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: Tuesday, 05/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 Constanze Veeh "The EU Critical Raw Materials Act - the vital role of research and knowledge in policy making"
Location: Audimax
Session Chair: Christoph Hilgers, Karlsruhe Institut Für Technologie - Kit
 
Topics: Plenary Talk

The EU Critical Raw Materials Act - the vital role of research and knowledge in policy making

Constanze Veeh

European Commission, Belgium

In March 2023, the EU Commission proposed a Critical Raw Materials Act. The Act puts a legislative framework in place that addresses security of raw materials supply and provides stability for actors in this field. Its foundation is extensive intelligence gathering and research, allowing for the development of sound a mid- to long-term strategy. This talk will highlight both the provisions of the act as well as the knowledge that underpins them.

 
9:20am - 9:40amAwards: Prof. Dr. Ralf Littke, RWTH Aachen – Gustav-Steinmann-Medaille I Dr. Frank Junge, Taucha – Serge-von-Bubnoff-Medaille | Prof. Dr. Nicole Richter, RWTH Aachen – Distinguished Lecturer 2024
Location: Audimax
9:40am - 10:00amCoffee Break
Location: Foyer (Henry Ford Building)
10:00am - 11:15am3.28-1 Developments and progress in regional geology
Location: Hall A (HFB)
Session Chair: Guido Meinhold, TU Bergakademie Freiberg
 
10:00am - 10:30am
Invited Session Keynote
Topics: 3.28 Developments and progress in regional geology

Shaping the northern Gondwana margin before the Variscan orogeny: large-scale geodynamic processes and paleogeography

Jiří Žák

Institute of Geology and Paleontology, Faculty of Science, Charles University, Czech Republic

The Cadomian accretionary orogeny at the end of Neproterozoic to early Cambrian was one of the principal crustal growth events in Europe, as indicated by a number and widespread distribution of Cadomian basement units within the Variscan and Alpine orogenic belts. Although the evolution of the Avalonian–Cadomian active-margin of northern Gondwana has been well established, geodynamic causes of its collapse and processes of its transition to a passive margin are significantly less understood. The particularly intriguing issues, which have a significant impact on interpretations of paleogeography and course of the subsequent Variscan orogeny, include: (1) how and when the Cadomian orogeny ended, (2) what was the provenance of the Avalonian, Cadomian, and other terranes, i.e., where they started their journey from Gondwana to Pangea, (3) how was the Cambro–Ordovician rifting phase expressed along the former active margin and what was its exact timing, duration, style, and magnitude, and (4) how far east reached the Rheic Ocean rift system and what was the nature of its eastern termination. Integrated geochronological and tectonic information suggest that (i) the active-to-passive-margin transition was step-wise, protracted over Cambrian and early Ordovician, (ii) strongly controlled by tectonic inheritance whereby an inherited suture in the Avalonian ribbon terrane facilitated complete rifting and rift–drift transition while the Cadomian terranes remained attached to Gondwana, and (iii) magmatism may have been an important geodynamic driver of rifting during at least the initial stages, before being overridden by the slab pull force of the subducting Iapetus Ocean.



10:30am - 10:45am
Topics: 3.28 Developments and progress in regional geology

The Harz Mountains (Germany) – Cadomia meets Avalonia and Baltica: U-Pb ages of detrital and magmatic zircon as a key for the decoding of Pangea´s central suture

Ulf Linnemann1, Maren Zweig2, Mandy Zieger-Hofmann1, Tim Vietor3, Johannes Zieger1, Jessica Gärtner1, Andreas Gärtner1, Katja Mende1, Rita Krause1, Friedhart Knolle4

1Senckenberg Naturhistorische Sammlungen Dresden, Germany; 2Sächsisches Landesamt für Umwelt, Landwirtschaft und Geologie, Germany; 3Nationale Genossenschaft für die Lagerung radioaktiver Abfälle (Nagra) , Switzerland; 4UNESCO Global Geopark Harz, Germany

The nature of Pangea´s internal suture in the Central European Variscides is evaluated on the example of the Harz Mountains (Germany). U-Pb ages of detrital (n = 2273) and magmatic zircon grains (n = 170) were obtained by LA ICP-MS for provenance studies and absolute age dating. Provenance studies point to a docking of East Avalonia onto southern Baltica at c. 430 Ma and to a closure of the Rheic Ocean at c. 430-420 Ma. In the aftermath, the re-opening of a narrow Rhenish Seaway happened in mid-Devonian time. Devonian aged sedimentary rocks of the Harz Mountains were formed at the north-western (Rheno-Hercynian) and on the south-eastern (Saxo-Thuringian) margin of the Rhenish seaway. Deposits formed on the Rheno-Hercynian margin display sedimentary supply from southern Baltica, while most East Avalonian sources were buried and not available for erosion. Siliciclastic shelf deposits of Saxo-Thuringia were derived from Cadomia and its West African hinterland. Provenance studies and spatial arrangement of the tectonostratigraphic units in the Harz Mountains allow to reconstruct the style of obduction of the Harz Mountains onto the southeastern margin of East Avalonia (Rheno-Hercynian Zone). As a result of the closure of the Rhenish Seaway and the collision with the Mid-German Crystalline Zone, the Harz Mountains show a building plan strongly dominated by thin skinned tectonics. Our new data favour a two-plate model for the origin of Pangea´s internal suture in the Central European Variscides, but a re-opening of a narrow oceanic seaway is necessary after closure of the Rheic Ocean.



10:45am - 11:00am
Topics: 3.28 Developments and progress in regional geology

The Ellesmerian orogeny of Laurussia – A far-field effect of the late Devonian collision of Gondwana with North America

Uwe Kroner1, Tobias Stephan2, Thorsten Nagel1

1TU Bergakademie Freiberg, Germany; 2Lakehead University, Canada

Convergent tectonics of the Ellesmerian orogeny affected Arctic Canada and Svalbard in late Devonian - early Carboniferous times. The coeval ultra-high pressure metamorphism in NE-Greenland, the formation of the Maritimes Basin in the Canadian Appalachians, and tectonic activity in the Antler orogeny (Nevada, USA), raised a controversy about whether the Ellesmerian orogeny was related to either late Caledonian plate tectonics or renewed, i.e., post-Caledonian convergence of Laurentia with the rest of Laurussia. Here, we argue that the Ellesmerian orogeny represents a far-field effect of the collision of a Gondwanan promontory with the Appalachian segment of Laurussia. This collision caused the decoupling of the North American lithosphere from Laurussia. The northward motion of this lithospheric domain relative to Laurussia explains the tectonic events along its boundaries, namely the Ellesmerian and the Antler orogenies along the frontal and the Panthalassan margins, respectively. Furthermore, it triggered the reactivation of the NE segment of the Greenland Greenland-Scandinavian Caledonides under dextral transpression causing UHP metamorphism. To the southeast, the formation of the Maritimes Basin reflects dextral transtension and associated strike-slip faults parallel to the edge of SE-Greenland. Strain compatibility requires the existence of a dextral lithospheric-scale strike-slip fault that links the tectonic structures and transects the Greenlandian part of the North American Craton. Because this proposed shear zone in SE Greenland follows small-circle trajectories of the motion of Gondwana relative to Laurussia, we interpret the southeastern edge of Greenland as a dextral transform boundary of the decoupled North American lithosphere.

 
10:00am - 11:15am3.06 Present and past sediment routing systems
Location: Hall B (HFB)
Session Chair: Laura Stutenbecker, University of Münster
Session Chair: Matthias Hinderer, Technical University of Darmstadt
 
10:00am - 10:15am
Topics: 3.06 Present and past sediment routing systems

Partitioning of organic carbon across submarine slope environments

Yvonne Spychala1, Jutta Winsemann1, Miquel Poyatos-Moré2, Martin Blumenberg3

1Leibniz University Hannover, Germany; 2Universitat Autònoma de Barcelona, Spain; 3Federal Institute for Geosciences and Natural Resources (BGR), Hannover, Germany

Although the burial of organic carbon in submarine fans and its importance for the carbon cycle have recently received growing attention, our understanding of the mechanisms at play is still lacking compared to other organic carbon storing environments.

Here, we present insights on the distribution of organic carbon throughout marine slope environments from the Arro System, Aínsa Basin (Spain). Evaluation of TOC content by C/S analysis from 82 samples show that there are distinct partitioning patterns of organic carbon between different depositional slope environments and mass transport complexes (MTC). Channel axes are relatively poor in organic carbon (average 0.1% TOC), while overbank deposits are relative enriched (average 0.49% TOC). Intraslope lobes show high variability between their sub-environments. Lobe axis deposits have an average TOC content of 0.13%, lobe fringe deposits 1.21% and the lobe distal fringe deposits 0.55%. Mass transport complexes have an average TOC content of 0.53 %. Integration of Hydrogen Indeces (HI) and Tmax, established by RockEval analyses, points towards our samples falling within the range between Type III and Type II kerogen (terrestrial and marine matter), while δC13 show a range between 24.5 and 26.5‰, indicating a predominantly terrestrial source.

Our study shows the partitioning of organic carbon across slope environments that are dominated by different depositional processes. The understanding of this variability is important as wrong assumptions about carbon content can be made from studies that ignore spatial differences and potentially lead to false interpretations of climatic/tectonic changes and estimations on carbon budgets.



10:15am - 10:30am
Topics: 3.06 Present and past sediment routing systems

Ambiguity of provenance studies in complex source-to-sink settings – sediment recycling, basement exhumation and signal mixing in the Schilfsandstein (Central European Basin)

Matthias Franz1, Sebastian Niegel1, Karsten Obst2,3, Armin Zeh4

1Geowissenschaftliches Zentrum der Georg-August-Universität Göttingen, Germany; 2Geologischer Dienst, LUNG M-V; 3Institute of Geography and Geology, University of Greifswald; 4Karlsruhe Institute of Technology, Institute for Applied Geosciences,

Provenance studies in the Central European Basin are challenged by the complex geology of source areas. The Variscan orogen represents a puzzle of Cadomian terranes, Variscan-aged domains and Palaeozoic sediments with Baltica-/Gondwana-derived detritus. The Caledonian-Fennoscandian source area comprises the Caledonian Belt, Archean to Neoproterozoic domains (Baltica), Variscan molasse sediments and Permo-Carboniferous igneous rocks.

The low-maturity Schilfsandstein (Stuttgart Formation), composed of first- and second-cycle sands, is an ideal candidate to evaluate provenance tools in a complex setting. Within a basin-scale study, subsurface facies maps, heavy minerals, and U-Pb zircon ages were applied to samples from Germany and onshore UK. Results show that the Schilfsandstein represents variable mixtures of recycled sediments and eroded basement. Heavy minerals are dominated by the Gt-Zr assemblage in North Germany (Fennoscandia), by the Ap-Zr-Ep assemblage in southern NW Germany (Rhenish Massif), and by Gt-Zr, Ap-Zr or Ap-Gt-Zr assemblages in Central and South Germany (Bohemian Massif, Vindelician Land). The clear discrimination of Variscan and Fennoscandian sources based on heavy minerals and subsurface facies maps is less constrained by zircon age spectra. Samples from North Germany either show a mix of Fennoscandian and Variscan spectra or typical Variscan spectra comparable to spectra of samples from Central and South Germany. The statistically identical age spectra of samples from North and South Germany (except UK) suggests mixing of source signals in Schilfsandstein rivers or recycling of Variscan molasse sediments in Fennoscandian catchment areas. The results show that complex source-to-sink settings need integrated approaches, individual provenance tools may lead to ambitious results.



10:30am - 10:45am
Topics: 3.06 Present and past sediment routing systems

Variscides everywhere? Multi-stage sedimentary recycling in Central Europe

Johannes Zieger, Mandy Zieger-Hofmann, Andreas Gärtner, Jessica Haschke, Ulf Linnemann

Senckenberg Naturhistorische Sammlungen Dresden, Germany

We used original detrital zircon morphology, trace element, and U-Pb age data obtained from Upper Rotliegend II strata (Upper Permian) to reveal sedimentary fluxes within the Central German Basin. Understanding the evolution of such a system is crucial for further studies, given that the North German Basin is storage to vast natural gas resources and may also serve as an intermediary sedimentary repository for younger strata.

The detrital zircon dating results revealed the presence of main age clusters from the Permian, Carboniferous, and Cambrian periods. Additionally, several minor clusters from the Neo-, Meso-, and Palaeoproterozoic eras were also identified. These ages are remnants of the Cadomian and Variscan orogenies and the opening and closure of the Rheic Ocean. Zircon grain morphologies varied from completely unrounded to completely rounded grains across the age range. The heterogeneity of the data obtained from the studied mineral grains is vital to understanding the sedimentary history of the Central German Basin. It suggests that the basin fill is most likely a mixture of repeatedly recycled material and directly derived material from bedrock sources.

The detrital zircon trace element data support these findings, showing a wide range of values indicating different magma sources. These results underline the complexity of detrital zircon, and shed further light on the sedimentary history of the Central German Basin. We also found that the North German Basin is an integral part of a sedimentary recycling system spanning Central Europe, which is active since the Neoproterozoic.



11:00am - 11:15am
Topics: 3.06 Present and past sediment routing systems

Rapid downdip textural and compositional maturation of Moodies Group siliciclastics, Barberton Greenstone Belt, South Africa and Eswatini

Deon Johannes Janse van Rensburg, Sebastian Reimann, Christoph Heubeck

Friedrich-Schiller-Universität-Jena, Germany

The Paleoarchean Moodies Group (ca. 3.22 Ga) of the Barberton Greenstone Belt (BGB) is the oldest known well-preserved, shallow-water siliciclastic sequence on Earth. Proximal-to-distal textural and petrographic examination of selected units across adjacent terrestrial, coastal, and shallow-marine depositional facies of this strongly deformed unit provides the opportunity to constrain Archean weathering conditions by source-to-sink analysis, complementing previous bulk analyses. We examined conglomerate, sandstone, and shale composition by detailed geologic mapping and facies analysis along progressive downdip sediment routing systems, after excluding regions of syndepositional hydrothermal alteration. The majority of quartz and feldspar grains in the central BGB was sourced from intermediate to felsic intrusives and (sub-)volcanics of the Hooggenoeg Formation of the Onverwacht Anticline (OA). Downdip textural and mineralogical maturation from immature, F-, L- and matrix-rich, coarse-grained debris-flow-style units to texturally and compositionally supermature fine-grained sandstone occurs within a few km; facies belts fringe the OA. Chemical weathering and mechanical disaggregation of latite-dominated clast populations in proximal facies accompanied decomposition of F to clay (now partially preserved as sericite grains) and of intermediate volcanic grains to quartz-sericite-mosaic grains within a few km from their source. Energetic reworking in wide coastal-facies belts winnowed the abundant clay from the sediment and generated supermature sand, possibly aided by high tides. We deduce that Moodies Group sediment generation appears to have occurred in an aggressive weathering environment; in the coastal zone, only sediment which was silicified surficially and pre-compaction escaped transformation to a sedimentary “restite”.

 
10:00am - 11:15am1.03 Exploration of near-surface geological structures using active and passive seismic methods
Location: Hall C (HFB)
Session Chair: Manuel Hobiger, Bundesanstalt für Geowissenschaften und Rohstoffe
Session Chair: Sonja Halina Wadas, Leibniz Institute for Applied Geophysics
Session Chair: Ulrich Polom, Leibniz Institute for Applied Geophysics
Session Chair: Thomas Spies, Bundesanstalt für Geowissenschaften und Rohstoffe (BGR)
 
10:30am - 10:45am
Topics: 1.03 Exploration of near-surface geological structures using active and passive seismic methods

The southern Baltic Sea – a geoarchive to investigate Quaternary fault reactivation due to glacial isostatic adjustment

Elisabeth Seidel1, Holger Steffen2, Rebekka Steffen2, Niklas Ahlrichs1,3, Christian Hübscher1

1University of Hamburg, Germany; 2Lantmäteriet, Sweden; 3Federal Insitute for Geosciences and Natural Resources (BGR), Germany

The southern Baltic Sea between the German and Polish coast in the south and the Danish and Swedish coast in the north comprises the well-investigated structural-geological situation along the Tornquist Fan area. Different tectonic features tell the story of this polyphase activated weakness zone, like the Paleozoic Tornquist Zone in the NW, Mesozoic NE trending fault zones or salt structures with crestal grabens above, such as various Late Cretaceous to Paleogene inversion structures.

Time-migrated reflection seismic sections indicate neotectonic activity and fault reactivation, a fact supported by recent earthquakes and ongoing isostatic movements of up to 1 cm/a. Due to the reduced resolution of this thin Quaternary layer within the seismic sections, the fault activation could not be dated more precisely so far. Stress variations of the existing background stress are assumed to result from glacial isostatic adjustment (GIA) processes within the lithosphere. This study analyses fault reactivation due to GIA, covering the past 200 ka. For the first time, this glacially triggered faulting could be studied and compared on a variety of faults that differ in their strike and dip direction, age, depth, and character. Using finite element simulations, we tested if and when faults were reactivated during ice advances and retreats within the European Saalian and Weichselian glacial phases.



10:45am - 11:00am
Topics: 1.03 Exploration of near-surface geological structures using active and passive seismic methods

Visualizing blind faults with shear-wave seismic reflection surveys: a case study from the Sorgenfrei-Tornquist Zone, northern Denmark

Christian Brandes1, Ulrich Polom2, Jutta Winsemann1, Sandersen Peter3

1Institut für Geologie, Leibniz Universität Hannover, Callinstr. 30, 30167 Hannover, Germany; 2Leibniz Institut für Angewandte Geophysik, Stilleweg 2, 30655 Hannover, Germany; 3Geological Survey of Denmark and Greenland, Department of Near-surface land and marine geology, University City 81, Building 1872, 8000 Århus C, Denmark

So-called ‘blind’ faults, which are not visible at the Earth’s surface may be the source of unexpected and potentially disastrous earthquakes and thus represent a major hazard, especially in urban areas. Detecting such hidden faults is highly important for the seismic hazard assessment of a region, but often remains a challenge, because the faults are covered by young sediments. To overcome this limitation, we visualize blind faults in the area of the Sorgenfrei-Tornquist Zone in northern Denmark with shear-wave seismic reflection surveys. The faults on the seismic surveys are interpreted based on systematic reflector offsets, the presence of continuous transparent zones that separate individual fault blocks, abrupt lateral changes in the reflector pattern, and the presence of fault shadows. The seismic surveys give evidence for a near-surface strike-slip fault system, based on the presence of flower structures and the dominance of steep faults. The distribution of the faults on the seismic surveys and the occurrence of fault-related shear-deformations bands that occur in outcrops along the nearby seas-cliff, together with fault-related basins that are developed in the study area, indicate that the northern boundary fault of the Sorgenfrei-Tornquist Zone is not an isolated fault, but a wider fault array. The study demonstrates that the shear-wave reflection seismic method is a powerful tool to image near-surface faults and is very suitable for palaeoseismological studies. The significantly improved resolution of shear-wave seismic surveys compared to those of the common P-wave reflection method is an advantage, especially in the case of small fault displacements.

 
10:00am - 11:15am1.23-1 Sustainable Groundwater Management to mitigate Water Scarcity:...
Location: Hall D (HFB)
Session Chair: Irina Engelhardt, TU Berlin
Session Chair: Peter Dietrich, Helmholtz-Zentrum für Umweltforschung GmbH - UFZ
Session Chair: Martin Sauter, Leibniz-Institut für Angewandte Geophysik
 
10:00am - 10:15am
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Can we characterize groundwater reservoirs in central Europe from air pressure induced seismic velocity changes?

Richard Kramer, Yang Lu, Götz Bokelmann

University of Vienna, Austria

Given the increasing challenges posed by climate change, especially more frequent and severe droughts experienced globally, effective exploration and management of groundwater resources is essential to ensure a sustainable and resilient society. As part of this effort, it is necessary to acquire comprehensive knowledge of the distribution of significant and readily accessible freshwater reservoirs on continents. This outlines the critical need for an efficient and cost-effective imaging method to assess this vital resource. In response, we propose a novel imaging method that utilizes observations of air-pressure-induced seismic velocity changes. We utilize findings of our study (Kramer et al., 2023) which shows atmospheric tides and their interaction with the groundwater body are the primary cause of sub-daily seismic velocity changes. Analyzing these velocity changes can reveal valuable information on the hydro-geophysical properties of the underlying groundwater body. Building on this knowledge, we introduce this imaging method and apply it to the seismic data collected across South and Central Europe. For this purpose, we use coda-wave-interferometry to investigate four years of continuous data from AlpArray and other locations throughout Europe.

Kramer, R., Lu, Y., & Bokelmann, G. (2023). Interaction of air pressure and groundwater as main cause of sub-daily relative seismic velocity changes. Geophysical Research Letters, 50, e2022GL101298. https://doi.org/10.1029/2022GL101298



10:15am - 10:30am
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

From Struggle to Solutions: Understanding the Concerns of People's Groundwater Usage Habits and Environmental Awareness for Sustainable Water Management in Ca Mau Province

Van Cam Pham1,2, Jonas Bauer1,2, Felix Dörr1,2, Hoan Viet Tran1,2, Stefan Norra3

1Karlsruhe Institute of Technology (KIT), Institute of Applied Geosciences; 2Laboratory for Environmental and Raw Materials Analysis (LERA); 3Potsdam University, Institute of Environmental Sciences and Geography, Soil Sciences and Geoecology

The Mekong Delta, including Ca Mau province in the south, faces severe land subsidence, attributed in part to the excessive groundwater extraction. Addressing this issue requires finding alternative water sources while considering technical, environmental and social challenges. This study aims to understand the significance of groundwater to the people of Ca Mau, their water usage habits and awareness with environmental issues. Supported by local Provincial People's Committees, a comprehensive survey and group interviews were conducted across 9 districts of Ca Mau province. The research aimed to identify the spatial distribution of the required water management solutions and acceptance levels of alternative water resources. Water samples were collected and analyzed to establish the connection between water quality and people's water usage habits. Groundwater plays a vital role in people’s life, serving various purposes such as washing, cooking, drinking, and other activities. Groundwater usage depends on people's perceptions of its quality. For activities requiring higher levels of hygiene, additional water treatment or alternative water sources are preferred. The analytical approach from general viewpoints to details in this study investigates deeper into the story behind their water usage habits. It emphasizes the need to inform people about environmental challenges and raise awareness of cause-effect relationships. Evaluating alternative water resources and designing new water utilization concepts is based on local demands and willingness to change water-related habits. This research sheds light on people's awareness and concern while providing valuable insights for sustainable water management strategies in the Mekong Delta, specifically in Ca Mau province.



10:30am - 10:45am
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

The Hidden Drought: A Hydrogeochemical Perspective on the Challenges of Sustainable Groundwater Management in the Vietnamese Mekong Delta

Jonas Bauer1,2, Hoan Viet Tran1,2, Van Cam Pham1,2, Felix Dörr1,2, Stefan Norra3

1Karlsruhe Institute of Technology (KIT), Institute of Applied Geosciences, Adenauerring 20b, 76131 Karlsruhe, Germany; 2Laboratory for Environmental and Raw Materials Analysis (LERA), Adenauerring 20b, 76131 Karlsruhe, Germany; 3Potsdam University, Institute of Environmental Sciences and Geography, Soil Sciences and Geoecology, Campus Golm, Building 12, 14476 Potsdam - Golm, Germany

With escalating global freshwater scarcity, the Mekong Delta basin has emerged as one of the most socially and ecologically vulnerable regions, experiencing severe freshwater stress and storage loss. This vulnerability is primarily driven by the progressive "loss of land and freshwater" phenomenon, which encompasses a range of interconnected environmental issues, including land subsidence and seawater intrusion. The exponential growth in population, urbanization, climate change and rapid industrial and agricultural development has significantly increased the demand for freshwater, placing already limited supplies under immense pressure. In the coastal zones of the Mekong Delta, groundwater has become the primary and increasingly overexploited source of freshwater. Consequently, a decline in hydraulic heads and the threat of saline intrusion have become pressing concerns. To gain a comprehensive understanding of the hydrogeochemical processes at play, a meticulous investigation was conducted in the coastal province of Ca Mau, Vietnam. Through extensive sampling campaigns and rigorous hydrogeochemical analysis, this study sheds light on the intricate dynamics of groundwater chemistry in the region. The results reveal that ion-exchange processes and the decomposition of organic matter play dominant roles in shaping the groundwater chemistry. These findings hold significant implications for the sustainable management of water resources in the Mekong Delta. By unraveling the past and current hydrogeochemical groundwater dynamics, stakeholders can develop effective strategies to mitigate freshwater scarcity. The knowledge gained from this research contributes to the scientific understanding of hydrological systems and aids in the formulation of integrated water management policies for the region's long-term sustainability.



10:45am - 11:00am
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

The Ohangwena aquifer system in Angola and Namibia – a fresh paleo-groundwater resource in an arid and saline environment

Roland Bäumle, Kevin de Vriendt, Georg Houben

Bundesanstalt für Geowissenschaften und Rohstoffe, Germany

The transboundary Cuvelai-Etosha Basin (CEB), located in Southern Angola and Northern Namibia, is part of the Kalahari Basin, one of the world´s largest intracontinental basins. It contains mostly unconsolidated sandy sediments, often deposited by so-called megafans. The most prominent one in the CEB is the Cubango Megafan (CM). Megafans can contain large aquifers and thus have huge potential for water supply, especially in semi-arid regions. The CM hosts three aquifers: a locally present, perched aquifer, a regional mostly unconfined and a deep confined aquifer.

The regional climate is semi-arid, with very high evapotranspiration (> 2000 mm/yr) that far exceeds the highly seasonal and variable precipitation (400-800 mm/yr). The widespread salinity in the contemporary groundwater of the CM can be attributed to both sub-recent and co-sedimentary evaporative processes.

In the lower parts of the CEB, specifically at the southwestern rim of the megafan towards the Etosha Pan, saline groundwater predominates. Hydrochemical data indicate large-scale and long-term ion exchange processes. Together with environmental tracers, this shows that younger groundwater infiltrating to the north of the basin is slowly displacing the originally brackish-saline pore water. 81Kr ages range between 40 to 170 ka indicating the fossil nature of this resource. Analysis of stable isotopes and noble gases reveals that climatic conditions during recharge of the confined aquifer were approximately 3 – 5°C colder than today.

Considering the population growth and predicted impact of climate change on water availability, careful management of this vulnerable and only partially replenishable resource is advisable.

 
10:00am - 11:15am3.16-1 Assessing biosphere geosphere interactions in the subsurface, at leaking wells, and natural vents and seeps
Location: Wiwi 101
Session Chair: Sebastian F. A. Jordan, Federal Institute for Geosciences and Natural Resources
Session Chair: Oliver Schmale, Leibniz Institute for Baltic Sea Research (IOW)
Session Chair: Jens Kallmeyer, GFZ Potsdam
 
10:00am - 10:30am
Invited Session Keynote
Topics: 3.16 Assessing biosphere geosphere interactions in the subsurface, at leaking wells, and natural vents and seeps

Current understanding of sources and quantities of geological and biological methane emissions into the atmosphere

Giuseppe Etiope

Istituto Nazionale di Geofisica e Vulcanologia, Italy

Methane (CH4) is an important greenhouse gas, but our understanding of the magnitude of its sources is fraught with considerable uncertainties. Quite neglected in early atmospheric methane budget studies, Earth’s degassing is today considered a major natural source of methane. Geological (natural fossil) methane emissions, including gas seepage in petroliferous sedimentary basins (macro-seeps, microseepage, marine seepage) and geothermal exhalations, were estimated at the global scale by several research groups, based on bottom-up and top-down procedures, and accounting for ~40-50 Tg CH4 yr-1 (latest review and discussions on conflicting estimates are in Etiope and Schwietzke, 2019, and Thornton et al. 2021). This value is equivalent to roughly one-third of the average emission attributed to wetlands, and it rivals with the high uncertainty of freshwater sources. Global gridded mapping was developed to provide the spatial distribution of the geological methane sources, as well as their isotopic (13C/12C) composition and potential intensity (Etiope et al. 2019), and it has been used to refine fossil fuel industry and microbial CH4 emission budget. Geological emission breakdown at continental scale could be derived (e.g., Petrescu et al. 2023), with the emission values that must be considered only in terms of “order of magnitude”. The geo-CH4 sources are now included in the methane budget of the Global Carbon Project (Saunois et al. 2020), where they are compared to other natural and anthropogenic sources, including an analysis of double-counting with some biological sources. Correct definitions, source attribution, uncertainties and limits define the roadmap strategy for refining emission estimates.



10:30am - 10:45am
Topics: 3.16 Assessing biosphere geosphere interactions in the subsurface, at leaking wells, and natural vents and seeps

Methane release from inactive oil and gas wells in Romania - preliminary results

Calin Baciu, Eduard Ghiorghiu, Mustafa Hmoudah

Babes-Bolyai University, Romania

In spite of the decreasing production, Romania remains one of the most important oil and gas producers in Europe. The European inventories of anthropogenic methane release reveals unexpectedly high emissions related to the oil and gas industry in Romania. The number of drilled wells in Romania is exceeding 60,000, with the majority of them currently being inactive. A first approach to quantify the methane emissions from active wells was conducted within the ROMEO project. The highest emissions were observed at the facilities with poor technical maintenance. As part of the UNEP-funded project Global Analysis of Methane Emissions from Abandoned Oil and Gas Wells, an evaluation of methane release from inactive wells is ongoing. No comprehensive inventory of the inactive wells is available for the moment at a national level. The ENVERUS (DrillingInfo), database provides information on 6348 wells in Romania, out of which 776 wells in the Transylvanian Basin. More than 72% of the reported wells were dry, while different amounts of oil and/or gas have been found in the others. According to the nationally applicable closure procedure, most of the wells are plugged and buried, making their identification and detection of gas leaks difficult. In a few cases, substantial methane emissions have been reported, which may pose a threat to neighboring residents.

Acknowledgment: this contribution was supported by the project Global Analysis of Methane Emissions from Abandoned Oil and Gas Wells, funded by UNEP.



10:45am - 11:00am
Topics: 3.16 Assessing biosphere geosphere interactions in the subsurface, at leaking wells, and natural vents and seeps

Geochemical detection of minor hydrocarbon seepage in marine subsurface sediments

Ellen Schnabel, Jens Kallmeyer

GFZ Potsdam, Germany

All hydrocarbon reservoirs leak slightly. At sites with only minor leakage the hydrocarbons (HC) infiltrating the sediment from below are completely metabolized before reaching the sediments surface due to microbial activity, thus not creating any surface manifestations, e.g. seeps. Nevertheless, the HC influx will change geochemistry as well as microbial community composition and activity in the affected area because electron donors are added into the system. The PROSPECTOMIS project wants to detect these changes to develop a minimally invasive and low-cost tool do detect HC reservoirs using omics and geochemistry techniques.

In November 2021 we recovered fifty 2-3 m long sediment cores from three minor HC seepage zones and two non-seepage reference zones in the southern Barents Sea and sampled sediment and pore water with high spatial resolution.

While Fourier-transform ion cyclotron resonance mass spectrometry and cell abundances did not show any differences between HC seepage zones and reference zones, multiple pore water concentration profiles e.g. for Manganese, Calcium, Silicon, Strontium, Sulfide revealed differences. Also, higher fluxes of sulfate and alkalinity in HC zones indicate that the sink for sulfate and the source of alkalinity must be shallower in HC zones, most probably caused by anaerobic oxidation of methane (AOM) below the sampled depth interval. Linear sulfate pore water profiles indicate no net turnover of sulfate. Nevertheless, we observed low rates of sulfate reduction using radiotracer incubations, mostly in HC zones.

Combining these parameters with multi-omics datasets will reveal potential indicators for minimal HC seepage.



11:00am - 11:15am
Topics: 3.16 Assessing biosphere geosphere interactions in the subsurface, at leaking wells, and natural vents and seeps

Chasing strong seismic reflections in the basement of a giant gas accumulation - the Norwegian Troll mystery

Nicola Kerstin Möller, Christian Gram, Hartmut Hubertus Schütt

Equinor, Norway

The crystalline basement below the giant Norwegian Troll field has been subject to research and publication for many decades. Still no well bore has penetrated the deep crystalline basement. An ever-increasing amount of geophysical information, documents pronounced basement heterogeneity. The seismic reflection patterns suggest the presence of mappable fluid reservoirs within metamorphic basement rocks.

High-reflection-low-density geobodies appear to be connected to major detachment zones with varying seismicity, but avoiding younger transform lineaments. The features are considered to have formed during the collapse of the Caledonian mountains, opening the precursor basins of the North Sea and the Northern Atlantic Ocean. The structures are partly inherited from contractional features, formed during the Caledonian continental collision between Baltic and North American plates. Former and present-day fluid migration, using this inherited deformation pattern, is significant for understanding the development of one of the most important energy sources for Europe.

While earlier speculations about origin and significance of the strong seismic reflections had to be based on presumed analogues on the Norwegian mainland, we will present evidence from new, high quality seismic, gravity, magnetic and magneto-telluric data and propose new working hypotheses for their geologic origin. Pointing to low density, low magnetism and low resistivity, our mapped „geo-bodies“, could form fluid reservoirs that have influenced the regional development of the Greater Troll area.

 
10:00am - 11:15am2.03-1 Setting the stage for a habitable planet: Solid earth processes through time
Location: Wiwi 104
Session Chair: Sara Vulpius, Freie Universität Berlin
Session Chair: Liam Hoare, Ruhr-Universität Bochum
 
10:00am - 10:15am
Topics: 2.03 Setting the stage for a habitable planet: Solid Earth processes through time

Experimental and isotopic constraints on the formation of Archean continental crust

Liam Hoare1, Christopher Beyer1, J. Elis Hoffmann2, Raúl O.C. Fonseca2

1Ruhr-Universität Bochum, Germany; 2Freie Universität Berlin, Germany

Remnants of Earth’s juvenile continental crust are preserved in the form of Archean Tonalite-Trondhjemite-Granodiorites (TTGs). However, much controversy surrounds the composition of TTG protoliths and whether the geodynamic setting involved convergent-style plate tectonics. Thus, a combination of high-pressure and high-temperature experiments combined with robust geochemical proxies are required to gain insight into TTG petrogenesis. Numerous experimental studies have demonstrated that partial melting of hydrated basalt at 0.8 to 2 GPa is sufficient to produce TTG-like melts. The compositions of starting materials used in these experiments vary significantly between studies and has profound implications for the solidus, melt composition, and the type, composition and modal abundance of solid phases. This is problematic especially given most studies have utilised MORB-like starting compositions, which differ significantly in composition to the least altered Archean metabasalts which posses higher MgO and lower Al2O3. We present the results of partial melting experiments conducted at 1-1.5 GPa and 940 to 1100 °C in a piston cylinder apparatus using synthetic starting materials with varying H2O (4-6 wt.%), based on the compositions of Eoarchean metabasalts from the Isua supracrustal belt in southern West Greenland. The run products of these experiments will be analysed to assess their phase assemblages and melt composition, and to constrain the magnitude of mineral-melt trace element and isotopic (Ti) fractionation during partial melting. Ultimately this experimental campaign will ascertain if partial melting of high-Mg, low-Al metabasalts is a viable mechanism to produce melt compositions resembling those of Archean TTGs.



10:15am - 10:30am
Topics: 2.03 Setting the stage for a habitable planet: Solid Earth processes through time

Tectono-magmatic evolution of the Lewisian Gneiss Complex, NW Scotland: constraints from in situ U-Pb, Lu-Hf and trace element analysis of TTG-derived zircon.

Annika Dziggel1, Silvia Volante2, Tim E. Johnson3, Lanita Gutieva1, Noreen Evans3, Christopher L. Kirkland3, Vitor Barrote4

1Ruhr-Universität Bochum, Germany; 2ETH Zürich, Siwtzerland; 3Curtin University, Australia; 4Paul Scherrer Institut

The mainland Lewisian Gneiss Complex (LGC) in NW Scotland is dominated by Archean tonalite-trondhjemite-granodiorite (TTG) gneisses. It consists of at least three distinct crustal blocks that have different magmatic and metamorphic histories. The LGC is regarded to either represent i) a once-contiguous fragment of Archean crust that was later disaggregated and reassembled along major shear zones into the northern, central and southern regions, or ii) a collage of discrete terranes. To better assess the tectono-magmatic evolution of the LGC, we use in situ U-Pb, Lu-Hf and trace element analysis of zircon grains derived from a representative set of TTG gneiss samples. The crystallization ages of TTGs range between 2778 and 2609 Ma in the northern region (Rhiconich terrane), 3003 and 2731 Ma in the central region (Assynt/Gruinard terranes), and 3110 and 2675 Ma in the southern region (Rona terrane). Zircon εHf(t) values of the oldest samples from the southern region are broadly chondritic. Samples from the southern part of the central region (Gruinard terrane) are more radiogenic, indicating a major period of juvenile magmatism at c. 2900-2800 Ma. Zircon derived from TTGs < 2800 Ma is characterised by chondritic to sub-chondritic Hf isotope signatures, pointing to increased crustal reworking during the late stages of TTG magmatism. Collectively, our data show that TTGs in the different parts of the LGC formed at different conditions and from different sources. We propose that the LGC is composed of at least three terranes that were assembled during the Neoarchean to Paleoproterozoic.



10:30am - 10:45am
Topics: 2.03 Setting the stage for a habitable planet: Solid Earth processes through time

Metamorphism and the tectonic evolution of the Archean

Jian Kuang1,2, Gabriele Morra3, David Yuen4, Shihua Qi2

1Freie Universität Berlin, Berlin; 2China University of Geosciences, Wuhan; 3University of Louisiana at Lafayette; 4Columbia University

The tectonics on the Archean Earth is intricate and contentious, with ongoing debate concerning the dominant surface processes controlled by either a plate tectonics regime or alternative forms of tectonics (stagnant lid, heat pipe, drip tectonics, sluggish plates and other planetary modes of heat loss). In this study, we assess the viability of interpretations of tectonics during the Archean using a newly compiled metamorphic database. We relate Archean cratons and continental history, crustal growth and reworking, and horizontal motion of ancient cratons to infer which tectonic styles and processes operated. Our analysis is synthetized by the highlighting of three distinct Archean periods with different tectonic activity, starting at 3.8 billion years (Ga), from when the first metamorphic data are available. We find that in the interval 3.8-3.5 Ga, tectonics was dominated by short-lived subduction tectonics and non-subduction tectonics, possibly in cohabitation. Between 3.4 and 3.0 Ga, subduction was present and contributed to the lateral growth of the continents. In the 2.8-2.5 Ga period, the assembly of supercontinent/supercratons signals the action of modern-style plate tectonics. In summary Archean metamorphic data allow timing the Earth progression from pre-modern tectonics to modern plate tectonics including the supercontinent cycle.



10:45am - 11:00am
Topics: 2.03 Setting the stage for a habitable planet: Solid Earth processes through time

Growth of non-typical garnet textures during amphibolite facies metamorphism: Dwalile Supracrustal Suite, Ancient Gneiss Complex, Eswatini

Valby van Schijndel1, Kathryn Cutts2, Gary Stevens3, Elis Hoffmann4, Markus Ohl5, Yuntao Ji5, Oliver Plümper5

1Helmholtz Centre Potsdam Deutsches GeoForschungsZentrum GFZ, Germany; 2Geological Survey of Finland, P.O. Box 96, FI-02151 Espoo, Finland; 3Centre for Crustal Petrology, Department of Earth Sciences, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa; 4Institut für Geologische Wissenschaften, Freie Universität Berlin, Malteserstrasse 74-100, 12249 Berlin, Germany; 5Department of Earth Sciences, Utrecht University, Budapestlaan 4, 3584CD Utrecht, The Netherlands

The Dwalile Supracrustal Suite of the Ancient Gneiss Complex (Eswatini) represents one of the oldest greenstone belts in the world with a crustal evolution history from Palaeo- to Mesoarchaean times. The main metapelitic rock type is dominated by garnet and staurolite porphyroblasts in a layered matrix of biotite, muscovite, quartz and retrograde sericite. Minor components are andalusite, chlorite and chloritoid with accessory ilmenite and monazite. The age for the amphibolite facies metamorphism is recorded by monazite at ca. 3.15 Ga.

The garnet-staurolite bearing metapelites have thus similar mineralogy and bulk rock compositions, but differ due to their unusual garnet microstructures. In some samples the garnet grains are distributed as thin layers consisting of elongated ribbons, with local resorption textures and peninsular features together with coarse recrystallised quartz. The euhedral garnet cores are only visible in compositional maps, which show a typical bell-shaped growth zoning.

EBSD maps of the crystallographic orientations of the garnet are created for four samples and two samples were imaged using high-resolution X-ray tomography for the visualization of the garnet morphology in order to test the relationship of the garnet porphyroblasts and consider the implications for the formation mechanism. For example, do the garnets share the same crystallographic orientation or is there evidence for deformation and/or rotation processes during growth. How are the garnets orientated in 3D space and are the ribbon textures build up by subgrains caused by deformation or are they separate grains formed by multiple nucleation events, possibly caused by fluid-rock interaction processes.



11:00am - 11:15am
Topics: 2.03 Setting the stage for a habitable planet: Solid Earth processes through time

In-situ analysis of lead and multiple sulfur isotopes in southern West Greenland peridotite sulfide grains reveal evidence for Eoarchean crustal recycling

Jonathan A. Lewis1, Esther M. Schwarzenbach1,2, Moritz Liesegang1, Julia van de Löcht3, Alexander Schwarz1, Harald Strauss4, Carsten Münker3, Minik T. Rosing5, Martin J. Whitehouse6, Heejin Jeon6, Elis Hoffmann1

1Freie Universität Berlin, Germany; 2University of Fribourg, Switzerland; 3Universität zu Köln, Germany; 4Westfälische Wilhelms-Universität Münster, Germany; 5University of Copenhagen, Denmark; 6Naturhistoriska riksmuseet, Stockholm, Sweden

Eoarchean peridotites from the area south of the Isua Supracrustal Belt (SOISB) in southern West Greenland have been found by previous studies to contain sulfur subject to mass independent fractionation (MIF-S), with positive Δ33S values indicating that these rocks have incorporated sedimentary sulfur recycled from Earth’s surface [1]. New in-situ secondary ion mass spectrometry measurements of sulfide grains found within these peridotites reveal that this MIF-S is hosted within the sulfide grains. Electron microprobe analyses of the sulfide grains reveal that they are predominantly composed of pentlandite and pyrrhotite, consistent with the typical sulfide mineralogy of mantle rocks. The peridotites displaying the least petrographic evidence for melt overprint (Group 1) were found to contain the highest average in-situ Δ33S values, +0.20±0.02‰, while those bearing more evidence for melt overprint (Group 2) had lower average in-situ Δ33S values, +0.09±0.03‰. These findings are in good agreement with previous bulk rock S isotope results [1]. In-situ Pb isotope measurements of the sulfide grains reveal unradiogenic compositions consistent with an Archean origin. Furthermore, petrographic observations reveal that the sulfide grains are crosscut by amphiboles, indicating that the sulfide grains predate Neoarchean amphibolite-facies metamorphism. Our data support previous interpretations that these rocks are the oldest known mantle peridotites. These findings reinforce previous interpretations that SOISB peridotites preserve evidence of crustal recycling in the Eoarchean.

[1] Lewis et al. (2022) EGU 22-5226

 
10:00am - 11:15am3.11-3 Triassic Revolution
Location: Wiwi 104a
Session Chair: Stephan N.F. Spiekman, Naturkunde Museum Stuttgart
 
10:00am - 10:15am
Topics: 3.11 Triassic Revolution

The Carnian Pluvial Episode in Tethys Realm: Insights from multiproxy paleoclimate data

Mina Mazaheri-Johari1, Jacopo Dal Corso2, Guido Roghi3, Evelyn Kustatscher4,5, Tamsin Mather6, Piero Gianolla1

1Department of Physics and Earth Sciences, University of Ferrara, Via G. Saragat 1, Block B, Ferrara 44100, Italy; 2State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; 3Institute of Geosciences and Earth Resources - CNR, Via Gradenigo 6, Padova 35131, Italy; 4Department of Earth and Environmental Sciences, Paleontology & Geobiology, Ludwig-Maximilians-Universität München, Richard-Wagner-Straße 10, 80333 München, Germany; 5SNSB-Bayerische Staatssammlung für Paläontologie und Geologie, Richard-Wagner-Straße 10, 80333 München, Germany; 6Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, UK

The Carnian Pluvial Episode (CPE, 234–232 Ma) was a major climate change event in the Triassic. The CPE brought substantial changes in ecological community structure and the appearance of many key groups dominating modern marine and terrestrial ecosystems. Here we present an interdisciplinary study of Upper Triassic strata in the Tethys realm to reconstruct the vegetation history and infer environmental changes during the Carnian. Furthermore, we applied Mercury (Hg) concentrations and Total Organic Carbon (TOC) to unwrap the role of volcanic activity as a major driver of this episode of climate warming and environmental perturbations. Palynological and paleobotanical data collected from the Northern Tethys (Kope-Dagh basin, NE Iran) show a shift towards hygrophytic elements reflecting the expansion of wet habitats on the continent during the latest early Carnian to late Carnian. The sedimentological and palynological patterns and plant fossil assemblages in the Northern Tethys closely resemble those observed in Western Tethys during CPE. This record represents the only clear record of the CPE in the Iranian plateau. Our geochemical data from Carnian marine sedimentary sequences of the Western Tethys demonstrate discrete spikes in Hg/TOC ratios during the CPE. The results suggest a direct link between the CPE and repeated pulses of the Wrangellia submarine Large Igneous Province that could have played a major role in the evolution of biota and the environment at that time. However, despite progress in understanding the CPE, significant uncertainty remains in addressing how the volcanic eruptions influenced different ecosystems/biotic communities, which deserves further studies.



10:15am - 10:30am
Topics: 3.11 Triassic Revolution

The Lower Keuper (Erfurt Formation, Middle Triassic) fossillagerstätten from SW Germany: flourishing tetrapod ecosystems

Eudald Mujal1,3, Raphael Moreno1,2, Rainer R. Schoch1,2

1Staatliches Museum für Naturkunde Stuttgart, Germany; 2Universität Hohenheim, Germany; 3Institut Català de Paleontologia Miquel Crusafont, Spain

Even if the knowledge of Triassic tetrapod communities and their role in terrestrial ecosystems has increased in the recent decades, the paucity of fossil sites from this time interval has hindered their complete understanding. In order to shed light on how the Triassic tetrapod communities were, evolved and interacted in their habitats, we are carrying out a series of multidisciplinary studies on the Ladinian Lower Keuper successions (Erfurt Formation) of southwestern Germany. These facies were deposited in a vast epicontinental platform of the Central European Basin, influenced by the Tethys Sea. The Lower Keuper in the study areas consists of a 20–25 m thick succession of alternating siliciclastic and carbonate deposits, mostly grey to green mudstones and marlstones, and yellowish to blueish dolostones, as well as occasional sandstones. The succession is divided in more discrete units, some of which forming exceptional fossillagerstätten with thousands of tetrapod remains recovered and tens of new tetrapod taxa (including basal members of different lineages) described to date. Sedimentological, taphonomic and palaeoecological data show that ecosystems were complex, with several levels within the trophic chain and including at least two top predators: a pseudosuchian archosaur and a giant capitosaur temnospondyl. Of note, fish diversity is particularly high, with at least 14 taxa so far known. The occurrence of the same vertebrate taxa, but in different proportions and from different ontogenetic stages throughout the stratigraphic succession and in different localities corresponding to slightly different environmental settings, indicates stability of the ecosystems.



10:30am - 10:45am
Topics: 3.11 Triassic Revolution

Reappraisal of the environmental setting and taphonomy of the Trossingen Plateosaurus bonebeds

Joep Schaeffer1, Eudald Mujal1,2, Rainer R. Schoch1,3

1Staatliches Museum für Naturkunde Stuttgart, Germany; 2Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain; 3Universität Hohenheim, Stuttgart, Germany

The Norian Trossingen Plateosaurus bonebeds have piqued the interest of many researchers over the past 100 years. Several investigations took place in the 1910’s to 1930’s excavating over 80 skeletons, but was then left to rest until 2007. In 2007, 2008 and 2010 small excavations took place, resulting in one and a half skeleton of Plateosaurus trossingensis. The depositional environment of the site has had a controversial history with several theories, ranging from a sandy desert to a catastrophic mudflow, to a watering hole with a muddy bottom. In the summer of 2022 an exploratory investigation was performed at the Trossingen site to prepare for large scale excavation in 2023, which will incorporate stratigraphical, sedimentological and taphonomic investigations to further dive into the evolution of the environment and its relation to the fossil remains. Here we present the first results of both the 2022 and 2023 field campaigns with a revised depositional history. The preliminary investigations in 2022 already showed the section is not as homogenous as previously thought and uncovered several structures, most of which not previously recognised, such as: (1) several small channel–like deposits likely of fluvial origin and (2) a carbonate layer with a possible lacustrine origin in the lower beds, (3) large pedogenetic carbonate nodules in the middle beds, and (4) large mudcracks in the upper beds. All these features, together with preliminary taphonomic data from the bones, suggest a potential upwards aridification trend across the entire section.



10:45am - 11:00am
Topics: 3.11 Triassic Revolution

A taxonomic Gordian Knot - the sauropodomorph diversity in the Germanic Basin during the Late Triassic

Omar Rafael Regalado Fernández

Eberhard-Karls Universität Tübingen, Germany

The sauropodomorph-bearing localities from the Norian-Rhaetian of Europe have been traditionally interpreted as monospecific, attributing the morphological disparity in Plateosaurus to intraspecific variability. The Norian and Rhaetian stages are currently not chronostratigraphically defined, making comparisons between the different deposition environments cumbersome. However, from the base of the Norian to the Rhaetian, the sizes of sauropodomorphs increase, with small to medium-sized sauropodomorphs found in the oldest layers of the Löwenstein Formation, to larger and more robust-sized sauropodomorphs from the Tübingen Sandstone (Rhaetian). This contribution presents the results of a basin analysis to reconstruct the environmental changes in the Germanic Basin during the Late Triassic, integrating stratigraphy, fossil record and structural geology. The results of this are that during the Carnian, the opening of Meliata, Pindos and Maliac Oceans in Western Pangaea created rift zones on the carbonate platforms. Towards the Norian, the sea-spreading ceased as these southern oceans started to close just before the new rifting of the Neothetys began. The complex fault systems generated an epicontinental sea that separated portions of Europe as an archipelago that fully developed when the Rhaetian Sea occupied the Germanic Basin. Independently, several iterations of specimen-level phylogenetics of sauropodomorphs found that the three specimens that have been traditionally referred to as Plateosaurus are placed at the base of a comb-like arrangement that includes robust forms, such as Schleitheimia and Tuebingosaurus—two sauropodomorphs that have been previously nested within sauropodiformes. The phylogenetic patterns in a comb-like arrangement suggest a combination of vicariance and migration in the archipelago.



11:00am - 11:15am
Topics: 3.11 Triassic Revolution

Climatic controls on the ecological ascendancy of dinosaurs

Emma Dunne1, Lisa Schnetz2, Alexander Farnsworth3, Richard Butler2, Roger Benson4, Pedro Godoy5, Sarah Greene2, Paul Valdes3, Daniel Lunt3

1Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany; 2University of Birmingham, Birmingham, UK; 3University of Bristol, Bristol, UK; 4University of Oxford, UK; 5Universidade de Sao Paulo, Sao Paulo, Brazil

The rise of dinosaurs during the Late Triassic was a pivotal event in the history of life on Earth, which led to them becoming dominant members of terrestrial ecosystems throughout the remainder of the Mesozoic. However, the drivers of this geographic expansion and explosion in biodiversity have been poorly understood. Early studies have hypothesized that the extinction of co-occurring vertebrate groups such as aetosaurs, rauisuchians, and therapsids at the end-Triassic mass extinction, provided early dinosaurs with the opportunity to diversify into new niches. However, this pattern could instead be a response to climatic changes during this interval, especially given the increasing evidence that climate played a key role in constraining Triassic dinosaur distributions. Our work is the first to quantitatively explore the opportunistic expansion model by examining changes in dinosaur and tetrapod ‘‘climatic niche space’’ across the Triassic-Jurassic boundary. We found that Late Triassic sauropodomorph dinosaurs occupied more restricted climatic niche spaces than other dinosaurs, and were excluded from the hottest climate zones at low latitudes. The geographic expansion of sauropodomorphs after the mass extinction is linked to the expansion of their preferred climatic conditions. Evolutionary model-fitting analyses provide evidence for an important evolutionary shift from cooler to warmer climatic niches during the origin of Sauropoda, the clade that later in the Mesozoic became the iconic long-necked forms. Together, our results provide support for the key role of climate in the ascendancy of dinosaurs.

 
10:00am - 11:15am3.27-1 Alkaline rock and carbonatite related magmatism
Location: Wiwi 107
Session Chair: Benjamin Florian Walter, Karlsruhe Institute of Technology
Session Chair: Tomas Magna, Czech Geological Survey
 
10:00am - 10:15am
Topics: 3.27 Alkaline rock and carbonatite related magmatism

The Chatham Islands: A window into the geochemical evolution of Zealandia

Stephan Homrighausen1, Kaj Hoernle1,2, Folkmar Hauff1, Johanna Schenk1, Hamish Campbell3

1GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany; 2Institute of Geosciences, Kiel University, Kiel, Germany; 3GNS Science, Lower Hutt , New Zealand

The temporal geochemical record of Zealandian alkaline intraplate volcanism reveals a significant geochemical evolution from Cretaceous HIMU (high time-integrated μ = 238U/204Pb Mantle) end member to Cenozoic HIMU-like volcanism with overall lower 207Pb/204Pb and variable 208Pb/204Pb ratios at a given 206Pb/204Pb ratio. In general, this temporal geochemical evolution has been reconstructed by piecing together volcanism taking place at many different localities covering different but limited age ranges. The Chatham Islands, covering an area of ~800km2, represent the only known locality within Zealandia where volcanic activity has taken place nearly continuously over ~85 Ma and record the geochemical evolution from HIMU end member to HIMU-like volcanism. Therefore, the Chatham Islands are a key locality for reconstructing and understanding the geochemical evolution of Zealandia. Numerous models, such as an asthenospheric heritage (e.g. mantle plume) or metasomatic overprint of the SCLM by: 1) subduction zone fluids or 2) interaction with Hikurangi Plateau, have been proposed, but the style of geochemical change (abrupt or progressive), as well as the origin of the HIMU end member and HIMU-like sources remain enigmatic, as is the unique longevity of intraplate volcanism over ~85 Ma at a single locality. Geochemical analysis (major and trace elements, radiogenic Sr-Nd-Pb-Hf isotope ratios and mineral composition) of alkaline lavas and enclosed mantle xenoliths from the Chatham Islands, will be used to reconstruct their spatio-temporal geochemical evolution of HIMU to HIMU-like volcanism on the Chatham Islands and associated volcanism on Zealandia over the last ~85 Ma.



10:15am - 10:30am
Topics: 3.27 Alkaline rock and carbonatite related magmatism

Formation and compositional variation in igneous garnets from the Tezhsar Alkaline Complex (Lesser Caucasus, Armenia)

Ralf Halama1, Krzysztof Sokół2, Khachatur Meliksetian3, Ivan P. Savov4, David Chew5

1School of Geography, Geology and the Environment, Keele University, United Kingdom; 2Department of Earth Sciences, University of Oxford, United Kingdom; 3Institute of Geological Sciences, Armenian National Academy of Sciences, Yerevan, Armenia; 4School of Earth and Environment, University of Leeds, United Kingdom; 5School of Natural Sciences, University of Dublin, Republic of Ireland

Garnet in alkaline igneous rocks is of interest due to its compositional and textural variability that provides insights into magmatic and hydrothermal processes. This study investigates textures and mineral chemistry of garnets from the Tezhsar Alkaline Complex (Armenia) to constrain their petrogenetic origin by determining whether the garnets are a primary magmatic liquidus phase or whether they have a secondary, subsolidus origin. Element mobility during garnet formation is evaluated, focusing on rare earth elements (REE), for which alkaline igneous rocks are a globally important resource and which are a valuable geochemical tracer to understand the evolution of rock-melt-fluid systems.

In the Tezhsar Alkaline Complex, K-rich plutonic and volcanic rocks occur in concentric units, representing the remnants of a palaeocaldera (Sokół et al., 2018). Garnet occurs in euhedral to subhedral clusters in pegmatitic nepheline syenite and more rarely as phenocrysts in syenites. The calcic garnets have a high Ti content (c. 2-4 wt.% TiO2), which is typical for garnet in alkaline igneous rocks. Garnet in the pegmatitic nepheline syenite is devoid of inclusions and shows only limited chemical variability, interpreted to reflect crystallization from a melt. In the syenite, garnet is rich in mineral inclusions and is interpreted to reflect a metasomatic origin during late/post-magmatic growth. Trace element data is being acquired to constrain the physicochemical conditions of garnet growth and evaluate REE incorporation into garnet.

Reference: Sokół, K. et al., 2018. Lithos 320-321, 172-191.



10:30am - 10:45am
Topics: 3.27 Alkaline rock and carbonatite related magmatism

The connection between perovskite, magnetite, titanite and schorlomitic garnet in nephelinitic rocks from Burko volcano, Tanzania

Fabian H. Schmitt, Michelle Siegel, Mika Henzler, Michael Marks, Gregor Markl

University of Tübingen, Germany

Burko is a nephelinitic volcano in the Gregory Rift of the East African Rift System (EARS), situated in northern Tanzania. The rocks are olivine-free and phonolitic nephelinites, deposited as tuffs, agglomerates and lavas that frequently contain plutonic inclusions. Based on geochemical data, a carbonatite-metasomatized mantle source has been assumed for these rocks (Mana et al., 2015).

We present a detailed mineralogical and petrological study of the variably evolved Burko rocks (whole-rock Mg numbers <50), which contain either nepheline + Fe-Ti oxide + perovskite + diopsidic pyroxene or nepheline + Fe-Ti garnet + titanite + hedenbergitic pyroxene ± alkali feldspar assemblages. Such an evolution of relatively oxidized and strongly SiO2-undersaturated alkaline magmas towards peralkaline compositions may be a common process and is probably controlled by T-aSiO2-fO2 changes. Based on a comparison with spatially associated nephelinitic volcanos like Sadiman and Ol Doinyo Lengai, we discuss similarities and differences in their genesis.

Mana, S., Furman, T., Turrin, B. D., Feigenson, M. D., and Swisher, C. C., III, 2015, Magmatic activity across the East African North Tanzanian Divergence Zone: Journal of the Geological Society, v. 172, no. 3, p. 368-389.



10:45am - 11:00am
Topics: 3.27 Alkaline rock and carbonatite related magmatism

Rare Earth Elements in Alkaline-Silicate Roof Zones: Late-Stage Magmato-Hydrothermal Processes in the Motzfeldt Igneous Centre, South Greenland

Curtis James William Rooks1, Donald Angus Herd1, George Frangeskides2, Adrian Anthony Finch1

1University of St Andrews, United Kingdom; 2Stallion Resources Limited, United Kingdom

The Motzfeldt Centre forms part of the Igaliko Complex: one of the major complexes of the Mesoproterozoic Gardar Igneous Province of Southern Greenland. This syenite hosts a Ta-Nb-Rare Earth Element (REE)-Zr alkaline-silicate roof zone, containing several metals classed as “critical” to the economy by the EU.

This study carries out detailed mineralogical, geochemical, and microtextural analysis of REE-enriched syenite variants from Motzfeldt using BSE-SEM imaging, EPMA, WDS mapping, and RAMAN spectroscopy. These data provide evidence that an aggressive, magmatically derived, F-rich fluid (F1) altered primary magmatic pyrochlore (P0), replacing it with mineralogically heterogeneous pseudomorphs formed of secondary pyrochlore (P1) and several alteration phases. Also found also encrusted on the surface of P1, these intergrown secondary phases are formed of elements lost from P0 during alteration including Nb, REEs, F, Ca, Zr. In a second hydrothermal event (F2), these crusts are “scrubbed” from the surface of P1, dissolving into and enriching that fluid (F2) in the elements scavenged from those minerals. The escape structures formed by the fluid F2 as it exits the system are breccia pipes, cemented by a rock mineralogically reminiscent of carbonatite. Previously interpretations were that these structures were entirely magmatic, but our findings indicate these structures are late-stage hydrothermal in origin. This may be a novel mechanism by which carbonatite-type rocks are formed.

These processes display how early intensive hydrothermal events can prime an ore body for further alteration, through conversion of refractory primary phases into secondary phases more vulnerable to hydrothermal attack.



11:00am - 11:15am
Topics: 3.27 Alkaline rock and carbonatite related magmatism

Fluid Evolution in the Iivaara Alkaline Complex (Finland): a Fluid Inclusion Study

Fahmi Hakim, Tobias Fusswinkel, Sven Sindern

RWTH Aachen University, Germany

Alkaline igneous rocks are known to host a variety of rare metal deposits, including HFSEs and REEs. The Iivaara alkaline complex (Finland) and the surrounding fenite aureole show Ti-dominated enrichment of HFSEs carried by titanite and apatite. Mineralogy and textural observation indicate a shallow intrusion level, fast cooling, and steep temperature gradients, as well as expulsion of different fluids. So far, the roles of different fluids in rare metal enrichment in such systems have not been fully understood. New results of a fluid inclusion (FI) study including FI petrography, microthermometry, phase identification using Raman spectroscopy, and quantification of elements by LA-ICP-MS reveal the fluid evolution in the Iivaara alkaline complex. Three stages can be distinguished: magmatic fluid, post-magmatic fluid, and late aqueous fluid. Magmatic fluid is characterized by relatively high salinity, with a dominance of methane in the vapor phase. This fluid type is responsible for the fenitization process as well as transporting some important elements and metals like HFSEs and REEs. The post-magmatic fluid is characterized by relatively low salinity with very low to no methane concentration in the vapor phase. This fluid is responsible for recrystallization of some minerals, especially apatite and the formation of cancrinite as a replacement mineral and as a vein. And the last fluid is an aqueous fluid which is very low in salinity, interpreted as meteoric water influx at the very late stage.

 
10:00am - 11:15am1.11-1 Unlocking CO2 storage potentials for Germany
Location: Wiwi 108
Session Chair: Gesa Kuhlmann, BGR
Session Chair: Sebastian Bauer, Christian-Albrechts-Universität zu Kiel
 
10:00am - 10:30am
Invited Session Keynote
Topics: 1.11 Unlocking CO2 storage potentials for Germany

Legal framework for CCS – Overview and first lessons learnt

Johanna Kemper

Wintershall Dea AG, Germany

The advancement of CCS-techniques is a significant tool to mitigate climate change and achieve net zero emissions. On European Level, the CCS-Directive (2009/31/EG) provides for a legal framework for, i.a., exploration and storage permits for storage sites, monitoring during and after the operational phase, requirements for closure and transfer of responsibility. The member states and associated countries have implemented these rules into national legislation. This contribution aims to, firstly, provide an overview over the regulatory framework in Europe and exemplary member states. It seeks to, secondly, outline first practical experiences from individual approval processes and to, thirdly, draw conclusions for further implementation. In this part, the focus will be on the evolving legal framework in Germany, i.p. the necessary legislative steps and possible accelerating tools.

Wintershall Dea is actively involved in developing CCS-solutions: The first Carbon Storage Project “Greensand” marks a milestone, demonstrating how CCS can move across borders through an international infrastructure that connects emissions sources with storage capacities. In the first quarter of 2023, the leading consortium partners INEOS and Wintershall Dea received the storage license from the Danish authorities and concluded the pilot phase with a first injection in the world’s first cross-border, offshore CO2 storage project. Wintershall Dea holds or has a applied for further storage licenses in Norway and the Netherlands. This allows to tackle the procedural law issues targeted in this contribution from a practical angle.



10:30am - 10:45am
Topics: 1.11 Unlocking CO2 storage potentials for Germany

Exploring for CCS

Gesa Luise Netzeband, Susanne Kuchling

DGMK e.V., Germany

CCS has been identified as a key element for limiting global warming. The adoption of the EU Green Deal and other European regulation have made carbon capture and storage technologies an important part of the EU decarbonisation effort.

The technology has been established in a different contexts, but CCS is not yet a routine industry application and it requires upscaling, if subsurface storing of the hard-to-abate emissions and later on Carbon dioxide from DAC and BE are to make a difference in the emerging climate crisis.

Several studies assessing storage potential in Europe have been conducted identifying large potential storage volumes, while the decision-making process regarding the application of CCS is still ongoing in many countries.

Regardless of the outcome, for CCS to become a valid option in 2030, exploration has to start now, as thorough exploration and compiling nationwide portfolio of potential sites will take several years.

In this presentation, a possible route through the site development process is delinated, covering all aspects of safe and permanent CO2 injection from exploration execution to field development. Risk assessment and mitigation play a crucial role in this framework. In addition, project-specific parameters like reservoir parameters, drill sites and well paths and in addition to absolute storage volume, the storage capacity over time are discussed, providing key input for a comprehensive analysis leading to a balanced portfolio.

A systematic assessment of potential sites is the basis for selecting the optimal locations, constructing efficiently dimensioned plants and establishing a process of maximum safety.



11:00am - 11:15am
Topics: 1.11 Unlocking CO2 storage potentials for Germany

CO2 storage potential of the Middle Buntsandstein in the Exclusive Economic Zone (EEZ) of the German North Sea

Arne Fuhrmann, Stefan Knopf, Niklas Ahlrichs, Heidrun Stück, Felix Kästner, Hauke Thöle, Gesa Kuhlmann

Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Hannover

The storage of CO2 in deeply buried geological formations provides an important contribution to mitigate residual emissions from heavy industry in order to limit global warming below 2 °C. Robust geological models and storage capacity estimations are crucial for the successful planning and implementation of long-term storage projects. This study focuses on the CO2 storage potential of the Middle Buntsandstein within the Exclusive Economic Zone (EEZ) of the German North Sea. We mapped a total of 69 potential storage sites based on existing 3D models, seismic data and 39 exploration wells. Static CO2 volumes are calculated for each structure using a Monte-Carlo-Simulation with 10.000 iterations to account for uncertainties. All potential reservoirs are evaluated based on their volume, burial depth, top seal integrity (thickness, faults) and trap type (salt-pillow and -domes, fault, stratigraphic and combined types). The best storage conditions are associated with salt-controlled anticlines on the “West Schleswig Block” with moderate burial depths, large volumes, and limited lateral flow barriers. Poor conditions are encountered in small, deeply buried (down to 7500 m), and structurally complex parts of the Horn- and Central Grabens. We identified 39 potentially technical feasible storage sites with burial depths above 4500 meters and suitable reservoir volumes (P50 confidence level above 5 Mt CO2). The estimated total static storage capacity ranges between P90 =948 Mt, P50 = 2695 Mt and P10 =5794 Mt. This comprehensive overview about the static CO2 storage capacities highlights the most prolific reservoirs and indicates locations for further exploration.

 
10:00am - 11:15amEarth Learning Ideas Workshop
Location: Wiwi 103
Session Chair: Sylke Hlawatsch, Richard Hallmann Schule
Session Chair: Martin Meschede, Universität Greifswald
Earthlearningideas (ELI) have been devised for schools, colleges or for the general public. They enrich geoscience teaching by offering engaging activities which increase knowledge and understanding, whilst enhancing the interest and enthusiasm of students and developing their critical thinking skills. More than 400 Earthlearningideas are currently published for free use online at: https://www.earthlearningidea.com/.
Since 2019 the European Geoscience Union - EGU has instructed Geoscience Education Field Officers (GEFO) from 19 countries in Europe and beyond. They provide short interactive workshops to support school teachers in teaching geoscience using Earth Learning Ideas.
All conference participants are welcome to join the workshop. You will get familiar with about 6 - 8 ELI and at the same time experience a conception for a teacher training workshop that has shown impact in the UK, Europe and beyond.
11:15am - 11:30amBreak
Location: Foyer (Henry Ford Building)
11:30am - 1:00pmPlenary Discussion: Nachhaltige Energie- & Rohstoffverfügbarkeit, sowie gesellschaftliche Herausforderungen
Location: Audimax
Session Chair: Britta Bookhagen, BGR
Die Plenardiskussion will das Zusammenspiel zwischen grundlegenden Erdprozessen, der Nutzung natürlicher Ressourcen und dessen Auswirkungen auf die Gesellschaft beleuchten. In jüngster Zeit haben die geopolitischen Entwicklungen weltweit den Bedarf an krisensicherer Energie- und Rohstoffversorgung, sowie sicherer und nachhaltiger Lieferketten verdeutlicht. Die Geowissenschaften besetzen in Rohstofffragen naturgemäß eine zentrale Rolle, sollten jedoch in Zukunft vermehrt als Bindeglied zwischen Industrie, Politik und Soziologie wirken. Dies wollen wir mit Vertreterinnen aus genannten Bereichen weiter erörtern.
1:00pm - 2:00pmDV-GEO Townhall Meeting mit Mittagsimbiss
Location: Wiwi 103
In diesem offenen Format stellt der Vorstand des DVGeo seine Aktivitäten rund um die stärkere Vertretung der Geowissenschaften in Politik und Gesellschaft, den GeoNachwuchs, der Unterstützung von GeoVerbundprojekten, das Projekt GeoDE und die AG "Mehr Geowissenschaften in der Schule" vor. Wir freuen uns darauf, mit Ihnen ins Gespräch kommen!
1:00pm - 2:00pmLunch Break | Exhibition and CO2-Live Injection Event @ Wintershall Dea Booth
Location: Foyer (Henry Ford Building)
2:00pm - 3:30pm3.28-2 Developments and progress in regional geology
Location: Hall A (HFB)
Session Chair: Jonas Kley, University of Göttingen
 
2:00pm - 2:15pm
Topics: 3.28 Developments and progress in regional geology

The Namaqua Metamorphic Complex: Geochronology and geochemical signatures of the Aus Crystalline Complex (Southern Namibia)

Jessica Haschke1, Mandy Zieger-Hofmann1, Johannes Zieger1, Ulf Linnemann1, Anja Sagawe1, Andreas Gärtner1, Sebastian Haschke2

1Senckenberg Naturhistorische Sammlungen Dresden, Germany; 2Technische Universität Bergakademie Freiberg, Germany

The Namaqua Metamorphic Complex (NMC) forms a basement unit of the Grenvillian-Kibaran collisional orogen in southern Namibia and South Africa. The Aus Crystalline Complex is a terrane within the NMC and consists, predominantly, of gneisses, granites, metavolcanites, and metasediments. The objective of our study is to generate new knowledge about crustal evolution during the Kibaran orogeny using age dating and whole rock geochemistry of various basement units of the crystalline complex around Aus.

Outcropping basement rocks were Aampled in the Namib Desert, southwestern Namibia, east of the coastal town of Lüderitz, within a 20 km radius around Aus. Rock types encountered included granulites, gneisses, charnockites, granites, and pegmatites. Geochemical and geochronological analyses were performed to gain information on the timing of crystallisation and crust production processes, using U-Pb dating on magmatic zircons with LA-ICP-MS. Analysed zircon grains are often complex, U-Pb ages range from 1700 Ma to c. 700 Ma. The oldest rock is a charnockite showing an age of intrusion of c. 1700 Ma, which represents a Palaeoproterozoic part of the cratonic basement. U-Pb zircon ages of the gneisses point to protolith ages of c. 1155 Ma – 1145 Ma. This coincides with a major tectono-magmatic event in the NMC, which occurred in a time span of c. 1190 - 980 Ma. Such processes led to the amalgamation of the supercontinent Rodinia in late Mesoproterozoic time. A younger suite of granitoids (c. 700 Ma) is most probably related to Rodinia dispersal.



2:15pm - 2:30pm
Topics: 3.28 Developments and progress in regional geology

The Early Permian Bromacker paleoenvironment: Preliminary results from scientific drilling in the Tambach Basin (Thuringia, Germany)

Jakob Stubenrauch, Thomas Voigt, Rebecca Lellau, Niklas Störer, Anna Pint, Christoph Heubeck, Peter Frenzel

Friedrich-Schiller-Universität Jena, Germany

The Bromacker Project (https://bromacker.de/) investigates the paleoecology of the Early Permian vertebrate “Ursaurier” lagerstätte of the same name in the red beds of the Tambach Formation, Thuringia. Its geologic-paleontologic subproject aims to contribute key paleoenvironmental parameters such as temperature variation, precipitation estimates, paleoelevation, soil hydrology, detailed paleogeography, and depositional environments, based on sedimentology, paleoichnology, facies analysis, petrography, geochemistry, and precise depositional ages.

Two new deep research boreholes will complement information from shallow legacy boreholes and outcrops near the Bromacker excavation site. Forschungsbohrung (Fb) Altenbergen 01/2022, 3 km to the north, cored 250 m of the Tambach Formation and terminated in conglomerates (Bielstein Member) after having cored the topmost Finsterbergen Conglomerate Member and the Tambach Sandstone Member. Contacts between members in core are gradual but differences pronounced: The basal Bielstein Member is dominated by well-rounded intermediate volcanic clasts, in contrast to felsic volcanic clasts described from outcrops. Fossiliferous pelitic-arenaceous redbeds of the overlying Tambach Sandstone Member show all indications of floodplain facies, including mudcracks, variable burrowing, root horizons, calcareous paleosol concretions, climbing ripples, and common laminated siltstones. Conglomerates of the topmost Finsterbergen Member consist of subangular plutonic, metamorphic and (sub-)volcanic clasts. Several newly documented thin felsic tuffs may be datable. Geophysical logs suggest rhythmic deposition suitable for cyclostratigraphic analysis. Fb Gallberg 01/2023, located 2 km south of the Bromacker excavation site, will complement Fb Altenbergen. Information from both boreholes will contribute to a robust sedimentologic-stratigraphic frame for paleogeographic-paleoecologic analyses. A substantial education and outreach program accompanies excavation, drilling and core analysis.



2:30pm - 2:45pm
Topics: 3.28 Developments and progress in regional geology

The geology of the South-Eastern Harz Foreland visualized in a 3D-Model

Melanie Siegburg, Alexander Malz, Tilman J. Jeske, Christian-Olaf Müller, Ivo Rappsilber

Landesamt für Geologie und Bergwesen Sachsen-Anhalt (LAGB), Halle (Saale), Germany

The Central European Basin is an intracontinental basin filled with Permian to Quaternary sediments. The southeastern basin rim, an area roughly covering the southern part of Saxony-Anhalt and eastern Thuringia (Central Germany), is characterized by complex facies distributions with a stratigraphic gap of approximately 200 Ma, where Cenozoic sediments unconformably cover the lower Triassic strata. The sedimentary rocks include several hundreds of meters thick evaporites, sandstone, shale, and carbonates of Permian to Late Triassic age, covered by unconsolidated sediments.

Various tectonic structures like NW-SE trending uplifted basement e. g. the Harz and Kyffhäuser Mountains and narrow fault zones where some abruptly ending along-strike; subordinated NE-SW trending faults sub-parallel to the Permian basin rim and salt structures characterise the area. These structures evolved during several phases of extension and contraction during Mesozoic to Cenozoic times. Due to the stratigraphic gap of the upper Mesozoic, tectonic and halokinetic processes can be well correlated with the wider Central European Basin and earlier structures. Local halokinetic processes and subrosion of evaporites indicated by the distribution of Tertiary deposits as well as variation of the thickness of evaporites influencing the geomorphology at the South-Eastern Harz Foreland until today.

Here, we used 3D modelling techniques and compiled data from drilling, seismic reflection profiles and historic mining surveys to visualize the temporal - spatial distribution and structural configuration of the South-Eastern Harz Foreland. This model will be used to unravel kinematic processes over geologic times, which will be a basis for future underground planning efforts.



2:45pm - 3:00pm
Topics: 3.28 Developments and progress in regional geology

The structure of Börnersdorf (Osterzgebirge) - an evidence of a maar volcano

Ottomar Krentz1, Frank Horna2

1Dr. Spang GmbH Witten/Freiberg, Germany; 2Sächsisches Landesamt für Umwelt, Landwirtschaft und Geologie Dresden/Freiberg

During a mapping-project in 2011, evidence of a sediment occurrence was discovered within a morphological depression of a gneiss area in the Osterzgebirge near the village of Börnersdorf (Saxony). Marls and partly sandstones, presumably Cretaceous in age, were described by means of drill cores from the 1960s.

The short wells drilled around 2010 supported this assumption. Results of several geophysical investigations displayed a basin structure with 600 m in diameter and up to 350 m in depth. Paleontological data of the examined marls pointed to a Coniacian age of the sediments that infill the structure. Until recently, the structure was interpreted as either a tectonic pull apart basin or a maar structure.

In 2021, first investigations for a new railway track from Dresden to Prague were carried out.

In order to realize this project, a tunnel of about 30 km in length crossing the Erzgebirge is planned. Therefore, several new wells were sunk in the area of investigation. One of the cores near Börnersdorf provided a breccia of grey marl and black silt pebbles and cobbles. As there is not a tectonic contact between the breccia and the surrounding gneiss, the sediment is interpreted as a collapse breccia. New paleontological examinations proof a late Turonian to middle Coniacian age of the marls.



3:00pm - 3:15pm
Topics: 3.28 Developments and progress in regional geology

The regional significance of the potash deposits in the Danakhil depression, Ethiopia

Sebastiaan van der Klauw, Christian Fritze, Stephan Pfeifer

ERCOSPLAN, Germany

The Danakhil depression is a regional structure in Ethiopia that extents over about 450 km from the Gulf of Djibouti to the NW approximately parallel to the Red Sea coast. It has a maximum width of about 75 km. On surface the SE part of the depression is dominated by recent volcanic rocks with only local windows to the sedimentary rocks below. The part NW of the Erte Ale volcanic structure at an elevation lower than 100 m below sea level is dominated by recent evaporite rocks and alluvial fan deposits with only few recent volcanic structures and is the focus for this contribution.

Although already since the early twentieth century potash and sulphur were mined from the region providing an incentive for investigations, the first regional geologic studies were published only in the 1970’s. These studies were based on interpretation of aerial photographs with minor ground checks. Although recently some further papers about the region have been published, the wealth of information about the regional geology that has been obtained from potash exploration that started in 2008 is hidden in publically accessible technical reports, not usually in focus of geo-scientists. The exploration targeted a neogene or quarternary potash-bearing evaporite sequence within the NW part of the depression. In this contribution we want to present some consequences for the understanding of the regional geology that were developed as a by-product of more than 10 years of potash exploration in the Danakhil depression.

 
2:00pm - 3:30pm4.08-1 Geological surveying as services for the public delivered by the State Geological Surveys of Germany - Current Issues
Location: Hall B (HFB)
Session Chair: Birgit Futterer, Landesamt für Bergbau, Geologie und Rohstoffe
 
2:00pm - 2:30pm
Invited Session Keynote
Topics: 4.08 Geological surveying as services for the public delivered by the State Geological Surveys of Germany - Current Issues

Action Plan "Digitalization of the Swiss Geological Subsurface" 2022 - 2029

Roland Baumberger

Federal Office of Topography swisstopo - Swiss Geological Survey

A coordinated and effective use of the subsurface requires in-depth knowledge and easily accessible and uniformly described data. The 2022 Action Plan supports the securing of future investments in the subsurface through the provision of structured and harmonized digital geological data.

The efficient use of geological data in Switzerland is hindered by these factors: 1) Existing data sets are neither completely available in digital form, nor comprehensive, nor harmonized; 2) Uniform access to federal and cantonal data is lacking; 3) Information systems for 3D visualization and analysis of geological and non-specialist (geo-referenced) data are being developed.

In the future, the main benefit of geoinformation will be generated from the improvement of efficiency in the processing of existing data and from increased data quality, not from new products. The action plan starts here and defines these fields of action: Standards, Harmonization, Production and Access. In doing so, it is aligned with various strategies and policy areas. The digitalization called for in the action plan will facilitate the exchange and use of geological data and improve their availability. A coordinated approach with the most important national data owners is in focus, as is the use of new technologies.

The success of the action plan will be measured after completion by the state of digitization of analog archives as well as the achieved standardization, harmonization and completion of geological data and models throughout Switzerland.

The presentation will highlight the background, scope, ongoing implementation and future of the action plan using practical examples.



2:30pm - 2:45pm
Topics: 4.08 Geological surveying as services for the public delivered by the State Geological Surveys of Germany - Current Issues

150 Jahre Geo-Sammlungen – von der Königlich Preußischen Geologischen Landesanstalt (KPGLA) bis zur Bundesanstalt für Geowissenschaften und Rohstoffe (BGR)

Angela Ehling

BGR, Germany

Der Beginn des systematischen, wissenschaftlichen Sammelns von Mineralen und Fossilien in Berlin ist eng verknüpft mit der Gründung der Berliner Bergakademie durch Friedrich II. Ab 1801 erhielt diese Sammlung die Bezeichnung „Königliches Mineralienkabinett“.

Mit der Gründung der Königlich Preußischen Geologischen Landesanstalt (KPGLA) 1873, der Integration der Bergakademie in jene wurde der systematische Aufbau des Probenarchivs - insbesondere in Zusammenhang mit der geologischen Kartierung Preußens und der Lagerstättenerkundung im In- und Ausland, inkl. der deutschen Kolonien forciert und es begann der Aufbau eines Geologischen Landesmuseums in Berlin. Ihrer Bestimmung nach dienten die Sammlungen in erster Linie als Archiv für das Belegmaterial aus der geologischen Kartierung und der wissenschaftlichen Erkundungsarbeiten. Der geschätzte Gesamtbestand umfasste 1939 ca. 1200 doppelseitige Schränke.

Nach erheblichen Verlusten des Sammlungsbestandes im 2. Weltkrieg, und der Abgabe von großen Teilen der im damaligen Ostteil Berlins befindlichen Sammlungen an das benachbarte Museum für Naturkunde durch die Staatliche Geologische Kommission der DDR hatte sich der Umfang der Sammlungen etwa halbiert. In den Jahren bis 1990 wuchs der Bestand wieder beträchtlich, insbesondere im Rahmen der intensiven und extensiven Rohstofferkundungen im Zentralen Geologischen Institut der DDR (ZGI).

Bei der Übernahme der Sammlungen durch die BGR 1990 lag die Anzahl der Schränke bei ca. 800. Seit 1996 sind die historischen geowissenschaftlichen Sammlungen sehr repräsentativ in Dienstbereich Berlin-Spandau in den ehemaligen Stallungen eines preußischen Kasernenkomplexes untergebracht. Die Digitalisierung und virtuelle Nutzbarmachung des umfangreichen Sammlungsbestandes für Wissenschaft und Öffentlichkeit stehen seither im Fokus der Arbeiten. Stand 2023 sind ca. 65 % des Bestandes online recherchierbar.



2:45pm - 3:00pm
Topics: 4.08 Geological surveying as services for the public delivered by the State Geological Surveys of Germany - Current Issues

Easy access to geological and geophysical data for the planning of underground spaces or subsurface project management in Mecklenburg-Western Pomerania

Karsten Obst, Juliane Brandes, Sabine Matting, André Deutschmann, Lisa Schwark, Johannes Kalbe

Geologischer Dienst, LUNG Mecklenburg-Vorpommern, Germany

The search for saline water springs started in the area of Mecklenburg-Western Pomerania several hundreds of years ago. First drillings to find coals seams were reported from the end of the 18th century. Mining for brown coal lasted from 1817 until 1960. Three mines produced between 1900 and 1926 potash and rock salt. First oil exploration wells were drilled in the 1920/30s without success. Numerous deep wells drilled between 1950 and 1990 reaching depths up to 8,009 m and about 3,600 seismic lines enabled the detection of several oil deposits. The huge amount of subsurface data allowed to find geothermal resources in the 1980s and is still the base for new scientific investigations and to develop projects of underground uses.

The archive of the Geological Survey of Mecklenburg-Western Pomerania comprises lithology data from 700 deep wells. More than 2,250 well logs exist, most of them are SP and GR logs. 70,000 m of cores from 400 wells document rocks from different eras beginning with the Mesoproterozoic basement of Baltica, covering the Caledonian deformed Ordovician on Rügen and the Devonian to Carboniferous strata of the Variscan foreland as well as the volcanics and sediments filling the North German Basin since the Permian. More than 11,000 rock samples and c. 26,000 thin sections used for petrographic descriptions are preserved. Countless analogue data gained from petrophysical and geochemical analyses still have to be digitized to fulfill the requirements of the Geological Data Act (GeolDG), especially for making geological data available for the public.



3:00pm - 3:15pm
Topics: 4.08 Geological surveying as services for the public delivered by the State Geological Surveys of Germany - Current Issues

Geological Archives in space and time – new challenges for vintage data

Alexander Malz, Thomas Häusler, Klaus-Jörg Hartmann, Bodo-Carlo Ehling

Landesamt für Geologie und Bergwesen Sachsen-Anhalt, Germany

The Geological Archives (geoarchives) of State Geological Surveys have an over 150 years old tradition. Since the first geological surveys were funded in the early 1870s State Geological Surveys collected, inventoried and provided samples, maps and reports from geoscientific exploration and analysis. As a result, geoarchives comprise a huge store of knowledge for geologic surveying and further applied questions. Thereby, work tasks in geoarchives have special focusses: (1) In contrast to classical steady-state archives, the inventory must be permanently available and usable for geological surveys and economic companies. (2) All inventory can accurately be georeferenced, i.e. even documents must be assumed to contain geoinformation. (3) Geoarchives contain material, e.g. rock samples, drill cores on the one hand and printed reports, maps and paper rolls on the other hand, with a broad spectrum of requirements on the storage conditions. With the commencement of the Geological Data Act (GeolDG) these tasks were recently expanded to aspects of digitalization and digital provision of geoarchive inventory. Therefore, all material must be completely checked, categorized and indexed with keywords to make the inventory FAIR (findable, accessible, interoperable and reusable). In our contribution we present the historical evolution and relevance of the geoarchive of the Landesamt für Geologie und Bergwesen Sachsen-Anhalt (LAGB) and explain our recent concepts against the background of the GeolDG.



3:15pm - 3:30pm
Topics: 4.08 Geological surveying as services for the public delivered by the State Geological Surveys of Germany - Current Issues

Digitalisierung von unüblichen geologischen Informationsträgern - vom Handstück zum 3D-Objekt

Rouwen Johannes Lehné, Heiner Heggemann

Hesssiches Landesamt für Naturschutz, Umwelt und Geologie (HLNUG), Germany

Im Rahmen der geologischen Landesaufnahme werden in Hessen, wie in allen anderen Bundesländern auch, seit weit über 100 Jahren wertvolle Gesteinsproben (Bohrkerne, Handstücke, Fossilien, Mineralien) gesammelt, beschrieben, analysiert und archiviert. So liegen aktuell alleine für das Gebiet Hessens über 45.000 Handstücke, mehrere 1000 Makrofossilien und ca. 700 Bohrungen vor. Der Öffentlichkeit bzw. interessierten Dritten stehen diese Archivalien zwar grundsätzlich zur Verfügung, jedoch stellen die bisher gegebenen Zugangsmöglichkeiten kein niederschwelliges Angebot dar. Im Zuge der digitalen Transformation sollen deshalb auch diese "unüblichen Informationsträger" digitalisiert und als 3D-Objekte funktional, performant und um weiterführende Informationen "angereichert" über das Internet abrufbar sein. Hierzu wird das Hesssische Landesamt für Naturschutz, Umwelt und Geologie (HLNUG) seit 2022 durch das Hessische Ministerium für Digitale Strategie und Entwicklung gefördert. Die Projektarbeiten adressieren sowohl die Erstellung von geologischen 3D-Objekten wie auch deren Visualisierung bzw. Veröffentlichung im Internet. Im Rahmen des Vortrages werden die bisherigen Bemühungen, der nunmehr präferierte methodische Ansatz und erste serienreife Ergebnisse vorgestellt. Dabei handelt es sich sowohl um Handstücke wie auch Bohrkerne. Auch wird das Konzept zur Veröffentlichung der erarbeiteten 3D-Objekte im Internet unter Berücksichtigung diverser Anwendungsfälle vorgestellt. Mit dem Vortrag möchte das HLNUG potenzielle Mitstreiter erreichen, sei es im Kreise der Staatlichen Geologischen Dienste oder auch Universitäten, wo die Digitalisierung der Lehre im Bereich der Grundlagenvermittlung auch und besonders bei den Geowissenschaften eine große Herausforderung darstellt.

 
2:00pm - 3:30pm1.04-1 Hydrogen: energy carrier in nature and for society – from natural hydrogen occurrences to large-scale hydrogen storage
Location: Hall C (HFB)
Session Chair: Maximilian Hasch, Bundesanstalt für Geowissenschaften und Rohstoffe
Session Chair: Peter Klitzke, Federal Institute for Geosciences and Natural Resources (BGR, Germany)
Session Chair: Philipp Weniger, Bundesanstalt für Geowissenschaften und Rohstoffe (BGR)
 
2:00pm - 2:30pm
Invited Session Keynote
Topics: 1.04 Hydrogen: energy carrier in nature and for society – from natural hydrogen occurrences to large-scale hydrogen storage

Natural Hydrogen – Is it a new game changing energy resource?

Jürgen Grötsch

Friedrich-Alexander University of Erlangen, Germany, Germany

The drive towards net-zero emissions as per the Paris 2015 agreement has resulted in significant efforts to develop sustainable energy resources. In order to change the current energy system, alternative resources need to replace wood, coal, oil and gas. One of the recent new findings in the Geo-Energy sector is natural hydrogen which can be found in many places around the globe as seeps.

Reasons for the lack of interest in hydrogen exploration so far are multi-fold, like nobody considered natural hydrogen as a viable option, hydrogen cannot be detected easily, other energy resources were available in large quantities and at low cost and more. However, many indications point towards a major clean energy resource of the future considering that in the last few years some 300 seeps have been reported. One of the most famous ones is the eternal fires of Chimaera in Turkey, know to burn since more than 2500 years. In the meantime, the first hydrogen exploration companies have formed and even a first long-term production test is ongoing.

Natural (white) hydrogen was until now not considered in the energy transition. If further developments turn out to be successful, this may result in another unexpected game changer in the energy sector similar to coal replacing peat in 1880. However, the question remains, what such a potential new energy opportunity could look like as part of the future energy mix. This talk will highlight the current status and potential ways forward on this new energy resource.



2:30pm - 2:45pm
Topics: 1.04 Hydrogen: energy carrier in nature and for society – from natural hydrogen occurrences to large-scale hydrogen storage

DEPTH STRUCTURE FEATURES OF LARGE ZONES OF HYDROGEN DEGASSING IN GERMANY BY RESULTS OF FREQUENCY-RESONANCE PROCESSING OF SATELLITE AND PHOTOS IMAGES

Nikolay Yakimchuk1, Ignat Korchagin2, Arzu Javadova3

1Institute of Applied Problems of Ecology, Geophysics and Geochemistry, Laboratorny Lane, Kyiv, Ukraine; 2Institute of Geophysics, NAS of Ukraine, 32, Palladin Ave., Kyiv, 03680, Ukraine; 3Micropro GmbH , Germany

The results of the application of the mobile direct-prospecting technology of frequency-resonance processing and interpretation of satellite images and photographs in large areas and local areas of hydrogen degassing in German various regions are presented. Experimental reconnaissance studies were carried out to study the features of the deep structure of hydrogen-degassing areas.

Instrumental measurements confirmed the presence of large zones of hydrogen degassing in the areas of basalt volcanoes in Bavaria. Signals at the frequencies of hydrogen, basalts and healing water were recorded at the sites performed for the hydrogen migration. Measurements recorded the facts of hydrogen migration into the atmosphere. When scanning the cross-section, responses from hydrogen are recorded from the upper edges of basaltic volcanoes to their roots. Signals at hydrogen frequencies were also recorded from limestones, dolomites, and marls overlying the basalts from above (including at shallow depths). Experimental studies have also shown that siliceous rocks can be a good seal for hydrogen. There is no hydrogen migration into the atmosphere within basalts, overlapped by siliceous rocks. The obtained results of experimental work are also additional evidence in favour of the "volcanic" model of the formation of various structural elements and the external appearance of the Earth, as well as deposits of combustible and ore minerals (including hydrogen and water).

The use of mobile and low-cost technology will significantly speed up the exploration process for hydrogen, as well as reduce the financial costs for its implementation.

Keywords. Hydrogen,basalts, limestones,healing water, abiogenic genesis,volcano,direct searching,remote sensing data



2:45pm - 3:00pm
Topics: 1.04 Hydrogen: energy carrier in nature and for society – from natural hydrogen occurrences to large-scale hydrogen storage

A Proof-of-concept study of microbial activity in water-filled pore space: an experimental investigation of methanogenic conversion of hydrogen to methane in reservoir rocks

Saeed Khajooie1, Garri Gaus1, Anja Bettina Dohrmann2, Martin Krüger2, Ralf Littke1

1Institute of Geology and Geochemistry of Petroleum and Coal, Energy and Mineral Resources Group (EMR),RWTH Aachen University, Germany; 2Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR), Germany

The activation of methanogenic Archaea in the context of subsurface hydrogen storage may lead to permanent hydrogen conversion to methane. The objective of this proof-of-concept study is to experimentally investigate these activities, and it is focused on reservoir analogues from the Cretaceous and Triassic periods. These analogues have been selected based on their varying porosities, which range from 8% to 24%. Methanothermococcus thermolithotrophicus was used as the model organism due to its relatively high activity and growth rate. The microbial activities in various water-saturated reservoir rocks with either similar bulk or pore volumes, as well as inoculated media containing sand particles and rock fragments, were experimentally studied and compared to values obtained in bulk solutions. Measured activities in the water-saturated rock specimens with identical bulk volumes varied between 0.17 and 1.22 mM H2 /h largely correlating with the pore volume. Furthermore, the results indicated that activities in the water-filled pore space of the respective rocks were higher by a factor of 8-10 compared to activities in bulk solutions. This observation, in conjunction with the measured activities in inoculated media containing sand particles and rock fragments, as well as in rocks with similar pore volume, supported the notion that the surface area available for microbial colonization is another factor in controlling activity when the amount of substance is held constant. Additionally, the study suggests that methanogenic activities used to quantify hydrogen conversion in reservoirs must potentially be revisited because they are typically measured on bulk solution rather than within intact rocks.



3:00pm - 3:15pm
Topics: 1.04 Hydrogen: energy carrier in nature and for society – from natural hydrogen occurrences to large-scale hydrogen storage

Rapid microbial consumption of gaseous hydrogen injected into a shallow aquifer

Nina-Sophie Keller1, Michaela Löffler2, Götz Hornbruch3, Klas Lüders3, Markus Ebert3, Susann Birnstengel1, Carsten Vogt1, Andreas Dahmke3, Hans-Hermann Richnow1

1Helmholtz Centre for Environmental Research - UFZ, Germany; 2DECHEMA e.V.; 3University of Kiel, Institute of Geosciences

Hydrogen (H2) was injected into a shallow aquifer at the TestUM field site (close to Wittstock, Brandenburg, Germany) in order to simulate a H2 gas leakage scenario. The resulting biogeochemical processes were monitored in space and time by analyses of stables hydrogen isotopes, groundwater microbial community composition and geochemical parameters in two monitoring wells (D04, D06) close to the injection wells, and a reference well (D11) not directly affected by the injected H2. During the injection, initial shifts in the isotope signature of H2 were observed, probably caused by dissolution of H2 in the water phase and the migration of the gas phase through pores and channels in the aquifer. After the injection, H2 concentrations in D04 and D06 decreased within less than 80 days from maximal 850 µmol/L below the detection limit, accompanied by an equilibrium isotope exchange with water leading to a strong isotopic depletion of H2, a reaction typically catalyzed by the H2-cleaving enzyme hydrogenase. Microbial H2 oxidation and subsequent growth of hydrogenotrophic prokaryotes was further indicated by temporally increasing abundances of putative H2-oxidizing sulfate reducers, acetogens, nitrate reducers and aerobes, accompanied by nitrate disappearance and transiently increasing acetate concentrations. In summary, the results confirm our expectation that H2, being an excellent energy source for many microorganisms, is quickly microbiologically consumed in an aquifer after a leakage.

 
2:00pm - 3:30pm1.23-2 Sustainable Groundwater Management to mitigate Water Scarcity:...
Location: Hall D (HFB)
Session Chair: Irina Engelhardt, TU Berlin
Session Chair: Peter Dietrich, Helmholtz-Zentrum für Umweltforschung GmbH - UFZ
Session Chair: Martin Sauter, Leibniz-Institut für Angewandte Geophysik
 
2:00pm - 2:30pm
Invited Session Keynote
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Challenges in developing a transboundary groundwater model for the water stressed capital region of Berlin-Brandenburg

Bertram Monninkhoff1, Kerstin Kernbach2, Ulrike Hoermann2, Johannes Birner2, Felix Moehler3, Malte Kalter3

1Berliner Wasserbetriebe, Germany; 2Senatsverwaltung für Umwelt, Mobilität, Verbraucher- und Klimaschutz; 3GCI GmbH

Higher temperatures and increasing droughts are likely to lead to a reduction in available water resources in the Berlin-Brandenburg region. Concurrently, there is an increasing demand for water due to the population and economic development in the region. This results in serious water management challenges. To mitigate this water scarcity, in 2021, work began on setting up a coordinated joint groundwater management system based on a transboundary groundwater flow model for the capital region (approx. 2800 km², from which Berlin covers 892 km²). The central component is the modelling of the reciprocal effects of the groundwater abstraction by the water suppliers in the region with regard to sustainable management of the common groundwater body. In the first step, the hydrogeological structural model (HSM) for the region is created. In doing so, up-to-date geological sections from the Berlin and Brandenburg Geological Surveys as well as stratigraphical settings from existing calibrated groundwater models are brought together. The groundwater models of the Berliner Wasserbetriebe are also incorporated in this process. These models have been developed since approximately 20 years and are regularly updated. They are used both in approval processes and in daily operation. In the second step, the HSM is converted into a flow model. This flow model is calibrated and compared with the existing models. In the end, a model for the entire capital region will be available for the first time. At the conference, the current status of the project will be presented and the challenges will be highlighted.



2:30pm - 2:45pm
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Interaktives Grundwassermodell im Bereich Wassermanagement

Ferdinand Flechtner, Katja Eulitz

DHI WASY GmbH, Germany

In vielen Regionen zeigt die Auswertung der Grundwasserstandsentwicklung, dass ein Rückgang der Grundwasserstände zu verzeichnen ist (z.B. NLWKN, 2020). Jedoch steigen gleichzeitig der Wasserbedarf und die Anzahl der Wasserrechtsanträge, vor allem in landwirtschaftlich geprägten Regionen. Vor diesem Hintergrund, wird auch in der Forderung des Deutschen Vereins des Gas- und Wasserfaches e.V. (DVGW Wasser-Impuls: Zukunftsbilder 2030 bis 2100) beschrieben, dass bei der Entwicklung und Umsetzung langfristiger Zukunftskonzepte im Bereich Wassermanagement digitale Lösungen eine erhebliche Unterstützung sein sollen. Dazu werden u.a. Prognose- und Managementmodelle für ganze Einzugsgebiete vorgeschlagen.

In diesem Sinne wurde für den Landkreis Vechta ein Grundwassermodell in FEFLOW erstellt, um bei der Bearbeitung von Wasserrechtsanträgen zu unterstützen (Flechtner et al., 2022). Grundwassermodelle sind jedoch oft teuer und nur von Experten nutzbar. Das bedeutet, dass die Modellierung von weiteren Szenarien (z.B. erhöhte Pumpraten oder zusätzliche Brunnenstandorte), an denen der Kunde oder die Behörde interessiert ist, sprich die Weiterverwendung des Modells, meist von externen Experten durchgeführt werden muss. Um der Behörde ein wie vom DVGW beschriebenes Prognose- und Managementmodell bereitzustellen, welches von dieser selbstständig im täglichen Geschäft verwendet werden kann, wurde von DHI WASY das Grundwassermodell zu einem interaktiven Modell erweitert. Dieses kann die Behörde in Ihrem täglichen Geschäft über eine Benutzeroberfläche selbst, mit wenigen, einfachen Arbeitsschritten, bedienen, ohne auf externe Experten angewiesen zu sein. Die Modellergebnisse der von der Behörde erstellten Szenarien werden automatisch exportiert und in einem interaktiven HTML-Format angezeigt, so dass der Kunde alle relevanten Daten und Ergebnisse schnell und auf einen Blick für weitere Entscheidungen zur Hand hat.



2:45pm - 3:00pm
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Experimental and numerical investigations to calculate long-term recharge in a water stressed region and to optimize nature-based MAR solutions

Lucia Magnano1, Arif Chowdhury2, Ahmed Abdelrahman1, Ronjon Heim3, Irina Engelhardt1

1TU Berlin, Germany; 2University Stuttgart; 3Adelphi

Climate projections indicate that extreme weather events have increased in frequency and intensity in the past and will affect sensitive Germany in the near future. Our study site, the catchment of the lower Spree, is located in Brandenburg. The region is affected by water stress showing a water deficit of 80 Mio. m3 on an area of 3500 km2 with many competing water users. Our goal is to investigate the impact of shifts in climate, land use and vegetation on recharge and available groundwater resources. In four different catchments with different characteristics we monitor groundwater und lake levels, stream discharge, and depth dependent soil moisture. Isotopic composition of precipitation, groundwater, and surface water is investigated to calculate water fluxes between different compartments. Electrical conductivity down to a depth of 200m below surface is recorded. Measured NaCl concentrations reach up to 10 – 15 g/kg. Employing the hydrological model SWAT evapotranspiration, discharge and soil moisture are calibrated to calculate long-term groundwater ranges pattern, which ranges in average at 77 mm/a. The M-K test shows decreasing recharge from May to August, an increase from December to February, and almost no change from September to November leading to an overall decreasing trend over the last 20 years. We are planning to derive concepts for areas with highest economic or ecological value derived from socio-economic analyses for the implementation of artificial recharge using greywater, treated waste water or storm water to replenish the groundwater deficit and to retain uplift of the saline groundwater water.



3:00pm - 3:15pm
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Modeling the influence of climate on groundwater flow and heat regime in a water-stressed region – a case study of Brandenburg

Mikhail Tsypin1, Mauro Cacace1, Magdalena Scheck-Wenderoth1,2

1GFZ German Research Centre for Geosciences; 2RWTH Aachen University

We explore the effects of a changing climate on groundwater dynamics based on thermo-hydraulic simulations to reconstruct the temperature and pressure below the State of Brandenburg between 1950 and 2010. In this time period, observations point to ~1°C surface temperature warming, large annual fluctuations in groundwater recharge, and periods of high groundwater abstraction volume — all leading to water stress conditions. Our input structural model integrates Permian to Cenozoic sedimentary units with essential geological features controlling the regional groundwater flow, including salt structures, permeable glacial valleys, and aquitard discontinuities. We use a grid-based hydrologic model to derive inflow and outflow rates across the top boundary of the subsurface model. Simulation outputs are verified against data from available observation wells.

The simulation results demonstrate that the regional flow pattern in the deep aquifers (>1 km deep) is mainly controlled by the basin geometry, while shallow groundwater dynamics is heavily influenced by high-frequency climate forcing. Seasonal fluctuations in groundwater level are observed in areas of shallow (<10 m) water table, with the highest levels corresponding to months of greater recharge rates. Where the water table is deeper, it responds to precipitation pulses with a delay of several months. Seasonal groundwater heating and cooling is limited to the first 10–30 meters, except within glacial valleys where high hydraulic gradients and permeabilities lead to a deepening of the advective heat transport. In addition, we identified periods and regions of significant groundwater abstraction and sustained groundwater warming over the entire simulation period within urban areas.



3:15pm - 3:30pm
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Development of a water storage toolbox for surface-induced managed groundwater recharge

Jan Stautzebach, Jörg Steidl, Christoph Merz

Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e.V., Germany

Water stress is increasing in Northeast Germany due to climate change. New approaches for water management are needed to mitigate the impacts on the water system and water users. Therefore, our study deals with the development of a web-based toolbox for subsurface water storage with focus on the lower catchment of the river Spree in the federal state of Brandenburg.

Our approach is based on a systematic combination of site selection criteria and spatial data on land use, soil, groundwater and potential water sources. This will provide relevant information for the preliminary planning of managed groundwater recharge measures by authorities and water suppliers. Considering surpluses from runoff and surface waters, also caused by extreme weather events, suitable locations for surface-induced recharge will be identified.

Supported by additional modelling-based indications for implementation, efficiency and costs, as well as simplified site selection through a query system, the toolbox will offer an initial knowledge for such planning considerations.

 
2:00pm - 3:30pm3.16-2 Assessing biosphere geosphere interactions in the subsurface, at leaking wells, and natural vents and seeps
Location: Wiwi 101
Session Chair: Sebastian F. A. Jordan, Federal Institute for Geosciences and Natural Resources
Session Chair: Oliver Schmale, Leibniz Institute for Baltic Sea Research (IOW)
Session Chair: Jens Kallmeyer, GFZ Potsdam
 
2:00pm - 2:30pm
Invited Session Keynote
Topics: 3.16 Assessing biosphere geosphere interactions in the subsurface, at leaking wells, and natural vents and seeps

Fennoscandian Deep biosphere – similarities, differences and functions

Malin Bomberg

VTT Technical Research Centre of Finland, Finland

The continental subsurface contains approximately 12 – 20% of Earth’s biomass. In deep rock environments this biomass dwells in aqueous spaces, fractures and pores of the rock, either attached in biofilms or free-living in the fluids. Meta-analyses have suggested a core deep biosphere microbiome from pre-collected data but face issues such as difference in sampling procedures, DNA extraction methods, negative control protocols, sequencing primers etc., which may introduce false variation. Addressing this issue and striving for consistent methodology, 7 sites of the Finnish Fennoscandian Shield was studied between 2009 – 2021 ranging in depth from 100 to 2300 m. Some of the sites have deep groundwater with more than 50 Ma residence times, whereas in other places the groundwater is considerably younger. All microbiomes contained bacteria, archaea and fungi, and the microbial community composition differed greatly between sites indicating that rock type and hydrogeochemistry play a great role in moulding the communities. Chemoheterotrophy was the universally dominant predicted metabolic strategy. The bacterial numbers in the groundwater were between < 1 to more than 5 x 106 16S rRNA gene copies mL-1 but did not necessarily reflect sampling depth, but rather the concentration of DOC and DIC. In addition, dormant microbial communities activated within hours after introduction of CO2 or methane. Finally, groundwater monitored at one site for 10 years showed that the microbial communities did dot remain static but varied in size (up to 100-fold) and composition over time in a cyclic manner, interchanging between mainly two distinct community compositions.



2:30pm - 2:45pm
Topics: 3.16 Assessing biosphere geosphere interactions in the subsurface, at leaking wells, and natural vents and seeps

Experimental sulfidation of nano-magnetite at hydrothermal conditions – implications for the reconstruction of microbial life in ancient sulfide deposits

Eric A. Runge1,2, Muammar Mansor3, Andreas Kappler3,4, Jan-Peter Duda1,2

1Sedimentology and Organic Geochemistry, Department of Geosciences, University of Tuebingen, Germany; 2Geobiology, Geoscience Center, University of Goettingen, Germany; 3Geomicrobiology, Department of Geosciences, University of Tuebingen, Germany; 4Cluster of Excellence EXC 2124, Controlling Microbes to Fight Infection, Tübingen University, Germany

Nano-magnetite is a potential archive for biosignatures of iron-cycling microorganisms in hydrothermal systems, which are widely considered to be among the most ancient microbial habitats on Earth. Sulfidic diagenesis driven by hydrothermal fluids and microbial sulfur cycling potentially causes the rapid transformation of magnetite to iron sulfide minerals. Thus, identifying nano-magnetite and its transformation products in hydrothermal sulfide deposits is crucial for reconstructing iron- and sulfur-cycling microbial life in deep time. However, the identity and characteristics of iron sulfide minerals resulting from nano-magnetite sulfidation at hydrothermal conditions have previously not been constrained. Here we present experimental data on sulfidation reactions of synthetic and biogenic nano-magnetite at physical and chemical conditions relevant to microbial habitats in hydrothermal systems on early Earth (<121°C, anoxic, sulfidic). We characterize the resulting precipitates with analytical imaging techniques, mineralogical methods, and geochemical approaches (e.g., SEM-EDS, µXRD, Raman spectroscopy, sequential Fe extraction). Our results demonstrate a potential taphonomic bias against nano-magnetite in sulfidic hydrothermal habitats and suggest that biosignature records of iron- and sulfur-cycling microorganisms in ancient hydrothermal sulfides are affected by diagenetic fluid-mineral interactions.



2:45pm - 3:00pm
Topics: 3.16 Assessing biosphere geosphere interactions in the subsurface, at leaking wells, and natural vents and seeps

BioMetArchive - Subsurface biosphere metagenomics along the 1 Ma sedimentary archive of ferruginous Lake Towuti, Indonesia

Fatima Ruiz Blas1, Jens Kallmeyer1, Cynthia Henny2, James Russell3, Aurèle Vuillemin1

1GFZ German Research Centre for Geosciences, Section Geomicrobiology, Potsdam, Germany; 2Research Center for Limnology and Water Resources, National Research and Innovation Agency (BRIN), Bogor, Indonesia; 3Department of Earth, Environmental, and Planetary Sciences, Brown University, Providence, Rhode Island, 02912 USA

Lake Towuti, Indonesia is a stratified ferruginous (iron-rich, sulfate-poor) system whose deep basin experienced dynamic changes in trophic and redox conditions since the Middle Pleistocene. As wet and dry periods alternated and sediment accumulated, microbial life sustained by metals and organic substrates became entombed in the subsurface. A 1 Ma stratigraphic archive retrieved by the International Continental scientific Drilling Program (ICDP) was sampled aseptically on site for microbiology analysis. Through taxonomic and functional analyses (16S rRNA amplicons, metagenomics), the BioMetArchive project aims at the first comprehensive characterization of the lacustrine subsurface biosphere in terms of diversity, abundance and metabolic functions.

Metagenomic data combined with high resolution cell counts and pore water geochemistry allowed to characterize the distribution of microorganisms throughout the core and to identify which microbial taxa and metabolic features are involved in the major biogeochemical cycles and organic matter remineralization during sediment burial. Results show a drastic decrease in the cell counts (from 109 to 104) as electron acceptors in the pore water chemistry become depleted within the upper 5 m of the sediment. Results of taxonomic and metagenomic analyses indicate that the sediment ferruginous conditions predominantly select for fermentative Bathyarchaeia. Metabolic features attributed to this entirely uncultivated phylum explaining their selective growth were indicative of sulfur transformations, organic matter fermentation and homoacetogenic dark carbon fixation. Thus, Lake Towuti shelters a deep biosphere displaying similarities to early life’s processes in ferruginous systems, which provides a direct link between cryptic sulfur cycling and redox conservative fermentations.



3:00pm - 3:15pm
Topics: 3.16 Assessing biosphere geosphere interactions in the subsurface, at leaking wells, and natural vents and seeps

Assessment of Eger Rift subsurface microbial communities showcases archaeal and bacterial processes driven by mantel derived CO2 degassing and regular seismic events.

Daniel Lipus1, Zeyu Jia1, Alexander Bartholomaeus1, Robert Bussert2, Dirk Wagner1,3, Jens Kallmeyer1

1GFZ German Research Centre for Geosciences, Germany; 2Institute of Applied Geosciences, Technical University Berlin, Berlin, Germany; 3University of Potsdam, Institute of Geosciences, Potsdam, Germany

Seismic activity and consistently high CO2 fluxes make the Eger Rift in Western Bohemia (CZ) a rare subsurface ecosystem and scientifically relevant location to study microbial behavior and assess how geologically derived compound are used in the deep subsurface. Studying microbial life in this ecosystem provides the opportunity to investigate how high CO2 levels and mineralogy influence microbial community composition and metabolic activity. Seismic activity in this region can also release H2, a process which may provide the basis for primary production through methanogenic archaea and should be explored.

To assess microbial processes associated with the Eger Rift subsurface we investigated diversity, community structure and metabolic attributes of bacterial and archaeal communities in drill core sediments and groundwater samples. We also analyzed the geochemical conditions in this subsurface system and studied the physiological responses of native Eger microbial communities to high CO2 via enrichments

Genomic analysis of sediment and water samples, covering depths between 17m and 230m, provided novel insights into a CO2 adapted microbial community. We detected strong Cyanobacteria and Proteobacteria signatures as well as unexpected archaeal diversity in sediments, and high abundances of acidophiles and sulfate reducers in water samples. Enrichment cultures from the recovered sediments suggested subsurface populations can actively utilize CO2 and H2, while reconstruction and annotation of MAGs provided insights into microbial processes driven by CO2.

Going forward our data will be used to further investigate cellular processes under high CO2 conditions and identify pathways and biomolecules which may be of industrial and biotechnological relevance.

 
2:00pm - 3:30pm2.03-2 Setting the stage for a habitable planet: Solid earth processes through time
Location: Wiwi 104
Session Chair: Elis Hoffmann, Free Universität Berlin
Session Chair: Josua Pakulla, Universität zu Köln
 
2:00pm - 2:30pm
Invited Session Keynote
Topics: 2.03 Setting the stage for a habitable planet: Solid Earth processes through time

A new tool to trace the redox-state of the upper mantle in the Archaean

Craig Storey1, Hugo Moreira1,2

1University of Portsmouth, United Kingdom; 2Géosciences Montpellier, Université de Montpellier, CNRS, France

The redox state of the upper mantle in the Archaean through to the Proterozoic is a key parameter as it would have buffered atmospheric composition and interacted with the ocean-atmosphere system. There have been multiple approaches using geochemical proxies, such as V-Sc and redox sensitive stable isotopes (e.g. Fe) applied to mantle-derived rocks to investigate this problem. As whole rock samples are prone to overprinting (alteration, metamorphism) and as mafic rocks in particular are difficult to date, a technique using a robust U-bearing accessory mineral might allow better and more trustworthy temporal constraints to be measured. Recent work developing an oxybarometer based on S in apatite using µ-XANES has shown great promise as apatite can seamlessly incorporate reduced and oxidised S species and directly reflect the fugacity of host magmas. Nonetheless, apatite crystals in a matrix rock are prone to alteration and recrystallisation, but apatite inclusions trapped in zircon during magmatic crystallisation are robust, with the advantage that the enclosing zircon can be dated and the mantle source traced via Lu-Hf and O isotopes. To demonstrate that this approach works, we have studied 2.35 Ga TTGs and 2.13 Ga sanukitoids from the Mineiro Belt, Brazil. These rocks temporally straddle the Great Oxidation Event. Apatite inclusions in zircons from this TTG-sanukitoid transitional magmatic record reveal a change from reduced to more oxidised conditions from pre- to post-GOE. We then discuss how this approach has and can be further applied to Archaean rocks as a tracing tool for earlier oxygenation events.



2:30pm - 2:45pm
Topics: 2.03 Setting the stage for a habitable planet: Solid Earth processes through time

Early mantle processes inferred from high-precision 182W-142Nd isotope systematics of igneous rocks from the Singhbhum Craton, India

Arathy Ravindran1, Josua Pakulla1, Jonas Tusch1, Eric Hasenstab-Dübeler1, Jaganmoy Jodder2, Axel Hofmann2, Rajat Mazumder3, Carsten Münker1

1Institut für Geologie und Mineralogie, Universität zu Köln, Germany; 2Department of Geology, University of Johannesburg, South Africa; 3German University of Technology in Oman, Oman

The scarcity of well-preserved exposed Precambrian rocks as well as post-emplacement metamorphism and alteration hamper a detailed understanding of mantle differentiation processes on the early Earth. This issue can be overcome by powerful tools such as the short-lived isotope decay series such as 182Hf-182W and 146Sm-142Nd isotope systems that only record radiogenic ingrowth during the Hadean Eon.

This study focuses on high-precision measurements of 182W/184W and142Nd/144Nd isotope compositions using MC-ICP-MS ([1], [2]) of ultramafic, mafic and felsic rocks from the Singhbhum Craton (India) that range in their crystallization age from 3.5 to 1.6 Ga. Due to the susceptibility of W to secondary fluid-rock interactions, the rock samples that were chosen were initially tested for mobility of W by a comparison of W with other equally incompatible elements such as Th, Ta, U [3] that were obtained by ICP-MS with a focus on precise measurements of High Field Strength Element concentrations (<6% uncertainty). Preliminary 182W isotope data that ranges from µ182W= -1.6 to -0.7 (±2-3 ppm; 95% CI) shows a slight tendency to negative values that are unresolvable from the modern mantle value. This data, in combination with robust 142Nd isotope constraints can give fresh insights into early mantle differentiation of the Singhbhum Craton and access the timescales of homogenization of the ambient mantle with late accreted material.

[1] Tusch et al. (2022), PNAS 119

[2] Hasenstab-Dübeler et al. (2022), Chem. Geo. 614

[3] König et al. (2011), Geochim. Cosmochim. Acta 75



2:45pm - 3:00pm
Topics: 2.03 Setting the stage for a habitable planet: Solid Earth processes through time

142Nd and 182W systematics of Neoarchean rocks from the Yilgarn Craton, W-Australia

Max Hellers1, Eric Hasenstab-Dübeler1, Jonas Tusch1, Carina Gerritzen2, Mario Fischer-Gödde1, Andreas Schneider1, Chris S. Marien1, R. Hugh Smithies3, Stephen Wyche3, Martin J. Van Kranendonk4, Carsten Münker1

1Unversity of Cologne, Germany; 2Vrije Universiteit Brussel; 3Geological Survey of Western Australia; 4University of New South Wales

The short-lived isotope systems 146Sm-142Nd and 182Hf-182W were active during the first ca. 500 Ma and 50 Ma after solar system formation. As a result of recent analytical advances, it is now possible to detect small 142Nd-182W variations (≤ 3ppm) within terrestrial samples providing unprecedented information on Earth’s accretion, early differentiation, as well as mantle mixing and homogenization rates.

Here, we present high precision 142Nd/144Nd and 182W/184W data for Neoarchean samples from the Yilgarn Craton, W-Australia, using previously published MC ICP-MS protocols [1,2]. We report µ142Nd deficits as low as -4.2 ± 1.4 for 2.7 Ga mafic-ultramafic samples from the Kalgoorlie Terrane. A contemporaneous mafic-ultramafic suite from the Kambalda area displays small µ142Nd values between +0.4 ± 1.2 to -1.5 ± 0.9 that seem to correlate positively with ε143Nd. If interpreted to represent a differentiation model age, this event could not have happened earlier than 4.13 Ga. This suite reveals a correlation of long-lived ε143Nd-ε176Hf isotope systematics, suggestive of a pristine mantle source. We further suggest that µ182W excesses from the Kalgoorlie and Kambalda suites (+5.3 ± 3.6 and +4.5 ± 1.6) demonstrate a missing late veneer component in the mantle source, in line with previously reported ε100Ru excesses found in the same samples [3]. In conclusion, our results demonstrate that mantle-derived rocks from the Yilgarn Craton carry isotope signatures directly referring to Hadean processes.

[1] Hasenstab-Dübeler et al. (2022) Chem. Geol. 614, 121-141

[2] Tusch et al. (2019) GCA 257, 284-310

[3] Fischer-Gödde et al. (2021) Goldschmidt Abstract 4362



3:00pm - 3:15pm
Topics: 2.03 Setting the stage for a habitable planet: Solid Earth processes through time

A 182W isotope perspective on the sources of Paleoarchean TTGs from the Eastern Kaapvaal Craton, southern Africa

J. Elis Hoffmann1, Jonas Tusch2, Pauline Sandor1, Guillaume Florin1

1Freie Universität Berlin, Germany; 2Universität zu Köln

182W deficits in terrestrial rocks are currently strongly debated since their origin can be ascribed to different processes. These include (1) core-mantle interaction, (2) grainy late accretion, and (3) early silicate differentiation. Mantle-derived rocks from the eastern Kaapvaal Craton yield variably negative µ182W values that are systematically correlated with initial values of the long-lived Hf-Nd-Ce isotope systems. These have been interpreted to reflect incorporation of an early Hadean crustal restite either in the deep mantle sources of Archean mantle plumes or within the upper mantle or lower lithosphere of the Kaapvaal Craton. Interestingly, granitoids from the Kaapvaal Craton are either overlapping with the modern 182W isotope composition or carry a strongly negative µ182W of down to -10, overlapping with Mesoarchean diamictites from the Kaapvaal Craton. Deviation of some granitoids from the Kaapvaal 182W-176Hf and 182W-143Nd array are likely caused by disturbance of the whole-rock Hf-Nd data or by fluid mobility of W. Here we will further explore the 182W isotope composition of the Paleoarchean Ngwane Gneiss suite from the Ancient Gneiss Complex (Eswatini) and TTG plutons from the Barberton Mountain Land, that reveal a time-integrated increase of initial epsHf values in magmatic zircon. Our results provide further constraints on the origin of granitoids that plot at the upper end of the µ182W-epsHf array. We will present first 182W data produced on the NEOMA MC-ICPMS in Berlin, which have a high level of accuracy as revealed by replicate measurments from samples previously measured at University of Cologne.

 
2:00pm - 3:30pm1.27 Young Scientist Session
Location: Wiwi 104a
Session Chair: Joshua Sawall
Session Chair: Moritz Lang
Session Chair: Iris Arndt, Goethe University Frankfurt
Session Chair: Fiene Matthies
 
2:00pm - 2:15pm
Topics: 1.27 Young Scientist Session

An ecological assessment of southern Alaska through observations of floristic change, fire regime and volcanism.

Sophie Carter McSherry, Dr Lauren Jade Davies, Dr Matthew Adesanya Adeleye

University of Cambridge, United Kingdom

Defining patterns of environmental or ecological change on different spatio-temporal scales is key to tracking and addressing present and future biodiversity changes, which is particularly important considering the rapidly changing climate scenarios. Climate change in the arctic means shrinking glaciers, drying out of peatland and carbon release, more frequent forest and peatland fires, and thawing permafrost. Alaska hosts some of the largest Boreal peatlands and forests; however, little is known about the fine-scale dynamics of these ecosystems particularly over the last millennia, which is key to making effective management decisions into the uncertain future. In this presentation, I will be presenting the results so far from an ongoing work that employs different lines of evidence (pollen, non-pollen palynomorphs, charcoal, and tephra) from two peatland sites in southern Alaska to reveal interactions between vegetation, fire and climate in the area during the last millennia, as well as the potential influence of humans and volcanic eruptions on these interactions.



2:15pm - 2:30pm
Topics: 1.27 Young Scientist Session

Salts as proxies for water-soil interaction in the hyperarid Atacama Desert

Felix Leo Arens1, Alessandro Airo2, Jenny Feige2, Christof Sager2, Uwe Wiechert3, Dirk Schulze-Makuch1,4,5,6

1Astrobiology Research Group, Zentrum für Astronomie und Astrophysik, Technische Universität Berlin, 10623 Berlin, Germany; 2Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, 10115 Berlin, Germany; 3Department of Geochemistry, Freie Universität Berlin, 12249 Berlin, Germany; 4Section Geomicrobiology, German Research Centre for Geosciences (GFZ), 14473 Potsdam, Germany; 5Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), 12587 Stechlin, Germany; 6School of the Environment, Washington State University, Pullman, WA 99164, USA

The Atacama Desert is the oldest and driest non-polar desert on Earth, where salts have accumulated through atmospheric deposition over millions of years of hyperaridity. These salts can serve as an indicator to provide an understanding of the interaction between water and soil in changing environmental conditions. Therefore, four soil profiles were studied for their mineralogy, abundance of salts, and stable isotopic composition of sulfate. In all soil profiles, sulfates are the predominant salts showing a downward transition from gypsum to anhydrite accompanied by an increase in highly soluble salts and a decrease in δ34S and δ18O values of sulfate. These trends are consistent with downward water infiltration during rare rain events causing salt dissolution and subsequent precipitation in the deeper soil column. This conclusion is also supported by our Rayleigh fractionation model. The presence of anhydrite at >40 cm depth is attributed to their association with nitrate and chloride salts, which reduces water activity during sulfate precipitation and thus stimulates anhydrite formation. Along the elevation transect, the total salt inventories of the individual profiles show a tendency for nitrate and chloride concentrations to decrease with elevation. This observation, together with the stable isotopes of sulfate, suggests a fog-independent source and points to the remobilization of soluble salts by enhanced erosion of the hillslopes. These findings are essential for understanding pedogenetic processes and long-term regional habitability of hyperarid environments.



2:30pm - 2:45pm
Topics: 1.27 Young Scientist Session

In-situ hydrolysis rate constants of ATP as a function of p-T-X, exploring the limits of life

Christoph Moeller1, Christian Schmidt2, Denis Testemale3, Franoçois Guyot4, Maria Kokh1,5, Max Wilke1

1Institut für Geowissenschaften, Universität Potsdam, Germany; 2Helmholtz-Zentrum Potsdam, Deutsches GeoForschungsZentrum GFZ; 3Université Grenoble Alpes, CNRS, Institut Néel; 4IMPMC Muséum National d'Histoire; 5Institut für Mineralogie, Westfälische-Wilhelms-Universität,

In recent decades varies extremophiles were found deep in the lithosphere. Experimental studies showed that life is possible at 121 °C (Takai et al. 2008) and the gigapascal range (Sharma et al. 2002), which is beyond the p-T-range of the investigated lithosphere. Knowledge on the kinetic stability of vital molecular compounds, like ATP, can help us constraining the conditions possible for life.

All metabolism relies on the exergonic enzymatic hydrolysis of adenosine triphosphate (ATP) to adenosine diphosphate (ADP). At elevated temperatures, the enhanced kinetics of the non-enzymatic hydrolysis counteracts the enzymatic driven reaction; hence, it will limit the bioavailability of ATP.

We used an autoclave and a hydrothermal diamond anvil cell attached to a Raman spectrometer for in-situ investigation of the p-T-X-effects on the kinetics of the non-enzymatic ATP hydrolysis. At vapor pressure the half-lives were about 2-5 mins at 120 °C (Moeller et al. 2022). Up to 140 MPa, all results show an Arrhenian relationship in the T-range of 80-120 °C. The pressure effect can be best described by a power law; below 500 MPa the p-effect is vanishingly small, and above the rate constant increases exponentially. Addition of MgCl2 up too 4 wt% slows down the hydrolysis. A distinguished effect of NaCl and CaCl2 was not observed.

The proposed limit for ATP-based life of 195 °C by Moeller et al. (2022) is lowered by additional pressure or elevated by MgCl2, respectively. These observations strengthen the idea that life could exist far deeper in the lithosphere as discovered yet.



2:45pm - 3:00pm
Topics: 1.27 Young Scientist Session

Geochronology and trace element composition of zircon in granitoids from the Indus Syntaxis, northern Pakistan: new evidence for Palaeoproterozoic A-type magmatism in the north-western part of the Indian plate

Tanveer Ahmad1, Mohammad Arif2, Kirsten Drüppel1, Muhammad Qasim3, Muhammad Sajid2

1Department of Petrology, Institute of Applied Geosciences, Karlsruhe Institute of Technology; 2Department of Geology, University of Peshawar, Peshawar, Pakistan; 3Department of Earth Sciences, COMSATS University Islamabad, Abbottabad Campus, Abbottabad, Pakistan

Two granitic plutons are exposed at Dubair and Shang in the vicinity of Besham, northern Pakistan, in the northwestern part of the Indian plate. Both granitoids mainly consist of perthitic feldspar, plagioclase, and quartz together with minor biotite, amphibole, and accessory ilmenite, apatite, titanite, and zircon. They are peraluminous and alkali-calcic to alkaline in composition, with strong A-type affinity (Ahmad et al., 2021). La-ICP-MS U-Pb dating and trace element analysis of zircon from both plutons were performed to elucidate their emplacement ages and temperatures. Most of the zircons are characterized by oscillatory zoning, depletion in light REE, and enrichment of heavy REE, with pronounced positive Ce and negative Eu anomalies. U–Pb zircon dating of the Shang and Dubair granitoid reveals similar concordant Palaeoproterozoic ages of 1871± 8.1 Ma and 1862 ± 7.5 Ma, respectively. The calculated Ti-in-zircon temperatures mainly range between 800°C and 900°C. The U-Pb ages, zircon compositions, and high magmatic temperatures suggest solidification of the granitoids from a crustal-derived magma emplaced during the Paleoproterozoic.

Reference

Ahmad, T., Arif, M., Qasim, M., & Sajid, M. (2021). Petrology of granitoids from Indus syntaxis, northern Pakistan: Implications for Paleo-Proterozoic A-type magmatism in north-western Indian Plate. Geochemistry, 81(1), 125693.



3:00pm - 3:15pm
Topics: 1.27 Young Scientist Session

Extracting the source characteristics of the April 2022 Guanyuan landslide event from seismic signals recorded in the near-field

Rebeca Ursu1,2, Hui Tang1, Jens M. Turowski1, Ci-Jian Yang1, Jui-Ming Chang3

1GFZ German Research Centre for Geosciences, Potsdam, Germany; 2School of Geosciences, University of Edinburgh, Edinburgh, United Kingdom; 3Department of Civil Engineering, National Yang Ming Chiao Tung University, Taipei, Taiwan

The seismic signature of landslides preserves information of utmost importance in reconstructing the impact forces induced by landslides and, subsequently, the trajectory of motion and the dynamic properties of the sliding mass. Several studies focusing on large-scale events successfully inverted the source-time function and, therefore, the time-varying force exerted on the surface from the observed low-frequency (<0.1 Hz) seismic waves recorded in the far field. Nonetheless, most landslide events are small in terms of the displaced mass, which is more likely to excite rapidly attenuating seismic waves. With dominant frequencies above 1 Hz, these waves are noticeable only at the stations near the landslide. Analyzing the seismic signal generated by landslides in the near field is challenging. The proposed models would require a thorough description of the ground propagation medium, which is only available for some study cases. Here, we investigate using analytical solutions to Lamb’s problem to simulate the propagation history of the surface waves during the April 2022 Guanyuan landslide, Taiwan. This landslide mobilised more than 100,000 m3 of rock and stopped the traffic on the Taiwanese Central Cross-Island Highway for 43 days. The proximity of the landslide to a broadband station located about 6 km away allows the study of the near-field seismic signals. The duration and amplitude of the force retrieved in this fashion agree with qualitative observations, suggesting the potential of the model to extract source characteristics of landslides from seismic signals recorded in the near field.



3:15pm - 3:30pm
Topics: 1.27 Young Scientist Session

Analyzing the susceptibility for coastal and submarine landslides and their potential to trigger tsunami waves

Katrin Dohmen, Anika Braun, Tomás M. Fernandez-Steeger

Technische Universität Berlin, Germany

Tsunamis generated by submarine or coastal landslides are a growing area of scientific interest. Events like the 2018 tsunami in Palu, Indonesia, have highlighted their destructive potential. Landslides can generate extremely high tsunami waves, but typically have a limited propagation range beyond 100 km. Areas close to the landslide are most affected. Unfortunately, early warning systems are not effective for this type of tsunami due to the short warning time interval between wave initiation and coastal impact.

This study aims to analyze the coastal and submarine landslide susceptibility for coastal areas. Limited data availability, including high-resolution bathymetric data and historical landslide tsunami catalogs, poses a major challenge. A heuristic model is used, incorporating historical case studies to calibrate and weight the parameters. Geologic, morphologic, and geometric parameters of coastal areas are considered.

First results show a high correlation of landslides generated during the Palu earthquake with the size of catchment areas of rivers entering the ocean. This parameter is strongly related with the sediment load that is transported into the ocean. High sedimentation rates might lead to the formation of thick, unconsolidated sediment layers., which are susceptible to landslides. This correlation will be further analyzed.

The results of this susceptibility mapping can help raise the awareness of the risks associated with landslide tsunamis. Even minor earthquakes, not expected to trigger tsunamis, could induce submarine or nearshore landslides and generate a tsunami in vulnerable areas. Consequently, adapting tsunami evacuation strategies to account for landslide-induced tsunamis may be required in these areas.

 
2:00pm - 3:30pm3.27-2 Alkaline rock and carbonatite related magmatism
Location: Wiwi 107
Session Chair: Benjamin Florian Walter, Karlsruhe Institute of Technology
Session Chair: R. Johannes Giebel, Technische Universität Berlin
 
2:00pm - 2:15pm
Topics: 3.27 Alkaline rock and carbonatite related magmatism

Carbonates or carbonatites? Examples of alkaline silicate plutonic xenoliths from volcanoclastic rocks in the Eifel, Germany

Maria Sitnikova1, Sindern Sven2, Kramm Ulrich2

1BGR, Hannover, Germany; 2RWTH, Aachen, Germany

Plutonic xenoliths in volcaniclastic rocks from the Laacher See (LS), East Eifel and the Rockeskyller Kopf Volcanic Complex (RKVC), West Eifel, were studied. They show different ways of magmatic carbonate formation at plutonic levels.

Well-preserved original igneous textures of carbonate-bearing syenites were observed in LS plutonic xenoliths. Calcite is often crystallised in “micropegmatitic texture” with sanidine and nosean. These structures argue for syngenetic crystallisation of calcite and main silicate minerals in alkali syenite melts in the case of the LS volcano. Different proportions of euhedral calcite and silicate minerals point to calcite cumulate formation.

Occurrence of calcite associated to apatite, magnetite, phlogopite and pyrochlore in nosean syenite from xenoliths of the RKVC is in line with the assumption of magmatic carbonate formation in a highly fractionated undersaturated silicate magma.

Next to carbonatite - nosean syenite xenoliths and sanidinite, a series of different mafic xenoliths were found around the RKVC, from amphibolite to pyroxenite and magnetite cumulates, that could indicate one or more magma chambers below the volcano.

A comprehensive data set for geochemistry, mineralogy and mineral chemistry of the carbonates of LS and RKVC volcanoes is provided. Characteristic carbonate and whole rock trace element patterns are presented. Different chondrite normalised REE signatures of RKVC and LS argue for different ways of fractionation in these volcanic systems.



2:15pm - 2:30pm
Topics: 3.27 Alkaline rock and carbonatite related magmatism

Magmatic vs. metasomatic ijolite petrogenesis – constraints from the type locality Iivaara, Finland

Sven Sindern, Fahmi Hakim, Tobias Fusswinkel, Sajjad Ali, Ulrich Kramm

RWTH Aachen University, Germany

Complex field relationships and association to alkaline ultramafic rocks, textural diversity and locally marked isotopic heterogeneity of ijolites lead to contrasting petrogenetic concepts for these rocks. They may either be formed by magmatic differentiation from nephelinitic magmas or by assimilation of silicate wall rocks in a carbonatite melt formed after metasomatic reaction during its’ ascent from mantle to crustal levels. We show new petrographic and mineral chemical results from the ijolite type locality, Iivaara. It is the aim of this presentation to set constraints to ijolite formation in the Iivaara alkaline complex and to discuss applicability of contrasting petrogenetic concepts. Pegmatitic growth, comb layering or brecciation indicate ijolite crystallization from a low viscosity and volatile rich melt. Small scale textural heterogeneity reveals locally highly variable crystallization conditions characterized by steep temperature gradients and sudden pressure drop. Irregular clinopyroxene zonation points to repeated disturbance of magmatic crystallization at depth prior to emplacement at the actual erosion level. Veins and matrices of breccia are dominated by clinopyroxene next to titanite and apatite attesting to the high Ca-concentration of a fluid that is violently expelled from the magma. The transitional zone between wall rocks and ijolite, too, is dominated by pyroxenitic compositions. Lack of a clearly defined contact between ijolite and wall rock is in line with the observation of migmatitic textures in high grade fenites, which probably obtained plastic behavior with increasing degree of fenitization. Such fenites with syenitic composition or partial melts of them may have been assimilated by ijolite.



2:30pm - 2:45pm
Topics: 3.27 Alkaline rock and carbonatite related magmatism

The carbonatite melt – granite wall-rock interaction: A case study on the Bulhoek carbonatites, South Africa

Ole L. F. Sauter1, Johannes R. Giebel1,2, Benjamin F. Walter3

1Technische Universität Berlin, Germany; 2University of the Free State, South Africa; 3Karlsruhe Institute of Technology

The study aims to provide valuable insights into the dynamics of the interaction between carbonate melts and silicate wall-rocks during ascent and emplacement of carbonatitic intrusions. A specific focus is given to potential processes leading to rare earth element (REE) enrichment. It can be assumed that the interaction of silicate rocks with carbonate melt is diverse. Therefore, a study of granites interacting with a carbonatite melt was used to carefully assess the effects of a specific lithology.

The research centers the Bulhoek carbonatite complex, a bi-partite intrusion (Bulhoek North and South) situated in the eastern central region of the Bushveld Complex, approximately 35km west of Pilanesberg (South Africa), where it intruded the Nebo-granite (an integral part of the Bushveld Complex). The key characteristics of this intrusion are reflected by volcanic breccia, finitized Nebo-granite and beforsite (fine-grained magnesio-carbonatite) containing abundant apatite and strongly disaggregated granite xenoliths. Textural evaluation indicates that the element budget of the granites was resorbed by the carbonate melt. An integrated analytical approach, involving scanning electron microscopy (SEM), X-ray fluorescence (XRF), X-ray diffraction (XRD), and whole-rock analysis, is currently in progress to reveal the intricacies of the carbonate melt – granite interaction. While previous field studies have touched upon the fenitization of the Nebo-granite, a comprehensive understanding of the entire (and mutual) interaction remains a significant research gap. This study bridges this gap and will deepen our knowledge of carbonatite formation.



2:45pm - 3:00pm
Topics: 3.27 Alkaline rock and carbonatite related magmatism

Crustal contamination and rare earth element enrichment in the Nooitgedacht Volcano, South Africa

Mohsin Raza1,2,3, R. Johannes Giebel4,5, Jochen Kolb1,2, Benjamin F. Walter1,2

1Karlsruhe Institute of Technology (KIT), Institute of Applied Geosciences, Chair of Economic Geology and Geochemistry, Adenauerring 20b, 76131 Karlsruhe, Germany; 2Laboratory of Environmental and Raw Materials Analysis (LERA), Adenauerring 20b, 76131 Karlsruhe, Germany; 3Department of Geology, Bacha Khan University Charsadda, Pakistan; 4Institute of Applied Geosciences, Technische Universität Berlin, Ernst-Reuter-Platz 1, 10587 Berlin, Germany; 5Department of Geology, University of the Free State, 250 Nelson-Mandela-Drive, Bloemfontein 9300, South Africa

Carbonatites are igneous rocks with significant concentrations of rare earth elements (REEs) and other important metals. Despite their economic potential, their origin and evolution are poorly understood. Crustal contamination can significantly modify REE abundance in carbonatites. The current study provides new petrographic, geochemical, and stable isotopic insight into the processes that led to the formation of high field strength element (HFSE) bearing carbonatites i.e. pyrochlore-calcite carbonatite, and rare earth element (REE) bearing carbonatite i.e. quartz-ankerite-calcite carbonatite in the Nooitgedacht Volcano.

The Nooitgedacht Volcano is an oval-shaped body with approximately a 3 km diameter situated in the Kaapvaal Craton in South Africa. It comprises mostly calcite carbonatite with enclosures of dolomite carbonatite. Petrographically, calcite carbonatite is divided into pyrochlore-calcite carbonatite and quartz-ankerite-calcite carbonatite. The mineral assemblage of pyrochlore, apatite, magnetite, and forsterite indicate an ortho-magmatic origin while the mineral association of monazite, ankerite, and quartz represents a post-magmatic/ hydrothermal origin for the quartz-ankerite calcite carbonatite. Stable isotope data (δ13C = -5 to -4) and (δ18O = +7 to +16) indicate a primary mantle source for the carbonatite with subsequent crustal contamination.

In summary, petrographic, mineralogical, geochemical, and isotopic data provide significant insight into the evolution of the Nooitgedacht Volcano, highlighting a complex history of magmatic differentiation, mineral fractionation, and crustal contamination.



3:00pm - 3:15pm
Topics: 3.27 Alkaline rock and carbonatite related magmatism

The influence of crustal contamination on REE-enrichment in carbonatites of the Kalkfeld group (Namibia)

Andreja Ladisic1, Michael Marks1, Benjamin Walter2,3, Johannes Giebel4,5, Gregor Markl1

1Tübingen University, Department of Geosciences, Schnarrenbergstr. 94-96, D-72076 Tübingen, Germany; 2Karlsruhe Institute of Technology (KIT), Institute for Applied Geosciences, Chair of Economic Geology and Geochemistry, Adenauerring 20b, 76131 Karlsruhe, Germany; 3Laboratories of Environmental and Raw Material analyses (LERA), Adenauerring 20b, 76131 Karlsruhe, Germany; 4Technische Universität Berlin, Institute of Applied Geosciences, Ernst-Reuter-Platz 1, 10587 Berlin, Germany; 5University of the Free State, Department of Geology, 250 Nelson-Mandela-Drive, Bloemfontein 9300, South Africa

Carbonatites are mantle-derived igneous rocks which may comprise economically important mineralizations of REE and HFSE. Their emplacement into the crust is usually accompanied by fenitization, alkali metasomatism of country rocks caused by fluids expelled during cooling and crystallization. Often, carbonatites are associated with diverse silicate rocks like syenites, nepheline syenites or phonolites. Understanding magmatic differentiation and late-stage processes after emplacement, such as hydrothermal alteration and element remobilization and re-precipitation, is of great importance to understand the formation of HFSE and especially REE deposits.

Carbonatites and associated silicate rocks (syenites, phonolites, fenites) of the Kalkfeld group in Northern Namibia show a large range in whole-rock REE contents, heterogeneity and textural variety and are therefore perfectly suited to study the phenomena named above. Detailed petrographic and microtextural analysis of the samples was done and focused on understanding the paragenetic sequence and evolution of the samples. Within the carbonatites, the typical sequence sövite -> beforsite -> ferrocarbonatite is observed, as well as late-stage, hydrothermal mineralization of REE- bearing phases like ancylite and bastnäsite. Currently, the study focuses on mineral chemistry by means of EMPA to further differentiate processes involved in the formation and evolution of the observed assemblages. Furthermore, silicate minerals like pyroxene, biotite and feldspar observed in carbonatites of the Kalkfeld group may indicate wall-rock interaction and crustal contamination of the carbonatitic magma during ascent and emplacement. The importance of silica contamination on REE enrichment in the carbonatites of Kalkfeld group will be discussed.



3:15pm - 3:30pm
Topics: 3.27 Alkaline rock and carbonatite related magmatism

Can REE-enriched carbonatites be mapped from space?

Veronika Kopackova-Strnadova1, R. Johannes Giebel2, Vladislav Rapprich1, Tomas Magna1

1Czech Geological Survey, Czech Republic; 2TU Berlin, 10587 Berlin, Germany

Rare Earth elements (REE) belong to the most strategic materials of the 21st century with steadily growing economic importance. PRISMA, the hyperspectral satellite data, is used for the very first time to test its capability of detecting REE contents from space using distinct subtle diagnostic spectral absorption features of REE. The PRISMA hyperspectral sensor acquired 234 spectral bands over VNIR/SWIR optical regions (400–2500 nm) of the electromagnetic spectrum at a spatial resolution of 30 m and a spectral resolution ranging from 11 to 15 nm. The carbonatite occurences within the Ondoto area in North Namibia were selected as the test site. To detect the REE-related diagnostic spectral absorption parameters (absorption wavelength position and depth) the in-house toolbox (QUANTools) developed at the Czech Geological Survey was tested and four absorption features placed within 700–900 nm range were found to correlate with the carbonatites containing high loads of REE. As a result, three perspective carbonatite areas were identified as the most promising, with one site validated using the laboratory geochemical data from collected samples. The results showed a good correlation between the high REE loads mapped using PRISMA data and the ground truth data highlighting the future potential of state-of-the-art satellite hyperspectral data to explore REE deposits using contactless Earth Observation data and methods.

Funded by the Czech Science Foundation project 19-29124X.

 
2:00pm - 3:30pm1.11-2 Unlocking CO2 storage potentials for Germany
Location: Wiwi 108
Session Chair: Gesa Kuhlmann, BGR
Session Chair: Sebastian Bauer, Christian-Albrechts-Universität zu Kiel
 
2:00pm - 2:15pm
Topics: 1.11 Unlocking CO2 storage potentials for Germany

POTENTIAL CO2 STORAGE SITES IN THE GERMAN NORTH SEA? A RESERVOIR-MODELLING AND PARAMETRIZATION STUDY

Astrid Schlieder-Kowitz, Felix Kästner, Arne Fuhrmann, Hauke Thöle, Gesa Kuhlmann, Heidrun Louise Stück, Frithjof Bense, Björn Zehner

Bundesanstalt für Geowissenschaften und Rohstoffe, Germany

Carbon dioxide removal and storage is required for limiting global warming to the 2 °C goal of the Paris Agreement. One method is the storage of CO2 in deeply buried geological formations.

As part of the GEOSTOR project, we created static 3D models for two potential storage sites in the Middle Buntsandstein within the German North Sea Exclusive Economic Zone.

One 3D geological model (~1300 km2) located on the "West Schleswig Block" is based on 2D seismic data from various surveys and geophysical logs from four exploration wells. It encompasses a salt controlled anticline with 40-50 m thick Lower Volpriehausen Sandstones forming the primary reservoir target. The top seal consists of Upper Buntsandstein and unconformable Lower Cretaceous mudstones.

The other 3D geological model (~560 km2) is located within the “Entenschnabel” area and, in contrast, is based on several high-resolution 3D seismic data and geophysical logs from four exploration wells. The reservoir, which also consists of up to 65 m thick Lower Volpriehausen Sandstones, is located within the Mads Graben with erosional discordances at the top. The upper seal consists of Upper Jurassic clays and partly unconformable Lower Cretaceous mudstones.

For both models we conducted petrophysical analyses of all considered well data and calculated reservoir properties to determine the static reservoir capacity for these storage sites.

Finally, we parametrized both models in order to provide two complete reservoir models that are capable of further dynamic capacity simulations, geo-risk and infrastructural analyses aiming at an entire feasibility study within the project framework.



2:15pm - 2:30pm
Topics: 1.11 Unlocking CO2 storage potentials for Germany

Injection strategy development for CO2 storage in a multi-trap storage site considering hydrodynamic and geomechanical restrictions

Firdovsi Gasanzade, Hendrawan Diandaru Bayu Aji, Frank Wuttke, Sebastian Bauer

Institute of Geosciences, Kiel University, Germany

Geological storage of CO2 contributes to mitigating climate change, but successful storage depends on many subsurface hydrodynamic and geomechanical factors. This study outlines the development of a CO2 injection strategy for a potential multi-trap storage site in the German North Sea by jointly honouring the geomechanics as well as hydrodynamic and geological constraints. The site comprises three structural closures, each covering an area of tens of km2. Based on site-specific geology and petrophysical data, static storage capacities of the individual closures as well as the closure combinations are estimated. Each closure has a distinct configuration and drainage area, resulting in different CO2 phase dynamics in the subsurface, due to a different interplay of gravity, capillary and viscous forces. A 3D reservoir model is developed and used to simulate CO2 injection with a rate of 10 Mt/a over 30 years, followed by a 100-year post-injection phase, while accounting for the regional hydraulic boundaries. The allowable pressure limit is derived using dedicated geomechanical simulations. The individual settings of each closure result in varying depths and injectivities, which lead to different numbers of injection wells and their placement due to well interaction. Furthermore, pressure accumulation occurs depending on the relative position of the closure to the hydraulic boundaries, reducing achievable capacity. Consequently, injection well planning and optimisation efforts should prioritise settings that demonstrate high injectivity, high achievable storage capacity and a high allowable pressure window.



2:30pm - 2:45pm
Topics: 1.11 Unlocking CO2 storage potentials for Germany

Geomechanical analyses of submarine CO2 injection in the geological formations in the German North Sea

Hendrawan D.B. Aji, Firdovsi Gasanzade, Frank Wuttke, Sebastian Bauer

Institute of Geosciences, Kiel University, Germany

CO2 storage potential in sandstone formations in the German North Sea is investigated by GEOSTOR consortium. This contribution discusses some of the results from the investigation of the geotechnical impact of the storage process. We examine the injection pressure window with respect to the hydro-fractural risk of the reservoir layer or caprock in the vicinity of the injection well by performing coupled hydro-mechanical fracture analyses. Different modelling scales, formulations, failure parameters, and in-situ present day stresses are considered. The results show that 2D- or thin 3D-models may underestimate the material integrity and lead to early fracture initiation. Meanwhile, a medium-scale model of the geoformation may be advantageous in reducing computational burden while maintaining high accuracy. The results also show a good correlation with field-derived fracture gradients and formation strength tests data from the Dutch-German border.

To assess the geotechnical risk of induced seismicity on the offshore infrastructure, we enhanced our boundary element-finite element method dynamic simulator with the formulation to compute arbitrary layered half-space and double-couple dynamic sources. Verification of the numerical method shows an excellent agreement with the analytical solution. The hybrid method is able to take into account the spatially complex geometry of the geological structure. The results show that the impact of the storage process on the formations’ mechanical integrity or offshore infrastructure remains relatively low or manageable for the considered period.



2:45pm - 3:00pm
Topics: 1.11 Unlocking CO2 storage potentials for Germany

A benchmark gallery for hierarchical model verification of TH2M coupled process models: Examples for CO2 sequestration and nuclear waste disposal

Kata Kurgyis1, Aqeel Afzal Chaudhry1, Michael Pitz2,1, Norbert Grunwald3, Jörg Buchwald3, Dmitri Naumov3, Wenqing Wang3, Christoph Lehmann3, Olaf Kolditz3, Jobst Maßmann2, Thomas Nagel1

1Technische Universität Bergakademie Freiberg, Germany; 2Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Hannover, Germany; 3Helmholtz Centre for Environmental Research GmbH (UFZ), Leipzig, Germany

In this study, we introduce an open-source benchmark gallery for a systematic verification of numerical simulations of coupled multi-field processes in geological storage and sequestration. Here, the focus lies on assessing the integrity of a host rock and/or geological barrier, which requires understanding material failure and behavior under different thermal-hydraulic-mechanical-chemical (THMC) conditions. To support quality assurance of the simulation workflows, the gallery provides automated benchmarking and peer-reviewed code development.

Since closed-form solutions covering all aspects of non-isothermal two-phase flow in deformable media (TH2M) problems are not available, the verification procedure is subdivided into simpler conceptual models, up to single-variable processes (Grunwald et al., 2022). These reduced complexity problems can be described by semi- or fully analytical solutions. Extensive verification of very basic combinations (T/H/M/HM/TH etc.) was already conducted, therefore, focus lies on the investigation of more complex problems.

In the context of TH2M systems, the gallery includes three cases relevant to CCS:

  • THM problem: Thermally induced expansion of liquid and solid phases resulting in thermal strain in the surrounding solid matrix and fluid displacement. (Booker and Savvidou, 1985; Chaudhry et al., 2019)

  • TH2 problem: Phase change and heat transport in a thermal gradient (Udell and Fitch, 1985; Helmig et al. 1997)

  • TH2M: Heat loss to under- and overburden due to non-isothermal, supercritical CO2 injection into reservoir. (LaForce et al. 2014a and 2014b; Green at al. 2021)

The gallery consists of comprehensive browser-integrated problem descriptions, analytical solutions, and numerical simulations obtained with the open-source simulation tool OpenGeoSys (Bilke et al., 2022).



3:00pm - 3:15pm
Topics: 1.11 Unlocking CO2 storage potentials for Germany

Uncertainty Analysis of CO2 Storage Capacity Estimation in Saline Aquifers of the German North Sea

Jan Tecklenburg, Stefan Knopf, Franz May

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

The reliable estimation of the dynamic storage capacity for CO2 storage is a significant challenge due to the uncertainty of process parameters. In our study, we consider storage in the Triassic Bunter sandstone underneath the German sector of the North Sea.

We investigate CO2 injection into a saline aquifer, such as the Volpriehausen Sandstone by means of numerical simulations, to analyze the impact of parameter uncertainty on storage efficiency.

One of the main challenges for capacity estimations is the paucity of measurements regarding storage rock units like the Volpriehausen Sandstone for important process parameters such as relative permeabilities obtained from wells in the German North Sea. This requires the supplementation of measured parameters from the same storage rock units for instance from neighboring countries such as the Netherlands or Denmark.

We conduct flow simulations using TOUGH3 ECO2N and a self-developed framework for sensitivity analysis to investigate the parameter uncertainty of process parameters on storage efficiency.

Our results indicate that the level of uncertainty can significantly affect the estimation of storage capacity, and the accuracy of simulation results is highly dependent on certain input parameters.

This study provides insights into the impact of parameter uncertainty on the efficiency of CO2 storage. These findings are useful for future exploration, characterization, and operation of CO2 storage sites.



3:15pm - 3:30pm
Topics: 1.11 Unlocking CO2 storage potentials for Germany

Analysis of fluid migration pathways in the context of CO2 underground storage in the German North Sea using high-resolution 3D and 2D seismic data

Niklas Ahlrichs, Axel Ehrhardt, Michael Schnabel, Arne Fuhrmann, Heidrun Stück

Bundesanstalt für Geowissenschaften und Rohstoffe, Hannover, Germany

For successful and safe underground CO2 storage, a profound knowledge of the subsurface and its geological structures characterizing the selected reservoir is essential. Besides robust geological models and storage capacity estimations, seal integrity analysis and the identification of potential seal-bypass systems is crucial to ensure save long-term storage of CO2 in the deep subsurface. Within the framework of the GEOSTOR project, we assess potential Triassic and Jurassic CO2 reservoirs by analysing the integrity of overlying barrier formations below the German North Sea. For this purpose, we use recently acquired high-resolution 3D seismic data covering an area of 94 km² within the northwestern German North Sea (“Entenschnabel”) and high-resolution 2D seismic data from the central German North Sea (“West Schleswig Block”) covering a total length of about 1500 km. Seismic amplitude anomalies indicate the presence of fluids allowing the investigation of former fluid migration pathways and their connection to faults and salt structures. First results from the “Entenschnabel” show a highly resolved 3D image from the seafloor to the Zechstein covering the salt diapir Belinda. Bright spots indicate fluid migration along the crestal fault system. Direct fluid migration indicators are scarce within the West Schleswig Block. Locally, bright spots indicate fluid migration along crestal faults of salt structures. We compare and discuss the characteristics of identified fluid migration pathways near the salt diapir Belinda with fluid migration and its correlation with faults and salt structures from the central German North Sea in the context of barrier integrity for subsurface CO2 storage.

 
3:30pm - 4:00pmCoffee Break
Location: Foyer (Henry Ford Building)
4:00pm - 5:30pm3.28-3 Developments and progress in regional geology
Location: Hall A (HFB)
Session Chair: Guido Meinhold, TU Bergakademie Freiberg
 
4:00pm - 4:15pm
Topics: 3.28 Developments and progress in regional geology

New insights into the formation and distribution of Pleistocene tunnel valleys in northern Germany

Sonja Breuer, Anke Bebiolka, Axel Ehrhardt, Vera Noack, Jörg Lang

Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Germany

Tunnel valleys are among the deepest erosional structures in formerly glaciated areas. Our project aims to provide a synoptic model of the distribution, dimensions and evolution of Pleistocene tunnel valleys and their infills in northern Germany. The results will be used to assess the potential for future tunnel valley formation, which may pose a threat to the long-term (i.e., the next 1 Ma) safety of a radioactive waste repository.

In the first phase of our project, we produced a new overview map of the Pleistocene tunnel-valley network. From this map, we extracted the tunnel-valley thalwegs and classified them into zones of similar maximum depths. Zones of deep erosion (>400m) follow the large-scale geometry of the North German Basin. The map of maximum depth zones can be used as a planning tool for long-term safety assessments.

The next phase of our project includes a regional analysis of the tunnel valley network and local case studies. The regional analysis will compare the trends observed in the tunnel-valley network with regional geological features such as faults, salt structures and basin-fill architecture. The correlation between tunnel-valley trends and faults is ambiguous. Parallel trends occur mainly where ice advance directions were parallel to fault trends.

As a first case study, we use high-resolution 3D seismic data from the German North Sea that image two intersecting tunnel valleys. Initial results show at least three distinct seismic units correlating with different sediment types and patterns, and possible multiple use of the tunnel valley.



4:15pm - 4:30pm
Topics: 3.28 Developments and progress in regional geology

Paleoseismic and -tectonic structures in Hamburg and Peissen (Schleswig-Holstein)

Alf Grube

Geologisches Landesamt Hamburg, Germany

Paleoseismic investigations in Hamburg and Peissen document paleo-earthquake structures, e.g. large clastic dykes, infill structures, complicated folds, fault-systems and vertical injections as larger structures. Smaller structures include special forms of diapirs, seismically induced soft-sediment deformation structures (SSDS), special flame structures, shear bands, among others. Plastic deformation is dominant in Hamburg, brittle deformation dominates in Peissen. The seismic deformations can be attributed to different mechanisms, e.g. compression as a result of seismic shock or sediment intrusion, liquefaction, fluidization, strain, shear stress, volume loss and subsequent collapse as a result of blowout activity. The observed structures show certain properties that allow a distinction from non-seismic forms (e.g. glacitectonic and periglacial deformation). Dyke structures are partly of Holocene age.



4:45pm - 5:00pm
Topics: 3.28 Developments and progress in regional geology

A large regional structure from puzzle pieces - Gulf of Mexico structures on the western flank of the Eichsfeld-Altmark-Swell (EAS)?

Alexander Malz1, Jonas Kley2, Heinz-Gerd Röhling3

1Landesamt für Geologie und Bergwesen Sachsen-Anhalt, Germany; 2Georg-August-Universität Göttingen, Germany; 3DGGV e.V., Germany

We discuss the structures associated with the Eichsfeld-Altmark-Swell (EAS) in Central Germany, using observations from published cross-sections, outcrops, few boreholes and reflection seismics in a some 200 kilometres long swath in Central Germany. The EAS is well-documented as an approximately NNE-SSW-trending Permo-Triassic intrabasinal high, expressed by reduced thickness, facies changes and unconformities. It was accompanied by depocenters trending parallel to its axis, which changed in position and magnitude during geologic epochs. North of the Harz Mountains an approximately 10 km wide strip of the EAS´s western flank is strongly structured by faults of the Braunschweig-Gifhorn-Fault Zone (BGFZ). There, local thickness reductions of several hundred meters, in places culminating in complete absence of Lower and Middle Buntsandstein and apparently often associated with salt tectonics, are documented by seismics and well data, contrasting with the regional thickness reductions in the range of tens of meters typically attributed to the EAS. In Keuper time areas with large Buntsandstein hiatuses turned into depocenters. The spatial relationships of these depocenters with bordering normal faults and associated salt structures indicate that the western flank of the EAS was influenced by strong extension (up to 5 km) along low-angle normal faults detaching in Zechstein evaporites. No prominent basement offsets are observed, although they become prominent along trend of the BGFZ in the aligned westward terminations of the Flechtingen High, Harz and Thuringian Forest basement blocks. We discuss solutions for the mismatch of strong thin-skinned extension and apparently little deformed basement.



5:00pm - 5:15pm
Topics: 3.28 Developments and progress in regional geology

The role of Regional Geology as key aspect in the planning of large subsurface infrastructures

Marius Waldvogel1, Raphael Burchartz2, Bjorn Vink3, Pooya Hamdi2

1Geological Institute, RWTH Aachen University, Germany; 2Chair for Engineering Geology and Hydrogeology, RWTH Aachen University, Germany; 3NIKHEF

The Einstein-Telescope (ET), a next-generation gravitational wave-detector, is a triangular shape underground facility with 10 kilometres long arms to be constructed at a depth of 200-300 meters below surface. A potential location is the Meuse-Rhine Euroregion. The success of such mega-project requires a comprehensive understanding of regional geology in terms of lithology, lithological variations and dominant structures. A solid regional geology study, combining literature review, reconnaissance study, surface and subsurface mapping, sample collection, geophysical data collection, and remote sensing methods to identify the rock units and structures present, is part of assessing the feasibility of the area. The lithology consists of soft Upper Cretaceous sediments resting unconformable on Silesian, Dinantian and Famennian units. The Dinantian carbonates and the Famennian sandstones are the preferred target units for the cavern construction. A major goal is to understand the spatial distribution of the different rock units that may be encountered during construction of caverns and tunnel. Structurally, the region shows a complex pattern of NE- SW striking Variscan folds and thrusts and (N)NW –(S)SE striking faults linked to the Lower Rhine Embayment. Changes in the lithology due to folds and thrust are important in terms of tunnel planning. The (N)NW – (S)SE structures provide pathways for fluids and are potentially seismic active and hence may affect the construction and the operation of the ET severely. Understanding the regional geology allows for optimization of the location and orientation of the ET infrastructure and identifies the potential impacts during construction and operation of the ET.

 
4:00pm - 5:30pm4.08-2 Geological surveying as services for the public delivered by the State Geological Surveys of Germany - Current Issues
Location: Hall B (HFB)
Session Chair: Björn Panteleit, Geologischer Dienst für Bremen
 
4:15pm - 4:30pm
Topics: 4.08 Geological surveying as services for the public delivered by the State Geological Surveys of Germany - Current Issues

Using artificial intelligence to improve soil maps and geohazard mitigation efforts at state level

Michael Blaschek, Alexandra Kölbl, Kurt Rilling, Wolfgang Fleck

State Authority for Geology, Resources and Mining, Albertstraße 5, 79104 Freiburg, Germany

Both the sustainable use of our resources and the prevention of geohazards requires reliable information about the spatial distribution of soil and geological properties. Since direct measurements are costly, artificial intelligence (AI) methods are used to estimate these attributes, leveraging a machine learning algorithm which relates laboratory measurements or expert class information to environmental covariates derived, e.g. from relief, geology and climate data. This study evaluates random forest (RF) as an AI technique to predict the occurrence of debris on slopes of the entire Black Forest in 10 m resolution. It also examines whether RF models can be applied to measured geogenic radon potential (GRP) for assessing the risk of possibly harmful radon concentrations inside buildings in Baden-Wuerttemberg.

A suite of 6770 expert class labels indicating whether hillside debris of at least 1 m thickness occurs or not, were associated with main geological classes and various terrain attributes obtained from a LiDAR-based digital elevation model. RF classification showed very good results with an accuracy rate of 86 %. GRP mapping is currently based on 580 radon measurements in soil gas at 1 m depth and a set of covariates comprising soil attributes, climate variables and geological data such as uranium concentrations. Preliminary results indicate that the GRP map generated by using a state-specific RF model is highly useful in identifying municipalities as vulnerable areas for which action is needed to mitigate this particular threat to human health.



4:30pm - 4:45pm
Topics: 4.08 Geological surveying as services for the public delivered by the State Geological Surveys of Germany - Current Issues

Project ConSent: Harmonisation of the Large-Scale Geological Map Series of Baden-Württemberg and Bavaria

Matthias Franz1, Andreas-Alexander Maul2, Bernhard Wagner3

1Freiburg Regional Council, Geological Survey; 2Federal Institute for Geosciences and Natural Resources; 3Bavarian Environment Agency, Geological Survey

The increasing digital provision of geological maps leads to a growing need for data harmonisation in order to make the data usable across borders. An essential prerequisite for this is the harmonisation of the geological general legends. Therefore, the main objective of the ConSent project was to establish interoperability between the existing large-scale geological map series (GK25/50) for the example of the federal states of Baden-Württemberg and Bavaria. Furthermore, the project is about the automated derivation of small-scale from large-scale geological maps. First, the geological general legends of the GK25/50 of Baden-Württemberg and Bavaria were implemented as hierarchical vocabularies in the thesaurus management system of BGR (RDF-enabled using standardised vocabularies based on semantic web concepts). The next step was to identify the greatest common denominator of the geological legends of the two federal states. This was done by an overarching geological general legend (OGL). Subsequently, the geological general legends of the two map series were linked semantically to the OGL using the SKOS vocabulary. Then, a merged GIS dataset of the GK25/50 was created containing the original geometries of both federal states. The polygons are attributed with both the original terms and the harmonised terms of the OGL. The harmonised map is publicly accessible via the project web application at BGR. Finally, the map was successfully generalised into three superordinate map scales (GK250, GK500, GK1000). The project shall be extended to other geological surveys.



4:45pm - 5:00pm
Topics: 4.08 Geological surveying as services for the public delivered by the State Geological Surveys of Germany - Current Issues

A new model of the base of Quaternary deposits in Northwest Germany

Ines Bruns, Fischer Kerstin, Meinsen Janine, Wangenheim Cornelia

Landesamt für Bergbau, Energie und Geologie, Germany

The high-energy processes during the Elsterian glacial stage have formed a diverse relief of the base Quaternary with buried tunnel valleys, which are cut between a few tens of meters up to 400 m into the Tertiary bedrock sediments (Kuster & Meyer 1979). The Quaternary deposits host large groundwater reservoirs and are an important source for mining sand and gravel. The buried tunnel valleys also help to predict the erosion depth of future glaciations in the context of finding a site for a repository for radioactive waste in Germany. Therefore, it is crucial to provide a comprehensive geological model of the base Quaternary in order to support planning strategies in sustainable resource extraction and land use.

Kuster & Meyer (1995) published a contour map of the base Quaternary in Lower Saxony. Since then a vast number of new datasets were obtained. We started modelling a 3D surface based on these new datasets and the original contour map by Kuster & Meyer (1995) using SKUA-GOCAD™ (AspenTech). Here, we are presenting the first completed sub-region of this model, pointing out both the major advances that we achieved by integrating new borehole and seismic data (2D/3D) as well as the challenges of data harmonization. We were able to identify tunnel valleys that were unknown before and to revise the geometry and depth of known subglacial channels. The depth of the base Quaternary was adjusted by up to 150 m in certain areas.



5:00pm - 5:15pm
Topics: 4.08 Geological surveying as services for the public delivered by the State Geological Surveys of Germany - Current Issues

Integrating geological data of 100 years to model an area-wide map of the Quaternary base of Brandenburg

Sophia Rütters

Landesamt für Bergbau, Geologie und Rohstoffe Brandenburg (LBGR), Germany

Mapping the Quaternary base is required for various processes. Accordingly, it serves as a necessary horizon for set-up of 3D geological models of the subsurface, as well as a database for engineering geological processes. The most important field of application in Brandenburg considers hydrogeological questions such as the separation of the freshwater/ saline-water level in aquifers. Reliable and detailed working basis are needed for sophisticated modelling and to ensure the integration of all different data and information leading to area-wide maps.

At the geological survey of Brandenburg data of more than 200 000 drillings (from the beginning of 1900 until today), seismic profiles (average profile density of 0.7 km/km2) and gravimetric measurements (average point distance of c. 5 km) are available. In recent years maps of the Quaternary base were constructed independently by specific tasks and requirements. As a consequence, ten different maps were produced in the period from 1970 to 2014. Scaling varies between 1:10 000 to 1:1 000.000, while those with the higher resolution cover only parts of Brandenburg. The aim of this study is to combine all datatypes to create a holistic model, which can be used interdisciplinary. The varying quality and quantity, as well as the large age range of the incoming data pose a challenge being solved with different modelling approaches and geostatistical methods.



5:15pm - 5:30pm
Topics: 4.08 Geological surveying as services for the public delivered by the State Geological Surveys of Germany - Current Issues

The Geological Data Act - From the notification of geological investigations to the transmission and provision of geological data

Birgit Futterer1, Hans-Jürgen Brauner2

1Landesamt für Bergbau, Geologie und Rohstoffe Brandenburg (LBGR), Germany; 2Landesamt für Bergbau, Energie und Geologie Niedersachsen (LBEG), Germany

The Geological Data Act (GeolDG) came into force on June 30, 2020. It has replaced the Mineral Law (LagerstG) and has lead to a comprehensive new legal regulation in the field of recording, archiving and publishing geological data. The primary objectives of the Act are to safeguard geological data and make it available to the public, to ensure the sustainable use of the geological subsurface, and to be able to identify and assess geohazards.

Therewith it also affects clients of geological investigations and those commissioned to carry them out, e.g. drilling companies, etc. There is an obligation to notify the competent authority of all geological investigations at least two weeks before they begin. Data transmission and public provision is also regulated by means of deadlines. The term "geological investigation" includes all general geological, raw material geological, engineering geological, geophysical, mineralogical, geochemical, pedological, geothermal, hydrogeological and geotechnical measurements and recordings of earth's surface, geological subsurface, of ground or groundwater, obtained by means of prospecting, drilling, field or borehole measurements and other exploration methods such as remote sensing, as well as the processing of the data obtained in this way, as well as analyses and evaluations of these data, e.g. in the form of expert reports, surveys, and reports.

With the contribution here the law is presented fundamentally and for the execution of the law announcement procedures in the countries as well as processes of data transmission and administrative procedures for data supply.

 
4:00pm - 5:30pm1.04-2 Hydrogen: energy carrier in nature and for society – from natural hydrogen occurrences to large-scale hydrogen storage
Location: Hall C (HFB)
Session Chair: Rüdiger Lutz, BGR
Session Chair: Philipp Weniger, Bundesanstalt für Geowissenschaften und Rohstoffe (BGR)
 
4:00pm - 4:30pm
Invited Session Keynote
Topics: 1.04 Hydrogen: energy carrier in nature and for society – from natural hydrogen occurrences to large-scale hydrogen storage

Seepage of natural hydrogen: geochemical uncertainties and the need of a holistic approach

Giuseppe Etiope

Istituto Nazionale di Geofisica e Vulcanologia, Italy

Natural hydrogen (H2) exploration is particularly focused on surface emissions (seeps) and soil-gas prospections, similar to early petroleum reservoir explorations. However, defining the amount of H2 at the surface that indicates a potentially economic resource is impossible, and identifying its origin is challenging due to the fact that geological H2 concentrations and isotopic composition can overlap with the in-situ biological signature. The potential for H2 generation in surface environments as a result of microorganisms, corrosion of iron particles or minerals, or even drilling (artificial H2) must be extensively evaluated. Despite these limitations, similarities to hydrocarbon systems suggest that certain seeps, which typically occur in correspondence with faults, are an expression of advection (not diffusion), driven by pressure gradients, and thus can disclose the existence of pressurized pools (Etiope, 2023). The fluid dynamics of gas seeps can therefore reveal the nature of the H2 supply system. Comparing seep flux rates with potential H2 generation rates, either via radiolysis or serpentinization, is a fundamental exercise for determining whether the H2 system must include a reservoir, similar to conventional natural gas systems, or if the H2 observed at the surface originates from continuous flow crossing short-term accumulations or directly from the source rock, as some scholars have hypothesized. However, analyses of the gases associated with H2 (such as CO2, CH4, N2 and He) are always advised. Assessing the potential of a geological H2 resource necessitates a holistic approach that integrates multiple geochemical, ecosystem, and geological data.

References

Etiope G., (2023) https://doi.org/10.1016/j.ijhydene.2022.12.025



4:30pm - 4:45pm
Topics: 1.04 Hydrogen: energy carrier in nature and for society – from natural hydrogen occurrences to large-scale hydrogen storage

Key role of Fe-carbonates in natural H2 production? Evidence from the spatial link between barren ground depressions, gold deposit and H2 emissions

Benjamin Malvoisin, Fabrice Brunet

Univ. Grenoble Alpes, USMB, CNRS, IRD, UGE, ISTerre, France

Even if measurements of high H2 concentrations in continental rocks have significantly increased in the last decade, the origin of H2 remains enigmatic in this context. Here we show that the localities in continental rocks where H2-rich gases have been reported are mainly located near orogenic gold deposits. Two types of geomorphological features were identified near orogenic gold deposits on satellite images. They consist in both barren ground depressions and high densities of self-organized, small (< 20 m in diameter) circular- and comet-shaped white spots in 32 and 7 localities, respectively. Fe-carbonates commonly occur near gold deposits since gold is transported in CO2-rich fluids. Thermodynamic modelling reveal here that they can further dissolve in the presence of aqueous fluid to produce magnetite and up to ~ 1 mole of H2 per kg of rock. This reaction leads to a volume decrease of ~ 50 %. Based on these findings, we propose that Fe-carbonate dissolution could be the primary source of H2 in orogenic gold deposit areas, and involved in the formation of the geomorphological structures reported here. The association between H2-rich gas and ground depressions was also observed near other formations containing Fe-carbonates such as iron formations and carbonatites. This suggests that H2 production through Fe-carbonate dissolution is not restricted to gold deposits. The global H2 production in crustal rocks associated with Fe-carbonate alteration is estimated to 3 x 105 mol/yr.



4:45pm - 5:00pm
Topics: 1.04 Hydrogen: energy carrier in nature and for society – from natural hydrogen occurrences to large-scale hydrogen storage

Mineralogical evidence for Quaternary serpentinization in the New-Caledonian ophiolite: Implication for the low-temperature genesis of H2- and CH4-bearing alkaline fluids

Marianna Corre1, Fabrice Brunet1, Stéphane Schwartz1, Cécile Gautheron1,2, Arnaud Agranier3, Stéphane Lesimple4

1ISTerre - Univ. Grenoble, France; 2GEOPS, Univ. Paris-Saclay, France; 3GEO-OCEAN, Univ. Bretagne Occidentale, France; 4Service Géologique de Nouvelle-Calédonie, New Caledonia

H2-bearing fluids (pH 10 – 12) issued in alkaline springs found in several ophiolitic complexes worldwide are believed to result from the alteration of ultramafic rocks by infiltration of meteoric waters. The mineralogical fingerprint of the reactive percolation of such an alkaline fluid is revealed by veinlet mineralization occurring in the New Caledonian ophiolite (Massif du Sud). In two localities separated by ~ 15 km (Georges Pile and GR2H mines), late veins in a partially serpentinized peridotite contain magnetite crystals younger than 2 Ma as inferred from (U-Th)/He geochronometry. While the serpentinite host at Georges Pile is largely overprinted by lateritic weathering, primary parageneses are preserved at GR2H. There, magnetite occurs along with dolomite and Fe-poor lizardite as filling in millimeter sized veins cross-cutting the mesh texture of the partially serpentinized dunite. Temperature of the aqueous fluid from which the vein material precipitated is estimated to be ~95°C from in situ δ18O data on the magnetite-dolomite pair, indicating a low-temperature alteration process. Thermochemical calculation shows that this aqueous fluid was alkaline and most likely H2-bearing. Chemically, it strongly resembles waters that are issued today in H2 and CH4 – bearing (hyper)alkaline springs of the Massif du Sud. δ13C isotopic composition of dolomite is exceptionally high, between 7.1 and up to 17.3 ‰ and is interpreted as evidence for low-temperature methanogenesis.



5:00pm - 5:15pm
Topics: 1.04 Hydrogen: energy carrier in nature and for society – from natural hydrogen occurrences to large-scale hydrogen storage

Experimental alteration of ferroan brucite at temperature below 150°C: new thermodynamic and kinetic constaints on H2 production during ultramafic rock alteration at low temperature

William Carlin1,2, Benjamin Malvoisin1, Fabrice Brunet1, Bruno Lanson1, Nathaniel Findling1, Martine Lanson1, Tiphaine Fargetton2, Laurent Jeannin2, Olivier Lhote3

1Univ. Grenoble Alpes, USMB, CNRS, IRD, UGE, ISTerre, France; 2Storengy (ENGIE), France; 3Engie Research, ENGIE, France

The alteration of ferroan brucite, a common by-product of serpentinization, has been proposed as a H2 source at low temperature. Here, synthetic ferroan brucite with Fe/(Fe+Mg) = 0.2 was reacted with pure water at temperatures ranging from 348 to 573 K in 29 experiments either conducted in gold capsules or in Ti-based reactors. H2 production monitoring with time and characterization of the reaction products revealed the occurrence of the following reaction: 3 Fe(OH)2brucite = Fe3O4 + H2 + 2 H2O. This reaction proceeded completely in ~ 2 months at 378 K and was thermally activated. The small grain size of the synthetic brucite (40-100 nm) was similar to observations in natural samples, and was probably responsible for the high reaction rate measured. H2 production reached a plateau and Fe-bearing brucite also precipitated as a reaction product, suggesting the achievement of equilibrium. The thermodynamic properties of Fe(OH)2 were refined based on the experimental dataset and differ by less than 5 % from previous estimates. However, ferroan brucite is predicted to be stable at an hydrogen activity one order of magnitude lower than previously calculated. As a result, significant H2 production during ferroan brucite alteration at low temperature requires efficient fluid renewal. Such a mechanism strongly differs from olivine serpentinization which can occur even at high activity in H2 and thus with limited water renewal.

 
4:00pm - 5:30pm1.21 Distribution, reactivity and behaviour of TCEs in aquatic systems: surface-, ground-, hydrothermal- waters and brines
Location: Hall D (HFB)
Session Chair: Elisabeth Eiche, KIT
Session Chair: Teba Gil-Díaz
 
4:00pm - 4:30pm
Invited Session Keynote
Topics: 1.21 Distribution, reactivity and behaviour of TCEs in aquatic systems: surface-, ground-, hydrothermal- waters and brines

Behind the scenes of the TCEs: what we are talking about and why

Montserrat Filella

University of Geneva, Switzerland

TCEs stands for technology-critical elements, a group of chemical elements for which imbalances between supply and demand exist or are considered likely to exist. The concept is economic and geopolitical and is not based on any scientific consideration. The term TCE is linked to competition for natural resources, now dramatically intensified by geopolitical instability and the green-energy transition.

Since it is a geopolitical concept, the elements that are considered as TCEs depend on the country and change over time; basically, they depend on the "eye of the beholder". For example, in the EU list of 2023, compared to the 30 Critical Raw Materials (CRMs) of 2020, there are six new CRMs (arsenic, feldspar, helium and manganese, plus copper and nickel as Strategic Raw Materials) and two have disappeared (indium and natural rubber).

Currently, the European Union considers a large number of materials to be technologically critical (mostly, but not all, chemical elements): 51. Given that the total number of elements in the periodic table is 118, of which 94 occur naturally on Earth and the remaining 24 are synthetic, this means that we are talking about ≈50% of all naturally occurring chemical elements!

In this context, what are the reasons for studying the environmental and (eco)toxicological effects of TCEs? Obviously, they will be different in the European Union than in the producer countries. In this communication, the reasons and research needs on both sides of the so-called supply chain (producers and end-users) will be analysed.



4:30pm - 4:45pm
Topics: 1.21 Distribution, reactivity and behaviour of TCEs in aquatic systems: surface-, ground-, hydrothermal- waters and brines

The ongoing race between emerging contaminants and analytical chemistry: New approaches in ICP-MS/MS and determination of technology-critical elements in marine biota reference materials

Dominik Wippermann1,2, Ole Klein1,2, Alexa Zonderman1,3, Anna Ebeling1,2, Tristan Zimmermann1, Daniel Pröfrock1

1Helmholtz-Zentrum hereon, Institute of Coastal Environmental Chemistry, Department Inorganic Environmental Chemistry Germany; 2Universität Hamburg, Department of Chemistry, Inorganic and Applied Chemistry; 3Universität Hamburg, Department of Biology, Institute of Marine Ecosystem and Fishery Science

Technology-critical elements (TCEs) show a dramatic increase in industrial applications in recent years and decades. Technological applications in our everyday life have come a long way in the number of used elements, with almost every element of the periodic table today. Based on the fact that many TCEs are recycled only to a very small extent or not at all, TCEs may become contaminants of high concern in the future.

Yet, important knowledge gaps remain about the environmental behavior of TCEs and their uptake into the food chain. Therefore, tools are needed that enable a sound and reliable determination of TCEs in order to further understand their impact on the environment. We present the advantages of N2O as a reaction gas for inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) for the multi elemental analysis of the majority of TCEs (e.g.: Ga, Ge, In and Ta). Thus, allowing the determination with LODs between 0.00023 µg L-1 (Eu) and 0.13 µg L-1 (Te). In addition, we used a microwave assisted closed vessel digestion to determine non-certified TCE mass fractions within four commonly used reference materials in the field of environmental marine chemistry: NIST 2976 (mussel tissue), NIST 1566a (oyster tissue), BCR 668 (mussel tissue) and NCS ZC73034 (prawn). Presenting mass fractions for Ga (11 µg kg-1 ± 9 µg kg-1 - 63 µg kg-1 ± 8 µg kg-1) and In (0.39 µg kg-1 ± 0.29 µg kg-1 – 0.7 µg kg-1 ± 0.7 µg kg-1) as non-certified elements within all of these CRMs.



4:45pm - 5:00pm
Topics: 1.21 Distribution, reactivity and behaviour of TCEs in aquatic systems: surface-, ground-, hydrothermal- waters and brines

From rivers to the sea: determination and tracing of TCEs in natural waters

Anna Ebeling1,2, Ole Klein1,2, Tristan Zimmermann1, Bettina Rust1, Dominik Wippermann1,2, Svenja Faust1, Johanna Irrgeher3, Daniel Pröfrock1

1Helmholtz-Zentrum Hereon, Germany; 2Universität Hamburg, Germany; 3Montanuniversität Leoben, Austria

TCEs have a wide-spread range of applications and are released into the aquatic environment in various ways. For their sound determination in natural waters not only new analytical methods are needed but also reference materials for method validation. Even though a wide variety of certified reference materials (CRMs) of different water matrices are available, certified values of many elements, especially TCEs, do not exist. In this study, an online preconcentration method coupled with ICP-MS/MS was used for the quantification of 34 elements among which are 21 TCEs. The method was applied to 17 water CRMs and measured data is combined with a comprehensive literature review on non-certified values in the CRMs resulting in the suggestion of consensus values for various TCEs.

The method is applied to a set field samples from German rivers and from the North Sea in order to trace different inputs of TCEs into the aquatic environment: In and Ga ware analyzed as tracers for offshore wind farms where they are applied in corrosion protection systems. The Gd anomaly was used as a proxy of coastal and riverine inputs into the North Sea in an attempt to differentiate anthropogenic from geogenic signal. The concentrations in seawater ranged between 0.011 ng L-1 ± 0.001 ng L-1 and 0.27 ng L-1 ± 0.15 ng L-1 for In and between 1.37 ng L-1 ± 0.05 ng L-1 and 4.9 ng L-1 ± 0.5 ng L-1 for Ga and Gd anomalies of up to 4 were found in the North Sea.



5:00pm - 5:15pm
Topics: 1.21 Distribution, reactivity and behaviour of TCEs in aquatic systems: surface-, ground-, hydrothermal- waters and brines

Distribution of rare earth elements and yttrium in fjord waters: evidence for geogenic and anthropogenic sources in Norwegian fjords

Anna-Lena Zocher1, Tomasz Maciej Ciesielski2,3, Stefania Piarulli4, Julia Farkas4, Michael Bau1

1Constructor University, Germany; 2Norwegian University of Science and Technology, Norway; 3The University Centre in Svalbard (UNIS), Norway; 4SINTEF Ocean, Norway

The picturesque fjords along Norway’s coastline play an important role for the country’s tourism and aquaculture industry. Despite their economic importance for the country, surprisingly little is known about the occurrence and behaviour of rare earths and yttrium (REY) in Norwegian fjords. We will present dissolved (0.2 µm-filtered) REY data for different sites and depths from several Norwegian fjords with focus on the Seaward Basin in the Trondheimfjord. Our sample set is complemented by data for rivers feeding into the fjord (Orkla, Gaula, Nidelva, Stjørdalselva) and for two waste water treatment plants (WWTPs) releasing their effluents into the Seaward Basin.

All fjordwaters show REY concentrations in a similar range with decreasing concentrations with increasing water depth. Their shale-normalised (SN) REY patterns share common features with typical seawater patterns, however, light and middle REY are less fractionated compared to open-ocean water. Samples taken close to river mouths have notably higher REY concentrations in surface layers with very flat REYSN patterns, similar to the rivers investigated and characteristic of boreal rivers with a high nanoparticle and colloid load. In contrast, the truly dissolved (< 1 kDa) REY in river water of the Nidelva show patterns similar to those of seawater.

The effluents of the WWTPs carry a strong anthropogenic Gd signal into the Trondheimfjord, which results from the application of Gd-based contrast agents in magnetic resonance imaging. However, no anomalous enrichment of Gd is detected in the Seaward Basin itself because the large water volume immediately dilutes and obliterates the anthropogenic signal.



5:15pm - 5:30pm
Topics: 1.21 Distribution, reactivity and behaviour of TCEs in aquatic systems: surface-, ground-, hydrothermal- waters and brines

Rare earth element mobility in contrasting sediments

Christoforos Zamparas, Teba Gil-Díaz, Elisabeth Eiche

Karlsruhe Institute of Technology (KIT), Institute of Applied Geosciences, Adenauerring 20b, 76131 Karlsruhe, Germany

Contrasting sediments behave radically differently in aquatic systems, releasing elements of concern. Their behavior is a function of mineralogy, geochemical composition, and the conditions of the medium (e.g., ionic composition, pH). One way of understanding the reactivity of contrasting sediments, but also the operationally defined fraction of the associated elements is to use selective extraction protocols. Nevertheless, these are generally used without verifying the adequacy of the extraction times, in accordance with the sediment characteristics, nor the potential impact of element-specific behavior to the extracting reagents, biasing the final interpretation. This study aims at providing such understanding for the rare earth elements (including lanthanides, yttrium, and scandium). The sediments used originate from modern aquatic sedimentary environments of both terrestrial and marine-transitional origin, associated to either natural (beach and riverbank sediments) or anthropogenic (mine tailings) sources. A qualitative mineralogical determination of the sediments was performed via XRD. Element mobility was studied via selective extraction protocols applied in parallel, with a kinetic approach, and sequentially. Quantitative analysis of the total concentrations of major and trace elements was determined via XRF-EDX, ICP-OES and ICP-MS, to obtain elemental correlations and total REY+Sc sediment content for mass balance purposes. For each extraction solution, the elemental concentrations were quantified via ICP-MS. The information gained in this study provides further experimental results on the unknown aquatic behavior of REY+Sc elements, for which there is currently an increasing demand for major technological applications.

Acknowledgements:

Funded as part of the Excellence Strategy of the German Federal and State Governments.

 
4:00pm - 5:30pm1.29 Breakthrough technologies and innovations along the mineral raw materials supply chain
Location: Wiwi 101
Session Chair: Siyamend Al Barazi, BGR
 
4:15pm - 4:30pm
Topics: 1.29 Breakthrough technologies and innovations along the mineral raw materials supply chain - towards a sustainable and secure raw material supply

Quantification of greenhouse gas emissions from copper mining to refining

Martin Erdmann1, Rüdiger Durchholz2, Gudrun Franken1

1Federal Institute for Geosciences and Natural Resources, Germany (BGR); 2DMT GmbH & Co. KG

Material flow data are generally used to assess the environmental footprint of economic activities, e.g. through life cycle assessments (LCAs). This is particularly relevant for the resource-intensive sector of primary raw material extraction and the associated raw material supply chains. As LCAs are firmly established in industry, research, and governmental organizations to support decision-making, e.g. for comparing the environmental impact between recycling processes and primary raw material extraction, an up-to-date and transparent database is the basis for meaningful results. However, the ecological parameters for primary raw material extraction up to refining in the databases often do not reflect the current status. In addition, the data for many metals are often only aggregated values and not available for individual process steps of mining, processing, smelting and refining.

To address this challenge, we conducted a comprehensive survey of emissions data and other project- or deposit-specific data on copper mining, smelting and refining, and correlated the results with currently available general sector data. The data collection was carried out, on the one hand, through a customized questionnaire completed by the companies participating in the studies and, on the other hand, through literature research. The newly acquired project-specific knowledge enables improved calculation of the carbon footprint and greenhouse gas emissions of representative mining projects and smelters/refineries. Furthermore, it serves for a direct analysis of the calculation bases for life cycle assessments and the data on CO2 emissions of other data providers and their evaluation.



4:30pm - 4:45pm
Topics: 1.29 Breakthrough technologies and innovations along the mineral raw materials supply chain - towards a sustainable and secure raw material supply

Market power Indonesia – from the largest ore exporter to the leading nickel supplier for the green transition

Michael Szurlies

BGR, Germany

Because of its specific properties, nickel is set to play a key role in the implementation of new megatrends such as the energy and mobility transition. Nickel is used in many industries, primarily in the manufacture of stainless steel and nickel alloys. In addition to these established areas of application, a considerable increase in global nickel demand for battery production is expected until 2030, particularly due to the rapid global ramp-up of electric mobility.

Within this decade the global nickel demand is forcast to double. While the battery production in recent years was based mainly on the dissolution of nickel metal (so-called class 1), things changed in 2022 with intermediates (mainly MHP and nickel matte) representing the by far dominant nickel feed for the batttery production.

Currently, Indonesia is the only country to significantly increase the mine production to provide the necessary nickel intermediates to meet the future demand. Indonesia holds the largest nickel reserves and until 2013 was the worldwide leading nickel ore supplier. With the introduction of an nickel ore export ban, the country became the leading producer of refined nickel products within less than ten years. Moreover, Indonesia is already the by far largest exporter of nickel intermediates for the global battery value chain. However, this dramatic change is based mainly on Chinese investments. It raises questions on the secure and sustainable global nickel supply.



4:45pm - 5:00pm
Topics: 1.29 Breakthrough technologies and innovations along the mineral raw materials supply chain - towards a sustainable and secure raw material supply

Hyperspectral airborne and satellite data from EnMAP for mineral mapping of raw material at Gamsberg-Aggeneys area, South Africa

Martin C. Schodlok, Michaela Frei

BGR, Germany

Hyperspectral remote sensing already is important in geoscientific research in the fields of geology, soil, exploration and mining. New hyperspectral satellite systems are already in operation (e.g. EnMAP, PRISMA and DESIS) and more systems are planned e.g. the European Copernicus Next Generation Hyperspectral Satellite CHIME. Investigated are the information contents of hyperspectral data for exploration target recognition and their dependency on spatial resolutions of different sensor platforms. Airborne data offer high spatial resolution of 2.5 m with limited areal data acquisition, whereas hyperspectral spaceborne sensors guaranty nearly worldwide data availability with the same spectral characteristics but medium spatial resolution (30 m). The aspects of high spectral resolution and high versus medium spatial resolution targeted mineral mapping is demonstrated. Hyperspectral satellite data are analyzed successfully to map major mineralogy and proxy minerals such as hematite for the ore mineralization at Gamsberg. The results indicate, that hyperspectral satellite data are an important data source for exploration activities despite the moderate spatial resolution. However, for detailed mapping especially within a mineralization zone, hyperspectral high spatial resolution data from airborne or unmanned aerial vehicle (UAV) systems are important, to understand and to map the mineralogy of such a zone in their complete complexity.



5:00pm - 5:15pm
Topics: 1.29 Breakthrough technologies and innovations along the mineral raw materials supply chain - towards a sustainable and secure raw material supply

The development of a microwave-assisted laboratory hard rock cutting machine

Sair Kahraman1, Ramazan Comakli2, Masoud Rostami1

1Hacettepe University, Türkiye; 2Nigde Omer Halisdemir University, Türkiye

Mechanical excavators have been widely used for the excavation of rocks in mining and civil engineering projects. The excavation of hard rocks by mechanical machines is difficult due to low advance rate and high tool wear. This difficulty can be overcome by exposing hard rocks to microwave energy just before cutting. This paper presents the newly developed a microwave-assisted laboratory hard rock linear cutting machine. The cutting machine which can be equipped with disc cutter or conical cutter has been integrated with a microwave treatment system. The microwave system is composed of 25 kW-magnetron with a frequency of 915 MHz, wave guide, circulator, water load, stub tuner, and directional coupler. A rock sample is first exposed to microwave energy, then cut by cutter using the test system. During cutting tests, normal and cutting forces are measured, and specific cutting energy values are calculated. A preliminary cutting tests were carried out on some rock types using the cutting machine at different microwave power levels. It was observed that the optimum specific energy values ​​of the samples exposed to microwave energy were considerably lower than those that were not exposed to microwave energy. It was also observed that the optimum specific energy values ​​decreased quite steadily with increasing microwave power. The experiments using the new microwave assisted laboratory hard rock cutting machine showed that microwave treatment of rocks before cutting was an efficient method for the excavation of hard rocks.

 
4:00pm - 5:30pm2.03-3 Setting the stage for a habitable planet: Solid earth processes through time
Location: Wiwi 104
Session Chair: Arathy Ravindran, Universität zu Köln
Session Chair: Stephan Homrighausen, GEOMAR Helmholtz Centre for Ocean Research Kiel
 
4:00pm - 4:30pm
Invited Session Keynote
Topics: 2.03 Setting the stage for a habitable planet: Solid Earth processes through time

The complimentary records of ancient differentiation events preserved by Archean-aged crust and modern ocean island basalts

Bradley James Peters1, Arathy Ravindran1,2, Marc Halfar1, Andrea Mundl-Petermeier3, Marie-Theres Herret3, Courtney Jean Rundhaug1,4, Valerie A. Finlayson5

1Institute of Geochemistry and Petrology, ETH Zürich, 8092 Zürich, Switzerland; 2Institute of Geology and Mineralogy, University of Cologne, 50674 Cologne, Germany; 3Department of Lithospheric Research, University of Vienna, 1090 Vienna, Austria; 4Center for Star and Planet Formation, University of Copenhagen, 1350 Copenhagen, Denmark; 5Department of Geology, University of Maryland, College Park, MD 20742, United States

Modern terrestrial mantle-derived rocks display a rich diversity of isotopic compositions that have been key to understanding the assembly of the silicate Earth over the last 2-3 billion years. Parallel to these advancements was an increasing understanding that Archean-aged cratonic rocks provide a window into foundational terrestrial processes that occurred in the first 1-2 billion years of Earth history. The study and application of these distinct records remained mostly independent until statistical and instrumental precision improved enough to measure meaningful heterogeneity in short-lived radiogenic isotopes (especially 142Nd and 182W) among young mantle-derived rocks. Recent developments in the study of ocean island basalts have revealed that some early domains in Earth’s mantle have never been fully homogenized and may also preserve information about foundational Earth processes.

The 182W/184W records of Archean and modern rocks are especially complimentary and reflect differing perspectives on core formation and subsequent late accretion processes. On the other hand, the 142Nd/144Nd signatures of some ocean island basalts may reflect the same global differentiation event preserved by many less altered cratonic rocks of Archean age. Continuing advancement in analytical precision will increase the potential to integrate the study of Archean-aged and modern rocks as mutually beneficial tools to understand processes such as core and dynamo formation, crustal differentiation, plate tectonics, and impact events. In turn, a detailed understanding of our planet’s early history in these respects is critical to identify which terrestrial exoplanets have the geological propensity to host life.



4:30pm - 4:45pm
Topics: 2.03 Setting the stage for a habitable planet: Solid Earth processes through time

Combined 182W – 142Nd data for the Deccan Large Igneous Province and the role of crustal and lithospheric reservoirs

Josua J. Pakulla1, Jonas Tusch1, Arathy Ravindran1, Eric Hasenstab-Dübeler1, Mike W. Jansen1, Purva Gadpallu2, Raymond A. Duraiswami2, Carsten Münker1

1Universität zu Köln, Institut für Geologie und Mineralogie; 2Savitribai Phule Pune University, Department of Geology

Recently, high precision isotope measurements revealed anomalies of the short-lived 182W and 142Nd system in modern Ocean Island Basalts (OIBs) [1, 2]. These anomalies indicate the presence of an ancient primordial component within OIB sources, however, their origin remains enigmatic. Core-mantle interaction [2] or the involvement of early differentiated and isolated silicate reservoirs [e.g. 3] are the most plausible scenarios to account for the observed isotope anomalies. To better understand the involvement of primordial components within OIBs, comparing plume heads and tails might be key to answering this question since the amount of incorporated material changes during the lifetime of plumes [4].
Here, we present new 182W and 142Nd data for basalts from the Deccan Large Igneous Province (DLIP; 65Ma). By investigating Pb and 143Nd isotopes as well as W-Th-Ta systematics, we investigated the role of crustal and lithospheric contamination during plume ascent on the short-lived isotope compositions. Our combined 142Nd-182W data for pristine DLIP lavas fall within the range of Réunion lavas [1, 5] that were interpreted as late-stage eruptions tapping the Deccan-Réunion plume. Consequently, while the short-lived isotope compositions can be altered due to lithosphere assimilation, pristine DLIP lavas display the same short-lived isotope compositions as their respective tail. In contrast to previous studies [4], this argues for a consistent entrainment of the same primordial components into a plume head and tail.

[1]Peters et al. (2021), G-Cubed. [2]Mundl et al. (2017), Science. [3]Tusch et al. (2022), PNAS. [4] Jones et al. (2019), EPSL. [5]Jansen et al. (2022), EPSL.



4:45pm - 5:00pm
Topics: 2.03 Setting the stage for a habitable planet: Solid Earth processes through time

Drilling the Crust – Mantle transition zone in the Oman ophiolite - the formation of massive dunites.

Sven Merseburger, Felix Marxer, Francois Holtz, Jürgen Koepke

Leibniz Universität Hannover, Germany

The formation of oceanic crust at mid-ocean ridges is one of the dominant processes in the chemical differentiation of our planet. Oceanic crust formed at fast-spreading ridges exhibits a relatively uniform seismic stratigraphy and is regarded as layered and relatively homogeneous. Because of the lack of in-situ exposures at the base of recent oceanic crust, existing models on the geodynamics of the deep processes during crustal accretion have never been tested directly using natural samples. The ICDP Oman Drilling Project penetrated at two sites the crust/mantle boundary in the Oman ophiolite, the best analogue for fast-spreading crust on land (drill cores CM1, CM2). We started a study investigating a continuing and densely spatial resolved sample set of both drill cores in order to shed light on the nature of this poorly understood zone at the base of the Oman paleocrust. The drill cores CM1 and CM2 cover the upper mantle harzburgites at the bottom, followed by a 90 m thick massive dunite layer with layered gabbros on top. Ni and Mg# in olivine as well as Cr#, Mg# and trace elements in chrome spinel were analyzed by EPMA and fs-LA-ICP-MS. The data reveals a homogeneous harzburgitic upper mantle composition and a dunite section showing decreasing Mg#, implying an increase in differentiation towards the top. We conclude that the zone of massive dunite was formed as a first cumulative crystallization event of a mantle-derived, primitive MORB melt, while the residual melt was fed into the stockwork system of the layered gabbros.

 
4:00pm - 5:30pm-
Location: Wiwi 104a
4:00pm - 5:30pm3.27-3 Alkaline rock and carbonatite related magmatism
Location: Wiwi 107
Session Chair: Tomas Magna, Czech Geological Survey
Session Chair: R. Johannes Giebel, Technische Universität Berlin
 
4:00pm - 4:15pm
Topics: 3.27 Alkaline rock and carbonatite related magmatism

Stable zirconium isotope constraints on the petrogenesis of carbonatites

Tomas Magna1, Vladislav Rapprich1, Shengyu Tian2, Frederic Moynier3, R.Johannes Giebel4

1Czech Geological Survey, Czech Republic; 2Max Planck Institute, Germany; 3IPGP Paris, France; 4TU Berlin, Germany

Refractory as well as insoluble nature of zirconium (Zr) dictates that its behavior mostly is driven by magmatic fractionation whereby Zr-rich phases, such as zircon or baddeleyite, and to a lesser amount pyroxene, can control stable Zr isotope systematics of silicate systems. In carbonatites, HFSE often are carried by pyrochlore, garnet and/or pyroxene, and scavenging of these phases during magmatic evolution of carbonatite liquids may result in significant depletions, particularly apparent for Ti, Zr and Hf. Therefore, fractional crystallization of HFSE-bearing phases may bear on the understanding of the role of carbonatites for HFSE distribution in the mantle.

We have analyzed Zr stable isotope systematics (δ94/90ZrIPGP-Zr) of several carbonatites from various geotectonic positions to further constrain their petrogenesis. The preliminary data shows ~0.4‰ variation which is not easily related to major element chemistry of carbonatites, nor emplacement age. Samples of unmodified carbonatites from continental rifts and hot-spots plot above the mantle value (δ94/90Zr = 0.04 ± 0.04‰), with δ94/90Zr of up to ~0.35‰ whereas carbonatites from shear zones display resolvedly lower δ94/90Zr. Carbonatites overprinted by F-rich fluids carry distinctly low δ94/90Zr, associated with high Nb/Ta, suggesting high mobility of HFSE in F-rich fluids. In contrast, δ94/90Zr of carbonatites carrying sulfide mineralization does not deviate from that of unmodified carbonatites. These cumulative observations indicate stable Zr isotope fractionation between silicate and carbonate melts in the mantle. Besides, they also indicate strong mineralogical control of HFSE-bearing phases on the stable Zr isotope systematics of carbonatites.



4:30pm - 4:45pm
Topics: 3.27 Alkaline rock and carbonatite related magmatism

Deep-stuck Ti-rich carbonatites: A link to the composition of primitive carbonatite melts?

R. Johannes Giebel1,2, Benjamin F. Walter3, Michael A.W. Marks4, Gregor Markl4

1Technische Universität Berlin, Germany; 2University of the Free State, South Africa; 3Karlsruhe Institute of Technology, Germany; 4Eberhard Karls Universität Tübingen, Germany

Carbonatitic melts are subject to different processes during their ascent (e.g., fractional crystallization and crustal contamination), which may cause a strong change in their composition. Their original composition has not been definitively determined. In order to find indications of the primitive composition, it appears reasonable to investigate the deepest known carbonatite occurrences. One of the deepest known carbonatites is the Palabora complex in South Africa. Most of the complex is represented by varieties of pyroxenite, while the center of the complex comprises a multiple calcite carbonatite intrusion (called Loolekop). A new discovery of a second carbonatite in the southern part of the complex, reveals a head section of a stuck carbonatite intrusion, which is reflected by isolated veins on the surface and a more extensive abundance with depth. This carbonatite shows a strong enrichment in Ti (>10 wt.% TiO2) with up to 20 modal% ilmenite. Fenitising fluids exsolved from the carbonatitic melt have even titanitised the surrounding pyroxenite. Additionally, previous investigations of the Loolekop show that the Ti content of the carbonatite increases systematically from the center of the intrusion to the margin. This could indicate a noticeably higher Ti content in the more primitive melt that crystallized in the marginal areas in comparison to a slightly more evolved melt that formed the center. Could this be an indication that primitive carbonatite melts are rich in titanium and lose the titanium rapidly during their evolution?



4:45pm - 5:00pm
Topics: 3.27 Alkaline rock and carbonatite related magmatism

The eruption interface between carbonatitic dykes and diatremes – the Gross Brukkaros volcanic field Namibia

Benjamin Florian Walter1, R. Johannes Giebel2, Pete Siegfried3, Dominik Gudelius1, Jochen Kolb1

1Karlsruhe Institute of Technology, Germany; 2Technische Universität Berlin, Germany; 3Camborne School of Mines, UK

Carbonatites are relatively rare rocks with only about 600 occurrences world-wide. While dominated by intrusive carbonatites the rock record only shows about 50 occurrences of extrusive carbonatites. The geochemical link between intrusive and extrusive equivalents is essentially unstudied. To shed light on this topic the interface between fine-grained dolomite-carbonatite dykes and associated diatremes of the Gross Brukkaros in central Namibia was investigated. Whole rock geochemistry and petrography provide evidence that the carbonatite dykes contain significant amounts of Si and Al, which is assigned to assimilation of crustal xenoliths. At the transition from carbonatite dyke to diatreme formation, the carbonatite melt degassed (release of CO2 and other volatiles to the atmosphere), while the Si, Ca, Mg and Fe load together with a high amount of trace elements became precipitated from a hydrothermal “magmatic-provenance-dominated” fluid during rapid temperature drop in the course of decompression as a mixture of micro- and cryptocrystalline quartz (quartz I) and aegirine-augite (plus minor magnetite). This mineral assemblage forms the matrix of the diatreme breccia. A second quartz generation (quartz II) is formed in the post-eruption environment by precipitation from a fluid resulted by a mixture of remaining fluids and an influx of meteoric waters. All measured trace elements show significantly higher contents in quartz I compared to quartz II (with exception of Li). This study provides the first holistic dataset that show how a carbonatite geochemically behave during eruption.



5:00pm - 5:15pm
Topics: 3.27 Alkaline rock and carbonatite related magmatism

Gravitational collapse of a volcano edifice as a trigger for explosive carbonatite eruption? - a lesson from Kaiserstuhl

Vladislav Rapprich1, Benjamin F. Walter2, Veronika Kopačková-Strnadová1, Tomáš Magna1

1Czech Geological Survey, Czech Republic; 2Karlsruhe Institute of Technology, Germany

The Miocene Kaiserstuhl Volcanic Complex in the Upper Rhine Graben is known for simultaneously exposing both intrusive and pyroclastic calciocarbonatites. This makes Kaiserstuhl a promising candidate for studying the field and genetic relations between intrusive calciocarbonatite and its eruptive equivalent, and the processes enabling eruption of the calciocarbonatite at the surface in particular. Eruptive calciocarbonatites in Kaiserstuhl are represented by carbonatite tuff and lapilli-stone beds covering a agglomerate fan on the western flank of the volcano. The debrites represent lahar (debris flow) and possibly also debris avalanche deposits. Based on observed textures, the debris flows were most likely derived by water-dilution from debris avalanches resulting from edifice failure, which occurred in the central part of the Kaiserstuhl Volcanic Complex and ultimately exposed the intrusive system. The carbonatite pyroclasts (lapilli and ash) were ejected from narrow vents represented by open framework tuff-breccias aligned along the detachment scarp. Since the Ca-carbonates break down rapidly at high temperatures and low pressures, calciocarbonatites are unlikely to form surface lavas. On the other hand, the presence of the calciocarbonatite pyroclastic deposits suggests that some geological process faster than the high-temperature break-down of Ca-carbonate may facilitate calciocarbonatite eruption. Prompt exposure of a suprasolidus high-level carbonatite intrusion by edifice collapse may be a suitable scenario enabling calciocarbonatite eruption. The absence of edifice failures on alkaline volcanoes, where carbonatite intrusion is either supposed or exposed, may explain overall scarcity of erupted calciocarbonatites.

 
4:00pm - 5:30pm4.09 3D models in education and outreach - synergy of research, geotourism, conservation and georisk assessment
Location: Wiwi 108
Session Chair: Mathias Knaak, Geologischer Dienst NRW
Session Chair: Gösta Hoffmann, Deutsche UNESCO Kommission
Session Chair: Edouard Grigowski, University of Bonn
Session Chair: Valeska Decker, RWTH Aachen University
 
4:00pm - 4:15pm
Topics: 4.09 3D models in education and outreach - synergy of research, geotourism, conservation and georisk assessment

Mining rock salt – using a 3D model with respect to economic requirements

Anne Engler1, Thomas Kießling1, Marie-Luise Richter1, Anne Baum2

1ERCOSPLAN Ingenieurgesellschaft Geotechnik und Bergbau mbH; 2Glückauf Sondershausen Entwicklungs- und Sicherungsgesellschaft mbH

Intending to improve mining and exploration processes within a rock salt producing mine all available geological information were collected, evaluated and prepared to create a 3D subsurface model. Besides geological information the drifts were visualized in 3D, too. Amongst other data borehole information from above and subsurface were considered to create a block model showing the grade distribution within the deposit and the geological mining boundaries. One challenging aspect was to harmonize the borehole database that grew over several decades. The block sizes of the model were created due to the customers’ needs with respect to dimensioning issues.

Based on the results of the geological model drift planning and excavation processes can be optimized. With respect to the geological exploration program the targets can be outlined in a more distinct way using the 3D model. By precising mine design and exploration targets workflows for short and long term mine planning can be improved. Beyond that reserves and resources of the deposit can be described more precisely. By updating the model on a regular basis thickness, depth and distribution maps as well as profiles can be requested easily from the model considering all available information.

As the geological model was created with the help of SKUA-GOCAD (AspenTech®) and AutoCAD® data exchange can be realized using for example CAD-based formats as well as column-based files. Furthermore, the geological model can be implemented into a mine planning software to improve daily routine at the mine site.



4:15pm - 4:30pm
Topics: 4.09 3D models in education and outreach - synergy of research, geotourism, conservation and georisk assessment

A Technical Approach to 3D Modelling of the Subsurface Geology in the South-Eastern Harz Foreland

Tilman J. Jeske, Melanie Siegburg, Alexander Malz, Olaf-Christian Müller, Ivo Rappsilber

Landesamt für Geologie und Bergwesen Sachsen-Anhalt, Halle (Saale), Germany

The digitization of geological data is becoming increasingly important in the assessment of the subsurface geology, and 3D visualization offers new possibilities. To extend the visualization of the subsurface geology of the State of Saxony-Anhalt, a 3D structural model of Permian to Quaternary stratigraphy of the South-Eastern Harz Foreland has been created. The model is based on pre-existing data consisting of maps from large-scale subsurface exploration, seismic profiles, and c. 5,660 stratigraphic profiles from the extensive borehole database from over 100 years of drilling exploration. Data preparation consisted of extracting borehole data, digitizing and vectorizing maps and seismic profiles, and subsequent processing with ArcGIS. Modelling of the surface mesh of stratigraphic boundaries and faults was performed using SKUA-GOCAD 22 in the 'Structure and Stratigraphy' workflow. In this iterative process, inconsistencies in the topology and geometry of the mesh have to be resolved manually in several steps in order to create a consistent model. Challenges arise from low data density in some areas and conflicting information in data from different sources. The resulting model shows the arrangement and relationship of stratigraphic units and major faults of the area in a refined level of detail. Within the requirements of publication and provision of state geological data by the Geological Survey of Saxony-Anhalt (LAGB), the model was prepared to be published via the GST (Geosciences in Space and Time) framework at the LAGB.



4:30pm - 4:45pm
Topics: 4.09 3D models in education and outreach - synergy of research, geotourism, conservation and georisk assessment

3D geological modelling of the surficial aquitards in the German “Central Oder” sub-catchment.

Klaus Duscher

Federal Institute for Geosciences and Natural Resources, Germany

The „Central Oder“ sub-catchment in Germany is the first of three areas for which structural models of the surficial aquitards down to the latest Elsterian till are being constructed as part of the Geo3D-Oder project. All other areas are interpreted as undifferentiated aquifers. The data base is taken from the "Lithofacies map of the Quaternary 1 : 50,000" (LKQ 50).

The model consists of ten stratigraphic layers, each bounded by a top and base horizon, and the ground surface. The data combines polygons defining the extent of the strata and point data of elevations derived from contour lines and stratigraphic logs. The data was processed and transferred to the SKUA-GOCAD modelling platform.

The geological 3D model contains only a concordant sequence of horizons with no faults. The challenge in constructing 3D models of Quaternary glacial sediments lies in the variable and sometimes very small layer thickness. Especially in the case of unavailable information on the elevation of upper horizons, layers below cannot be correctly reproduced. A new method has been developed to avoid this. For each horizon, the uppermost proven elevations of all underlying strata were identified in search quadrants. This data was used to interpolate 'virtual horizons', which are constraints on the maximum depth for each horizon. The resulting horizons were finalised using automated routines and manual post-processing.



4:45pm - 5:00pm
Topics: 4.09 3D models in education and outreach - synergy of research, geotourism, conservation and georisk assessment

Digital educational content in geosciences

Mandy Duda, Julia Godlewska, Marc Sören Ogan, Alexander-Dean Seiling, Tobias Backers

Ruhr-Universität Bochum, Germany

Fieldwork represents a highlight for most students in geosciences but is associated with challenges related to diversity. Due to long periods of absence, high costs, remote destinations, and physical and mental stresses, not all students can equally benefit from the offer, for example, people with care obligations, challenges due to sociocultural status, insufficient financial resources, or illnesses. Some outcrops are generally inaccessible.

The Engineering Geology and Rock Mass Mechanics Group at Ruhr-University Bochum realizes projects towards a more diversity-friendly education in geosciences.

Within Digifit, the geological mapping course in the Bachelor’s curriculum was digitized. With 360° tours and 3D models of outcrops and rock samples, the course can be offered digitally and provides high-quality teaching material for the preparation and postprocessing of fieldwork.

DRAGON Ruhr.nrw develops digital teaching material for geosciences and civil engineering. By content relating to climate change and geohazards, such as 3D models of outcrops in the Ahr valley, students are faced with the significance of their future roles.

As part of research-based learning projects, students are currently working on a comparison between manual mapping of discontinuity orientations and the derivation of orientations from digital models.

We highlight limitations of digital fieldwork and ways to counteract them. The resulting educational material offers a diversity-open access to fieldwork. The media competence of the graduates is strengthened and the attractiveness of geosciences is increased. In addition, digital teaching content offers great potential for interdisciplinary collaborations and can be used by third parties, for example in the context of ESD.



5:00pm - 5:15pm
Topics: 4.09 3D models in education and outreach - synergy of research, geotourism, conservation and georisk assessment

Enabling virtual teaching with Unreal Engine 5 (3D/XR): The 30 Geotope³ virtual museum

Pascal Michael Woiton, Edouard Grigowski

University of Bonn, Germany

Fieldwork and outcrops are an essential component of geoscience education, providing students with a hands-on learning experience that enhances their understanding of geological processes. This is reflected by the importance personal field experience has in the teaching of geology. While classic fieldwork remains the best way to grasp the extent and underlying processes of geological structures, 3D and VR teaching applications offer a unique opportunity to explore and visualize geological features that may be difficult to access or too large from a human’s perspective. However, state-of-the-art virtualising technology is sparsely used in geoscientific education. The commonly used toolkits to handle three-dimensional geological data are not able to process large amounts of polygons, as well as their accompanying texture-sets, derived from detailed photogrammetry datasets in real-time or VR. Here we present our current digitising workflow within the 30 Geotope³ project and how we visualise highly detailed, large- and small-scale outcrops with the use of Unreal Engine 5s Nanite and Virtual Texturing technologies. This virtual museum enables students to experience a variety of geological features in an immersive and interactive way, bridging the gap between theory and practice and enabling collaborative and remote learning. We understand the virtual museum as a starting point for interactive educational environments covering outcrops from all around the world, thus making geoscience more accessible and preserving outcrops for future research.



5:15pm - 5:30pm
Topics: 4.09 3D models in education and outreach - synergy of research, geotourism, conservation and georisk assessment

Observing a century of volcanic morphodynamics using photogrammetric analysis of recent and archive data

Alina V. Shevchenko, Thomas R. Walter

GFZ, Germany

Volcanoes are the most dynamic landforms, capable of changing their shape and environment in a matter of minutes, posing a significant threat to the environment and populations. While modern monitoring approaches can detect short-term changes, the long-term evolution is not well understood. Through the collection and photogrammetric processing of optical data, we can now reconstruct the precise topographies of volcanic edifices during the last decades to study different stages of volcanic development. By comparing the obtained topographies, we calculate volume flows, including eruptive and eroded materials, and evaluate the resulting geomorphic changes. Recent advances in technology and algorithms have opened unique opportunities for the collection and processing of photogrammetric data, allowing quantitative analysis of aerial photographs from the mid-last century to modern satellite and drone data. Here, we present ultra-high-resolution point clouds and digital elevation models to study long-term morphological and structural changes at volcanoes. In particular, the availability of archive ground and aerial stereo imagery from the last century allows us to look into the past and reconstruct volcanic activity in glaciated regions, and explore the complex interactions and geomorphic changes these regions undergo. We illustrate volcano-cryosphere interactions in Kamchatka and Iceland, highlighting the use of the method by pioneers since the beginning of the last century. We describe the main features of the use of photogrammetry in volcanological research and discuss possible further developments in terms of improved visualization and virtual reality application for educational purposes.

 
5:30pm - 7:00pmPoster social - Themes: 1.03 | 1.07 | 1.09 | 1.21 | 1.22 | 1.23 | 1.27 | 1.29 | 2.06 | 3.06 | 3.16 | 3.27 | 3.28 | 4.08 | 4.09 | 4.10
Location: Foyer (Henry Ford Building)
 
Tue: 1
Topics: 1.03 Exploration of near-surface geological structures using active and passive seismic methods

Quaternary fault reactivation in Antarctica associated with Glacial Isostatic Adjustment

Ingra Malucelli Barbosa1, Holger Steffen2, Rebekka Steffen2, Elisabeth Seidel1, Karsten Gohl3, Christian Hübscher1

1Institute of Geophysics, University of Hamburg, Hamburg, Germany; 2Geodetic Infrastructure, Lantmäteriet, Gälve, Sweden; 3Alfred Wegener Institute Helmholtz-Centre for Polar and Marine Research, Bremerhaven, Germany

Available research on glacial isostatic adjustment (GIA) in Antarctica is sparse, and there are few records of how the stress field is affected by it compared to Arctic and northern regions. Circum-Antarctic coastal and offshore tectonics reveal the presence of faults and rift systems, particularly in West Antarctica, the Weddell Sea, and Prydz Bay. These areas are characterized by a series of complex faults that displace upper sedimentary sequences to depths of 2.5 km. In this study, we investigate the potential for reactivation of glacially induced faults (GIFs) by altered lithospheric stress conditions during ice advances and retreats in past glacial periods. We compiled available information on the dip and strike directions of Antarctic rift systems from the literature and databases. Using finite element simulations that incorporate fault geometries, various rheological and current stress parameters in solid and ice sheet models, it is possible to analyse the probability of fault reactivation due to GIA for the last 200 ka. Because West Antarctica has been subject to greater changes in its ice sheet in recent recorded years compared to East Antarctica, identifying potential sources of GIFs could help us better understand how seismotectonics in Antarctica have been affected by past glacial phases and what the implications of current global climate trends might be.



Tue: 3
Topics: 1.03 Exploration of near-surface geological structures using active and passive seismic methods

Combined analysis of H/V and passive seismic array measurements to investigate the shallow underground of the Quaternary Weser terraces south of Hamelin

Manuel Hobiger1, Christine Thiel1, Thomas Spies1, Koen Van Noten2, Martin Zeckra2, Aida Azari Sisi1, Andreas Steinberg1, Stefanie Donner1

1Federal Institute for Geosciences and Natural Resources, Federal Seismological Survey, Hanover, Germany; 2Royal Observatory of Belgium, Seismology-Gravimetry, Brussels, Belgium

The geology of the Weser river terraces to the south of Hamelin is characterized by Quaternary sediments, consisting of thin alluvium and several meters of sand and gravels, overlying the seismic bedrock. We investigated a study area along the left Weser bank south of the village of Kirchohsen using different ambient seismic vibration techniques. Borehole logs show that the thickness of the Quaternary sediments varies from around 15 m to 33.5 m.

The fundamental frequency at a measurement point can be determined with the H/V method, which is based on the ratio between the horizontal and vertical spectra of the ambient seismic vibration signals. In the study area, the resonance frequency varies from 2.6 to 6.3 Hz, where low frequencies coincide with thicker Quaternary sediments and higher frequencies with thinner sedimentary layers. Assuming a continuity of the geological units, we can directly link the H/V frequencies to the sedimentary thickness and map the transition zone between the boreholes by H/V measurements along several profiles and additional individual points. We complement these H/V measurements by a new passive seismic array measurement and the reanalysis of older measurements in order to retrieve the dispersion curves of Rayleigh and Love waves and invert them for the shear-wave velocity profile.

The combination of the different data provides a detailed overview of the lateral changes within the shallow underground structure of the sedimentary layers of the study site.



Tue: 4
Topics: 1.03 Exploration of near-surface geological structures using active and passive seismic methods

Multi-Method Geophysical Investigation of Fault Structures in the Northern Upper Rhine Graben: Insights from the NeoNORG Project

Johannes Mair1,2, Hermann Buness3, Andreas Henk2, Rouwen Lehné4, Lajos Röhlinger2

1BfS (German Federal Office for Radiation Protection), UR2, Berlin, Germany; 2Technical University of Darmstadt, Institute of Applied Geosciences, Darmstadt, Germany; 3Leibniz Institute for Applied Geophysics (LIAG), Hannover; 4Hessian Agency for Nature Conservation, Environment and Geology, Wiesbaden, Germany

Within the framework of the project Neotectonics in the Northern Upper Rhine Graben (NeoNORG), we used a multi-method geophysical approach to obtain a detailed understanding of the fault structures within the sedimentary basin.

Using parts of a 3D seismic data set originally conducted by the petroleum industry we were able to obtain a detailed 3D structural model. It consists of two main faults originating from the basement at a depth of 2 km to about 350 m below the surface. To close the gap between the 3D Seismic data and the surface, we conducted 2D P-wave profiles with geophone spacings of 2.5 m. For the uppermost 200 m, an even higher resolved image of the subsurface was obtained using 2D S-wave seismics with geophone spacings of 1 m. Geoelectrics with varying electrode spacings and georadar using 200Mhz antennas were used to resolve the uppermost 50 m.

The combination of these different geophysical investigation methods allowed us to trace the fault zones within the sedimentary basin from the crystalline basement at a depth of 2 km into the quaternary strata, several meters below the earth's surface. We thereby reveal the (neo)-tectonic activity of the investigated area. Overall, the study provides valuable insights into the development of fault zones in the Northern Upper Rhine Graben and demonstrates the importance of using a multi-method geophysical approach to investigate the tectonic development. The obtained fault outcrop at the surface is concurrently used to investigate the relationship of radon in soil gas and fault zones.



Tue: 5
Topics: 1.03 Exploration of near-surface geological structures using active and passive seismic methods

Full microtremor H/V and phase velocity dispersion curves inversion for S-wave velocity profiles of subaqueous slopes in Lake Lucerne (Switzerland)

Agostiny Marrios Lontsi1,2, Anastasiia Shynkarenko2, Donat Fäh2

1Department of Civil and Architectural Engineering, Faculty of Engineering and Technology, University of Buea, Buea, Cameroon; 2Swiss Seismological Service, Swiss Federal Institute of Technology, Zurich, Switzerland

The assessment of seismic hazard and potential earthquake secondary effects such as tsunamis in offshore environments requires, similar to onshore environments, a good knowledge of the subsurface shear-wave velocity (Vs) distribution with depth. Between 2018 and 2020, a seismological campaign with Ocean Bottom Seismometers (OBS) was performed on selected subaqueous slopes with unconsolidated sediment cover in Lake Lucerne (Switzerland) to measure ambient vibrations and to monitore earthquakes. OBS were deployed in the single station and array configurations. First, we use the single station ambient vibration data to estimate the microtremor horizontal-to-vertical (H/V) spectral ratio. Second, we follow a robust preprocessing workflow to extract the phase velocity dispersion curves (DC) from OBS ambient vibration array measurements. The estimated H/V spectral ratios and the DC are used as targets in an inversion process for the Vs profile determination. The microtremor H/V spectral ratio forward modelling routine uses a new model that is based on the seismic interferometry principles under the diffuse field assumption and considers the presence of the water layer.

Keywords: Microtremor H/V spectral ratios, Phase velocity dispersion curves, Ocean
Bottom Seismometer, Site effects, Shear-wave velocity



Tue: 6
Topics: 1.03 Exploration of near-surface geological structures using active and passive seismic methods

Determination of seismic resolution: Some practical aspects from land seismic data

Patrick Musmann

BGR, Germany

Reflection seismics is the most common geophysical method for obtaining structural images of the subsurface. It can image subsurface structures over large areas and depth ranges at high resolution. In order to make a reliable assessment of seismic imaging results, e.g. to quantify uncertainties, it is important to understand the concepts of seismic resolution. At brief, seismic resolution is the ability to distinguish between two seismic features from one another and resolve them separately.

Theoretical considerations to seismic resolution criteria and their implications for seismic imaging are discussed in many textbooks, but the practical use in interpretation is often difficult to achieve. This is, because the underlying parameters, e.g. the bandwidth and the velocity of the seismic signal, are not explicitly visible on the final stacked image, especially if the sections are depth converted.

However, the measure for vertical resolution is the dominant wavelength and the resolution criteria is expressed as a fraction of it, e.g. λ/4 criterion, whereas a measure of the lateral resolution is the Fresnel zone. Both of which can be computed by common functions that are available in most interpretation systems. As a result, seismic sections showing the spatial variability of both vertical and horizontal resolution are obtained that can be blended into the stacked seismic section. This gives a tool at hand – just like a seismic attribute – to estimate the limits of seismic resolution and access uncertainties in the final seismic image.



Tue: 7
Topics: 1.03 Exploration of near-surface geological structures using active and passive seismic methods

The reactivated intraplate Osning Lineament in northern Germany – Near-surface investigations using P- and SH-wave reflection seismics

Sonja Halina Wadas, David Colin Tanner

Leibniz Institute for Applied Geophysics, Germany

Neotectonic movements can cause severe hazards and are scientifically and socially relevant for seismic hazard assessment and utilisation of the subsurface. In northern Germany, a presumed aseismic region, little is known about these processes and the associated structures, despite proven neotectonic activity, because many faults are hidden beneath sediments. To improve the knowledge of neotectonic activity, investigations of recently-active fault zones, like the Osning Lineament (OL) in North Rhine-Westphalia, are required.

To better understand the neotectonic evolution of the OL, we used a combined approach using high-resolution 2D P- and SH-wave reflection seismics to investigate four different sites at the Bielefeld-Segment of the OL. Overall, we acquired three P-wave profiles with which we were able to image the underground down to 700 to 800m depth, and four SH-wave profiles that imaged the subsurface down to 100m depth.

The seismic profiles show good results with respect to mapping the fault inventory. In the Cretaceous, Triassic, and Quaternary several, previously unknown, northward-dipping thrust faults are evident, which have upthrusted the formations toward the south. The faults form fault splays that developed due to the propagation of the OL into the footwall. The slow shear-wave velocities, especially in the Quaternary, allow for very high-resolution imaging of the subsurface and the identified faults are evidence for neotectonic activity. More to the south, we also observed some southward-dipping normal faults, which are interpreted as basin faults of the Münsterland Basin dipping towards the basin center.



Tue: 8
Topics: 1.03 Exploration of near-surface geological structures using active and passive seismic methods

A multi-seismic approach to characterize the shallow subsurface for hosting the Einstein-Telescope infrastructure

Marius Waldvogel1, Nils Chudalla2, Shahar Shani-Kadmiel3, Soumen Kouley4, Stefan Back5

1Geological Institute, RWTH Aachen University, Germany; 2Institute for Applied Geophysics and Geothermal Energy, RWTH Aachen University, Germany; 3Royal Netherlands Meteorological Institute (KNMI); 4Gran Sasso Science Institute; 5Geological Institute, RWTH Aachen University, Germany

Within the feasibility study regarding the construction of the Einstein – Telescope (ET), at a depth of 200 – 350 m in the Meuse-Rhine Euroregio, various seismic methods are used for subsurface investigation and imaging. The study includes a 40 km long two-dimensional active seismic-reflection survey using vibroseis. The vibroseis data provide a medium-resolution overview of the subsurface architecture including continuous reflection intervals and major discontinuities. Parts of the vibroseis survey were re-investigated using an electric vibrator to evaluate the potential of this environmental friendly seismic source. Extracted refraction data allowed to calculate a velocity model for the shallow subsurface. Additionally, passive seismic data were collected prior and during times of active surveying in the wider study area; linear data was used to optimise the station spacing for the area set-up and for the acquisition of seismic data perpendicular to the active survey. “Passive” area data were used to gather 3D insights. Geological interpretation of the various seismic reflection and refraction data integrated with subsurface knowledge from boreholes documented a major impedance contrast in the shallow subsurface caused by a prominent unconformity between Palaeozoic basement rocks covered by soft, partly consolidated Upper Cretaceous sediments. The soft-sediment cover effectively dampens surface-induced sounds in the target depth. This hampers the quality of subsurface imaging but is considered as beneficial for the operation of the ET in the Palaeozoic basement. With the collected passive seismic data, the main directions of surface generated noise and its denudation with distance from the respective sources can be identified.



Tue: 10
Topics: 1.21 Distribution, reactivity and behaviour of TCEs in aquatic systems: surface-, ground-, hydrothermal- waters and brines

Colloidal transport and seasonal variations of technology critical elements in aquatic systems

Teba Gil-Díaz1,2, Elisabeth Eiche1,2

1Karlsruhe Institute of Technology (KIT), Institute of Applied Geosciences, Adenauerring 20b, 76131 Karlsruhe; 2Laboratory for Environmental and Raw Materials Analysis, Institute of Applied Geosciences, Karlsruhe Institute of Technology, Karlsruhe

Technology critical elements (TCEs) are widely understudied in aquatic systems. Many unknowns particularly are linked to the mechanistic understanding of TCE transport mechanisms in contrasting river systems. In this work, we aim at characterizing the colloidal vs truly dissolved TCE concentrations in three contrasting rivers in Germany (Rhine, Neckar and Danube) by comparing two filtering meshes (0.45 vs 0.02 µm). The seasonal component of such transport is also investigated based on monthly collections of water samples in 2023. TCEs were analysed via external calibration at the ICP-MS (iCAP series, Thermo®). Results suggest that each river has a different load on TCE concentrations, of which the colloidal transport differs even within the Rare Earth Elements and Yttrium (REEY) list. The seasonal influence is compared to water discharges and temperature ranges. These results provide further understanding of the watershed dynamics and can help identifying relevant processes that determine the unknown aquatic transport and fate of TCEs. This information can be used for developing scenarios for potential risk assessment of anthropogenic discharges from both stable and/or radioactive origin in surface aquatic environments in Germany.

Acknowledgements:

This work was funded by the Federal Ministry of Education and Research (BMBF) and the Baden-Württemberg Ministry of Science as part of the Excellence Strategy of the German Federal and State Governments. The authors also acknowledge the extensive contribution of the Landesanstalt für Umwelt Baden-Württemberg (LUBW, Germany) and the Amt für Umwelt und Energie (AUE, Switzerland) for the collection of water samples.



Tue: 11
Topics: 1.21 Distribution, reactivity and behaviour of TCEs in aquatic systems: surface-, ground-, hydrothermal- waters and brines

Understanding the potential mobility of geogenic metals of concern from heavy mineral sands

Christoforos Zamparas1, Teba Gil-Díaz1, Dieter Schild2, Elisabeth Eiche1

1Karlsruhe Institute of Technology (KIT), Institute of Applied Geosciences, Adenauerring 20b, 76131 Karlsruhe, Germany; 2Karlsruhe Institute of Technology (KIT), Institute for Nuclear Waste Disposal, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany

Iron oxide and hydroxide minerals are widespread in many aquatic environments and as such, can determine the fate of several metals of concern. Their role on metal mobility is generally studied under controlled conditions using synthetized materials. However, natural systems are complex and present a wide range of conditions, which may release metals differently to laboratory settings. In this study, we aim at understanding the mobility of geogenic, technology critical elements such as vanadium, nickel, cobalt, niobium, and tantalum from black sand sediments. These sediments from the OIB volcanic environment of the Canary Islands are the product of weathering and erosion of relatively geologically recent, ultramafic volcanic rocks composed of basanitic, phonolitic, nephelinitic and, locally, melilitic lavas and tuffs, sources of mafic heavy minerals deposited as a placer. The sediments were extracted through magnetic separation, characterized via XRD and SEM-EDS techniques, and further processed with a series of parallel selective extractions following widely applied protocols. Desorption kinetics during the extraction procedures were also investigated in order to understand the efficiency of the protocol for such sediments. Total element concentrations were quantified via XRF and LA-ICP-MS, whereas dissolved concentrations were determined via ICP-MS. Our results point towards contrasting selectivity during the extractions and different iron oxide mineral fractions in which these metals are bound. This information has a broad application for the potential environmental risk of metal mobility in aquatic systems.

Acknowledgements:

This work was funded as part of the Excellence Strategy of the German Federal and State Governments.



Tue: 13
Topics: 1.22 Contaminants in groundwater – curse and blessing

GCI Rohrpassivsammler – An innovation for the integrative monitoring of water quality

Jörg-Helge Hein

GCI GmbH, Germany

The GCI Rohrpassivsammler (tube-installed passive collector) is an innovative measuring device that uses the accumulation of water contaminants onto collector materials for integrative monitoring of varying concentrations, even for trace substances over long periods of time. The precise and adjustable flow and substance-specific calibration allow for a high level of sensitivity and quantitative evaluation of the collection results.

The patented measuring principle can be used with all water sources. The device has been successfully tested at production wells (installed in a bypass) and with treated wastewater, for the detection of explosives, industrial chemicals, and pharmaceuticals. Currently, applications for the detection of PFAS, Monochlorobenzene, and Lead are prepared.

In the latest design, concentrations are measured at short time intervals using substance-specific (bio)sensors, e.g. for Valsartan and Valsartanic Acid. A special design for installation in filter sections of groundwater monitoring wells is being developed which measures the concentration in-situ instead of pumping water to the surface. This design was successfully tested for detection of NSO Heterocycles. Future development is aimed at applications for surface water.

Quality and operation parameters are recorded digitally and wirelessly transmitted from the field for online access and visualisation.

Research and development are the Berliner Wasserbetriebe (BWB), the Fraunhofer Institute (IZI-BB), the Federal Institute for Materials Research and Testing (BAM), the Technical University of Applied Sciences Wildau (TH Wildau) and the Institute for Bioprocessing and Analytical Measurement Techniques (IBA). Development was funded by the German federal government (ZIM) and the state of Brandenburg (BIG ILB).



Tue: 14
Topics: 1.22 Contaminants in groundwater – curse and blessing

Influence of pH and Na-concentration on facilitated and hampered transport of metoprolol by montmorillonite colloids in water-saturated quartz sand

Joshua Sawall1, Wiebke Warner2, Tobias Licha2, Ferry Schiperski1

1Technische Universität Berlin, Institute of Applied Geosciences, Dept. of Applied Geochemistry, 10587 Berlin, Germany; 2Ruhr-Universität Bochum, Institute of Geology, Mineralogy and Geophysics, Dept. of Hydrogeology-and -chemistry, 44801 Bochum

The role of clay colloids in facilitating or hampering the transport of cationic contaminants, such as heavy metal cations or radiogenic nuclides, in groundwater is well established. However, it is unclear whether this phenomenon occurs with positively charged organic contaminants to the same extent.

Laboratory column studies were conducted on water-saturated quartz sand for investigating the influence of colloids on the transport of metoprolol (MTP), a β-blocker with an acid dissociation constant (pKa) of 9.6, under varying pH and ionic strength conditions. The experiments were carried out at pH 3, 6, and 11, with sodium concentrations of 1 and 100 mmol L–1. Experiments were conducted with and without 0.5 g L–1 Na-montmorillonite colloids (diameter: 100–1000 nm). The results show that the presence of colloids increases the transport velocity of MTP, particularly at pH 6 and low sodium concentrations, indicating colloid-facilitated transport as the primary mechanism. Upon reducing the pH, the magnitude of colloid-facilitated transport decreases, but the bimodal breakthrough curve still suggests some co-transport of MTP. At pH 6 and high sodium concentration (100 mmol L–1) and pH 11, where MTP is predominantly uncharged, the presence of montmorillonite did not significantly impact the transport of MTP.

These findings highlight the dependence of MTP transport on the existence of clay colloids, salt concentrations, and the speciation of the contaminant determined by water pH. Thus, considering these variables is crucial for accurately predicting the mobility of positively charged organic contaminants in groundwater.



Tue: 16
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Groundwater monitoring in Niamey, Niger: Is groundwater an alternative drinking water supply under the current quality conditions?

Issa Bakayoko1, Didier Zinsou2, Manal Wannous1

1Federal Institute For Geoscience and Natural Resources BGR, Germany; 2Directorate of Niger Basin Authority

Groundwater in Niger represents an essential resource for survival in remote areas far from the Niger River and a reserve in areas where access to surface water is secured as in Niamey itself. The monitoring of this resource offered as a part of the technical cooperation with the Niger Basin Authority NBA enabled to obtain data on groundwater quality and observe changes in groundwater levels over the last decade. The monitoring targeted the three main aquifers existing in the area: the alluvial aquifer, the Continental Terminal aquifer and the fractured basement aquifer. Several boreholes in the first and second aquifers show high concentrations of NH4, NO2 and heavy metals. The boreholes belonging to the third aquifer show concentrations of NO3 considerably exceeding the WHO recommendation value between 100-1500 mg/l making this resource unfit for water supply. Reasons behind these excessive levels were mainly explained through the direct discharge of wastewater which is common in the Sahel region into the underground. However, the increased concentrations of NO3 in some wells during the rainy season imply a source in the unsaturated zone which mobilizes the nitrate during the infiltration.

In addition to nitrate, elevated concentrations of heavy metals such as arsenic and cadmium were detected in the basement aquifer proving the possible infiltration of contaminants from the top layers.

These results show that the monitoring tools offered within the technical cooperation framework enable to detect and trace the contaminants. however, they alarm the authorities to meet measures to protect this resource urgently.



Tue: 17
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Assessing and improving the groundwater quality monitoring network of the State of Brandenburg, Germany

Florian Jenn1, Patrick Wieder1, Silvia Dinse1, Tania Birner2, Ute von Daacke2

1GCI GmbH, Königs Wusterhausen, Germany; 2Landesamt für Umwelt Brandenburg, Potsdam, Germany

The project “Groundwater Quality Monitoring Network Improvement 2021/2022” aimed to assess and improve the groundwater quality monitoring network of the Environmental Agency of the State of Brandenburg, Germany. This comprised six major steps:

  1. Developing a catalogue of criteria for verifying the suitability of monitoring wells for representative groundwater sampling and for fulfilling specific reporting duties of the Environmental Agency (considering best practices)
  2. Assessing the currently active monitoring wells regarding the suitability criteria
  3. Reviewing the monitoring network in each groundwater catchment area regarding its capability to fulfil the different reporting duties
  4. Identifying deficits in the network and researching further existing suitable monitoring wells in focus areas, e.g. from the Environmental Agency’s water level monitoring network or from district authorities’ networks
  5. Testing the researched monitoring wells on site
  6. Suggesting locations for constructing new monitoring wells where no suitable wells exist

A total of 936 active monitoring wells have been assessed. These results have been aggregated for 63 groundwater catchment areas as basis for the deficit analysis. 10 focus areas have been identified for researching and testing existing monitoring wells and for suggesting new sites.

One major project outcome is a three-page factsheet for each catchment area including detailed information on land use, hydrogeology and available monitoring wells as well as statistical analyses of the monitoring well distributions and their suitability. It also contains a prioritised list of measures (adding existing wells to the network, high and low priority new locations) to implement in the next years.



Tue: 18
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Inferring deep soil moisture variations in Central and Southern Europe using seismic method

Yang Lu1, Qing-Yu Wang2, Götz Bokelmann1

1University of Vienna, Austria; 2Massachusetts Institute of Technology, USA.

Soil moisture is a key metric to assess soil health. Water held in the shallow subsurface between soil particles enables various biogeochemical and hydrological processes indispensable to soil functions. Potential soil moisture deficit may rise the irrigation demands, which further exacerbates the stress on the water supply. The changes in soil moisture can impact climate, further amplifying the climatic anomalies and intensifying extreme weather events. Thus, understanding soil moisture and its dynamics over time are of broad scientifical interest and practical implications.

Despite the vital importance of soil moisture, it still lacks sufficient means to properly assess the parameter at a regional scale, which is an essential research dimension for addressing practical issues in the agricultural and environmental sectors.

Ambient noise seismology provides new possibilities to infer subsurface changes in a real-time, non-intrusive, and cost-effective manner. In this study, we map the temporal variations in soil moisture for the great Alpine region and the Italy peninsular with ambient seismic noise. It is the first time that the seismic method has been applied to map water resources at a regional scale using an ordinary national seismic network set-up. The seismic method helps in bridging the resolution gap between current pointwise (e.g., tensio-, electrical- and neutron-meter) and global (e.g., satellite-based remote sensing) investigations, providing complementary information for both scientific research and public decision-making.



Tue: 19
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Model-based impact study of forest restructuring on groundwater recharge and hydrodynamics in a waterworks catchment (Briesen, Brandenburg, Germany)

Franziska Mehler1, Felix Möhler1, Matthias Clausen2, Ines Schwenzer2

1GCI GmbH, Germany; 2FWA Frankfurter Wasser- und Abwassergesellschaft mbH, Germany

The waterworks Briesen supply drinking water for the city of Frankfurt (Oder). The catchment of the waterworks is dominated by monoculture pine forests (Pinus sylvestris). Several forest-hydrological studies found that groundwater recharge under pine forests is lowest in comparison to other forest types. Hence, the question arose if forest restructuring could contribute to secure the drinking water supply of the region in the context of climate change and decreasing groundwater recharge.

Site classes of the forestry mapping were researched for all relevant forest restructuring areas. The Ministry of Environment of the State of Brandenburg published a recommendation of tree species mixtures which are suitable for the local conditions and for resisting climate change. Based on this recommendation, five tree species were selected. The tree mixture was set as percentage of these five tree species for each forest site class in the catchment.

The groundwater recharge below five tree species was calculated in a soil-water-balance model separately. Then the groundwater recharge was calculated for the forest site classes based on the percentage tree composition of each site. Finally, several scenarios of forest restructuring were developed, considering complete and partial restructuring as well as climate change. The resulting distributions of groundwater recharge were assigned as boundary conditions in a groundwater model.

The simulations with the groundwater model show that forest restructuring can increase groundwater recharge compared to current forests by 20 - 30 % and reduce the groundwater level decline and catchment expansion which is expected in the context of climate change.



Tue: 20
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Climate projections for the waterworks Lindau in Saxony-Anhalt as planning basis for proactive and sustainable catchment management

Felix Möhler, Alexandra Pavlova

GCI GmbH, Germany

The waterworks Lindau (Zerbst) are an important part of the interconnected system of drinking water supply in the region of Magdeburg, Saxony-Anhalt, Germany. The pumped water is exclusively fed by groundwater recharge. Measured groundwater heads show a continuous climate-induced decline of more than 3 meters for the last 50 years independent of waterworks management.

As basis for strategic planning of future waterworks management and optimization of the monitoring network, groundwater model based studies with climate projections were carried out. For this purpose, an approx. 1,200 km² transient groundwater flow model was set up. The present recoverable groundwater resources and their development in the catchment area until the year 2100 were modelled under changing climatic conditions. The underlying climate scenarios (RCP 2.6, RCP 4.5 and RCP 8.5) are based on the current state of global and regional climate research.

Available climate projections were statistically evaluated for the model domain. A bias correction for precipitation and evapotranspiration was applied and groundwater recharge was calculated transiently for each projection up to the year 2100 using a soil water balance model. This revealed a wide range of potential changes in groundwater recharge. The change ranges from about -35% to +50% by 2100 compared to the 1975-2020 period. The wide range results from high uncertainties of projected precipitation and spatial as well as temporal distribution patterns of precipitation.

The investigations show that in the long term further considerable changes in groundwater resources and hydrodynamics in the catchment are to be expected.



Tue: 21
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Case study at a model site "Green Economy Park" in Bremerhaven, Germany "Luneplate": High resolution 3D subsurface models in flow modeling with a focus on climate resilience

Katherina Seiter, Björn Panteleit, Sina Julius

GeologicalSurvey Bremen (GDfB), Germany

The Luneplate in Bremerhaven consists largely of nature reserves and bird sanctuaries. The soils have a thick alluvial clay horizon. Climate change threatens the region through seasonal heavy rain events, but also through the drying out of clay soils and the spread of saltwater inland due to rising sea levels. The region has traditionally been primarily agricultural, and in the northern part there is an economic area that will be complemented by a carbon-neutral GreenEconomy Park.

The planners of the new business park want to take various measures, including the use of excess rainwater, the creation of compensation areas and infiltration basins to drain surface water. This should also prevent the organic-rich alluvial clay from drying out, reducing the risk of higher CO2 release. This pilot project on the Lune Plate will explore, as part of the Interreg Blue Transition project, how the region can be made more climate resilient through targeted groundwater management measures that are already planned, as well as new measures such as infiltration wells. Infiltration wells can reduce saltwater intrusion and dissipate heavy rainfall. A high-resolution 3D groundwater model is used to simulate the effects of these measures and estimate their impact on climate resilience. The aim of the project is to enter into a dialog with investors and project managers in order to realistically assess the impact of measures and make a meaningful contribution to climate resilience.



Tue: 22
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Managed Aquifer Recharge for sustainable development in the Northern Coastal Aquifer System of Sinai Peninsula, Egypt

Ashraf Sayed Seleem1, Mona Morsy2, Peter Dietrich3

1Geology Department, Faculty of Science, Suez Canal University, Ismailia, Egypt; 2Geology Department, Faculty of Science, Suez Canal University, Ismailia, Egypt; Department; Monitoring and Exploration Technologies, Helmholtz Center for Environmental Research GmbH — UFZ; Geo- and Environmental Sciences, University of Tübingen.; 3Department; Monitoring and Exploration Technologies, Helmholtz Center for Environmental Research GmbH — UFZ; Department of Geosciences, Soil Science and Geomorphology, University of Hannover; Geo- and Environmental Sciences, University of Tübingen.

The groundwater is a main issue in sustainable development of the Sinai Peninsula, Egypt. Because of extensive groundwater abstraction, the Quaternary coastal aquifer system in the study area is now facing a serious salt water intrusion problem. Seleem (1996) has developed a saltwater intrusion numerical model by using MOCDENCE software which is developed by Sanford & Kinikow (1985). He found that the saltwater intrusion increases the salinity of groundwater in the wells over time. The isohytal map of Sinai Peninsula also shows that the isohyetal contour lines increase towards the northern direction in the Northern Province of Sinai peninsula where the annual rainfall rate is 104.7 mm/year at El-Arish station and 304.1 mm/year at Rafah station.

In the presented study, we suggest a network of rainfall harvesting units to collect the amount of high intensity rainfall water from the cities in the study area. The harvested rainfall water could be injected in the frame of a managed aquifer recharge (MAR) project into the calcareous sandstone (Kurkar) aquifer to attenuate the salinity of this aquifer and to prevent the progress of freshwater-saltwater interface.

For the suggested scenario, the SEAWAT software is applied to simulate the three dimensional variable density groundwater flow and solute-transport in the Quaternary aquifer system in the northern Sinai, Egypt. SEAWAT was developed by the USGS based on MODFLOW and MT3DMS packages. The numerical study with the SEAWAT software allows to investigate the potential impact of MAR on the movement of freshwater-saltwater interface in the study area.



Tue: 23
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Evaluation of geogenic and anthropogenic impacts on spatio-temporal variation in the quality of the drinking water sources under the impact of land-use and land-cover: A case study of the Erbil Central Sub-Basin, Iraq

Jawhar Mohammed-Shukur TAWFEEQ1, Erkan DİŞLİa1, Masoud Hussein HAMED2

1Department of Environmental Engineering, Faculty of Engineering, Van Yuzuncu Yil University, Van, Turkey; 2Department of Geology, College of Science, University of Salahaddin, Erbil, Iraq

The study area, Erbil Central Sub-Basin, is located within the foothill zone in the stable shelf tectonic unit of Iraq (northern Iraq) on the Arabian plate. Recently, groundwater demand has increased significantly due to insufficient surface water resources for agricultural, industrial, and domestic water uses depending on ever-increasing socio-economic development and population in the study area. Sampling studies were carried out in two different periods, May 2020 (wet season) and September 2020 (dry season), to determine the water quality in water resources located throughout the sub-basin. For this purpose, a total of 30 samples, including 27 groundwater wells, and 3 wastewater samples from channels, were collected and analyzed. The general hydrochemical analysis indicates that overall well water quality is suitable for drinking purposes except where elevated NO3, COD, and BOD5 concentrations are found. Most trace metal analysis results (except for Fe) in wells and wastewater channels show that they are below the permissible limits (0.3 mg/L) from IQWS (2010) and WHO guidelines (2011). The results of the factor analysis for the wet and dry season hydrogeochemical indicate that the first five and six-component extracted have eigenvalues>1 and correspond to approximately 94.844 and 96.26 % of the total variance, respectively. The factor analysis indicated that groundwater quality in the wet and dry season are significantly associated with anthropogenic pollution sources such as leaching from soil layers, cesspools wastes, industrial wastes, and agriculture activities rather than natural, geogenic processes such as reverse ion exchange, the weathering of carbonate minerals from geologic formations outcropping throughout the Erbil Central Sub-Basin.



Tue: 24
Topics: 1.27 Young Scientist Session

Kinematic analysis of a left step over along the dextral Kallar Kahar Fault, Salt Range, Pakistan.

Nowrad Ali1,2, Azmatullah Orakzai3, Asghar Khan3

1Institute of Geosciences, University of Potsdam, Germany; 2Department of Geology, University of Peshawar, Pakistan; 3Department of Geology, Shaheed Benazir Bhutto University, Sheringal Dir Upper, Pakistan

The Kallar Kahar area falls in the sub-Himalayas. The structural geometry of the area has been assessed using geological mapping and structural analysis. At the surface the study area comprises of the rock units ranging in age from Precambrian to Pliocene with several major unconformities. The Precambrian Salt Range Formation is exposed in the form of diapiric intrusions. The strike slip Kallar Kahar Fault (KKF) controls the structural fabric of the area. It is a NW-SE trending structure characterized by an overall transpressional tectonics with a right lateral strike slip component. An en echelon pattern of NW-SE trending folds, a back thrust and a couple of fore thrusts occurs in the immediate south of the Kallar Kahar Lake. These thrusts are out of sequence thrusts cutting up section the thrust sheet of the Salt Range Thrust (SRT). The fore-thrusts represents a relatively younger phase of deformation than the back thrust as the former cross cut the later one. These folds and faults formed as a result of transpression associated with a left step over along the KKF. The rigorous compressional structures in the southeastern portion of the mapped area, and a clear discontinuity on the Landsat images are in line with the presence of a left step over along the KKF. The restraining along this stepover during ramping along the SRT, resulted in salt diapirism in the area. The KKF is believed to have formed to accommodate the variable stresses generated during the differential propagation of the SRT’s thrust sheet.



Tue: 25
Topics: 1.27 Young Scientist Session

Daily growth rate quantification in fossil giant clam shells with Daydacna

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

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

Tridacna shells feature macroscopically visible bands (at mm scale) as well as microscopically visible daily banding (at µm scale). To evaluate the lifespan of an individual, the presumably seasonal macroscopically visible bands can be counted, or stable oxygen isotope analysis can be used to identify seasonal cycles. However, these approaches may not always be conclusive, especially for Tridacna which at times display irregular seasonal growth patterns and often grow in equatorial areas with low seasonal SST variability and heavy seasonal precipitation, influencing δ18O seawater values. Counting the daily bands (manually or with software-based image analysis) gives a more accurate internal age model with high temporal resolution, but daily banding is not always visually retrievable in fossil specimens, hampering the production of a precise age estimate. We show that daily geochemical cycles can be measured with highly-spatially resolved laser-ablation inductively coupled plasma mass spectrometry (LA-ICPMS; 3 x 33 µm laser slit) in our Miocene (~10 Ma) specimen, even in areas where daily banding is not visible. We present a python script Daydacna, in which we use wavelet transformation on the measured daily geochemical cycles to quantify varying daily growth rates throughout the shell. This provides a robust alternative to visual band counting. The resulting age model can be used to quantify seasonal growth rate variability over several decades and provide a basis for time resolved sub-seasonal paleoenvironmental proxy evaluation.



Tue: 26
Topics: 1.27 Young Scientist Session

Mineral material for use in dermocosmetic products based on a modification kaolin from the Jegłowa deposit (Poland)

Anna Czarnecka-Skwarek, Agnieszka Rożek, Michał Pilaszkiewicz

University of Warsaw, Poland

The aim of the research was to produce a microbiologically safe, modified mineral material with increased sorption parameters, enabling use in the cosmetics industry as an active substance in the line of dermocosmetic products. Samples of selected kaolin (from the Jegłowa deposit, part of Silesia, Poland) were subjected to thermal (at 600 ℃) and chemical activation (using 2 or 4 M HCl). The modified material was characterized using the XRD, SEM and gas porosimetry methods (the specific surface of the samples was determined based on the assumptions of the BET model). The microbiological purity of the newly manufactured materials has been tested in accordance with the applicable standards ISO 21149:2017-07 (for bacteria) and ISO 16212:2017-08 (for yeasts). The results showed that both modifications affected the structure and properties of the tested samples. The acid activation caused the displacement and increase in the intensity of XRD reflections of kaolinite, which is the result of the removal of poorly crystalline mineral phases from the sample, present in unmodified samples. SEM imaging confirmed the change in the morphology of kaolinite plates. The measured surface properties of the samples (specific surface area, micropore area) were significantly higher in the case of acid activation and increased with the use of a stronger acid (4M HCl). Microbiological tests have shown that both the thermally and acid-activated samples meet the quality requirements for materials used in the dermocosmetics. The conducted research proves that kaolin from Jegłowa can be an attractive raw material for the cosmetics industry.



Tue: 27
Topics: 1.27 Young Scientist Session

Leaf-wax n-alkane composition of an extinct Middle to Late Jurassic plant assemblage dominated by bennettitaleans

Lisa von Nolting1, Alexander Rohrmann2, Christian Pott3, Baoyu Jiang4, Manja Hethke1,3

1Fachrichtung Paläontologie, Institut für Geologische Wissenschaften, Department Geowissenschaften, Freie Universität Berlin; 2Fachrichtung Tektonik und Sedimentäre Systeme, Institut für Geologische Wissenschaften, Department Geowissenschaften, Freie Universität Berlin; 3LWL-Museum für Naturkunde, Westfälisches Landesmuseum mit Planetarium, Referat Paläontologie, D-48161 Münster, Germany; 4Center for Research and Education on Biological Evolution and Environments, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China

Leaf-wax n-alkane concentrations and average chain lengths (ACL) significantly vary among extant gymnosperm groups. When investigating deep-time archives, further plant groups need to be considered that since went extinct. Also, entirely aquatic plants, as known in the angiosperm clade, are not known to be amongst any fossil or extant gymnosperm group. The Middle to Late Jurassic macroplant assemblage preserved in the volcanic lake deposits of the Haifanggou Formation in Inner Mongolia, China, and attributed to the Yanliao Fossillagerstätte, reflects such a gymnosperm-dominated environment, amongst which the extinct Bennettitales constituted the dominant seed-plant component, with ginkgophytes and cupressoid conifers as additional major components. This fossil environment existed c. 35 million years prior to the rise of the angiosperms. The current study examines the relative n-alkane concentrations preserved in 33 samples from two excavations in the Haifanggou Formation. Despite the high age of the sampled strata, n-alkane preservation is excellent. In addition, the two excavations yield mean ACL25–37 values of 28.2 and 27.8, respectively, and the n-alkane distributions are dominated by n-C27 alkanes and, in some samples, by n-C25 alkanes. Thus, given that Bennettitales were the dominant plant group in the assemblage, we hypothesize that bennettitalean cuticles were composed of n-alkanes with relatively short chain lengths compared to extant gymnosperm groups. To corroborate this hypothesis, further verification through direct analysis of well-preserved fossil cuticles of Bennettitales is warranted.



Tue: 28
Topics: 1.27 Young Scientist Session

Climatic Impact of the Little Ice Age on Sumatra, Indonesia

Franziska Schwonke1, Alexander Rohrmann1, Anne Bernhardt1, Katleen Wils2

1Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany; 2Renard Centre of Marine Geology (RCMG), Department of Geology, Ghent University, Ghent, Belgium

The Little Ice Age was a period of colder climate and extended glaciation mainly observed in Europe and North America between the middle of the 14th and the end of the 19th century. However, the climatic impact of the Little Ice Age on tropical regions is still unclear. In this study, we sampled two short (1m), dated sediment cores (MJ17-01A-G and MJ17-01B-G) that were taken in 2017 within Lake Maninjau for leaf wax compound-specific analysis. Lake Maninjau is a 99.5 km2 caldera lake located at the equator in the Padang Highlands on the Island of Sumatra, Indonesia. Here, we extracted leaf-wax compounds of 34 samples – so called n-alkanes – measured their concentration and calculated the average chain length (ACL) and carbon preference index (CPI) of the individual samples. The ACL is a first-order proxy for overall humidity/precipitation and ranges between carbon numbers of C26 and C31 with a trend to lower values towards the top of the section. We interpret this shift from higher to lower ACL-values to represent a shift from dryer to more humid conditions between 1550 and 1850 AD in the period of the Little Ice Age and into the modern. We interpret that the Little Ice Age in Europe and North America indeed also affected tropical regions like Southeast Asia.



Tue: 29
Topics: 1.29 Breakthrough technologies and innovations along the mineral raw materials supply chain - towards a sustainable and secure raw material supply

Bioleaching of Rare Earth Elements from Primary Resources using Heterotrophic Organisms

Debby Schmidt1, Uwe Altenberger2, Sabine Kutschke3

1Universität Potsdam; 2Universität Potsdam; 3Helmholtz-Institut Freiberg für Res­sourcen­tech­no­logie

Rare earth elements (REE) are essential for various modern "green" technologies. However, conventional mining and extraction methods for REEs are energy-intensive, environmentally harmful, and call for the evaluation of alternative extraction procedures for these critical raw materials. Bioleaching processes have been successfully employed in the industrial extraction of metals and offer a promising and eco-friendly approach to enhance the sustainability of REE extraction. This study evaluates the potential of bioleaching REEs from unprocessed carbonatitic and alkaline bulk rocks.

Batch and supernatant leaching experiments were conducted on a Carbonatite sample from the Fen-Complex (Norway) and two nepheline syenites (a Grennatite and a pegmatitic Grennaite from Norra Kärr, Sweden), utilizing the heterotrophic organisms Yarrowia lipolytica and Tea fungus Kombucha. The influences of bulk mineralogy on microbial growth and metabolite production, as well as leaching rates and applicability of the different approaches were assessed.

The results demonstrate varying recovery rates based on mineralogy and leaching methods, with preferential leaching of light or heavy REEs depending on the selected organisms. Notably, the highest leaching efficiency of 54% REE recovery was achieved with Y. lipolytica supernatant leaching on pegmatitic Grennaite during a 19-day experiment. Carbonatite and Grennaite samples exhibited lower maximum leaching rates of 5% and 8%, respectively.

The findings demonstrate the proof-of-concept feasibility of bioleaching REEs from unprocessed bulk rock materials and highlight its strong potential, especially in providing a sustainable solution for utilizing low-grade ores and mine waste.



Tue: 30
Topics: 1.29 Breakthrough technologies and innovations along the mineral raw materials supply chain - towards a sustainable and secure raw material supply

New advances in particle size and shape measurements using complementary optical technologies based on dynamic image analysis

Andre Klicpera

Microtrac Retsch GmbH, Germany

Determination of particle size distribution of sediments and soils is a crucial property in several fields of industry and geoscientific research. The consequence of improper analyses can result in poor product quality, high rejection rates, or incorrect research data.

Most currently used particle sizing methods such as laser diffraction, sieve analysis or microscopy, are established over decades or even centuries and have been deployed in many different fields. However, their significance is often limited due to low resolution, limited capabilities in terms of quality control requirements or simply the lack of particle shape information. The concept of imaging particle analysis is a relatively new technology, dating back to the late 1970s as CCD sensors for capturing and computers for processing image data began to evolve. Further developments such as Dynamic Image Analysis (DIA) based on one or two high-speed cameras provided enhanced access to morphological particle size and shape information in high-resolution and with statistical robustness by a simple measurement of usually less than three minutes.

Here we introduce two new technologies in the context of dynamic image analysis. Designed as a hybrid-laser diffraction particle-analyzer, the Microtrac Sync provides conventional laser-based optics, equipped with a digital camera for precise particle size and shape information.

Another ground-breaking technology comes with the new Camsizer3D. It uses particle tracking technology, allowing to follow each particle of a sample in up to 30 different orientations. The resulting high-resolution 3D dataset provides digital size and shape information of real morphological particle geometries.



Tue: 31
Topics: 2.06 Interior, surface and atmosphere processes on rocky worlds

Redox state and interior structure control on the long-term habitability of stagnant-lid planets

Philipp Baumeister1,2, Nicola Tosi1,3, Caroline Brachmann1,3, John Lee Grenfell1, Lena Noack3

1Institute of Planetary Research, German Aerospace Center (DLR), Germany; 2Department of Astronomy and Astrophysics, Technische Universität Berlin, Germany; 3Department of Earth Sciences, Freie Universität Berlin, Germany

A major goal in exoplanet science is the search for planets with the right conditions to support liquid water. The habitability of a planet depends strongly on the composition of its atmosphere. Interiors and atmospheres of rocky planets are linked through feedback processes and evolve as a coupled system. In particular, volcanic outgassing shapes the atmospheric composition, but the exact composition of outgassed species not only depends on the volatile content and redox state of the mantle, but also on the current state of the atmosphere.

In an extensive parameter study of rocky exoplanets, we investigated the emergence of habitable surface conditions for a wide range of initial conditions, including the planet mass, interior structure, volatile content and redox state. The model accounts for the main mechanisms controlling the long-term evolution of stagnant-lid rocky planets (i.e. bodies without plate tectonics). It includes a large number of atmosphere-interior feedback processes, such as a CO2 weathering cycle, volcanic outgassing, a water cycle between ocean and atmosphere, greenhouse heating, as well as escape processes of H2.

We find that only a narrow range of the mantle redox state around the iron-wüstite buffer allows forming atmospheres that lead to long-term habitable conditions. At more oxidizing conditions, most planets instead end up in a hothouse greenhouse state (akin to Venus) due to strong CO2 outgassing. On the other hand, on planets with more reducing mantles, the amount of outgassed greenhouse gasses is often too low to keep the surface above the freezing point of water.



Tue: 33
Topics: 2.06 Interior, surface and atmosphere processes on rocky worlds

Modelling thermal evolution of molten and tidally heated Io-Like planetary mantles

Mathilde Kervazo, Lena Noack, Enrique Sanchis

Freie Universitat, Germany

Internal heating in rocky bodies shape their interior and surface characteristics as well as their evolution. Among internal heat sources, tidal dissipation is a key one. The most striking evidence in the Solar System is the case of Io, archetype of tidally-heated world hosting extreme volcanism.

Io’s internal dynamics is complex due to the large and tidally-produced heat flux, leading to widespread melting in the interior. For Io-like bodies, the dissipation and heat transport models have thus to incorporate interactions between solid and liquid phases. Io’s mantle is commonly modelled either as a solid convective mantle, adapting models of terrestrial planets, or as a fluid magma ocean, adapting models of fluid water oceans of icy moons. However, neither of these two classifications likely accurately describes Io’s partially molten interior.

In that context, we model Io's mantle thermal evolution following the work of Sanchis et al (2022, EPSC), who developed a magma ocean modelling, using the CHIC convective code (e.g. Noack et al. 2013, Infocomp). In addition, we take into account heat generated by tidal dissipation accounting for the effect of melt presence on the viscous and elastic parameters of the mantle following Kervazo et al. (2021).

Our study provides valuable insights into the role of a large amount of melt in the thermal evolution of rocky planets and moons, and our modeling approach is applicable to other rocky planets with hot interiors, including the Trappist-1 planets and various known rocky exoplanets.



Tue: 34
Topics: 2.06 Interior, surface and atmosphere processes on rocky worlds

Kinetic Deflection of an asteroid: Impact Simulations of the DART impact in a heterogeneous target

Robert Luther1, Mallory DeCoster2, Dawn M. Graninger2, Emma S. G. Rainey2, Angela Stickle2, Sebastian Baldauf1, Kai Wünnemann1,3

1Museum für Naturkunde Berlin, Germany; 2Johns Hopkins University - Applied Physics Lab; 3Freie Universität Berlin

On 26th of September 2022, NASA’s DART spacecraft impacted the secondary of the Didymos system, Dimorphos [1]. Its impact shortened the orbit of Dimorphos by 33 minutes to 11.37 h [2]. The change of the orbit is caused by a change of Dimorphos’ momentum due to the impact. A fraction of the momentum-change related to the transfer of the spacecraft momentum. The more important fraction of momentum is caused by the ejection of material from Dimorphos. The momentum-enhancement-factor β for vertical impacts is defined as β=1+pEj/pImp, with the ejecta and impactor momentum pEj and pImp, respectively, and was predicted to fall between ~2 and 5, based on impact simulations into homogeneous materials, [3,4,5]. The estimates for β depend on Dimorphos’ properties. For a density of 2400 kg/m³, the estimate is β = (1σ) [6]. Recent studies have shown that heterogeneities in the target (e.g. boulders) affect material ejection and β [7, 8]. In this study, we use impact models to simulate the DART impact with 1-10m-sized boulders, and we test the influence of a potential stronger and denser subsurface layer on β. We find an increase of beta by ~5% for such a subsurface layer in 5m depth, so that we conclude that heterogeneities in >5m depth do not affect β.

We acknowledge the computing time provided for our project bek00041on the supercomputer Lise and Emmy, part of the NHR infrastructure.

[1]Daly et al.(2023),Nature616,443.[2]Thomas et al.(2023),Nature616,448.[3]Raducan et al.(2019),Icarus329,282-295.[4]Stickle et al.(2022),PSJ 3:248.[5]Luther et al.(2022),PSJ3:227.[6]Cheng et al.(2023),Nature616,457.[7]Ormö et al.(2022),EPSL594,117713.[8]Raducan et al.(2022),A&A 665,L10.



Tue: 35
Topics: 2.06 Interior, surface and atmosphere processes on rocky worlds

Critical external and internal factors for plate tectonics

Oliver Henke-Seemann, Lena Noack

Freie Universität Berlin, Germany

Convective mantle flow in terrestrial planets is governed by a temperature- and pressure-dependent rheology. This results in a stagnant-lid regime observed on most terrestrial planets. Plastic deformation can lead to breaking of the strong upper lithosphere, which resembles plate tectonics on Earth. Most efforts to model mantle convection with self-consistent plate tectonics combine Newtonian diffusion creep with a stress-dependent pseudo-plastic rheology in the form of a yield criterion. However, in the uppermost mantle, where stresses are high, deformation is thought to be driven in large parts by deformation via dislocation creep. As numerical models get more robust and capable of more complexity, viscoplastic models should therefore include non-Newtonian dislocation creep.

In our models we employ a composite viscosity, combining both Newtonian and Non-Newtonian power laws in a viscoplastic approach. We study the influence of varying rheologies on plate tectonics simulations, by testing several internal and external parameters, such as grain size and surface temperature. In a 2D-spherical annulus geometry we employ an interior structure model for an Earth-like planet to obtain local information on thermodynamics properties of the main minerals present in Earth’s mantle. We evaluate the models by computing common diagnostic values used to recognize plate-like surface deformation. The goal of this study is to identify key planetary factors for the occurrence or absence of plate tectonics.



Tue: 36
Topics: 3.06 Present and past sediment routing systems

Provenance changes in NW Borneo and the development of the Miocene Baram Delta: implications from detrital zircon geochronology and heavy mineral analysis

H. Tim Breitfeld1, Juliane Hennig-Breitfeld1,2, Thomson Galin3

1TU Bergakademie Freiberg, Germany; 2SE Asia Research Group, Royal Holloway University of London, UK; 3Department of Mineral and Geoscience Malaysia, Sarawak

The Cenozoic of Borneo consists of thick clastic sedimentary rocks that were deposited in various fluvial-lacustrine, shallow marine and deep-marine settings. From the Eocene onwards, the sedimentary successions play an important economic role. Onshore, Eocene sediments comprise coal seams of commercial interest, while Miocene deposits offshore are important hydrocarbon reservoirs. In principle there are two main sediment sources that have contributed to the successions. The Cretaceous arc-related Schwaner Mountains in the south of the island, and the Triassic tin belt granites from the Malay Peninsula. Characteristic detrital zircon U-Pb ages and heavy mineral signatures reveal a change of these sources through time, related to major tectonic developments, such as the opening of the South China Sea. The Miri Zone in NW Borneo consists of Eocene turbidites of the Rajang Group, unconformably overlain by tidally-influenced delta deposits of the Oligocene Nyalau Formation. The Rajang Group turbidites overall reveal a provenance related to the Schwaner Mountains, while the Nyalau Formation indicates a Malay tin belt source, bypassing southern Borneo. The Miocene deposits of the Baram Delta form the youngest successions of the Miri Zone, and comprise fluvial, tidal, deltaic and shallow marine deposits. They are the analogue for the hydrocarbon reservoir offshore Brunei and northern Sarawak. In contrast to the underlying Nyalau Formation, the Baram successions were sourced directly from uplifted Rajang Group tubidites from the interior of Borneo. Thus, studying compositional variations and provenance characteristics help to understand sources and sedimentary routing pathways.



Tue: 37
Topics: 3.06 Present and past sediment routing systems

Provenance of Paleozoic diamictites in the southern Black Forest: petrography, geochemistry and detrital U-Pb-zircon chronology

Calvin Diehl1, Johannes Lukas1, Henri Paul Meinaß1, Armin Zeh2, Matthias Hinderer1

1TU Darmstadt, Germany; 2Karlsruhe Institute of Technology, Germany

In the Badenweiler-Lenzkirch Zone (BLZ) of the southern Black Forest, lower Paleozoic metasedimentary rocks of the Sengalenkopfschiefer Formation contain intercalations of diamictites which have been linked to the Hirnantian glaciation. This interpretation is based on lithological arguments and rare palynological remains showing Ordovician to Devonian Acritarch and Chitinozoa associations. This interpretation is challenged by new results of U-Pb dating of detrital zircon grains from four samples of diamictites and associated fine-grained schists. The diamictite layer consists of strongly elongated clasts up to 5 cm in diameter, comprising vein quartz, volcanic detritus, pelites, and minor magmatic pebbles. In total 509 detrital zircon grains were dated by LA-ICP-MS at KIT. These reveal similar age spectra for all four samples, characterized by significant age peaks at ~ 380 Ma, ~ 400 Ma, ~ 480-500 Ma, ~ 600-620 Ma, ~ 700-750 Ma and ~ 1.8-2.2 Ga, and ~ 2.6 Ga, and very small peaks at 0.9-1.1 Ga. The pre-Silurian age populations correspond to the spectra of West Gondwana with minor Mesoproterozoic and very minor Grenville zircons (ca. 1.0 Ga). The two younger age populations fit to a subduction model with an active magmatic arc and published ages for the adjacent Randgranite nappe. The youngest zircon grains reveal maximum depositional ages of ca. 360 Ma, which is close to the Devonian-Carboniferous boundary. This discards the former assumption of Hirnantian glaciation. Instead we hypothesize that the diamictites are linked to the Upper Devonian glaciation which affected North America, South America and West Africa.



Tue: 39
Topics: 3.16 Assessing biosphere geosphere interactions in the subsurface, at leaking wells, and natural vents and seeps

Methane emission and microbial oxidation at buried abandoned wells in Northern Germany

Sebastian F. A. Jordan, Stefan Schlömer, Martin Krüger, Martin Blumenberg

Federal Institute for Geosciences and Natural Resources, Germany

As we are risking to exceed the 1.5-degree target in the next decade, effective measures to cut back greenhouse gas emission are necessary. Methane became the focus of attention as the target to mitigate global warming, since the mean atmospheric lifetime of this strong greenhouse gas is at least an order of magnitude shorter than carbon dioxide. Here we will focus on the oil and gas sector, which represents the second largest anthropogenic methane source after agriculture. Abandoned oil and gas wells are seen as important targets, since they can (in some cases) emit up to several tons of methane per day. However, only about a dozen countries have measured data on methane emissions and even less include it in their yearly greenhouse gas inventory. Germany has about 20,000 abandoned wells, which are generally filled and buried, however, it is unclear, whether they are emitting methane or not.

Here, we present an overview of methane emission and microbial methane turnover at about 50 onshore oil and gas wells in Northern Germany covering both abandoned exploration and production wells. Using isotopic methane composition we were able to link the methane emissions at three well sites in an active peat-cutting area to methanogenesis. Furthermore, elevated potential methane oxidation rates suggest that the majority of the microbially formed methane was oxidized before reaching the atmosphere. Our data demonstrates the necessity for detailed knowledge on methane cycling and background emissions to assess abandoned wells, particularly in areas where natural methanogenesis is present.



Tue: 40
Topics: 3.06 Present and past sediment routing systems

Inversion of an open-source forward stratigraphic model: a case study from the Bengal Fan

James M. Lovell-Kennedy, Peter Burgess

QUEST, Department of Earth, Ocean and Ecological Sciences, University of Liverpool, United Kingdom

Inverting forward models to constrain output against data is critical for predicting and understanding sedimentary systems. We present an open-source workflow using SciPy functions to invert a Python Badlands model with spatially variable tectonic and rainfall parameters.

Tectonic uplift and rainfall maps are input to model surface uplift, erosion, transport and sediment deposition across the model grid. A SciPy function optimises against an objective function to calculate error and invert the model to find the optimal tectonic and rainfall parameters required to reproduce key aspects of the observed strata.

The workflow has four steps:

  1. Collate paleoDEM’s, paleogeographic, thermochronological and climatic data to create initial topography, tectonic uplift and rainfall input maps

  1. Run the Badlands forward stratigraphic model to calculate evolving topography and basin-fill strata

  1. Use an objective function to calculate error from the comparison of model output and observed stratal properties

  1. Use SciPy to iteratively optimise parameters through steps 2 and 3 to minimize model error

This approach generates a useful series of best-fit models for the Bengal Fan source-to-sink system. The nature of the objective function reveals important aspects of the model behaviour and indicates that climatic factors increasing erosion and sediment yields were the main forcing of Miocene deep-water sedimentation in the Bengal Fan.



Tue: 42
Topics: 3.27 Alkaline rock and carbonatite related magmatism

The Kuboos-Bremen Line in Namibia and South Africa: new insights about emplacement and composition

Jorge Correia Leite Arthuzzi1,2, Benjamin F. Walter1,2, Robert Johannes Giebel3,4, Lorenz Kemmler3, Jochen Kolb1,2

1Karlsruhe Institute of Technology (KIT), Chair of Geochemistry and Economic Geology, Adenauerring 20b, 76131 Karlsruhe, Germany; 2Laboratory of Environmental and Raw Material Analyses (LERA), Adenauerring 20b, 76131 Karlsruhe, Germany; 3Technische Universität Berlin, Institute of Applied Geosciences, Ernst-Reuter-Platz 1, 10587 Berlin, Germany; 4University of the Free State, Department of Geology, 250 Nelson-Mandela-Drive, Bloemfontein 9300, South Africa

The Kuboos-Bremen Line (KBL) is an alignment of intrusions that extent for 250 km in South Africa and Namibia. Its deepest exposed parts occur near Alexander Bay (RSA) and it continues into the continent trending SW-NE, with the higher intrusion level at the Great Karas Mountains (NAM).

The KBL complexes are divided in three sections: Western KBL is predominantly granitic; Central KBL is composed of granites, syenites, foid-syenites and carbonatites; and Eastern KBL is composed of a field of more than a hundred small carbonate-bearing intrusions (carbonatite dykes, sills and breccia pipes, and lamprophyre and alnöite dyke swarms).

The project aims to understand the genetic relationship between the variety of lithologies at the KBL by: investigating whether the behavior of HFSE and REE in carbonatitic magmas is influenced by source contamination and silicate wall-rock interaction; investigating the cross-cutting relationships of individual complexes and their age data, to understand the progressive evolution from granitic to foid-syenitic/carbonatitic compositions with time and location; and study the rock associations to establish if different magma suites derived from one or variable sources and also if they used the same zone of weakness for ascent and emplacement.

After field work and sample collection from all main complexes the first results from geological mapping and petrography show an even broader variety of lithologies than expected. Individual units from individual complexes share textural and mineralogical similarities and also provide us hints of the role of crustal assimilation in the genesis and magmatic to hydrothermal evolution of these rocks.



Tue: 43
Topics: 3.27 Alkaline rock and carbonatite related magmatism

Disclosing the magma genesis and storage beneath the Cretaceous Ebersbrunn diatreme, Saxony: Evidence from mineral chemistry and juvenile fragments

Hripsime Gevorgyan1, Alexander Repstock2, Irka Schüller3, Horst Kämpf3

1TU Bergakademie Freiberg, Institute for Mineralogy, Brennhausgasse 5, 09599 Freiberg, Germany; 2Saxon State Office for Environment, Agriculture and Geology (LfULG), Department of Geology (Saxon Geological Survey), Halsbrücker Straße 31a, 09599 Freiberg, Germany; 3German Center for Geosciences (GFZ), Telegrafenberg, 14473 Potsdam, Germany

The Mesozoic to Cenozoic intraplate to rift-related magmatic activity in central Europe spawned both, intrusive and extrusive carbonatites. Located within the intersection of the Regensburg-Leipzig and Gera-Jachýmov fault zones, the eroded diatreme of Ebersbrunn provides a unique opportunity for mineralogical and petrographic investigations to explore the magma genesis and its lithospheric evolution. Electron microprobe analyses on several mineral phases were acquired to obtain thermobarometric estimations and unravel the internal textures. Moreover, detailed microscopic studies on juvenile fragments are used for the characterization of volcanic facies. Here, the compositional variation in amphibole (with Mg# from 0.804 to 0.932) and mica (Al-rich phlogopite and eastonite) can be linked to the presence of lamproite components in the generation of supplying magma system and show a multi-episodic crystallization history. Thermometric estimations for the carbonatitic magma showed a wide range from 450 to 672°C (obtained on low- and high-Mg calcite and dolomite). The joint presence on high-T amphibole (872 to 965 °C) and mica ( ca. 950 °C) suggests the contemporaneous crystallization from a single magma storage and the presence of mid-crustal magma storage at 15 to 21 km.

The petrographical studies on circular/ ellipsoidal juvenile fragments revealed different populations of peletal lapillis, with either dry or wet silicate, Fe-Ti-oxide, and/or carbonate phases in the kernel and a carbonatitic and/or silicic shell composition. This indicates the influence of hybrid magma and emphasizes the multi-stage layering process. The oriented prolate-shaped apatite crystals at the rim of pelletal lapillies are addressed to turbulent motion during magma ascent.



Tue: 44
Topics: 3.27 Alkaline rock and carbonatite related magmatism

Mineralogy and origin of a silico carbonatite mega xenolith in the alvikites of the Dicker Willem Complex (Namibia)

Lorenz Kemmler1, R. Johannes Giebel1,2, Benjamin F. Walter3

1Technische Universität Berlin, Ernst-Reuter-Platz 1, 10587 Berlin, Germany; 2University of the Free State, 250 Nelson-Mandela-Drive, Bloemfontein 9300, South Africa; 3Karlsruhe Institute of Technology (KIT), Institute for Applied Geosciences, Chair of Economic Geology and Geochemistry, Adenauerring 20b, 76131 Karlsruhe, Germany

The Eocene (49 Ma) Dicker Willem carbonatite complex represents an “Inselberg” (5 km2) forming a subvolcanic intrusion in southern Namibia. It consists of several stages of carbonatitic intrusions including, alvikite, sövite, nepheline sövite as well as carbonatite breccia. Associated silicate rocks (ijolite and nepheline syenite) are rare but found as xenoliths of various sizes embedded in carbonatite (sövite and alvikite). To decipher the genetic relation between carbonatites and silicate rocks and the formation of nepheline sövite (which is seen as a transitional lithology), we investigated a center-margin profile within a silicate-rich carbonatite xenolith (Ø 7 m) enclosed in fine-grained calcite-carbonatite (alvikite). Detailed observations show systematic mineralogical and mineral chemical variations depending on the contact proximity. Multiple element diffusions and transformation reactions can be traced. Mineralogically, feldspathoids are increasingly replaced by K-feldspar. Secondary biotite crystallized at the expense of feldspar and clinopyroxene close to the contact. Clinopyroxene compositions develop from a Ca (Mg, Fe) dominated to a Na (Fe) bearing variety. Excess iron (Fe3+) not being incorporated in biotite crystallized as hematite. With closer proximity to the host rock the dominant mineral within the xenolith becomes calcite (up to 95 modal%). These besides other indications suggest that a magmatic replacement of a silicate xenolith resulted in the successive transformation into a carbonatite, that is barely distinguishable from a coarse grained sövite. This process thus reflects the origin of the nepheline sövites rather than the liquid immiscibility that was thought to follow the genetic link between silicate rock and carbonatite at depth.



Tue: 45
Topics: 3.27 Alkaline rock and carbonatite related magmatism

Global Sr-Nd-Os isotope compositions and highly siderophile elements of carbonatites

Ladislav Polák1,2, Tomáš Magna1, Lukáš Ackerman1,2, Vladislav Rapprich1

1Czech Geological Survey, Prague, Czech Republic; 2Czech Academy of Sciences, Czech Republic

The examination of more than 500 samples of worldwide carbonatites on the basis of Sr-Nd isotope systematics allows dividing them into three groups which do not follow conventional grouping. Carbonatites with a mantle signature and variable amounts of incorporated sedimentary material form the first two groups. The carbonatites in the third group have resolvedly lower 143Nd/144Nd signatures at a given eSr(i) value that cannot easily be explained by crustal contamination but rather by derivation of carbonatite parental melts from the mantle source metasomatized by 2-6% of slab-derived melts with low Sm/Nd during the late Archean (~2.7 Ga).

As a consequence of high concentrations of Sr and Nd, this system is more resilient to overprint compared to Re-Os elemental and isotope systematics. Overall, 44 carbonatite samples were investigated for Re–Os compositions; of these, 15 samples were excluded due to modification by late-stage hydrothermal alteration. The remaining carbonatites still yield a wide range of gOs from ~4 to 4000. Whether this wide range is a result of the presence of recycled crust or originates from previous carbonatite metasomatism remains unclear.

Extremely low concentrations of highly siderophile elements (HSE) in carbonatites and common nugget effects observed are the result of the behavior of sulfur-bearing phases as the main HSE carrier and oxygen fugacity. Carbonated silicate melts are capable to host significant amounts of PGE but during ascent, S-rich magma will separate from carbonatite melts leading to the sequestration of PGE due to higher distribution coefficients, leaving carbonatite melt depleted in PGE.



Tue: 46
Topics: 3.27 Alkaline rock and carbonatite related magmatism

Magmatic to hydrothermal REE mineralization in Mesoproterozoic ankerite carbonatite, Swartbooisdrift, NW Namibia

Albert Riehm, Kirsten Drüppel

Karlsruhe Institute of Technology (KIT), Germany

Strong local REE enrichment is observed in Mesoproterozoic ankerite carbonatite exposed at Swartbooisdrif, NW Namibia (Drüppel et al., 2005). The carbonatite dykes transect older anorthosites of the Kunene Complex and are themselves surrounded by sodalite-rich Na-metasomatic aureoles. The magmatic assemblage of ankerite, magnetite, pyrochlore, burbankite, and apatite indicates that the carbonatite magma was rich in Fe, Nb, P, Na, Sr, and LREE. Primary REE hosts are euhedral burbankite, pyrochlore, and apatite, which can be enriched in irregular layers formed during flow-banding.

Along cracks burbankite is altered to secondary burbankite and carbocernaite. With progressive alteration, burbankite and carbocernaite were partially to completely replaced by complex intergrowths of fluorcarbonates (mainly bastnaesite, hydroxylbastnaesite, parisite and synchysite), ancylite, monazite, barite, strontianite, celestine, calcite, fluorapatite, and/or hematite. Similar mineral assemblages also occur as discrete REE-rich pods and schlieren, suggesting fluid-related remobilization of REE and P. These zones are mainly restricted to the ankerite carbonatite, indicating locally restricted REE mobility.

The composition of early metasomatic and later hydrothermal fluids was determined by microthermometry and synchrotron-micro-XRF analysis of primary fluid inclusions in sodalite and secondary fluid inclusions in ankerite. Early high-temperature (> 550°C) sodalite-forming fluids were highly saline alkaline brines (19-30 wt% NaCl eq.) containing minor Sr, Ba, LREE, Nb, S, K, and Fe. Secondary fluid inclusions in ankerite, entrapped at lower temperatures of c. 400-500°C, are NaCl-poor (4-6 wt% NaCl eq.) and strongly enriched in Sr and REE. These fluids are presumably related to the late REE remobilization.

Drüppel et al. 2005, J. Petrol., 46, 377–406.



Tue: 47
Topics: 3.27 Alkaline rock and carbonatite related magmatism

The geochemical evolution of the Late Cretaceous intraplate volcanism on the Chatham Islands (NZ)

Johanna Schenk1, Stephan Homrighausen1, Hamish Campbell2, Kaj Hoernle1,3

1GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany; 2GNS Science, Lower Hutt, New Zealand; 3Institute of Geosciences, Kiel University, Kiel, Germany

The Chatham Islands, situated on the eastern Chatham Rise ~800 km east of New Zealand, comprise two main (Chatham and Pitt) and many smaller islands. Collision of the oceanic Hikurangi Plateau with the Chatham Rise jammed the long-lived subduction system, causing Zealandia to separate from Gondwana. The breakup was accompanied by volcanism on the South Island of New Zealand, Hikurangi Plateau (Hikurangi seamounts) and Chatham Rise and islands, many of which were formed by the volcanism. The Late Cretaceous volcanism is characterized by HIMU (high time-integrated μ=238U/204Pb Mantle) endmember composition, which sensu stricto is defined by oceanic islands associated to deep-rooted mantle plumes. Consequently, an heritage of the HIMU source from the lower mantle transferred to the surface by a mantle plume is debated, but numerous alternative models have been proposed to explain the HIMU volcanism in Zealandia, including sub-continental lithospheric mantle modified by subduction or interaction with the partly subducted Hikurangi plateau. Our major and trace element analyses of 52 Cretaceous whole-rock samples from the Chatham Islands display characteristic HIMU trace element compositions, but the major element (MgO vs. CaO) and olivine composition indicate a predominantly pyroxenitic (or phlogopitic) rather than peridotitic source, which is usually associated with HIMU lavas. Further investigation on the composition of primitive melts, melting conditions and source lithologies will be used to evaluate the potential role of a mantle plume causing HIMU end member volcanism and separation of Zealandia from Antarctica in the Late Cretaceous.



Tue: 48
Topics: 3.28 Developments and progress in regional geology

Triassic to Cretaceous magmatic record in SE Vietnam and southern Borneo: the southern limit of the Paleo-Pacific subduction

H. Tim Breitfeld1,2, Juliane Hennig-Breitfeld1,2

1Institute of Geology, TU Bergakademie Freiberg, Germany; 2SE Asia Research Group, Department of Earth Sciences, Royal Holloway University of London, UK

The eastern margin of Asia formed an active Andean-type margin from the Triassic until the Cretaceous. SE Vietnam and West Borneo were located at the southern end of this subduction zone. Triassic igneous rocks in Indochina are usually interpreted to be related to the closure of the Paleo-Tethys. However, in West Borneo Triassic I-type granitoids and associated fore-arc volcaniclastic turbidites can be attributed to west-directed subduction of the Paleo-Pacific. The arc can be traced through the South China Sea to SE Vietnam and Hainan with magmatism continuing into the Jurassic, although with a diminished intensity. Thus, West Borneo can be correlated with the Indochina basement. With the beginning of the Cretaceous and docking of the Banda block (which consists of SW Borneo) with West Borneo, large Paleo-Pacific subduction-related magmatic provinces formed in southern Borneo and SE Vietnam. Lower Cretaceous I-type granitoids are thereby dominant in Borneo, while in SE Vietnam Upper Cretaceous I-type rocks are more abundant. At around 80 to 85 Ma magmatism changed from I-type to A-/S-type affinities, suggesting cessation of the Paleo-Pacific subduction and a switch to post-orogenic magmatism that lasted until the end of the Cretaceous. The Mesozoic igneous record of the West Borneo and SE Vietnam provinces is remarkably similar and indicates a common tectonic history associated with the various stages of Paleo-Pacific subduction beneath eastern Asia.



Tue: 49
Topics: 3.28 Developments and progress in regional geology

The Muskau Arch - a geomorphological and geophysical approach on glacial tectonics

Sebastian Donke

Landesamt für Bergbau, Geologie und Rohstoffe Brandenburg, Germany

The Muskau Arch (MA) is located in the border area of the federal states of Brandenburg and Saxony and Poland.

The Muskau Arch is part of the main Warthian terminal moraine in Germany. With its U-shaped form, it is the southernmost extension of the Warthe glaciation in Germany. The width reaches c. 20 km and the arc depth c. 22 km.

The morphology of the Muskau Arch is characterized by compression, folding and overthrusting of Tertiary strata. Including special features, such as a multitude of Gieser structures or folded Pleistocene channel deposits. The so-called Gieser (Wendish Jeser/ jezero: swamp) are terrain furrows with a maximum depth of 20 m, a width of 10 m to 30 m and a length of up to several kilometers. Thus they represent a characteristic geomorphological element. They were formed by weathering and oxidation of the tertiary lignite seams, which were folded by glacial deformations.

In addition to these structures, there are further glacial forms in the area of the Muskau Arch, which are partly visible in the morphology and partly can only be mapped as glacial structures by geological exploration.

In this Study glacitectonic structures (i.e. diapirs, rupture structures, folding and faulting) are analysed and reconstructed focussing on scales, depth range characteristic shapes. These structural geological investigations were based on geophysical methods (near-seismic, gravimetry, geoelectric soundings and mapping as well as borehole geophysical measurements).



Tue: 50
Topics: 3.28 Developments and progress in regional geology

Early Permian rhyolite volcanism and Jurassic alteration, Northern Schwarzwald, Germany - new evidence from geochemistry and U-Pb dating of zircon, monazite, uraninite, and xenotime

Kirsten Drüppel1, Emre Agca2, Armin Zeh1, Jens Grimmer1, Michael Waitzinger3

1KIT Karlsruhe, Germany; 2gbm, Ettlingen, Germany; 3Geological Survey of Austria, Wien, Austria

Formation of Early Permian rhyolites in the Schwarzwald postdates the exhumation of Variscan granites and gneisses. Although similar Permian volcanics are recognized across Central Europe, little is known so far about their source(s), precise ages, magmatic evolution, and later alteration. To answer these questions, we investigated 68 rhyolite samples (lavas, tuffs, ignimbrites, diatremes) from five different localities in the Northern Schwarzwald.

Most rhyolite samples contain phenocrysts of quartz, K-feldspar, and biotite set in a fine grained groundmass rich in secondary illite and hematite. Igneous zircon, monazite, Fe-Ti oxides, apatite, and uraninite are common accessories. All samples are peraluminous high-SiO2 rhyolites with calc-alkaline compositions. Mantle-normalized trace element patterns show negative Ba, Sr, Eu, and Ti anomalies, indicating plagioclase and Fe-Ti oxide fractionation. REE patterns with LREE enrichment and deep negative Eu anomalies characterize them as hot-dry-reduced rhyolites, typically occurring above areas of mantle upwelling. A likely source are lower crustal dry metasediments.

Secondary alteration is correlated with increases in Al2O3, LOI, Li, and As. At one locality, a unique secondary REE-P-As-Th-S assemblage, comprising monazite, gasparite, thorite, xenotime, and galenite, is observed. The As-REE-rich phases presumably originated from alteration of primary monazite, zircon, and apatite by As-rich aqueous fluids.

U-Pb La-ICP-MS dating of igneous zircon, monazite, and uraninite from different localities yields consistent crystallization ages of 296.0 ± 1.3, 297.5 ± 2.9 Ma, and 296.2 ± 1.1, respectively. A later Early Jurassic alteration event is evidenced by U-Pb ages of 181.5 ± 2.1 and 173.5 ± 1.6 Ma determined for secondary xenotime.



Tue: 51
Topics: 3.28 Developments and progress in regional geology

Geophysical signature of the early Carboniferous Saxothuringian Basin, Central European Variscides

Hamed Fazlikhani1, Uwe Kroner2, Harald Stollhofen1, Wolfgang Bauer1, Daniel Koehn1

1Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany; 2Institut für Geologie, TU Bergakademie Freiberg

The Early Carboniferous Saxothuringian Basin (SXB) is exposed on the northwestern side of the Bohemian Massif in Central Europe. SXB is bordered by the Mid-German Crystalline Zone (MGCZ) to the NW and N, by the Lausitz block and the Elbe Zone to the NE and E and the Tepla-Barrandian to the SE. Basin boundaries are defined based on the structural, metamorphic and stratigraphic observations of the exposed Variscan and pre-Variscan units in the Bohemian Massif. However, to the SW across the Franconian Fault System (FFS), Permian-Mesozoic sedimentary rocks cover the Variscan units including the possible SW extension of the SXB.

In this study we integrate geophysical (gravity, magnetic and seismic reflections) and well data to investigate the SW extension of the SXB and discuss implications for the Variscan tectonics. Our observations and forward modeling results show that the remnant of SXB extends about 60 km to the W-SW from the present-day FFS and terminates near the NE part of the Kraichgau Terrane. We also show that SXB units are most likely preserved below the Permo-Mesozoic units farther south, west of the Fichtelgebirge area. Based on our study, we discuss that the SXB developed as a low-strain and isolated area in the Saxothuringian Zone, receiving erosional material from the surrounding high-strain and uplifted areas during the Variscan tectonics in early Carboniferous, before being overfilled by the Middle Mississippian (Visean) time.



Tue: 52
Topics: 3.28 Developments and progress in regional geology

Early Jurassic K-Ar illite age data of fault gouge from a reverse fault of the Gernsbach-Neuenbürg flexure in crystalline basement rocks of the Nordschwarzwald (SW Germany)

Jens Carsten Grimmer1, Klaus Wemmer2, Mathias Hueck3, Jonas Kley4

1Karlsruhe Institute of Technology (KIT), Germany; 2University of Göttingen, Germany; 3University of Göttingen, Germany; 4University of Göttingen, Germany

We investigated a SSE-dipping reverse fault zone of the ENE-striking Gernsbach-Neuenbürg flexure within c. 325 Ma old coarse grained two-mica granite. The fault zone consists of a hematized, cataclastic 15-20 cm thick, damage zone, predominantly developed in the hanging wall, and a c. 1 cm thick greyish-greenish clay-rich fault core. We took two gouge samples, spaced c. 1 m apart from each other.

Both samples were fractionated into three grain sizes (<0.2 µm, <2 µm and 2-6 µm), all of which yielded ages between 198 Ma and 171 Ma. The fact that these ages are much younger than the age of the faulted host rock, and that both samples exhibit variations between the different fractions of a few tens of Myr at most, indicates efficient authigenic clay growth. This authigenic crystallization probably occurred between 200 °C and 300 °C, based on the illite “crystallinity” Index and the predominance of the 2M1 illite polytype in the samples.

The Gernsbach-Neuenbürg flexure plunges to the ENE beneath deformed Triassic strata of the ENE-striking, c. 100 km long „Neckar-Jagst-Furche“, which is yet kinematically poorly understood. Its large strike length and apparent low bulk displacements are consistent with reactivation of the southern boundary fault zone of the Permocarboniferous Kraichgau basin as suggested by mapping of the Gernsbach-Neuenbürg flexure. The widespread Jurassic radiometric age data in southern Germany indicate major hydrothermal activity and a structurally complex, yet poorly resolved, deformation pattern, most likely associated with oblique rifting that developed into formation of the North Penninic ocean.



Tue: 53
Topics: 3.28 Developments and progress in regional geology

On the nonexistence of a Saxo-Thuringian Ocean – a review

Uwe Kroner1, Rolf L. Romer2

1TU Bergakademie Freiberg, Germany; 2GFZ German Research Centre for Geosciences, Potsdam, Germany

As demonstrated by the Saxo-Thuringian Ocean, some regional geological models originated prior the advent of plate tectonics and evolved little since. Despite the abundance of facts that neither prove nor need the existence of such an ocean, this plate tectonic scenario is still widely used. The Saxo-Thuringian and Moldanubian zones represent classical areas of the Central European Variscides. The Saxo-Thuringian Zone originally was defined as a narrow marine basin with Paleozoic lithologies overlying a Precambrian basement. Early mobilistic models proposed an allochthonous origin of the Münchberg Massif, representing remnants of the Moldanubian Zone, thrusted onto a southeastern ramp of the autochthonous Saxo-Thuringian Basin. With the advent of plate tectonics, the Saxo-Thuringian Zone was reinterpreted as an independent microplate that is surrounded by oceanic lithosphere. In such a view, the subduction of a so-called Saxo-Thuringian Ocean beneath a Moldanubian microplate is necessary to transport Moldanubian crust onto the autochthonous Precambrian / Paleozoic units of the Saxo-Thuringian microplate. Over the last decades abundant new geoscientific data, including the results of the continental deep drill hole (KTB), challenged the Saxo-Thuringian Ocean hypothesis. Today there exist ample evidence (i) that the allochthonous units of the Saxon Granulite Massif and the Fichtelgebirge-Erzgebirge nappe pile experienced pervasive and prolonged Variscan tectono-metamorphic overprint and do not represent an older Precambrian ramp and (ii) that early Paleozoic Saxo-Thuringian marine lithologies were deposited on a vast contiguous Peri-Gondwana shelf. Incomplete recycling of extended continental crust during prolonged Gondwana Laurussia collision can explain the geological record of the Saxo-Thuringian Zone.



Tue: 54
Topics: 3.28 Developments and progress in regional geology

Upper Ediacaran carbonates on the Digermulen Peninsula, Finnmark, Arctic Norway: insights into syn- to post-depositional processes at the edge of Baltica

Guido Meinhold1, Sören Jensen2, Magne Høyberget3, Arzu Arslan1, Anette E. S. Högström4, Jan Ove R. Ebbestad5, Teodoro Palacios2, Heda Agić6, Wendy L. Taylor7

1TU Bergakademie Freiberg, Germany; 2Área de Paleontología, Universidad de Extremadura, Spain; 3Rennesveien 14, Mandal, Norway; 4Arctic University Museum of Norway, UiT – The Arctic University of Norway, Norway; 5Museum of Evolution, Uppsala University, Sweden; 6Department of Earth Science, Durham University, United Kingdom; 7Department of Geological Sciences, University of Cape Town, South Africa

The Digermulen Peninsula in eastern Finnmark has attracted renewed research interest in recent years due to discoveries of new Ediacara-type fossils, marking the rise of macroscopic life on Earth. The entire upper Ediacaran and Cambrian sedimentary succession was considered to be siliciclastic. However, carbonates were discovered within the 2nd cycle of the Manndrapselva Member of the Stáhpogieddi Formation of the Vestertana Group (Meinhold et al., 2019, Precambrian Research, 328, 99-110). These carbonates occur as calcareous siliciclastic beds, lenses, and concretions, some with calcite spherulites and cone-in-cone calcite, in a mudrock to fine-grained sandstone succession approximately 40 m below the Ediacaran–Cambrian boundary. The calcite spherulites were probably formed at the sediment–water interface or a few centimetres below, either in a coastal littoral environment or in situ in the sublittoral zone under high alkaline conditions. In situ calcite U−Pb isotope data from an upper Ediacaran carbonate concretion provide timing constraints for depositional, diagenetic, and potentially metamorphic processes, overlapping and confirming previous estimates based on relative bracketing of events (Meinhold et al., 2020, Geological Magazine, 157, 1367-1372). The cone-in-cone calcite formed during burial diagenesis and clearly before low-grade metamorphism and cleavage formation, the latter being caused by the Scandian Orogeny.



Tue: 55
Topics: 3.28 Developments and progress in regional geology

Nappe tectonics in the south-eastern Rhenish Massif (Central European Variscides, Germany) – Plate interactions between Gondwana and Laurussia

Katja Mende1, Ulf Linnemann1, Heinz-Dieter Nesbor2, Peter Königshof3, Ulrich Jansen3, Mandy Zieger-Hofmann1, Axel Gerdes4

1Senckenberg Naturhistorische Sammlungen Dresden, Germany; 2Hessisches Landesamt für Naturschutz, Umwelt und Geologie, Germany; 3Senckenberg Gesellschaft für Naturforschung Frankfurt, Germany; 4Goethe-Universität Frankfurt, Germany

The Lahn-Dill-Area, the Kellerwald and the Lindener Mark in the southeastern Rhenish Massif (Germany) are part of the Rhenohercynian Zone of the Central European Variscides. They contain various Devonian and Lower Carboniferous sandstones and greywackes, which differ significantly in their facies circumstances and fossil-content from surrounding autochthonous materials. U-Th-Pb- and Lu-Hf-analyses on detrital zircons of these allochthonous siliciclastic sediments indicate a provenance in the Saxothuringian zone and thus a Gondwanan hinterland. They show U-Pb-age clusters of ~530–700 Ma, ~1.8–2.2 Ga, ~2.5–2.7 Ga, and ~3.0–3.4 Ga. In contrast, samples from the autochthonous and par-autochthonous units of these areas show a provenance representative of Laurussia with debris primarily derived from Baltica and Avalonia with age clusters at ~400–450 Ma, 540–650 Ma, 1.0–1.2 Ga, ~1.4–1.5 Ga, ~1.7–2.2 Ga, and 2.3–2.9 Ga. These results, combined with own thin section analyses and geochemical data on volcanic rocks as well as revised biostratigraphy and paleobiogeography of Lower Devonian from the literature, led to the interpretation that the southeastern Rhenisch Massif is a nappe stack of Rhenohercynian and far transported Gondwana-related nappes. They were thrusted onto the autochthonous part of southern Laurussia during the Variscan orogeny by closing a wide Rheic Ocean.



Tue: 56
Topics: 3.28 Developments and progress in regional geology

Geophysics combined with Petrography – a promising approach for 3D crystalline basement characterization?

Christian Olaf Müller, Manuela Zeug, Alexander Malz

Landesamt für Geologie und Bergwesen Sachsen-Anhalt, Germany

High-grade metamorphic and plutonic rocks in crystalline complexes are of increasing interest as host rock for geothermal plays and for understanding plate tectonics. In this regard the Pretzsch-Prettin Crystalline Complex (PPCC, Saxony-Anhalt) as a part of the Mid German Crystalline Rise is one prominent example of a late-orogenic intrusion in the former Rheic Suture Zone. Former 2D geophysical investigations focussing on the setting and outline of the PPCC remained ambiguous and suggested a combined interpretation with other geoscientific disciplines.

Recently, we applied a 3D geophysical and geological modelling to the PPCC incorporating well data, seismic depth maps and gravity data. 3D gravity modelling revealed important information on the general geological setting of the overburden and basement depth, but did not allow detailed interpretation in areas of similar basement density. Limiting the generally ambiguous gravity modelling results required incorporation of petrographic data like rock composition from thin sections and density measurements at rock samples, which were linked to the modelled density zones of the basement.

This approach revealed first evidence of a northward extension of the comparable low density monzogranites to granodiorites of the PPCC into the North German Basin. Quartz monzonites and monzodiorites with up to 25 % biotite and amphibole agree with up to 0.15 g/cm³ higher basement densities in the surrounding of the PPCC. Generally, incorporating petrographic data into the gravity modelling process enabled us to better confine zones of different crystalline compositions, which might be applicable to other areas.



Tue: 57
Topics: 3.28 Developments and progress in regional geology

Regional geology and structural control of copper-bearing vein formation in the Western Anti-Atlas of Morocco

Jasemin Ayse Ölmez1, Ida Maria Möckel1, Fatiha Askkour2, Moha Ikenne2, Atman Madi3, Christoph Hilgers1

1Structural Geology and Tectonics, Karlsruhe Institute of Technology, Germany; 2Faculté des Sciences, Université Ibn Zohr, Agadir, Morocco; 3Akka Gold Mining (Managem Group), Casablanca, Morocco

The Ouansimi copper mine is located south of the Kerdous inlier in the Western Anti-Atlas in Morocco. Neoproterozoic and Lower Cambrian sedimentary rocks record recurring transgressive and regression cycles by deposition of limestones, algae matts, or clastic rocks like conglomerates. The rocks are overprinted, likely due to the Variscan orogeny, resulting in an anticline formation showing internal large- and small-scale tectonic elements like folds, shearing, normal and reverse faults, as well as bend and drag folds.

The sedimentary rocks host mainly NW/SE striking veins with copper mineralisation, comprising e.g., chalcopyrite, chalcocite, sulfidic minerals, in combination with carbonates or quartz, as well as copper oxides (e.g., malachite) at the present-day surface. Processes, which lead to vein and ore formation and the possible tectonic influence are still not clearly understood. So far, the copper-bearing veins are mainly associated to the Variscan orogeny and hydrothermal influence. Field observations and structural measurements of stratigraphic bedding, fractures, and veins surrounding the Ouansimi mine are complemented with subsurface data, as well as transmitted and reflected light microscopy. Furthermore, microstructural observations are supplemented with cathodoluminescence microscopy.

This study will help to understand, if tectonic events beside the Variscan orogeny influenced the formation of veins and faults, as well as folds. Thus, the understanding of the regional geologic and tectonic processes of the Western Anti-Atlas region will be complemented.



Tue: 59
Topics: 3.28 Developments and progress in regional geology

The Late Paleozoic igneous suite between the Saxon granulite massif and the Altmark, central Germany: Petrogenetic and mineralogical constraints on the post-orogenic magma evolution

Alexander Repstock1, Manuela Zeug2, Elżbieta Słodczyk3, Hripsime Gevorgyan4, Michael Buchwitz5

1Sächsisches Landesamt für Umwelt, Landwirtschaft und Geologie, Geological Survey and Geophysics, Pillnitzer Platz 3, D-01326 Dresden, Germany.; 2Landesamt für Geologie und Bergwesen Sachsen-Anhalt, Department for Geology, An der Fliederwegkaserne 13, D-06130 Halle (Saale), Germany.; 3University of Wrocław, Institute of Geological Sciences, Ulica Cybulskiego 30, PL-50-205, Wrocław, Poland.; 4TU Bergakademie Freiberg, Institute for Mineralogy, Brennhausgasse 4, D-09596 Freiberg, Germany.; 5Museum für Naturkunde Magdeburg, Otto-von-Guericke Straße 68 -73, D-39104 Magdeburg, Germany.

The Late Paleozoic continental rift in the area of central Europe set the stage for intense magmatic activity, apparent in plutonic complexes (e.g. Brocken, Pretzsch-Prettin), large subvolcanic bodies (e.g. Halle laccoliths, Wurzen porphyries), and recorded by voluminous pyroclastic sheets in numerous caldera systems (e.g. Wurzen, Rochlitz, and Flechtingen ignimbrites). Since up to now, their petrogenetic evolution often remains veiled in mystery or is still under debate. Focussing on this post-Variscan magmatic flare-up, the obtained geochemical and mineralogical data set depicts selected magma reservoirs, their evolution, and storage.

The different compositions of the Cadomian to Variscan basement and the longevity of magma chambers set within these particular regions have a decisive influence on the geochemical characteristic. In detail, metasedimentary rocks (e.g. metamorphosed graywacke, mica schist) are most often directly responsible for Al2O3-supply and subsequently lead to corundum-normative magmas. The highest amount of normative corundum (up to 3.1 wt%) can be found in the Flechtingen ignimbrite, which magma system was capable of crystallizing almandine garnet (Ca0.03Fe0.84Mg0.13)3Al2Si3O12) in lower crustal levels (>7 kbar ≙ 25 km). A similar picture emerges within the subordinated diopside-normative parts of the Wurzen volcanic rocks (up to 3.28 wt%), where crystallization of calcic clinopyroxene took place at 6 to 10 kbar (≙ 22 to 36 km). Here, it is proposed that parental diopside normative alkaline to tholeiitic and garnet-bearing magmas are fast ascending and mingled into upper crustal magma bodies.



Tue: 60
Topics: 3.28 Developments and progress in regional geology

The tectonics of the Elbtalschiefergebirge-Osterzgebirge-Zone and the role of the Mid-Saxon-Fault

Lea Marie Schulze1, Uwe Kroner1, Ines Görz2

1TU Bergakademie Freiberg, Germany; 2Sächsisches Landesamt für Umwelt, Landwirtschaft und Geologie, Germany

The Elbe zone constitutes a complex fault zone on the northern edge of the Bohemian Massif. As part of this zone, the Elbtalschiefergebirge is juxtaposed with the Lausitz to the northeast and the Osterzgebirge to the southwest. The tectonic boundary with the Osterzgebirge is traditionally defined by the Mid-Saxon-Fault. In the course of a tunnel project for the railroad line Dresden-Prague structural geological investigations were carried out. Here first results are presented. The entire area was overprinted by the Variscan orogeny and can be divided into three principal units. (i) The northeastern section consists of very low-grade metamorphic lithologies representing the remnants of an early Carboniferous synorogenic basin. The adjoining unit (ii) is predominantly made up by phyllites that differs from unit (i) by its stronger tectonic and metamorphic overprint and partly inverted stratigraphy. Mylonites on both sides of the Mid-Saxon-Fault reveal the existence of a ductile shear zone (iii) affecting high- to medium-grade metamorphic units of the Osterzgebirge as well as low-grade units of the Elbtalschiefergebirge. This Elbe-zone parallel, i.e., NW-SE striking shear zone suite is characterized by dextral strike slip tectonics and the transition from ductile to brittle-ductile material behavior. The existence of ESE-WNW to E-W stretching lineations on both sides of the Mid-Saxon-Fault , however, indicates a more complex tectonic evolution. Furthermore, the mylonites adjacent to the “Tourmaline-granite” of the Elbtalschiefergebirge resemble the shear zone rocks of the Erzgebirge. Thus, the traditional view of the Mid-Saxon-Fault as a strict tectonic boundary between both units must be questioned.



Tue: 61
Topics: 3.28 Developments and progress in regional geology

Distribution of Holstein interglacial deposits in Brandenburg and Berlin (Germany)

Jaqueline Strahl, Sophia Rütters, Angela Sonntag

Landesamt für Bergbau, Geologie und Rohstoffe Brandenburg (LBGR), Germany

The Holstein interglacial is classified as the period between the end of the Elster glaciation to the beginning of the Fuhne glaciation. The deposits in Brandenburg are supplied by limnic to fluviatile sedimentary regimes. Thus, the deposits consist of organic mud and silt as well as bituminous peat. Related to higher energetic levels, the fluvial associated deposits are made up of sand. The stratigraphic classification is based on palynostratigraphy and on the occurrence of the index fossil Viviparus diluvianus.

In this study, a new map is constructed that focuses on the distribution of limnetic sediments. Contrary to this, the existing maps summarise the limnetic and fluviatile deposits including the sediments of the lower Saale. Two sets of maps have been published since 1971 (Lithofazieskarte Quartär - scale 1:50 000 and Zwirner & Ziermann 2010 - scale 1:1 000 000).

Based on more than 400 palynostratigraphically proven locations (via drillings), a map will be published that achieves a significant extension and clarification of the distribution of the limnetic Holstein. The accumulation area of these deposits can be associated with numerous channel systems and paleo-basins initiated during the Elster glaciation. Furthermore, transgressive pathways are revised in this study. These were derived from Holstein Stage sea-level changes that resulted in transgressive and regressive successions with brackish to marine facies in northwest Brandenburg.

Zwirner & Ziermann 2010. „Verbreitung und Tiefenlage der Holstein-Warmzeit und frühsaalezeitlicher Ablagerungen“ in Stackebrandt, W. (Hrsg.). Atlas zur Geologie von Brandenburg. Landesamt für Bergbau, Geologie und Rohstoffe Brandenburg, 53.



Tue: 62
Topics: 3.28 Developments and progress in regional geology

Changes in palynofacies and organic geochemistry as indicator for marine ingressions in the German Wealden

Fritz-Lukas Stoepke1, Annette E. Götz2, Martin Blumenberg3, Julia Gravendyck4, Jochen Erbacher3, Roberto Pierau2, Robert Schöner2, Ulrich Heimhofer1

1Leibniz University Hannover, Germany; 2State Authority for Mining, Energy and Geology, Germany; 3Federal Institute for Geosciences and Natural Resources, Germany; 4Rheinische Friedrich-Wilhelms University Bonn, Germany

New palynological and geochemical data from the KB Rehburg-2 core covering the German Wealden (W1-4) illustrate the unique development of this depositional setting. Despite the temporary isolation of the Lower Saxony Basin (LSB) from the open ocean, several marine flooding events into the basin were detected. Marine ingressions are suggested to have entered from the west via the East Netherlands High, supporting the existence of an - at least temporary - seaway to the Boreal Realm. In the central and eastern parts of the LSB, indicators of marine influence are less prominent. In this study, we use a combined approach including palynofacies analysis, sedimentological and geochemical data in order to improve the understanding of the highly variable German Wealden depositional environment. The new data provides evidence for marine ingressions into the isolated LSB, insights into vegetation dynamics and palaeoenvironmental conditions.

A total of five different types of palynofacies were distinguished, which indicate changes in the oxygenation state of the water column as well as variations in salinity. Based on changes in continent-derived particle abundance, the proximity to the Deister-Hils Delta can be estimated. The most proximal palynofacies type stems from palaeosols, which are described for the first time in the German Wealden. Marine ingressions were identified using ecological preferences of aquatic palynomorphs (dinoflagellates, acritarchs, prasinophytes, Botryococcus) across the studied sedimentary sequence. Based on changes in palynofacies and geochemical proxies, ingressions already postulated in other studies were identified and a new, previously unknown ingression is observed.



Tue: 63
Topics: 3.28 Developments and progress in regional geology

Precise Timing of Permian-Carboniferous magmatism in Saxothuringia

Marion Tichomirowa, Alexandra Käßner

TU Bergakademie Freiberg, Germany

Here we present published and new age data of plutonic and volcanic rocks from Saxothuringia obtained by the high-precision CA-ID-TIMS U-Pb zircon dating method. This method has an uncertainty of ca. 0.1-0.2 % (corresponding to < ± 0.5 Ma) that is ca. 10 times smaller than all other recently established dating methods. Consequently, the application of this method allows better establish the exact sequence of magmatic processes in time and space. We show that magmatism in the Erzgebirge and in the Lausitz mainly occurred during two larger magmatic phases and that volcanic rocks first appeared in the Eastern Erzgebirge. We present also dating results from several volcano-sedimentary basins in Saxothuringia that allows a better comparison of their temporal evolution.



Tue: 64
Topics: 4.08 Geological surveying as services for the public delivered by the State Geological Surveys of Germany - Current Issues

Problems with geothermal probes in evaporite deposits in Saxony-Anhalt

Christoph Gauert1,2, Jörg Steinborn1

1Landesamt für Geologie und Bergwesen Sachsen-Anhalt, Germany; 2University of the Free State, South Africa

Near-surface geothermal energy as a key technology for the sustainable provision of heating and cooling is increasingly coming into focus as renewable energy and alternative to fossil fuels. In Saxony-Anhalt with an estimated 6,000 geothermal systems operational, several hundreds are being installed annually, incresasingly also in public and commercial buildings.

Areas, where water-soluble rocks carry the risk of karstification and sinkhole occurrence, are clustered in places of the Zechstein outcrop on the Harz Mountain rim, on the contours of the Halle Permo-Carboniferous complex and the Flechtinger Höhenzug. Near-surface Upper Buntsandstein, Middle Muschelkalk and Gipskeuper karstable rocks occur in the Weferlingen-Schönebecker Scholle, in the Hakel, Huy, Fallstein, the Oschersleben-Egelner salt axis, and in the Subherzyn.

Karst areas often contain particularly concrete-aggressive waters, so that special measures must be taken to protect geothermal probes. In addition, in the often cavernous or fissured rock, mud losses are to be expected, or the proper backfilling of the borehole is problematic. Further aspects can be the reduced thermal conductivity.

There is a risk of volume increase due to the transformation of anhydrite into gypsum after contact with water, which can lead to uplift of the terrain above evaporite lithologies. Building ground hazards can occur in the area of salt mining and near-surface salt deposits.

Permitting practice shows that for site-specific projects in the karst areas of Saxony-Anhalt sensu lato, heat recovery from the ground via geothermal collectors is recommended in order to avoid scoring, dissolution and hydration of the rock at risk of subrosion.



Tue: 65
Topics: 4.08 Geological surveying as services for the public delivered by the State Geological Surveys of Germany - Current Issues

Das Geologische Landesamt Hamburg – Ein Zustandsbericht im Jahr 2023

Alf Grube, Susanne Aarburg, Kai Damerau, Christina Götz, Thomas Haupt, Jens Kröger, Lothar Moosmann, Udo Quek, Ingolf Stüven

Geologisches Landesamt Hamburg, Germany

Das Geologische Landesamt Hamburg wird in diesem Jahr 75 Jahre alt. Die Tätigkeiten der Vorläuferinstitutionen reichen über 100 Jahre zurück. Die heutige Kernaufgabe des GLAHH ist nach GeolDG die Sammlung, Digitalisierung, Interpretation und Veröffentlichung von geowissenschaftlichen Daten. Inzwischen sind ca. 315.000 Bohrungen bis in eine Tiefe von mehr als 3.000 m digital erfasst und zum Großteil veröffentlicht. Das Bohrdatenportal des GLA-HH bietet zusätzlich zahlreiche Kartendarstellungen zu geologischen, geothermischen und hydrogeologischen Themenbereichen, z.B. die Geologische Karte 1:5.000, Präquartär-Karten, ca. 65 Profilschnitte bis in ca. 400 m Tiefe, Wärmleitfähigkeit und Temperaturen für verschiedene Teufenbereiche und hydrogeologische Profiltypen. Ein wichtiger, und von Dritten intensiv angefragter Arbeitsbereich des GLAHH ist die 3D-Modellierung. Während das tiefe 3D-Strukturmodell gemeinsam von den norddeutschen Ländern entwickelt wurde, wird in Hamburg ein „mitteltiefes Modell“ mit Schwerpunkt auf den wasserwirtschaftlich genutzten Bereichen von Quartären und Neogenen Einheiten bis in ca. 400 m Teufe dargestellt. Das dritte Hamburger Modell stellt das Quartär dar, differenziert in Grundwasserleiter und -nichtleiter, wobei bei letzteren Tills und Beckenablagerungen unterschieden werden. Auf Grundlage der gewonnen Erkenntnisse aus Landesaufnahme und der 3D-Strukturmodellierung werden auch wasserwirtschaftliche Grundwasserströmungsmodelle aufgebaut, um aktuelle Fragen der Trinkwasserversorgung im Ballungsraum Hamburg zu beantworten. Zukunftsthemen, wie eine erfolgreiche Umsetzung der Wärmewende mithilfe der oberflächennahen, mitteltiefen und tiefen Geothermie nehmen einen immer größer werdenden Raum ein und werden von den Bürgerinnen und Bürgern sowie von Unternehmen in Hamburg stark nachgefragt. Die Arbeiten zu Geogefahren umfassen die Themenbereiche Verkarstung (Erdfallbildung; Mikroseismik), Massenverlagerungen (Rutschungen am Elbhang) und Bauwerksschäden durch wasserempfindliche Böden (u.a. Sackungen über austrocknendem Lauenburger Ton).



Tue: 66
Topics: 4.08 Geological surveying as services for the public delivered by the State Geological Surveys of Germany - Current Issues

Updating the depth map of the base Quaternary in Saxony-Anhalt

Simon Jagemann1, Christian Olaf Müller2

1Martin Luther University of Halle-Wittenberg, Germany; 2Landesamt für Geologie und Bergwesen Sachsen-Anhalt, Germany

Continuously growing demands for exploitation and storage in the near subsurface require up to date information on the setting of the unconsolidated Cenozoic rocks. Of special relevance are depth information on the base Quaternary for mapping Pleistocene tunnel valleys to answer hydrogeological questions and for preparing 3D subsurface models. Current studies in Saxony-Anhalt still incorporate the results of the map series “Lithofazieskarte Quartär” (LKQ), which was prepared between 1968 to 1984. However, newly available evidence from digitized seismic depth maps and drilling results suggest an update of the depth information of the base Quaternary in Saxony-Anhalt.

In a first step, wells penetrating the Quaternary were exported from the well database of Saxony-Anhalt and their stratigraphies were simplified. Relevant wells were subsequently selected by unambiguous stratigraphy, similarity of well elevation with DGM height, cross validation and comparison to the well database of the LKQ. The remaining 85.000 relevant wells were combined with newly stratified wells and digitized isobaths of the base Quaternary from seismic data and former studies to a new base map. Subsequent quality control comprised tests of different gridding algorithms and profile drawing.

The new depth map of the base Quaternary reveals updated pathways of Pleistocene tunnel valleys of up to 500 m thickness in the Altmark region and in Eastern Saxony-Anhalt. Here, changes to the LKQ are largest. Minor differences are observed in the western and southern parts of Saxony-Anhalt with thicknesses usually less than 50 m.



Tue: 67
Topics: 4.09 3D models in education and outreach - synergy of research, geotourism, conservation and georisk assessment

Publication and Accessibility of Structural 3D Models of Saxony-Anhalt

Tilman J. Jeske, Melanie Siegburg, Alexander Malz, Manuela Zeug, Christian Olaf Müller, Jacob Wächter, Lars Schimpf, Ivo Rappsilber

Landesamt für Geologie und Bergwesen Sachsen-Anhalt, Halle (Saale), Germany

The publication and accessibility of geological data is one of the main tasks of geological surveys. Provided data helps to understand the local geology, facilitates exploration of natural resources and thus benefits state services, businesses, and the public alike. The State Geological Survey of Saxony-Anhalt (LAGB) uses its database from decades of geological exploration to provide information of the subsurface geology. Past interpretations existed but provided only simple presentations of the three-dimensional space. More recently, huge datasets were used for the development of largely enhanced 3D models. So far, regional 3D models have been prepared for the deep subsurface comprising the Altmark region in the north, the Subhercynian Basin in the middle, and the South-Eastern Harz Foreland in the south of Saxony-Anhalt. These models are based on existing maps from subsurface exploration, seismic profiles, and borehole information. ArcGIS and SKUA-GOCAD were used as data management and modelling tools. Some challenges consist of low data density in some regions, contradictory or incorrect source data, as well as in achieving a coherent 3D model by smooth integration of modelled layers from different authors. The resulting three-dimensional geological models of Saxony-Anhalt illustrate the structural setting and the geology of the Earth's subsurface and will become subsequently filled with further lithological and petrophysical parameters. To publish the models for a broader audience, we use the GST (Geosciences in Space and Time) framework. This toolkit eventually enables the creation of customized sections, virtual borehole profiles, and the export of parts of the models.



Tue: 69
Topics: 4.09 3D models in education and outreach - synergy of research, geotourism, conservation and georisk assessment

Geological Mobile Digital Mapping (GeoMoDiM)

Pascal Michael Woiton, Mario Valdivia Manchego, Benjamin Kipp

University of Bonn, Germany

Geological mapping represents an important qualification within the framework of geoscientific programmes of study. The GeoMoDiM project, funded by Bonn University, aims to firmly integrate digitally supported geological mapping into the curriculum. In particular, the tablet- and cloud-based data collection in the field is to be prepared, carried out and evaluated with GIS support. This approach saves numerous work steps and avoids sources of error, allowing live communication and data exchange in the field.

This new procedure is already in practice, involving the students in the optimizing and streamlining process. Here we show that using tablets with QField the process of mapping can be improved through the ability of gathering all the data in one application compatible with the current workflow of QGIS, saving time and simplifying use. On top we integrate photogrammetry in the didactics, incorporating 3D models of outcrops into the subsequent analysis.

A second aim of this digital approach is to integrate students, who cannot participate in the fieldwork, into the process through video communication and live data exchange with partners in the field. Controlling of the fieldwork can be done online from a base station, evaluating, exchanging datasets and interpretative approaches with the participants in the field. Additionally, we focus on participants with disabilities, who are unable to join the field experience, they will benefit from this new didactic approach. The next step of this project is to open this new perspective to other research areas as botany and soil sciences.



Tue: 70
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?

ACTION RESEARCH AND REFLECTIVE PRACTICE: AN INTERVENTION PROGRAMME WITH PRE-SERVICE TEACHERS

Dulce Manuel Lima1, Nir Orion2, Clara Maria Vasconcelos1,3

1Interdisciplinary Center of Marine and Environmental Research (CIIMAR), Portugal; 2Department of Science Teaching, Weizmann Institute of Science, Israel; 3Interdisciplinary Center of Marine and Environmental Research (CIIMAR), Portugal; Unit of Science Teaching and Department of Geosciences, Environment and Land Planning, Faculty of Sciences, University of Porto, Portugal

Promoting quality education implies that teachers are reflective professionals, agents of innovation and change leaders, able to train students with critical thinking skills, problem-solving, creativity, collaborative work, and communication. In this conscious reflection, it becomes fundamental to shift the focus from teaching to learning, including the teacher himself, leading to developing new skills and attitudes, given the imperative of change. Thus, it is essential to establish teachers' continuous training relevant to initial training, which enhances their professional performance and, consequently, educational improvement. However, the pedagogical practices implemented in training must reflect congruent teaching with what is recommended as desirable in the professional version of future teachers, making the articulation between theory and practice a practical reality. In this action-research process, a pedagogical intervention programme was implemented in the course unit Didactics of Geology II of the master’s degree in biology and geology, according to an inquiry-based methodology focused on the active participation of the students and collaborative work among peers. With a holistic view of the Earth system for understanding the geological phenomena and processes, practical work was done. The laboratory and experimental geosciences activities were adapted from Orion’ previous work and contextualised according to the Portuguese Curriculum of the K7 grade. It was possible to collect evidence showing that pre-service teachers were encouraged to change their visions about how (geo)science can be learned and taught. Results reveal that the practical activities promoted (geo)science reasoning, meaningful learning, and professional development.



Tue: 71
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?

THE RELEVANCE OF MULTIPLE INTELLIGENCES AND THE LEARNING OF GEOSCIENCES: A CONTENT ANALYSIS OF PRE-SERVICE TEACHERS' REFLECTIONS

Dulce Manuel Lima1, Nir Orion2, Clara Maria Vasconcelos1,3

1Interdisciplinary Center of Marine and Environmental Research (CIIMAR), Portugal; 2Department of Science Teaching, Weizmann Institute of Science, Israel; 3Interdisciplinary Center of Marine and Environmental Research (CIIMAR), Portugal; Unit of Science Teaching and Department of Geosciences, Environment and Land Planning, Faculty of Sciences, University of Porto, Portugal

The concern with teaching centred on the characteristics and students’ needs is one of the reasons why the Multiple Intelligence (MI) theory is emerging and has become a trend in educational settings at the elementary, secondary, and higher education levels. Especial literature considers that intelligence is no longer restricted to cognitive talents but rather the capacity for abstraction, logic, understanding, self-awareness, learning, emotional knowledge, reasoning, planning, creativity, critical thinking, and problem-solving. These characteristics are based on eight types of intelligence Musical, Linguistic, Logical-Mathematical, Spatial, Bodily-Kinesthetic, Interpersonal, Intrapersonal and Naturalist intelligence. Exploring students' learning styles through their MI type allows teachers to identify their strengths and weaknesses and explore these styles in teaching methodologies. Additionally, teachers must understand students’ learning styles and MI to define activities that fit the different bits of intelligence by promoting better educational environment processes. In a pedagogical intervention program implemented in classes of the curricular unit of Didactics of Geology II (that integrates the curriculum of a master to train students to become biology and geology teachers), activities were carried out to teach and consolidate knowledge about Rock Cycle. After the intervention program, students presented the Rock Cycle in accordance with their style of learning. A content analysis was done on twenty-one “snapshot reports” done by the pre-service teachers. As in several studies that refer to the success of using the MI in the teaching process, our study gathered evidence of students' increased motivation to learn and a more active engagement.



Tue: 72
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?

STORYTELLING AS A MULTIDISCIPLINARY STRATEGY TO PROMOTE CRITICAL THINKING AND STUDENTS´ MEANINGFUL LEARNING

Dulce Manuel Lima1, Isabel Maria Teixeira1, Sofía Riaño2, Clara Maria Vasconcelos1,3

1Interdisciplinary Center of Marine and Environmental Research (CIIMAR), Portugal; 2KU Leuven, Department of Chemistry, B-3001 Leuven, Belgium; 3Interdisciplinary Center of Marine and Environmental Research (CIIMAR), Portugal; Unit of Science Teaching and Department of Geosciences, Environment and Land Planning, Faculty of Sciences, University of Porto, Portugal

The Science/Technology/Society perspective in promoting scientific literacy in metal recycling becomes fundamental for adopting good behaviours in our society that contribute to the independence of Europe on critical raw materials and, therefore, to the transition to greener technologies and circular economies. In this regard, researchers must develop recycling routes, manufacturers must design for recycling, and our society needs to become aware and educated about recycling and responsible consumerism. Teaching Natural Sciences to pupils from middle school is an opportunity to awaken and strengthen the student's curiosity about the world around them. Through an appealing and dynamic discussion exercise, the student’s learning process can be promoted by motivating them to understand the importance and impact of scientific problems, relating them to social issues and technological innovations in their daily life. The research reveals that storytelling is an enjoyable, meaningful, effective, and creative way to enhance teaching and promote learning. As a powerful education multidisciplinary strategy, storytelling should be promoted in Geoscience teaching, encouraging environmental sustainability behaviours and students' civic education. The created storytelling "Gil broke his mobile phone! Now what?" is a playful-sensorial animation for K7 students whose setting is a Natural Science class. Faced with the challenge “How can I contribute to sustainable development when my cell phone is no longer useful?” the plot appeals to students' awareness of behaviour change towards sustainable development. At the same time, it also addresses the issue of bullying in the school context.



Tue: 73
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?

UmweltNAVI Niedersachsen - an app for the presentation of geospatial data not only from the environmental sector.

Joachim Müller

wemove digital solutions GmbH, Germany

Governmental and scientific institutions often have a problem communicating their data treasure to people outside their community. Presenting geospatial data in an appealing and accessible way is a challenge, especially when non-scientific people are the target audience. The app "UmweltNAVI Niedersachsen" sets out to do just that and demonstrates it using institutional environmental data. A person can discover the data in the immediate vicinity or in other locations. The data can be displayed either as polygons or as map layers (e.g. geotopes, noise and radiation pollution, flood areas, occurrence of wolf and lynx). When opening a dataset, the person receives various detailed information combined from different sources, like Wikipedia or Observation.org.
The app was designed for a broad user community of education, interested individuals or experts. Easy navigation, understandable operation and various functions that invite to discover are here to appeal to people of all ages. A knowledge area deepens the topics and allows dedicated viewing of individual datasets. Other functions, such as "geo-caching" of datasets, a quiz or the possibility to upload own photos to the data, are intended to motivate people to engage with the topics.
The project was initiated by the Lower Saxony Ministry for the Environment, Energy and Climate Protection/Germany and was implemented together with the companies Bearingpoint and wemove digital solutions. The principle of presenting geodata can also be applied to other areas. The software is basically available for subsequent use.
The poster shows essential aspects of the app and intends to arouse interest.
https://umwelt-navi.info/



Tue: 75
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?

GEOWiki@LMU – an update

Donjá Aßbichler1, Carolin Otte1, Daniel Schmid1, 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 a constantly growing open platform for the promotion of practical and research-oriented knowledge acquisition. Its major objective is to provide information on methodologies relevant to geosciences, with focus on fieldwork, sample preparation and analytical methods. It offers students a quick overview including helpful practical tips and references to relevant literature. In addition, there are various new developments which are presented here:

OPEN-VHB: The GEOWiki@LMU team developed the course “Geosphere” on the platform of the “Virtuelle Hochschule Bayerns – VHB” to provide non-geoscientists an introduction into geoscience. Interactive tools are used to show how determination of minerals and rocks works, it also gives a short introduction in earth history or applied geology.

Moodle: This concept will be expanded to create a moodle based training-platform to provide interactive exercises not only for students but also for pupils and interested people.

The most fascinating aspect of GEOWiki@LMU is that it is elaborated by students of earth sciences. The contents are developed by students in courses or on their own initiative in interdisciplinary teams. The activity of the students is essential for the development of GEOWiki. It gives decisive impulses for the selection and structure of the topics, writing the articles and acquisition of funding. All topics are discussed in weekly editorial online-meetings and revised in close collaboration with lecturers and scientists. All graphics, icons and videos are created by the students. The website is also programmed by students, according to the motto: what doesn't fit is made to fit.



Tue: 76
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?

From planetary sciences, earth sciences, volcanology to robotics and agriculture: Highlights from the 7th Summer School on Vulcano, Sicily, 2023

Vikram Unnithan1, Frank Sohl2, Christian Riedel3

1Jacobs University Bremen, Germany; 2DLR; 3University of Potsdam

The annual Summer School on Vulcano, Sicily will take place at the end of June 2023. This poster gives an impression and an overview of the highlights of this successful field-activity based summer school. This two-week summer school, is being held for the 7th time, and provides an important training ground for students, scientists, researchers, and technicians by exposing them to a variety of disciplines from geology, volcanology, geophysics, astrobiology, to planetary sciences. This year's additional theme is going to be robotics and agriculture - how our advances in robotics, especially from the space sciences, can aid and support agriculture and food production. In addition to lectures, a number of scientific experiments are planned on Vulcano, such as geoelectrics, astrobiology, spectroscopy, robotics, and intelligent drone-based mapping for agriculture. The summer school participants get the opportunity to work in teams on the above topics and are involved in the data acquisition, processing, visualization, and presentation. Lunchtime lectures, evening social events such as poster sessions, astronomy, and GIS classes complement the field-based activities. The interaction and collaboration between researchers is encouraged to foster inter- and transdisciplinary learning and understanding.
In addition to institutional funding, the summer school would not have been possible without generous funding by the Helmholtz iFOODis project and EUROPLANET.

 
7:00pmDGGV Member Meeting | DGGV Mitgliederversammlung
Location: Audimax
Session Chair: Martin Meschede, Universität Greifswald
Session Chair: Heinz-Gerd Röhling, German Geological Society (DGGV)