central maximum.

Transposition of the foliation and lineation results from a change in the kinematics of flow at progressively lower temperature conditions, supported by a change from <0001> to <11-20> easy slip in the ribbons. Nevertheless, due to the generally high volume percentage of the Qtz-Kfs-Pl-(Bt)-matrix we assume diffusion creep s.l. involving grain boundary sliding to be the dominant deformation mechanism in all felsic granulites, suggesting a dominant linear-viscous rheology during the exhumation path.

References

Reinhardt, J., & Kleemann, U. (1994). Tectonophysics 238, 71–94, https://doi.org/10.1016/0040-1951(94)90050-7



Wed: 76
Topics: 3.21 Tectonic Systems - TSK Open Session

Magmatic and geodynamic evolution of the King’s Trough Complex – the “Grand Canyon” of the North Atlantic

Antje Dürkefälden1, Jörg Geldmacher1, Folkmar Hauff1, Dieter Garbe-Schönberg2, Maxim Portnyagin1, Johanna Schenk1, Michael Stipp3, Kaj Hoernle1

1GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany; 2Institute of Geosciences, Kiel University; 3Institute of Geosciences and Geography, Martin-Luther-University Halle-Wittenberg

The King’s Trough Complex (KTC) is a major canyon-like structure in the eastern North Atlantic and consists of several deep basins: The huge King’s Trough in the west is flanked by elongated ridges, while at its eastern opening the smaller Peake and Freen Deeps are separated by the Palmer Ridge. The King’s Trough is located in an area of elevated seafloor covered with numerous seamounts, which transitions to the Mid-Atlantic Ridge (MAR) flank toward the west. Here we present major and trace element and Sr-Nd-Hf-Pb isotope data from submarine volcanic rock samples obtained during RV METEOR cruise M168.

Whereas lavas from the eastern deeps show N- and E-MORB signatures and moderately depleted isotope compositions, samples from the western King’s Trough and surrounding seamounts display predominantly enriched OIB-like compositions. This geographic transition would be consistent with involvement of a mantle plume that was located beneath or near the MAR resulting in elevated seafloor of relatively enriched geochemical composition. The troughs probably formed subsequently by rifting and/or transtension when (36 to 42 Ma) the KTC area represented a temporary plate boundary between the Iberian and Eurasian plates. In the east, the KTC cuts into older (not elevated) crust, presumably formed prior to plume-ridge interaction, explaining why samples obtained from there possesses normal to transitional MORB compositions. Age and further isotope data are pending and will reveal if the ridges on the King’s Trough flanks represent younger, plume-related excess volcanism or simply the tops of tilted graben shoulders along the former plate boundary.



Wed: 77
Topics: 3.21 Tectonic Systems - TSK Open Session

Pseudotachylites along the Pustertal-Gailtal-Line, eastern Periadriatic Fault system, Austria

Muriel Odine Bülhoff, Erick Prince, Christoph Grützner, Kamil Ustaszewski

Friedrich-Schiller-University Jena, Germany

The Pustertal-Gailtal Line (PGL) belongs to the dextrally transpressive Periadriatic Fault system and forms the border between Southern and Eastern Alps. Although part of the ongoing convergence between Adria and Europe appears to be accommodated by this fault system, it reveals little instrumental and historical seismicity. In our study, we attempted to find evidence for past seismic activity along the PGL by investigating pseudotachylite occurrences.

We investigated an area of c. 19 km2 to either sides of the PGL around Maria Luggau (Austria). We identified cataclasites and fault gouges along the fault core zone, from which we investigated only the cohesive rocks. Cataclastic, foliated Oligocene granitoids as well as garnet-mica schists of the Austroalpine basement are crosscut by cm- to dm-scale veins containing black fault rocks, which were sampled for further analyses.

Polarisation microscopy reveals that the vein-forming black fault rocks are often optically isotropic, testifying to their origin as quenched melts. Sharp margins of mm- to cm-sized injection veins against the surrounding host rock, well-rounded quartz and feldspar clasts, the absence of hydrous minerals in the matrix, as well as spherulites are further hints at a seismogenic origin of the studied fabrics. Some of the optically isotropic veins are internally foliated; their in-situ µ-XRF analysis of major element concentrations revealed chemical composition variations in the foliation. Even if this foliation might suggest overprinting by aseismic creep, our observations indicate a seismogenic origin of the studied fabrics as pseudotachylites.



Wed: 78
Topics: 3.21 Tectonic Systems - TSK Open Session

The Bathymetrists Seamounts – intraplate volcanic province meets Riedel Shears (eastern Equatorial Atlantic Segment)

Elisabeth Seidel1, Christian Hübscher1, Froukje Marieke van der Zwan2, Nico Augustin3, Morgane Le Saout3

1University of Hamburg, Germany; 2KAUST - King Abdullah University of Science and Technology, Kingdom of Saudi Arabia; 3GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany

The Bathymetrists Seamounts (BSM) form a 900 km long and 200 km wide volcanic chain of about 40 volcanic edifices within the eastern Equatorial Segment of the Atlantic. They are located between the Vema Fracture Zone in the north and the 4°N Fracture zone in the south (both transcurrent faults). Like other submarine chains east of the Mid-Atlantic Ridge, the BSM trend NE-SW. Many of those volcanic chains are intensively studied and attributed to hot spot tracks above mantle plumes. However, the BSM is much broader and strongly associated with faults. Still, it remains unclear if a mantle plume, decompression melting along fracture zones, or small-scale upper mantle convection caused these seamounts. We present new insights to the BSM based on about 80,000 km² high-resolution bathymetric data with 50 m spatial resolution, and 4,000 km of 2D seismic reflection data, collected during expeditions RV Merian MSM70 in 2018 and RV Meteor M152/2 in 2019. Seismic sections across the volcanic edifices allow a simple estimation of their relative age distribution, as it is inferred by the stacking pattern of the volcanic successions. Moreover, the structural pattern includes flower structures and indicates transtension. The single seamounts are arranged along E-W to NE-SW lineaments that can be explained by large-scaling Riedel shears. This Riedel shear pattern reveals a NW-SE orientated extensional local stress field during its generation in the Paleogene. Therefore, deep mantle plumes and shallower tectonics on a lithospheric scale could play an important role in the emplacement of the volcanoes.



Wed: 79
Topics: 3.21 Tectonic Systems - TSK Open Session

Normal faulting around Kolumbo Volcano - exploring relationships between stress fields and volcanism

Gareth Crutchley1, Jens Karsten1, Jonas Preine2, Christian Hübscher2, Haakon Fossen3, Michel Kühn1

1GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany; 2University of Hamburg, Germany; 3University of Bergen, Norway

The Christiana-Santorini-Kolumbo volcanic field, in the Aegean Sea, has hosted more than 200 explosive eruptions in the past 360,000 years, including the 1650 eruption of Kolumbo Volcano. In this contribution, we use the first 3D seismic reflection data collected over the submarine Kolumbo Volcano to explore active faulting and its relationship to volcanism. The 3D data enable us to extract useful fault attributes (strike, dip, dip direction) which can be used to decipher local stress fields. Our results reveal clear NW-SE directed extension around the volcano, consistent with published focal mechanisms from microseismicity. The data also provide exceptional 3D imaging of the Kolumbo Fault Zone, which lies ~6 km northwest of Kolumbo Volcano. Interpreted horizons through the Kolumbo Fault Zone reveal distinct relay ramps between overstepping normal faults. We suggest that magma ascent within the fault zone likely exploits enhanced vertical permeability associated with distributed deformation within relay ramps. Further research is required to understand the range of scales over which relay ramps could affect crustal permeability, and by inference magma ascent, in the greater rift zone.



Wed: 80
Topics: 3.21 Tectonic Systems - TSK Open Session

High-Stress Crystal Plasticity of Calcite – Evidence from Ries Impact Breccias

Claudia Trepmann1, Lina Seybold1,2, Stefan Hölzl1,2, Falko Langenhorst3, Kilian Pollok3, Melanie Kaliwoda4

1Department of Earth and Environmental Sciences, Ludwig-Maximilians-University Munich, Germany; 2RiesKraterMuseum Nördlingen, Bavarian Natural History Collections; 3Institute of Geoscience, Friedrich Schiller University Jena; 4Mineralogical State Collection, Bavarian Natural History Collections

Abstract: Twinned calcite occurs in calcite-bearing metagranite cataclasites within crystalline megablocks of the Ries impact structure, Germany, as well as in cores from the FBN1973 research drilling. The calcite likely originates from pre-impact veins within the Variscan metagranites and gneisses, while the cataclasis is due to the Miocene impact. Quartz in the metagranite components does not contain planar deformation features, indicating low shock pressures (< 7 GPa). Calcite, however, shows a high density (> 1/µm) of twins with widths < 100 nm. Different types of twins (e-, f- and r-twins) crosscutting each other can occur in one grain. Interaction of r- and f-twins results in a-type domains characterized by a misorientation angle of 35-40° and a misorientation axis parallel to an a-axis relative to the host. Such a-type domains have not been recorded from deformed rocks in nature before. The high twin density and activation of different twin systems in one grain require high differential stresses (on the order of 1 GPa). Twinning of calcite at high differential stresses is consistent with deformation during impact cratering at relatively low shock pressure conditions. The twinned calcite microstructure can serve as a valuable indicator of high differential stresses and sufficient confining pressure to prevent brittle deformation. The stress conditions at relatively low shock pressures (< 7 GPa) during impact-cratering are comparable to those at hypocentral depths during seismic rupturing in the continental crust. Therefore, comparable high-stress crystal plasticity of calcite might likewise be expected from fault rocks deformed at hypocentral depths.



Wed: 81
Topics: 3.21 Tectonic Systems - TSK Open Session

Structural study of a shear zone in the Koralm Complex at Hirschegg-Pack (Austroalpine Nappes, Austria)

Pascal Michael Woiton, Ruth Keppler, Nikolaus Froitzheim

University of Bonn, Germany

The Koralm Complex in eastern Austria comprises various gneisses and eclogite lenses which record high-pressure metamorphism of Late Cretaceous age, acquired in an intracontinental subduction zone. The mechanism of exhumation of the Koralm Complex is either slab extraction or wedge extrusion. The present study aims at adding structural evidence to this problem. We studied an WSW-ESE-striking shear zone with SSE-dipping foliation and subhorizontal stretching lineation in the central part of the Koralm Complex. Based on quartz crystallographic preferred orientations (CPO) in gneiss, Krohe (1987) demonstrated sinistral shearing in this shear zone. We investigate microstructure and CPO of samples from the same shear zone using electron backscatter diffraction and photometry. Microstructures indicate grain-boundary migration, subgrain rotation, and static annealing. We find sinistral as well as dextral shear sense. This may either reflect flattening in the shear zone or two phases of deformation with contrasting kinematics. These two possibilities are discussed based on the textural data.

References

Krohe, A., 1987. Kinematics of Cretaceous nappe tectonics in the Austroalpine basement of the Koralpe region (eastern Austria). Tectonophysics 136, 171–196. https://doi.org/10.1016/0040-1951(87)90024-2.



Wed: 82
Topics: 3.22 From the ocean floor to the deep mantle and the arc: Element cycling through subduction zones and in orogens

Insights into multi-stage fluid-rock-interaction processes in HP metamorphic ocean floor basalts from the Tianshan, NW China

Sophie Scherzer1,2, Esther M. Schwarzenbach1,2, Timm John2, Maria Rosa Scicchitano3, Besim Dragovic4, Mirjam Kiczka5

1Department of Geosciences, University of Fribourg, Fribourg, Switzerland; 2Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany; 3German Research Centre for Geosciences (GFZ), Potsdam, Germany; 4School of the Earth, Ocean and Environment, University of South Carolina, Columbia, SC, USA; 5Institute of Geological Sciences, University of Bern, Bern, Switzerland

Slab fluids, which are released by the subducting oceanic lithosphere through compaction and dehydration processes, are an essential mechanism for the transfer of volatiles from the slab to the mantle wedge. However, migration processes of slab dehydration fluids are not well understood yet, particularly with regards to transport mechanisms of redox sensitive elements such as sulfur.

In this study we investigated an eclogite-facies metabasalt from the South Tianshan Orogen, NW China, which contains several omphacite-dominated HP veins. Using mineral chemical analyses combined with in situ δ34S measurements of pyrite, as well as isotope analyses of C, O, Sr and Pb in mineral and vein separates, we determined the metamorphic evolution of the studied sample and the speciation of sulfur during fluid infiltration and transfer.

Mineral chemical and isotopic compositions reveal seafloor alteration, affecting the protolith pillow basalt prior to subduction. This was followed by a two stage intra-slab fluid-flow under peak to prograde metamorphic conditions, forming the omphacite-dominated HP-veins. The first HP fluid originated from dehydrating ocean floor basalts, as documented by MORB-like pyrite δ34S signatures. The second HP fluid composition suggests, instead, an origin from the basalt-sediment transition with negative pyrite δ34S values of about -10‰. Pathways formed by the first fluid were reused and enlarged by the second fluid, which however also formed new pathways. This sample provides detailed insights into intra-slab fluid flow and fluid-rock-interaction processes at HP/LT metamorphic conditions and allows a better understanding of fluid transfer and sulfur speciation in subduction zones.



Wed: 84
Topics: 3.23 Mountain Building in the Alpine-Mediterranean domain – from mantle imaging to crustal and surface processes back in time - AlpArray and AdriaArray

Kinematics and rifting processes of the Liguro-Provençal Basin, Western Mediterranean

Alex Jensen1, Eline Le Breton1, Sascha Brune2, Anke Dannowski3, Dietrich Lange3, Louisa Murray-Bergquist3, Heidrun Kopp3

1Freie Universität Berlin, Berlin, Germany; 2GFZ German Research Centre for Geosciences, Potsdam, Germany; 3GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany

The Liguro-Provençal Basin, situated at the junction of the Northern Apennines and the Western Alps, formed due to the rollback subduction of the Adriatic-African plate underneath Europe and the subsequent upper plate extension in the Oligocene to early Miocene time. The opening of this basin was accompanied by the counter-clockwise rotation of the Corsica-Sardinia block relative to Europe until 16 Ma, with the basin widening towards southwest. It is yet unclear if the extension ever reached seafloor spreading with the production of oceanic crust, or whether it led to anomalously thin continental crust and/or to mantle exhumation. Although considered as tectonically inactive today, the Liguro-Provençal Basin shows active seismicity, indicating compression and potential basin inversion. Thus, it is crucial to better understand the opening of the basin and the tectonic inheritance due to rifting in order to better interpret the present-day seismicity. To this end, we compile existing geological and geophysical data, including recent data from the 4DMB project (“Mountain Building Processes in Four Dimensions”), to constrain the crustal and sedimentary thicknesses throughout the basin. We also focus specifically on two profiles in the NE (Corsica-Provence) and SW (Sardinia-Gulf of Lion) parts of the basin and compare these with the results of coupled thermo-mechanical and surface process modelling using Aspect and Fastscape codes. Finally, we discuss the effect of differences in various parameters, such as pre-rift crustal thickness, rift velocities and sediment supply, on rifting processes in the Liguro-Provençal Basin.



Wed: 85
Topics: 3.23 Mountain Building in the Alpine-Mediterranean domain – from mantle imaging to crustal and surface processes back in time - AlpArray and AdriaArray

Influences of slab breakoff on foreland basin architecture: inferences from stratigraphic forward modelling

Lucas H.J. Eskens1, Nevena Andrić-Tomašević1, Andrea Piccolo2, Marcel Thielmann2, Barbara Claussmann3, Mostfa Lejri4

1Karlsruhe Institute of Technology, Institute of Applied Geosciences, Germany; 2Bayreuth Universität, BGI, Germany; 3SLB UK, SLB Abingdon Technology Centre, UK; 4SLB Norway, SLB Norway Technology Center, Norway

One of the major tectonostratigraphic characteristics of foreland basins is the transition from deep marine (i.e. flysch) to terrestrial (i.e. molasse) depositional settings. Several mechanisms have been proposed to influence this flysch-to-molasse transition, including slab breakoff beneath the adjacent mountain range. However, this coupling has not yet been assessed quantitatively. We hypothesize that isostatic rebound following slab breakoff can lead to a spike in tectonic uplift of the orogen, resulting in increased sediment supply as well as uplift of the foreland basin, thereby causing shallowing.

This study aims at investigating whether slab breakoff leaves a stratigraphic fingerprint foreland basin stratigraphic architecture. To this end, we combine 2D geodynamic modelling of slab breakoff with Alpine-inspired rheologies with forward stratigraphic modelling using GPM (Geological Process Modelling) software. In this context, we extract subsidence and uplift velocities along 2D profiles during slab necking- breakoff to account for (1) fast/slow breakoff and (2) different slab bending angles. Second, the extracted velocity fields are used as input for creating forward stratigraphic models (FSM), in which eustatic sea level changes are introduced to test whether slab break-off has a first-order control on foreland basin sedimentation. Erosion, transport and deposition of sediments are modelled as diffusional processes (i.e. gravity driven).

Preliminary results indicate that a pulse in sediment supply corresponds to onset of slab necking whereas breakoff yields a small pulse instead. This could imply that already during necking the orogen is isostatically uplifted to such a degree that sediment supply towards to foreland basin increases significantly.



Wed: 87
Topics: 3.23 Mountain Building in the Alpine-Mediterranean domain – from mantle imaging to crustal and surface processes back in time - AlpArray and AdriaArray

SHmax orientation in the Alpine region from stress-induced anisotropy in nonlinear elasticity derived from ambient noise correlations

Yongki Andita Aiman1, Andrew Delorey2, Yang Lu1, Götz Bokelmann1

1University of Vienna, Austria; 2Los Alamos National Laboratory, USA

Major faults such as the Periadriatic Fault and the Giudicarie Fault have been active in the past, and they have even been central features of the larger-scale deformation in the Alps. It seems that these faults are not active anymore though and we investigate why this is so by inspecting the orientation of the regional stress field which loads the faults mechanically. The orientation of maximum horizontal compressive stress (SHmax) is commonly estimated from in-situ borehole breakouts and earthquake focal mechanisms. Borehole measurements are expensive, and therefore sparse, and earthquake measurements can only be made in regions with many well-characterized earthquakes. Here we derive the stress-field orientation using stress-induced anisotropy in nonlinear elasticity. We measure the strain derivative of velocity as a function of azimuth. We use a natural pump-probe approach which consists of measuring elastic wave speed using empirical Green’s functions (probe) at different points of the earth tidal strain cycle (pump). The approach is validated using a larger data set in the Northern Alpine Foreland region where the orientation of SHmax is known from borehole breakouts. The technique is then applied to the Southern Alps to understand the contemporary stress pattern associated with the ongoing deformation due to the counterclockwise rotation of the Adriatic plate with respect to the European plate. Our results explain why the two major faults in Northeastern Italy, the Giudicarie Fault and the Periadriatic Line (Pustertal-Gailtal Fault) are currently inactive, while the currently acting stress field allows faults in Slovenia to deform actively.



Wed: 88
Topics: 3.23 Mountain Building in the Alpine-Mediterranean domain – from mantle imaging to crustal and surface processes back in time - AlpArray and AdriaArray

Anisotropy of the mica rich lithologies in the north-western Tauern Window (Eastern alps, Austria)

Dustin Lang, Michael Stipp, Rebecca Kuehn, Rüdiger Kilian

Martin-Luther-University Halle, Germany

Anatomy and internal structure of the Alpine orogen are difficult to decipher as structural information is usually limited to surface and seismic data. Seismic results very much depend on the elastic wave velocity model of the rocks. Simple velocity models depend strongly on the rock composition. In the investigated rock samples, phyllosilicates are by far most decisive for the elastic anisotropy. We present here the first results of fabric analysis in a N-S profile of the Innsbruck quartzphyllite and the Bündner schist from the northern part of the Brenner Base Tunnel Project in order to obtain a refined anisotropy and velocity model.

Phyllosilicate-rich sections were selected from borehole and tunnel samples, from which 1.5 – 3.5 mm wide columns were drilled out from layers of different composition and structure. The CPO of phyllosilicates and graphite was measured using high energy X-ray diffraction at German Electron Synchrotron (DESY) and European Synchrotron Radiation Facility (ESRF). Pole figure data were directly extracted using single peak evaluation and compared to the optical microstructure and compositional distributions using µXRF measurements.

Texture strength is variable along the section with peak values at the transition from the Innsbruck quartzphyllite to the upper Bündner schist. The texture strength correlates positively with the content and distribution of phyllosilicates and graphite. By measuring the smallest representative volume element, we estimate the upper bound of expected intrinsic velocity anisotropies. The effect of (micro)structure-based upscaling on these anisotropies will be discussed.



Wed: 89
Topics: 3.23 Mountain Building in the Alpine-Mediterranean domain – from mantle imaging to crustal and surface processes back in time - AlpArray and AdriaArray

3D gravity modelling of the crust in the Eastern and eastern-Southern Alps using density data derived from compressional-wave velocities obtained by Local Earthquake Tomography

Richard Sanders1, Eline Le Breton1, Christian Haberland2, Ajay Kumar2, Denis Anikiev2, Magdalena Scheck-Wenderoth2,3

1Institute of Geological Sciences, Department of Earth Sciences, Freie Universität Berlin, Berlin, Germany; 2The Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences, Potsdam, Germany; 3Faculty of Georesources and Materials Engineering, RWTH Aachen University, Aachen, Germany

Detailed crustal structures and causative kinematic processes in the Alps continue to be a matter of ongoing research. Of particular interest is the crustal structure of the Adriatic indenter, the northern tip of the Adriatic plate that collided with and significantly deformed the Eastern Alpine Orogen in the Oligo-Miocene.

As part of the “Mountain Building in 4D” (4DMB/AlpArray) project, a high-density network of seismic stations was previously used to produce 3-D models of compressional wave velocity (Vp) of the crust and upper mantle in the Eastern and eastern Southern Alps using Local Earthquake Tomography (LET). This LET model shows a thickened high velocity zone within the lower crust beneath the Periadriatic fault, which is expected to relate to the local gravity field variations.

Here, we present results of gravity modelling using the IGMAS+ software and densities derived from the P-wave velocities of the LET model. Different possible empirical relationships between Vp and density are explored and compared to previous models as well as the AlpArray Gravity measurements to further constrain the present lithological and tectonic structures in the Eastern and eastern-Southern Alps. Strengths and weaknesses of the LET model and the gravity response of the derived densities, in particular regarding uncertainties of structures at greater depths, will be discussed.



Wed: 91
Topics: 3.25 The links between deep-seated mechanisms, surface processes and landscape evolution

Impact of Quaternary glaciations on denudation rates in the Kyrgyz Tian Shan inferred from cosmogenic 10Be and low-temperature thermochronology

Anna Kudriavtseva1,2, Alexandru T. Codilean2,3, Edward R. Sobel1, Angela Landgraf1,4, Réka-H. Fülöp2,5, Atyrgul Dzhumabaeva6, Kanatbek Abdrakhmatov6, Klaus M. Wilcken5, Taylor Schildgen7,1, David Fink5, Toshiyuki Fujioka5,8, Swenja Rosenwinkel1, Silke Merchel9, Georg Rugel9

1Institute of Geosciences, University of Potsdam, Germany; 2School of Earth, Atmospheric and Life Sciences, University of Wollongong, Australia; 3ARC Centre of Excellence for Australian Biodiversity and Heritage (CABAH), University of Wollongong, Australia; 4NAGRA, Switzerland; 5Australian Nuclear Science and Technology Organisation (ANSTO), Australia; 6Institute of Seismology, National Academy of Science of Kyrgyzstan, Kyrgyzstan; 7GFZ German Research Centre for Geosciences, Germany; 8Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), Spain; 9Helmholtz-Zentrum Dresden-Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Germany

We present 10Be-derived denudation rates from modern (n = 54) and buried sediment dated to 2.0–2.7 Ma (n = 3), and exhumation rates derived from published apatite fission track (AFT; n = 296) and apatite (U-Th-Sm)/He (AHe; n = 125) thermochronology from the Kyrgyz Tian Shan. Modern 10Be denudation rates are generally higher than the long-term AFT and AHe exhumation rates. On average, the highest 10Be denudation rates are recorded in the Terskey range, south of Lake Issyk-Kul. Here, 10Be-derived denudation rates from 2.0–2.7 Ma are comparable in magnitude with the AFT- and AHe-derived long-term exhumation rates, but modern 10Be-derived denudation rates are higher. We propose that denudation in the Kyrgyz Tian Shan, particularly in the Terskey range, remained relatively steady during the Neogene and early Pleistocene and increased after the onset and intensification of the Northern Hemisphere glaciations at 2.7 Ma due to glacial-interglacial cycles. Comparison with published data from the Pamir–Tian Shan region shows a spatial trend of decreasing modern denudation rates from west to east and an increase in the difference in magnitude between long-term exhumation rates and modern 10Be-derived denudation rates, suggesting that deformation controls denudation in the Pamir and Western Tian Shan, while farther east, the denudational response of the landscape to Quaternary glaciations becomes detectable by 10Be. We also find moderate correlations between modern denudation rates and topographic metrics and weak correlation between denudation rate and annual rainfall, highlighting complex linkages among tectonics, climate, and surface processes that vary locally.



Wed: 92
Topics: 3.25 The links between deep-seated mechanisms, surface processes and landscape evolution

Frontal fault growth and megafan construction control drainage development in the western Himalaya

Jonas Kordt1, Saptarshi Dey2, Bodo Bookhagen3, Georg Rugel4, Johannes Lachner4, Carlos Vivo-Vilches4, Santunu Kumar Panda5, Naveen Chauhan5, Rasmus Thiede1

1Institute of Geosciences, Kiel University, Kiel, Germany; 2Earth Sciences, Indian Institute of Technology Gandhinagar, Gandhinagar, India; 3Institute of Geosciences, University of Potsdam, Potsdam, Germany; 4Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; 5Atomic, Molecular and Optical Physics Division, Physical Research Laboratory, Ahmedabad, India

The evolution and course of Himalayan rivers when exiting the orogen is controlled by the interplay between tectonics, climate, and associated sediment flux. We investigate these interactions by studying a Late Pleistocene deflection of the Sutlej River at the southern margin of the western Himalayan. This part of the Himalaya is also referred to as Kangra Recess. Late Quaternary faulting and folding along the Main Frontal Thrust and related back thrusts has created anticlinal structures in the south and piggyback basins in the north. Combined field observations and chronological constraints have shown that the anticline evolved as multiple fault segments, which grew through lateral propagation and led to the permanent deflection of the Sutlej River by ~ 50 km to the southeast. In this work, we present new luminescence and cosmogenic nuclide chronologies combined with previously published data to better identify the sedimentation history. Most importantly, we focus on the cause and final timing of the permanent river deflection. We show evidence for widespread aggradation and sediment deposition by the Sutlej River megafan and its tributaries starting before 47 ka and continuing until ~ 26 ka. Our 10Be and 26Al results in combination with available OSL data document the last widespread throughflow of the Sutlej at ~ 30-25 ka. We argue that a combination of climate and tectonic factors, especially
the variability of monsoonal strength, led to major changes in sediment supply at short time scales and therefore affected the course of the Sutlej River system.



Wed: 93
Topics: 3.25 The links between deep-seated mechanisms, surface processes and landscape evolution

Does the Middle Miocene rise of the Greater Himalaya cause the slow down of Southern Tibet exhumation?

Rasmus C. Thiede1, Dirk Scherler2,3, Chistoph Glotzbach4

1Institut für Geowissenschaften, Christian Albrecht Universität zu Kiel, Germany; 2Institut für Geographische Wissenschaften, Freie Universität Berlin, Germany; 3Helmholtz Zentrum Potsdam, Deutsches GeoForschungs Zentrum GFZ, Germany; 4Institut für Geowissenschaften, Universität Tübingen, Germany

The Himalaya is the highest and steepest mountain range on Earth and forms today efficient north-south barrier for moisture-bearing winds. 1D-thermokinematic modeling of new zircon (U-Th)/He bedrock-cooling ages and >100 previously published mica 40Ar/39Ar, zircon and apatite fission track ages from the Sutlej Valley document a consistent rapid decrease in exhumation rates that initiated at ~17-15 Ma across the entire Greater and Tethyan Himalaya and the north-Himalayan Leo Pargil dome. We observe a rapid decrease from >1 km/Myr to <0.5 km/Myr. We explain the middle Miocene deceleration of exhumation with major tectonic reorganization of the Himalayan orogen, probably coincident with the onset of basal accretion, which resulted in accelerated uplift of the Greater and Tethyan Himalaya. The period of slow exhumation in the upper Sutlej Valley coincides with a period of internal drainage in the south-Tibetan Zada Basin farther upstream, which we interpret to be a consequence of tectonic damming. Comparison with other data from the Himalaya and Southern Tibet along strike suggests that by ~15 Ma, southern Tibet was high, located in the rain shadow of the High Himalaya and eroding slowly for at least 10 Ma, before erosion accelerated again by ~5-3 Ma, most likely due to climatic changes. Our new finding document that the location of tectonic deformation processes controls the first order spatial pattern of both climatic zones and erosion across the orogen. Therefore, we think that the rise of Greater Himalaya is linked to the deceleration of exhumation in Southern Tibet.



Wed: 94
Topics: 3.25 The links between deep-seated mechanisms, surface processes and landscape evolution

Links between Island morphology and endemism

Anaé Lemaire1,2, Jean Braun1,3, Esteban Acevedo-Trejos1

1Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Potsdam, Germany; 2Institut Polytechnique UniLaSalle, Beauvais, France; 3Institute of Earth and Environmental Sciences, University of Potsdam, Potsdam, Germany

Most islands host an endemic biota, i.e., present nowhere else on Earth. This is the case, for instance, of Madagascar. It has been shown that different populations of lemurs, endemic to the island, are mostly distributed along the watersheds surrounding Madagascar, creating a so-called micro-endemism, while the populations living on the high-elevated watersheds, on the central plateau, are not showing this micro-endemism. Here we wish to address the question whether there exists a correlation between the evolution of the landforms (i.e., the geometry of the watersheds) of Madagascar and the hybrid evolution of lemur populations? More broadly, can the tectono-geomorphic evolution of an island be advantageous or disadvantageous to the flourishing of micro-biodiversity?

To answer these questions in a quantitative manner, we combined a Landscape Evolution Model based on the Stream Power Law and taking into account flexural isostasy, with a speciation model. We first developed a morphometric index to differentiate between islands with a central plateau surrounded by smaller basins, like Madagascar, from conical islands, like Sri Lanka. We then predicted patterns of biodiversity as a function of the index value and its time evolution. We show that for the tectono-geomorphic evolution to influence patterns of biodiversity requires a specific range of model parameter values, in particular the parameters characterising dispersal and mutation. We finally used phylogenetic observations to constrain some of these parameters.



Wed: 95
Topics: 3.25 The links between deep-seated mechanisms, surface processes and landscape evolution

Morphological dating of fluvial terraces using high resolution GNSS profiles and satellite derived DEMs with application to Patagonia, Argentina

Lennart Grimm1,2, Victoria M. Fernandes1, Fergus McNab1, Taylor Schildgen1,2

1Section 4.6 Geomorphology, GFZ Potsdam, Germany; 2Institute of Geosciences, University of Potsdam, Germany

Changing climatic conditions cause alluvial rivers to aggrade and incise, which can result in the formation of multi-generational fluvial terrace sequences. Such records can be used to investigate past interactions between climatic conditions and the fluvial system and to predict channel responses to future climatic change. To accurately assess such interactions, precise dating of terrace sequences is vital. However, established methods such as 10Be exposure dating are costly and time intensive. Thus, they are impractical for application to spatially extensive areas and for establishing patterns of along-stream aggradation or incision.

An alternative approach of dating fluvial terraces is based on the degradation of the slope (riser) between successive terraces by down-slope sediment transport. Here we present a tool for analyzing high-resolution elevation profiles across alluvial terrace risers and inferring their age since abandonment, based on linear and nonlinear hillslope diffusion models. We extend this workflow to the analysis of DEM-derived riser profiles that can provide a greater spatial extent and resolution than GNSS profiles or exposure ages. A set of 10Be exposure ages dating back to ca. 1 Myr from terraces around the Río Santa Cruz, Patagonia is used for calibration and to test the method’s viability. Preliminary results highlight the importance of post-abandonment riser disturbances and variability in hillslope sediment-transport rates.

This technique provides a low-cost, spatially extendable way of dating fluvial terraces and analyzing landscape dynamics in fluvial systems. We are currently preparing to release an open-source Python package for performing these analyses.



Wed: 96
Topics: 3.25 The links between deep-seated mechanisms, surface processes and landscape evolution

On the impact of the bedrock erodibility on the depositional response time to a slab break-off using stratigraphic forward modelling

Paul Baville1, Andrea Piccolo2, Marcel Thielmann2, Nevena Andrić-Tomašević1

1Karlsruhe Institute of Technology (AGW), 76131 Karlsruhe, Germany; 2Bayerisches Geoinstitut, University Bayreuth, 95440 Bayreuth, Germany

Slab break-off is a geodynamic process in which the lower portion of a subducting plate detaches from its uppermost one. This process changes the force balance acting on the lithosphere causing tectonic uplift that can affect the sedimentary basin architecture by reducing the accommodation space and increasing the sediment supply due to source rejuvenation. While sediment supply intensity is commonly attributed to tectonic and/or climatic factors, recent studies have highlighted that the erodibility of the source area can have a significant effect on the timing of these signals.
To investigate this hypothesis, we modify the stratigraphic forward modeling software GPM (Geological Process Modeling software provided and produced by SLB), to consider the impact of topography-dependent steady flow. The simulation involved clastic deposition in a deltaic environment and included variations in source area erodibility, sea level changes, tectonic rates, and variable water discharge. Simulations were conducted with increasing complexity to quantify the sensitivity of catchment scale depositional rates to the aforementioned changes.



Wed: 97
Topics: 3.25 The links between deep-seated mechanisms, surface processes and landscape evolution

Pleistocene landscape evolution of Southern Patagonia: Insights from 10Be Dating of Fluvial Terraces

Victoria Milanez Fernandes, Taylor Schildgen, Andreas Ruby, Hella Wittmann, Fergus McNab

GFZ Potsdam, Germany

Southern Patagonia hosts uniquely well-preserved fluvial cut-and-fill terraces, formed along rivers fed by glacial meltwater, recording the onset of a regional phase of net incision. However, the timing and driving mechanism of incision remain debated. Published thermochronometric dating and modelling suggest increased exhumation in the last 1–3 Myr. Radiometrically dated basalt flows establish the existence of a eastward-draining paleo-valley with flows going existing terraces by 3.2 Ma. To better constrain the timing of Pleistocene river incision and landscape evolution in southern Patagonia, we present new cosmogenic 10Be exposure ages of terraces near Tres Lagos and the upstream reaches of the Río Santa Cruz (50ºS). Preliminary terrace surface exposure ages at Tres Lagos are between 70 ka–1.02 Ma, whereas upstream Río Santa Cruz terraces are between 390 ka and 1.04 Ma. The terrace age sequence shows that a phase of net incision started ~1 Myr after the widespread emplacement of basalts, concomitant with enhanced climatic forcing following the Mid-Pleistocene Transition. Our new exposure ages are in agreement with dated fluvial terraces of other Patagonian rivers, where ages range from 400 ka–1 Ma (47ºS; Tobal et al., 2021). Moreover, our record of Pleistocene landscape evolution is similar to other records throughout the Andes, where the timing of fluvial incision has been linked to enhanced climatic forcing after ~1 Ma. Our results point to a strong influence of the Mid-Pleistocene Transition on landscape evolution at a continental scale, notably including southernmost South America.



Wed: 98
Topics: 3.25 The links between deep-seated mechanisms, surface processes and landscape evolution

Quantification of plutonium in environmental samples at the University of Cologne, Germany: progress update

Joel Mohren1, Steven A. Binnie1, Erik Strub2, Stefan Heinze3, Tibor J. Dunai1

1Insitute of Geology and Mineralogy, University of Cologne, Germany; 2Division of Nuclear Chemistry, University of Cologne, Germany; 3CologneAMS, Institute of Nuclear Physics, University of Cologne, Germany

The measurement of 239,240Pu in environmental samples can play a key role in investigating Anthropocene Earth (sub-)surface processes. As a consequence of atmospheric nuclear weapon tests conducted in the 1950s and 1960s, Earth’s outermost skin was supplied with fallout radionuclides (FRNs), providing distinct geochronological markers. The application of FRNs is well established, with 137Cs being most commonly measured. However, 239+240Pu activities are more decay-insensitive (t1/2 239Pu: ~24.1 ka; 240Pu: ~6.6 ka), there is less soil inventory contamination arising from nuclear power plant accidents than reported for 137Cs, and only a few grams of sample material can be sufficient for a measurement. Ultimately, the (separate) quantification of 239,240Pu inventories measured by Accelerator Mass Spectrometry (AMS) represents a further evolution step towards more precise measurements than achieved by other mass spectrometry or decay counting techniques.

The development of 239,240Pu measurement capabilities at the Centre for Accelerator Mass Spectrometry (CologneAMS), University of Cologne (UoC), has given the go-ahead to exploit the wealth of possible 239+240Pu applications to decipher modern Earth (sub-)surface processes in different settings. Based on tailored sample processing protocols applied at the Institute of Geology and Mineralogy and the Division of Nuclear Chemistry (both UoC), we present first results from a selection of ongoing projects. The sample processing workflow applied together with the AMS measurement precision achieved allows for resolving specific activities below ~5 mBq kg-1. Accordingly, a spatial focus is laid on study sites where ultra-high precision of measurements is required (e.g., the Atacama Desert in northern Chile).

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Wed: 100
Topics: 3.29 Latest achievements in scientific drilling and ocean-continental feedbacks

Decoupled radiogenic Nd and Hf isotopes of clays reveal South Asian Monsoon control of silicate weathering intensity

Ed Hathorne1, Rasmus Thiede2, Anja Conventz2, Ralph Schneider2, Martin Frank1

1GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany; 2University of Kiel, Germany

The weathering of silicate rocks removes CO2 from the atmosphere-ocean system on geological timescales but the time required for weathering intensity to respond to changes in climate is poorly constrained. The radiogenic isotopes of hafnium and neodymium are decoupled during silicate weathering with the isotopic composition of river clays being offset from bulk rocks. Here we examine the decoupled Nd-Hf isotopes of clays deposited in marine sediments from the northern Bay of Bengal near the mouth of the Ganga-Brahmaputra rivers. The sediment core (SO188 17286-1) covers the last 130 kyrs and has been used to study the past intensity of the South Asian Monsoon (SAM). The deviation of the Hf isotope compositions from the array defined by global river clays (ΔεHf clay), has a pattern of variability similar to the record of SAM intensity inferred from the reconstructed δ18O of seawater and δD of leaf waxes. These variations in silicate weathering intensity occur on timescales near 20 kyrs and appear to be paced by orbital precession. This suggests a strong, and rapid (on geological timescales), link between SAM hydroclimate and silicate weathering in this region. In contrast, changes in the source provenance of the clays as recorded by their Nd isotope signatures follow a glacial-interglacial pattern indicating either a sea level or global climate influence on changes in sediment transport to the shelf. This contrast demonstrates the great utility of ΔεHf clay to record changes in weathering intensity while directly accounting for shifts in sediment source provenance.



Wed: 101
Topics: 3.29 Latest achievements in scientific drilling and ocean-continental feedbacks

1 Ma of water mass provenance in the South Atlantic Ocean revealed by authigenic neodymium isotopes in ODP 1093

Eva Marcella Rückert1, Moritz Hallmaier2, Norbert Frank1

1Institute of Environmental Physics, Heidelberg University; 2GEOMAR, Kiel

The deep Southern Ocean (SO) circulation is of major significance for understanding of the ocean´s impact on Earth’s climate as uptake and release of CO­­­2 strongly depend on the redistribution of differently ventilated water masses.

Here, we present new authigenic neodymium isotope data (εNd) of the deep-sea sediment ODP1093 in the Southern Atlantic that reveals several systematic temporal glacial-interglacial changes in a range of 6.3 e-units. Assuming Nd-isotopes as mostly conservative tracer and neglecting possible reginal influences, the observed radiogenic εNd values of up to -2.5 during peak glacial periods suggest a predominance of glacial PDW at depths of >3 km. This results in a volume increase of carbon-rich water, aiding in atmospheric CO2 drawdown during glacials.

The ability of εNd to trace water mass changes relies on the sensitivity of water masses to conservative Nd-isotope mixing. The εNd gradient ΔεNd is here defined as the North-South difference in εNd/10° latitude and is a measure for the sensitivity to changes in εNd signature over a given distance. Compared to further existing εNd records across the Atlantic Ocean the calculated mean εNd gradient for the Atlantic Ocean is approximately 0.89 ε-units/10° latitude and the εNd values of ODP1093 are constantly the most radiogenic. This suggests, that changes in ocean circulation during glacial-interglacial transitions are not purely induced by the Northern Hemisphere deep convection and southward flow but rather strongly influenced by equally strong changes of the SO circulation. This reinforces the importance of the SO in past and future climate changes.



Wed: 102
Topics: 3.29 Latest achievements in scientific drilling and ocean-continental feedbacks

Factors influencing the long-term interseismic behavior of the Main Marmara Fault, NW Turkey: a data-driven modelling approach

Naiara Fernandez1, Mauro Cacace1, Magdalena Scheck-Wenderoth1,2, Oliver Heidbach1

1GFZ - German Research Center for Geosciences, Potsdam, Germany; 2RWTH Aachen University, Aachen, Germany

In this contribution, we discuss our latest results from the project “Deformation Mechanisms along the Main Marmara Fault (DEMMAF)”, funded by the ICDP priority program of the German Science Foundation. The Main Marmara Fault (MMF), is the northern branch of the North Anatolian Fault along the Marmara Sea (NW Turkey). The MMF has produced several major earthquakes (M7+) in the past with a recurrence of about 250 years, and has not ruptured since 1766. The goal of the DEMMAF project is to investigate what controls the deformation mechanisms along the MMF, using data collected at the ICDP GONAF observatory (Geophysical Observatory at the North Anatolian Fault) and a combined work flow of data integration and process modelling approach.

Here, we use a forward numerical approach that implements frictional faults and visco-elastic off-fault materials to investigate the space- and time-scales of the long-term seismic behavior of the Main Marmara Faults and its main controlling factors. The MMF is modelled following a Coulomb frictional constitutive law and the spatially variable off-fault rock properties are derived from a data-integrative lithospheric-scale 3D structural model of the region around the MMF. The forward model is used to test the effect of varying boundary conditions (i.e. kinematic) and fault strength properties (i.e. coefficient of friction). Our modelling approach highlights the first order role of crustal rheology and fault-strength in the long-term behavior of the MMF (spatial distribution and recurrence of seismic events), as well as their potential to explain the along fault locking degree variability.



Wed: 103
Topics: 3.29 Latest achievements in scientific drilling and ocean-continental feedbacks

Triaxial experiments on marine sediments from the Middle America Trench of Costa Rica (IODP Expeditions 334 & 344)

Meggy Jessica Kerzig, Rebecca Kuehn, Michael Stipp

Martin Luther University Halle-Wittenberg, Germany

The erosive convergent plate margin offshore Costa Rica represents a seismic zone that produces high-magnitude earthquakes and tsunamis. The overriding Caribbean Plate is tectonically eroded by the subducting Cocos Plate, resulting in strong and widespread deformation of the upper plate. Differences in composition, compaction or deformation of the clay-rich marine sediments can have a significant impact on the strength of the continental plate, as well as the frictional behavior of the rocks entering the subduction channel.

Core samples from IODP Expeditions 334 and 344 of the Costa Rica Seismogenesis Project (CRISP) recovered from a depth range of 5–125 mbsf were experimentally deformed in triaxial tests under isotropic consolidated and undrained conditions at confining pressures of 400–900 kPa, room temperature, axial displacement rates of 0.0025–0.01 mm/min and up to ~50% axial compressive strain. Deviatoric stresses range between 127 and 418 kPa, pore pressure between 615 and 822 kPa. The samples exhibit internal friction angles of 8-42° and cohesion values of about 29-34 kPa.

The stress-strain records show exclusively structurally weak behavior and a higher consolidation of the upper plate compared to the incoming plate sediments. The sediments from prism toe and middle slope of the Caribbean Plate display systematically higher peak stresses despite a similar overburden. This together with the consolidation state indicate a loss of overburden, for example due to slumping at the continental slope. The mechanical properties might be crucial for fracturing and localized brittle deformation of the continental forearc during tectonic erosion.



Wed: 104
Topics: 3.29 Latest achievements in scientific drilling and ocean-continental feedbacks

A proposal for drilling “Geiseltal” – a near complete terrestrial section of the Eocene in Central Europe

Stefanie Kaboth-Bahr1, Andrè Bahr2, Christian Zeeden3

1Free University Berlin, Germany; 2Heidelberg university, Germany; 3Leibiz Institute for Applied Geophysics, Germany

As the world warms due to rising greenhouse gas concentrations, the Earth system moves toward climate sthistoricalhout historic precedent, challenging societal adaptation. One way to investigate these unprecedented conditions is to study past climates and ecosystems that share similarities to our current and future ones. One such period is the Eocene (~56 – 33 Ma), during which the climate changed from a hot-house to a greenhouse state, comprising a wide range of atmospheric CO2 concentrations. However, our knowledge of the Eocene climate evolution is incomplete because of a lack of terrestrial records covering the entire period. To address this gap in our understanding, we propose to obtain drill cores at Geiseltal in Eastern Germany.

This former lignite quarry is famous for its exceptionally well-preserved Eocene m. Still, itssils, but its potential as a climate archive has not yet been explored due to the lack of existing drill cores. By drilling a maximum of three cores, we aim to create a spliced 100-120 m long record comprising the entire Eocene archived in Geiseltal as an alteration of lignite seems intercalated with fluvial strata. High-resolution, multi-proxy analyses of the obtained sediments will allow the generation of a unique record of (sub)orbital climate variability under various atmospheric greenhouse gas concentrations. To advance this project, we welcome scientific input from a wide range of disciplines (e.g., stratigraphy, sedimentology, paleolimnology, paleobotany, paleontology, and organic/inorganic geochemistry) as well as are actively seeking interested groups and individuals to collaborate with us on this project.



Wed: 105
Topics: 3.29 Latest achievements in scientific drilling and ocean-continental feedbacks

Extending the age model for Lake Bosumtwi (Ghana) for climate- and environmental reconstructions in West Africa during the last million years

Mathias Vinnepand1, Christian Zeeden1, Anders Noren2, Stefanie Kaboth-Bahr3, William Gosling4, Jochem Kück5, Thomas Wonigk1

1LIAG, Leibniz Institute for Applied Geophysics, Germany; 2Continental Scientific Drilling Facility, University of Minnesota, Minneapolis, USA; 3University of Potsdam, Institute for Geosciences, Potsdam-Golm, Germany; 4University of Amsterdam, Netherlands; 5GFZ, Geoforschungszentrum Potsdam, Germany

Lake Bosumtwi, formed after a meteorite impact at ~1.07 Ma, contains a sedimentary archive that yields an excellent high-resolution record of climate- and environmental change in Sub-Saharan West Africa. The region is highly susceptible to climate changes due to shifts of the tropical rain belt and variation in dust dynamics in the tension field between the North African Monsoon (humid, wet) and the Harmattan (dry and dusty winds from the Sahara). Consequently, Lake Bosumtwi has been intensively studied and in 2004, supported by the International Continental Scientific Drilling Program (ICDP), sediment cores were recovered and downhole logs were performed that allow for the analysis of the complete ~300 m lacustrine sequence. However, detailed climatic and environmental reconstructions for the record are incomplete, mostly due to the absence of a robust age model prior to 500 ka. In 2022, we conducted core scanning natural gamma ray measurements for the ~300 m lacustrine sedimentary sequence. Based on the resulting data, we are generating a correlative age model that is tested by cyclostratigraphic tools and that can be directly compared to the available independently dated sections, but extends farther back in time. Our age model will provide critical chronologic context for the numerous existing and new proxy data that facilitate a study of changes in climate, environment, and ecosystems. This will allow a robust framework to analyse climatic interferences with archaeological findings that might shed new light on habitat availability for our ancestors in tropical Western Africa.



Wed: 106
Topics: 3.29 Latest achievements in scientific drilling and ocean-continental feedbacks

Mineral biosignatures record pore water geochemistry during microbial diagenesis - modern Lake Towuti as a ferruginous case study

Aurèle Vuillemin1, André Friese1, Fatima Ruiz Blas1, Alice Paskin2,3, Cynthia Henny4, Marina Morlock5, Hendrik Vogel6, Jens Kallmeyer1

1GFZ German Research Centre for Geosciences, Section 3.7. Geomicrobiology, Potsdam, Germany; 2GFZ German Research Centre for Geosciences, Section 3.5. Interface Geochemistry, Potsdam, Germany; 3Department of Earth Sciences, Free University of Berlin, 12249 Berlin, Germany; 4Research Center for Limnology and Water Resources, National Research and Innovation Agency (BRIN), Bogor, Indonesia; 5Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden; 6Institute of Geological Sciences & Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland

Ferruginous conditions prevailed in the oceans through much of Earth’s history. However, past biogeochemical cycling inferred from mineral components identified in ancient iron formations remain poorly understood in terms of microbial processes prior to lithification. In Lake Towuti, Indonesia, ferruginous sediments sink through a stratified water column and are deposited under anoxic conditions that mimic the Earth’s early oceans, thereby allowing the study of both geochemical conditions in pore waters and long-term diagenetic evolution of its 1 Ma stratigraphic record.

We combined detailed pore water geochemistry and stratigraphic proxies with scanning electron microscopy imaging of authigenic phases. Although variability in elemental profiles attests to climate- and tectonic-driven processes along the 100-m-long sediment sequence, deposition of ferruginous minerals appears transient as particulate iron, reworked from surrounding lateritic soils, undergoes partial dissolution-precipitation during sinking and after burial. Minerals found to form in situ included magnetite (Fe3O4), millerite (NiS), siderite (FeCO3) and vivianite (Fe3[PO4]2 ∙ 8H2O). Acicular millerite aggregates overgrown by siderite and vivianite indicate that they directly precipitated from saturated pore waters (Ostwald ripening). This also suggests that these mineral phases may constitute a diagenetic sequence stemming from the progressive consumption of terminal electron acceptors with sediment organic matter remineralization during shallow burial. Thus, we consider that these minerals act as biosignatures of redox processes driven by autochthonous sedimentary microbial populations that actively control pore water geochemistry after deposition, thereby differentially imprinting the stratigraphy of bulk sediment during burial.



Wed: 107
Topics: 4.03 Open Science and Data – challenges, opportunities and best practices

Accessibility of Geodynamic Models – Teaching Materials Developed Alongside the Open Source Software CHIC

Oliver Henke-Seemann, Theresa Büttner, Lena Noack

Freie Universität Berlin, Germany

To investigate the interior structure, dynamics and evolution of terrestrial planets, numerical models of varying complexity have become an essential tool for many researchers. Modelers often struggle with outreach and accessibility, especially when the demographic includes students and scientists who are less versed in programming and modeling. To provide easily available teaching material, we have compiled a collection of several codes developed at our institution.

Firstly, we present an updated Version of the code CHIC, which is a collection of applications, spanning 1D parameterized interior structure and thermal-evolution models to 3D thermo-chemical convection models. The code will now be published under an open-source software license. The release will include an updated documentation of the code. Once released, we plan to update the codebases, if sufficiently impactful changes have been implemented.

Furthermore, we will release multiple Python codes, mainly as teaching material. These will include models of:

- Tidal heat dissipation, for variable planetary systems.

- Interior structure in 1D, based on the planet’s properties.

- Thermal evolution in 1D, based on interior structure and tectonic regime.

- Simplified 2D thermal convection with temperature- and pressure-dependent viscosity.

Instructions on installation, application and evaluation, are presented in short tutorials. We also provide several educational examples and showcases of common benchmarks. The goal is to create a framework for our institute to publish software related to modeling of planetary interiors. The demographic includes students, teachers and scientists, as the codes range from educational material to advanced scientific models.



Wed: 108
Topics: 4.03 Open Science and Data – challenges, opportunities and best practices

Global Findability of FAIR Research Datasets

Elfrun Lehmann, Harry Becker, Tatjana Fritz, Florian Wille, Andreas Sabisch, Denise Siever, Birgit Schlegel

Freie Universität Berlin, Germany

Currently, no search engine is available for specific and easy searches of published research datasets stored in institutional repositories. Most commonly, primary research data in institutional repositories are accessed via its Digital Object Identifier (DOI), which must be known.

The global findability of research data can be increased by mapping its metadata to a search tool that allows finding and accessing information from a single search point. For this purpose, we mapped the TRR170-DB planetary data repository (https://planetary-data-portal.org/) with its XML metadata to the search engine PRIMO via the OAI-PMH method. PRIMO is the central search interface of Freie Universität Berlin for searching and accessing local and external resources. Metadata mapped to PRIMO can be found by global search engines such as Google.

Data in the TRR170-DB repository reflect the different methods and approaches applied to investigate planet formation in the collaborative research center ‘Late Accretion onto Terrestrial Planets’ (TRR 170). Datasets are stored in open electronic formats such as csv (tables), pdf (text), and jpeg and tiff (images). Once a dataset is published, the repository guarantees archival and long-term access to the dataset with a DOI persistent identifier. At present, most datasets are in the public domain and represent replication data of peer-reviewed articles which appeared in international journals since 2016. PRIMO’s harvesting of TRR170-DB metadata ensures that the datasets remain easily accessible to the global community in the long term while providing a setting that amplifies the use of best practices and collaborative and interdisciplinary research.



Wed: 109
Topics: 4.03 Open Science and Data – challenges, opportunities and best practices

The Transparent Virtual Round Table Of The Helmholtz Metadata Collaboration (HMC) Earth and Environment Hub

Andrea Pörsch1, Emanuel Söding2

1Helmholtz Metadata Collaboration (HMC) at GFZ German Research Centre for Geosciences, Potsdam, Germany; 2Helmholtz Metadata Collaboration (HMC) at GEOMAR Helmholtz Zentrum für Ozeanforschung, Kiel, Germany

The mission of the Helmholtz Metadata Collaboration (HMC, https://helmholtz-metadaten.de/en) is to facilitate the discovery, access, machine readability, and reuse of research data of the Helmholtz Association. Concepts and services are developed and established, allowing the enrichment of research data with standardized metadata in the various phases of their creation. The aim of HMC is to co-ordinate these services with the national and international scientific community in order to establish widely accepted practices in the handling of research data.

In the Earth and Environment Hub, we are in the process of setting up a transparent virtual round table where all communities can come together to decide which guidelines are recommended for the Helmholtz Association. Jointly agreed principles are discussed and agreed in a moderated co-design process.

Primary stakeholder profile

  • Infrastructures – leadership, technical personnel organising, standardising, and sharing their (meta)data
  • Data stewardship teams - these include personnel working for infrastructures, libraries, or thematic (meta)data management solutions/services
  • Personnel in research groups working to standardise and curate (meta)data

In this presentation we will introduce to the current HMC activities and outcome: Our process for developing a guideline is planned as a coordinated procedure. For every single implementation guide, we go through the same questions, up to tests - based on use cases and definition of abstract test classes, in order to be able to validate the implementation. Our planned results are recommendations and detailed implementation instructions that enable interoperability - not only in the Helmholtz Association, but also in national and international communities.



Wed: 110
Topics: 4.07 Data-driven digital twins of the subsurface and their applications

Thermal and gravity field implications of converting a mantle shear-wave velocity tomography of the South China Sea region to temperature and density

Yan Li1,2, Judith Bott1, Scheck-Wenderoth Magdalena1, Pingchuan Tan3, Shaowen Liu2

1GFZ German Research Centre for Geosciences, Germany; 2Nanjing University, China; 3Second Institute of Oceanography, Ministry of Natural Resources, China

The seismic wave velocity configuration of the mantle provides constraints on its thermal and hence density structure, although the proposed methods of wave velocity conversion differ significantly. The V2RhoT_gibbs is a Python tool that allows converting mantle seismic velocities to temperature and density using a Gibbs free energy minimization algorithm applied to a defined mantle chemical composition to guarantee thermodynamic stability of the correspondingpressure (P) and temperature (T) dependent phase and mineral assemblages. Alternative methods, in contrast, start the conversion process with a pre-defined, P and T independent mineralogical composition, while yet other conversion methods involve a set of empirical equations. To better understand the differences between these conversion approaches, we have applied different methods to a shear-wave velocity tomographic model of the mantle below the South China Sea region. The resulting thermal fields are compared regarding the depth of the 1300 °C-isotherm which is a proxy of the lithosphere-asthenosphere boundary. In addition, we present the conversion results in terms of their respective gravity responses. This sensitivity analysis has important implications for better understanding the thermomechanical state of the lithosphere in the region.



Wed: 111
Topics: 4.07 Data-driven digital twins of the subsurface and their applications

Deep thermal fingerprints of different tectonic environments in continental areas from data-integrated process models

Magdalena Scheck-Wenderoth1,2, Ajay Kumar1, Mauro Cacace1, Judith Bott1, Denis Anikiev1

1GFZ German Research Centre for Geosciences, Potsdam Germany; 2Faculty of Georesources and Materials Engineering, RWTH Aachen University, Aachen, Germany

The deep thermal field in the continental lithosphere varies significantly depending on the age of the lithosphere, its tectonic setting and the time since the last tectonic event. Accordingly, orogens with a thickened radiogenic crust will be hotter in their crust than cratonic areas that had billions of years time to equilibrate after the last tectonic event. Areas affected by continental rifting and passive margins also may be characterized by specific lithospheric configurations and a distinct geothermal fingerprint. Using data-integrated models of different continental areas we evaluate the first-order controlling factors of the related threedimensional temperature distributions. We find that the resolution of subsurface heterogeneities and the consideration of the appropriate heat transport mechanisms are key in predicting the characteristics of the deep thermal field. Accordingly, the superposed effects of varying thermal conductivities, contributions of radiogenic heat and variations of the thermal lithosphere thickness together result in setting-specific background 3D thermal fields. These effects are superposed by the effects of coupled fluid and heat transport in the the upper few km of the crust. Knowing the first-order characteristics of the local thermal fingerprint is key for geothermal exploration but also for estimating the expected mechanical thickness as well as the nature and magnitude of seismicity.



Wed: 112
Topics: 4.07 Data-driven digital twins of the subsurface and their applications

A 3D gravity-consistent model of the southern San Andreas Fault system

Angela Maria Gomez Garcia1, Ivone Jiménez-Munt1, Bart Root2, Magdalena Scheck-Wenderoth3

1Geosciences Barcelona (GEO3BCN), CSIC, Lluís Solé i Sabarís s/n. 08028, Barcelona, Spain; 2Delft University of Technology, Department of Space Engineering, Delft, the Netherlands; 3GFZ German Research Centre for Geosciences. Telegrafenberg, 14473, Potsdam, Germany.

Earthquakes are a direct response to the Earth’s state of stress, which is one of the key ingredients controlling the lithosphere rheological behavior. To first order, the total in-situ stress is a function of two main co-players: the long-term tectonic stress, and the short-term (seismic cycle) stress transfer. Despite their diversity in temporal and spatial scales, these components are not mutually independent, but they do interact in the final rheological configuration of the lithosphere

Understanding the relative importance of different tectonic loads and how the stress is transferred is of high relevance for robust earthquake simulators. As the stress transferred to a fault affects its mechanical behavior, it has a direct control on its potential to generate earthquakes.

Recent studies suggest that the regional tectonic environment surrounding the faults (e.g., off-fault lithology, lithospheric structure, and degree of coupling between crustal and mantle domains) can influence fault behavior. However, the importance of such heterogeneities in modulating background seismicity needs to be properly evaluated to unveil the behavior of these complex systems.

3D data-integrative and gravity-consistent models are useful tools for characterizing such lithospheric-scale heterogeneities, and ultimately, to analyze their potential relationship with background seismicity. In this contribution, we present the preliminary results of a 3D lithospheric model of the southern San Andreas Fault system, where the wealth of available data was considered. We demonstrate that this is an important step towards the calculation of the background off fault stresses due to local loadings, which likely influence background seismicity.



Wed: 113
Topics: 4.07 Data-driven digital twins of the subsurface and their applications

V2RhoT_gibbs: a tool for conversion of seismic velocity to temperature and density in a self-consistent thermodynamic manner

Ajay Kumar1, Judith Bott1, Magdalena Scheck-Wenderoth1,2

1GFZ German Research Centre for Geosciences, Potsdam Germany; 2Faculty of Georesources and Materials Engineering, RWTH Aachen University, Aachen, Germany

Seismic tomography provides important data to understand the physical properties (temperature, density) of the lithosphere and upper mantle. These physical properties are crucial for understanding e.g., strain localization, geothermal potential. However, interpreting tomography models in terms of composition and temperature conditions is highly complex and non-unique. There are mainly two approaches to interpreting seismic tomography models: empirical and thermodynamics-based. In the empirical approach, the tomography models are calibrated with respect to known temperature distributions, such as those derived from age-dependent oceanic lithospheric thickness or heat flow models or temperatures derived from mantle xenoliths in the continental regions. In contrast, the thermodynamics-based approach involves taking into account the composition of the minerals or deriving it from bulk-rock chemical composition using Gibbs-free energy minimization. Recently, a new approach has emerged that combines the second approach with geophysical (potential fields, topography) and seismological data (surface wave dispersion curves). However, this method assumes a steady-state temperature distribution, limiting its ability to infer the second-order temperature and density distribution. To address these challenges, a new thermodynamics-based conversion tool called V2RhoT_gibbs has been developed. This tool is based on open-source Python libraries and coupled with the Gibbs-free energy minimization algorithm Perple_X. It does not assume any thermal state and, using bulk-average chemical composition, derives the temperature and density distribution. Output from this tool could be easily used to incorporate e.g., as voxel in gravity field interpretations, or as lower temperature boundary condition to compute the thermal field.



Wed: 114
Topics: 4.11 Geo-scientific methods in Archaeology, Archaeometry and Experimental Archaeology

Erosion rate response to mining and deforestation, Elba Island

Nathalia Cerón Espejo1, Anne Bernhardt1, Dirk Scherler2,3, Alexander Rohrmann1, Wiebke Bebermeier2, Fabian Becker2, Hella Wittmann3, Tibor Dunai4

1Institut für Geologische Wissenschaften, Freie Universität Berlin, Germany; 2Institut für Geographische Wissenschaften, Freie Universität Berlin, Germany; 3German Research Centre for Geosciences GFZ, Potsdam, Germany; 4Institut für Geologie und Mineralogie, Universität zu Köln Cologne, Germany

Throughout history, humans have modified the landscape by farming, extracting natural resources, and deforestation. However, it is not fully understood to what extent such activities have changed vegetation structures and potentially caused accelerated soil erosion. In this study, we investigate the effects of human activities on vegetation and erosion rate changes on the island of Elba, Italy. Previous geoarchaeological studies succeeded in reconstructing human-environmental interaction in the past and providing an independent reference frame for the current study. Hence, we hypothesize that intense iron production on Elba since the 6th century BCE, first by Etruscans, and later by Romans, was accompanied by deforestation and thereby caused increased soil erosion. To test our hypothesis, we collected sediment samples from modern streams and from existing floodplain sediment cores to reconstruct the millennial-scale and more recent changes in landscape-scale erosion rates, and in vegetation and hydrology by means of leaf wax isotopes (d2H, d13C). We use in situ cosmogenic 10Be and 14C produced in quartz to obtain erosion rates. The different half-life of these two nuclides (~1.4 Myr for 10Be and ~5.7 kyr for 14C) makes them sensitive to changes in erosion rates that occur on human time scales. 10Be results indicate relatively uniform millennial-scale erosion rates on the order of 0.04 mm/yr across the eastern part of the island, where we collected most of the samples. We expect that the combination of these methods will reveal the impact and patterns of human-induced soil erosion in Elba.



Wed: 115
Topics: 4.11 Geo-scientific methods in Archaeology, Archaeometry and Experimental Archaeology

Geoscientific Approach to Diagnosis of Weathering Damage on Prehispanic Sandstone Monument Piedra Pintada de Aipe, Colombia

Ali Duran Öcal1, Thomas Cramer1, Mehmet Zeki Billor2

1Universidad Nacional de Colombia, Bogota, Colombia; 2Auburn University, Auburn, USA

Rock art is a common cultural manifestation throughout Colombia. Here the Painted Stone of Aipe represents a striking archaeological evidence as an outstanding masterpiece of pre-Hispanic rock art. Several pectorals of different shapes are observed as a central motif used by the pre-Hispanic communities of Quimbaya, Tairona and the southern tribes. In addition to the pectorals, the stylized devil or monkey is seen in various combinations along with nose rings, fishhooks, bead necklaces, pendants, and rattles, among others. The substrate of the Aipe Painted Stone is a yellowish sandstone of oval shape and the low-relieve carvings are mainly on the longer SE-side of the stone block. This study aims to assess the different decay phenomena affecting the ~500-year old pre-Hispanic rock art carved on the sandstone block which is at an altitude of 370m on a main road near the Magdalena River. The artwork has important conservation problems mainly due to weathering creating a complex set of mechanical, chemical and biological processes on the rock. In the sandstone, the ~0,1 mm quartz-grains (45%) and foraminifers (15%) are mainly cemented by cryptocrystalline SiO2; also phases like phosphates, clays, micas, opaques and a high open porosity of 15 % occur, enhancing chemical dissolution and precipitation of Fe-oxides. Among the main identified deterioration agents are water flows and humidity changes, solar radiation, abrasion caused by dust and sand carried by the often strong wind, internal pressure variations due to temperature variations and salt migration, plants and microorganisms, but also anthropic interventions.



Wed: 116
Topics: 3.10 Constraining the rate of change in the Earth System through integrated stratigraphic approaches

Astronomical calibration of the Early Jurassic Sinemurian Stage based on cyclostratigraphic studies of downhole logging data of the Prees-2 borehole, England (ICDP JET Project)

Katharina Leu1, Christian Zeeden1, Arne Ulfers2, Micha Ruhl3, Stephen Peter Hesselbo4, Thomas Wonik1

1Leibniz Institute for Applied Geophysics, Germany; 2Federal Institute for Geosciences and Natural Resources, Germany; 3Trinity College Dublin, Ireland; 4University of Exeter, United Kngdom

In late 2020, an approximately 650 m long core was drilled at Prees within the Cheshire Basin, England, as part of the ICDP project JET (Integrated Understanding of the Early Jurassic Earth System and Timescale). The main objective of this project is to obtain a complete and continuous sedimentary archive of the Early Jurassic. The Early Jurassic (~200-175 million years) was a period of extreme environmental changes, which will serve as an analogue for present and future environmental change. The project aims to provide a reference record for an integrated stratigraphy (bio-, cyclo-, chemo- and magnetostratigraphy) of this period.

Analysis of geophysical borehole logs will allow the description of sedimentary cycles related to orbital parameters and paleoclimatic history if depositional environment and sedimentation rate permits. Here, downhole logging data from the Prees-2 borehole are used to construct a floating astronomical timescale for the Sinemurian stage, contributing to an integrated timescale for the Early Jurassic. Cyclostratigraphic methods, including a statistical and a visual approach, lead to preliminary durations for the Sinemurian stage of ~6.2 and 6.8 million years, respectively.



Wed: 117
Topics: 3.10 Constraining the rate of change in the Earth System through integrated stratigraphic approaches

Exploring the Plio/Pleistocene stratigraphy of a core from Riedstadt/Hesse (Upper Rhine Graben)

Christian Zeeden1, Stephanie Scheidt2, Stefanie Kaboth-Bahr3, Christian Hoselmann4

1LIAG - Leibniz Institute for Applied Geophysics, Hannover, Germany; 2Institute of Geology and Mineralogy, University of Cologne, Cologne, Germany; 3Institute of Geological Sciences, Freie Universität Berlin , Berlin, Germany; 4Hessisches Landesamt für Naturschutz, Umwelt und Geologie, Wiesbaden, Germany

The last of a total of three main subsidence episodes of the northern Upper Rhine Graben took place during the Pliocene to Quaternary and allowed the accumulation of thick sedimentary sequences that can function as excellent data source for paleoclimate reconstructions. A 323 m long sediment core drilled in 2020-2021 near Riedstadt-Erfelden (~14 km WSW of Darmstadt) is therefore likely a high-resolution geoarchive documenting climate dynamics during the Plio-Pleistocene epochs. However, so far, the chronostratigraphic framework is based only on lithostratigraphic assignments. This study presents inclination values and magnetic susceptibility obtained from whole-core measurements and discusses initial stratigraphic ideas based on the resulting preliminary magnetic polarity stratigraphy and cyclostratigraphic assessments of the ‘Riedstadt-Erfelden’ core. Our results will be used to study the completeness of the geological record and will enable comparisons to be made with the cores investigated through the Heidelberg Drilling Project. Our aim is to verify the suitability and significance of the ‘Riedstadt-Erfelden’ core as geoarchive for Plio-Pleistocene climate dynamics in Central Europe.

 
7:00pmConference Dinner at Luise