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: Monday, 04/Sept/2023
 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
7:30am - 8:30amRegistration & Welcome Coffee
Location: Foyer (Henry Ford Building)
8:30am - 10:00am3.03-1 Advances in paleoclimate proxy development and application
Location: Hall A (HFB)
Session Chair: David Bajnai, University of Göttingen
8:30am - 9:00am
Invited Session Keynote
Topics: 3.03 Advances in paleoclimate proxy development and application

Triple oxygen isotopes of modern terrestrial mammalian tooth enamel –new implications for paleoenvironmental and physiological research

Dingsu Feng1,2, Jakub Surma3, Niklas Löffler4, Thomas Tütken5, Fabian zahnow1, Daniel Herwartz2, Andreas Pack1

1Abteilung Geochemie & Isotopengeologie, Geowissenschaftliches Zentrum,Georg-August-Universität,Goldschmidtstraße 1, D-37077 Göttingen,Germany; 2Institute für Geology und Mineralogy, Department für Geowissenschaften, Universität zu Köln, Greinstrasse, 4-6, D-50939, Köln, Germany; 3Presently at Earth-Life Science Institute, Tokyo Institute of Technology, 152-8550 Tokyo, Japan; 4Institut für Geowissenschaften, Goethe Universität Frankfurt, Altenhöferallee 1, D-60323 Frankfurt (Main), Germany; 5Institut für Geowissenschaften, AG Angewandte und Analytische Paläontologie, Universität Mainz, J.-J.-Becherweg 21, D-55128 Mainz, Germany

Triple oxygen isotope (Δ'17O) analysis has recently be shown to be a powerful tool for identifying metabolic oxygen signatures in mammalian tooth enamel (Pack et al., 2013; Feng et al., 2022). Atmospheric O2 is consumed by mammals for metabolic oxidation. The low triple oxygen isotope (Δ'17O) composition of air O2 serves as a natural tracer for identifying metabolic oxygen in body water. Bioapatite precipitates in isotopic equilibrium with its parental body water and consequently records information on the air O2. The Δ'17O of atmospheric O2 is directly linked to pCO2 and gross primary production, hence fossil teeth can be used for paleo- pCO2 reconstructions.

To provide a modern baseline for this approach, we measured 128 individual mammal teeth for their bioapatite Δ'17O by automatic BrF5 laser fluorination. The sample set includes diverse body size with a body mass range from 2 g to 6000 kg and physiology from different habitats. Taxon-specific oxygen mass balance models are developed for resolving principal dependencies and relationships.

The mass balance modelled data for all species agree within uncertainty with the measured data. The results show that Δ'17O not only correlates with body mass, but also with initial oxygen anomalies of inhaled air O2, which allows for pCO2 reconstruction on terrestrial mammalian tooth enamel. This documents the potential of tooth enamel Δ'17O analysis for metabolic rates of extinct vertebrates and paleoclimate reconstructions, especially for small mammals (Mb < 1 kg).

Pack et al. (2013) GCA, 102, 306–317.

Feng et al. (2022) GCA, 328, 85-102.

9:00am - 9:15am
Topics: 3.03 Advances in paleoclimate proxy development and application

Vital effects in biogenic carbonates in triple oxygen isotope space

Daniel Herwartz1, Swea Klipsch1, David Bajnai2, Jacek Raddaz3, Amelia Davies3, Eberhard Gischler3, Jens Fiebig3, Andreas Pack2

1Uni Köln, Germany; 2Uni Göttingen, Germany; 3Uni Frankfurt, Germany

Carbonate δ18O and Δ47 are used to reconstruct paleotemperatures. Because biogenic carbonate does not form in full equilibrium with seawater, species-specific temperature calibration curves are required for accurate temperature estimates. Apparent growth temperatures derived from corals, however, are generally inaccurate due to large and variable kinetic isotope effects, often termed “vital effect”. Triple oxygen isotope systematics can help identify if an organism forms carbonate in equilibrium with ambient water or not and thus if the δ18O and Δ47 values provide accurate paleotemperatures. In addition, the chemical nature of the “vital effect” can be identified, because individual kinetic effects fall on characteristic trajectories in triple oxygen isotope space.

To examine these concepts a series of cold water and warm water corals as well as brachiopods are analyzed for δ18O and δ17O (expressed as Δ’17O) using the CO2 spectrometer (TILDAS; Aerodyne Research) installed in Göttingen. Samples formed in equilibrium are expected to fall on the equilibrium curve. Most samples fall below the curve providing evidence that their oxygen isotope composition is biased by kinetic effects. We suggest that the “vital effect” in corals is dominated by a CO2 absorption effect. Similar conclusions are derived from dual clumped (Δ47 and Δ48) isotope analyses of the same samples [1]. These authors suggested to correct for kinetic effects by back extrapolation to the “dual clumped” equilibrium line. The same concept can be applied in triple oxygen isotope space by back-extrapolation to the “triple oxygen isotope” equilibrium line.

[1] Davies et al. (2022). GCA 338, 66–78.

9:15am - 9:30am
Topics: 3.03 Advances in paleoclimate proxy development and application

Assessing the belemnite archive for Mesozoic seawater temperature reconstruction by clumped isotope thermometry

Amelia Jane Davies1, Philip Staudigel1, Mattia Tagliavento1, Gregory Price2, Miguel Bernecker1, Julia Brugger3, Jens Fiebig1

1Goethe University Frankfurt; 2University of Plymouth; 3Senckenberg Biodiversity and Climate Research Centre

The reconstruction of Mesozoic seawater temperature is valuable to further understand the link between atmospheric carbon dioxide concentration and earth surface temperature variation. Belemnites are an effective archive for this purpose, owing to their distribution over an extensive latitudinal range in Jurassic and Cretaceous seas. However, uncertainty remains as to whether belemnites precipitate rostrum calcite in oxygen and clumped isotope equilibrium with surrounding seawater. Furthermore, recent study indicates that belemnite calcite may be more susceptible to thermal resetting of ∆47 values through oxygen isotope exchange with internal water than other calcites (Looser et al., 2023).

Here, we demonstrate identification of thermal resetting of ∆47 values in belemnite calcite using a combination of measured δ18O of fluid inclusions, δ18O and ∆47 values of belemnite calcite. We then apply dual carbonate clumped isotope thermometry (i.e. the simultaneous measurement of ∆47 and ∆48), to assess the potential importance of kinetic limitations during belemnite biomineralization (Bajnai et al., 2020; Guo, 2020). We demonstrate that Maastrichtian agebelemnites sampled at 4 sites with a range of paleolatitudes from 34 to 45 ˚N, yield ∆47 and ∆48 values that fall on the experimentally derived equilibrium calibration of Fiebig et al., (2021) indicating that rostrum calcite precipitated in clumped isotope equilibrium. ∆47-derived temperatures are combined with other proxy-based reconstructions of Maastrichtian seawater temperature to examine its latitudinal variability.

9:30am - 9:45am
Topics: 3.03 Advances in paleoclimate proxy development and application

New insights on the influence of biota on the Ce and U redox proxies: Evidence from experimental water-rock interaction with biogenic ligands under anoxic, hypoxic and oxic conditions

Dennis Kraemer1, Timmu Kreitsmann2, Stefan Weyer3, Michael Bau2

1Bundesanstalt für Geowissenschaften und Rohstoffe, Germany; 2Constructor University Bremen, Germany; 3Leibniz Universität Hannover, Germany

Microbes, plants and other organisms actively shape the Earth surface by a variety of processes. Current research on modern systems suggests that biota has a significant impact on the mobility of trace elements and there is growing evidence that it may have done so since the dawn of life. The secretion of extracellular compounds that bind strongly to iron and other micronutrients are evolutionary traits that may, besides acquiring bio-essential trace metals, also have helped in tackling with the toxicity of certain heavy metals. An example of such compounds are siderophores, which are produced today by many different plants, microbes and fungi. Besides iron, they promote the (bio)availability of different highly-charged cations in the natural environment.

In paleoclimate studies, the redox-sensitive trace elements Ce and U are commonly used as geochemical proxies (e.g., Ce anomalies, Th-U ratios, stable U isotopes) for reconstructing atmospheric oxygen levels through time. We investigated the effect of siderophores on the mobilization of rare earth elements, Th and U (isotopes) from natural rocks under anoxic, hypoxic and oxic conditions. We show that experimental water–rock interaction with siderophores under strictly anoxic conditions produces positive Ce anomalies – a geochemical signal that is usually attributed to the presence of atmospheric oxygen. Siderophores also influence the Th-U signal, but do not induce a significant U stable isotope fractionation. Thus, oxygen-independent fractionation during geo–bio interaction may hold the potential to use certain trace elements as a bio-proxy in addition to their current use as a redox proxy.

9:45am - 10:00am
Topics: 3.03 Advances in paleoclimate proxy development and application

Oxygen isotope variations in cherts from the Rhenish Massif record their diagenetic history, not climatic variations

Michael Tatzel1, Katharina Ebert1, Patrick Frings2, Tommaso di Rocco1, Andreas Pack1, N. Keno Lünsdorf1

1Universität Göttingen, Germany; 2GFZ Potsdam, Potsdam, Germany

Cherts are sturdy and ubiquitous throughout Earth history and therefore potentially ideal climatic archives, yet their diagenetic formation challenges straightforward interpretations. Previous work shows that oxygen isotope ratios (δ18Ochert) are not only controlled by seawater T and δ18Oseawater, but also by basal heat flow (Q) and burial rates, i.e. the diagenetic T-t path (Tatzel et al., 2022).

To strengthen the empirical evidence for the control of Q and burial rates on δ18Ochert we exploit the geological framework of the Rhenish Massif: During the Lower Carboniferous siliceous sediments were deposited onto stretched continental crust with variable Q across the basin. The opal mud then transformed during burial diagenesis into chert while tectonic nappes were stacked onto the autochthonous sediments during the Armorica- Laurussia collision.

To isolate the effects of the T-t-path on δ18Ochert we sampled isochronous cherts and siliceous shales from the Northern and Eastern margin of the Rhenish Massif. A decreasing trend in δ18Ochert from West-to-East (by >6 ‰) testifies to differences in burial rates and paleo-Q. We derive constraints on burial rates from peak diagenetic temperatures using Raman Spectrometry of carbonaceous matter and deconvolve for paleo-Q. Triple oxygen isotope compositions (Δ’17O) show increasing variations with increasing δ18Ochert – presumably a reflection of a wider range of diagenetic conditions in low-Q settings.

Tatzel, M., Frings, P.J., Oelze, M., Herwartz, D., Lünsdorf, N.K., Wiedenbeck, M., 2022. Chert oxygen isotope ratios are driven by Earth’s thermal evolution. Proc. Natl. Acad. Sci. 119.

8:30am - 10:00am3.20-1 Metamorphism and Deformation across scales
Location: Hall B (HFB)
Session Chair: Vasiliki Mouslopoulou, National Observatory of Athens
Session Chair: Marcel Thielmann, Universität Bayreuth
Session Chair: Gareth James Crutchley, GEOMAR Helmholtz Centre for Ocean Research Kiel
8:30am - 8:45am
Topics: 3.20 Multiscale Investigations of Convergent Margins: Unraveling Subduction Dynamics from Kinematic Transitions to Metamorphic Reactions

Megathrust stress drop as trigger of aftershock seismicity in subduction zone forearcs: Insights from the 2011 Mw 9.0 Tohoku earthquake, Japan

Armin Dielforder1, Gian Maria Bocchini2, Kilian Kemna2, Andrea Hampel1, Rebecca Harrington2, Onno Oncken3

1Leibniz Universität Hannover, Germany; 2Ruhr-Universität Bochum, Germany; 3GFZ Potsdam, Germany

Large megathrust earthquakes like the 2011 Mw 9.0 Tohoku earthquake (Japan) are followed by numerous aftershocks in the subduction zone forearc overlying the seismogenic fault. The aftershocks in the forearc can include normal-faulting events despite the thrust mechanism of the main shock. Postseismic normal faulting has been explained by stress changes induced by the coseismic stress drop along the megathrust. However, details of stress changes in the forearc and aftershock triggering mechanisms remain poorly constrained. Here we use numerical force-balance models combined with Coulomb failure analysis to show that the megathrust stress drop indeed supports normal faulting, but that forearc-wide triggering of aftershocks is feasible within a narrow range of megathrust stress-drop values and forearc stress states only [for details see Dielforder et al., 2023]. We determine this range for the Tohoku earthquake and show that the associated stress changes explain the aftershock seismicity in unprecedented detail. In particular, our analysis reveals that ~78% of the aftershocks and ~92% of the seismic moment release occurred in areas where the Tohoku earthquake caused a stress increase, and that the detailed aftershock distribution was also governed by spatial variability in fault strength and forearc topography. Our findings provide new insights into aftershock triggering and help to understand where aftershocks occur after great earthquakes at subduction zones.

Dielforder, A., Bocchini, G. M., Kemna, K., Hampel, A., Harrington, R. M., & Oncken, O. (2023). Megathrust stress drop as trigger of aftershock seismicity: Insights from the 2011 Tohoku earthquake, Japan. Geophysical Research Letters, 50, e2022GL101320.

8:45am - 9:00am
Topics: 3.20 Multiscale Investigations of Convergent Margins: Unraveling Subduction Dynamics from Kinematic Transitions to Metamorphic Reactions

Distribution, duration and size of slow-slip events in the eastern Mediterranean: insights from the Hellenic subduction system

Vasso Saltogianni1,2,3, Vasiliki Mouslopoulou2, Michail Gianniou4, Andrew Nicol5, Benjamin Männel3, Jonathan Bedford6, Onno Oncken3, Stelios Mertikas7

1Technical University of Berlin, Berlin, Germany; 2National Observatory of Athens, Athens, Greece; 3GFZ Potsdam, Germany; 4University of West Attica, Athens, Greece; 5University of Canterbury, Christchurch, New Zealand; 6Ruhr University Bochum, Bochum, Germany; 7Technical University of Crete, Chania, Greece

Slow-slip events (SSEs), although widely recorded in various convergent margins globally, only recently have been reported in the Eastern Mediterranean, with one of them triggering the 2018 ~M7 Zakynthos Earthquake along the western Hellenic Subduction System (HSS). Here, we explore the distribution, size and duration of SSEs along the HSS and assess their importance in subduction-related strain accumulation and release. To achieve this, we analyse geodetic timeseries from a dense network of permanent GNSS stations on Western Peloponnese, Crete and surrounding islands that collectively span a time-period of ~10 years. We use greedy linear regression techniques to estimate displacement trajectory models for each station and thus we identify transient displacement signals, associated with aseismic processes at depth. To further constrain the spatial extent and size of the SSEs we invert the GNSS transient displacements for variable distributed slip at depth and we, therefore, discuss likely scenarios of aseismic and seismic strain distribution (and partitioning) within the HSS’s complex plate-interface zone.

9:15am - 9:45am
Invited Session Keynote
Topics: 3.20 Multiscale Investigations of Convergent Margins: Unraveling Subduction Dynamics from Kinematic Transitions to Metamorphic Reactions

Transition from Subduction to Strike-slip: Insights from a well-expressed example in central New Zealand

Laura M. Wallace1,2,3

1GEOMAR; 2Christian-Albrechts-Universität zu Kiel; 3University of Texas Institute for Geophysics

Central New Zealand (southern North Island/northern South Island) occupies a complex transition from subduction to strike-slip at the southern termination of the Hikurangi subduction zone. This transition was also the site of the 2016 M7.8 Kaikoura earthquake, which is the most complex earthquake ever recorded, involving rupture of over a dozen faults. I will discuss how this transition from subduction to strike-slip occurs, through a joint interpretation of geologic and geodetic data. Approximately 2 cm/yr of convergence is accommodated at the Hikurangi Trough offshore the southern North Island, which decreases rapidly southward offshore the northern South Island (to a few mm/yr), where the majority of the relative plate motion is transferred onto strike-slip faults within the upper plate. This transfer of slip is facilitated via easterly-trending strike-slip faults (such as the Boo Boo fault in Cook Strait). Although the shallow megathrust offshore the northeastern South Island accommodates low rates of convergence, kinematic models based on geodetic data indicate that a large component of relative plate motion must be accommodated on the subduction interface at depth, down-dip of the major upper plate faults. This, along with geodetic evidence for interseismic coupling on the subduction interface beneath the northeastern South Island has implications for the potential southward extent of subduction interface earthquake rupture in central New Zealand. InSAR and GNSS evidence for large amounts of afterslip on the subduction interface following the Kaikoura earthquake also indicates the subduction zone continues as an important boundary well into the northern South Island.

9:45am - 10:00am
Topics: 3.20 Multiscale Investigations of Convergent Margins: Unraveling Subduction Dynamics from Kinematic Transitions to Metamorphic Reactions

Effects of an oblique collision on the evolution of foreland basins: Insights from 3D numerical modeling

Giridas Maiti1, Attila Balázs2, Lucas Eskens1, Taras Gerya2, Alexander Koptev3, Nevena Andrić-Tomašević1

1Institute of Applied Geosciences, Karlsruhe Institute of Technology, Germany; 2Institute of Geophysics, ETH Zürich, Switzerland; 3GFZ Potsdam, Germany

Flexural bending of a downgoing subducting plate in response to forces from slab pull and topographic load leads to foreland basin development in front of growing mountain belts. Many foreland basins worldwide show along-strike variable basin architecture and subsidence history. Various factors such as lateral variations in slab pull, the presence of lateral crustal heterogeneity, slab breakoff and tear propagation have been suggested as drivers. However, the effects of an oblique continental collision on the evolution of foreland basins are largely ignored. In this study, we use 3D thermo-mechanical numerical models coupled with surface processes (i.e., sedimentation and erosion) to simulate an oblique collision. In the initial model, the continental plate margin is placed at an oblique angle relative to the subduction trench and we vary the following parameters: (1) margin obliquity, (2) convergence velocity, (3) age of the subducting oceanic lithosphere, and (4) presence of pre-existing rigid blocks in the subducting plate. Our results show that models with no obliquity (i.e., straight continental margin) create simultaneous along-strike continental collision and foreland basin subsidence. However, higher margin obliquity (≥ 15° ) causes a delay in the along-strike collision and foreland basin development. Our results suggest that the along-strike propagation of foreland basin development is controlled by the initial margin obliquity and plate convergence velocity. Finally, we discuss the implications of our study on the 3D evolution of the Northern Alpine Foreland Basin (NAFB) and intramountain basins within the Betics where along-strike variations of the sedimentary basin architecture are reported.

8:30am - 10:00am4.13 Museen als Fenster in die Forschung
Location: Hall C (HFB)
Session Chair: Christina Ifrim, Staatliche Naturwissenschaftliche Sammlungen Bayerns
8:30am - 9:00am
Invited Session Keynote
Topics: 4.13 Museen als Fenster in die Forschung

Wie alt ist das eigentlich? Ein neues Exponat erklärt Plattenkalk-Forschung im Jura-Museum

Christina Ifrim

Staatliche Naturwissenschaftliche Sammlungen Bayerns, Germany

Das Jura-Museum widmet sich den Fossilien im weltberühmten Solnhofener Plattenkalk. Hier wird ein neues Exponat vorgestellt, dass sich den Solnhofener Plattenkalken über die Fossilien hinaus widmet. Es handelt sich um ein Festgesteins--Transferpräparat aus dem Steinbruch Ettling, das während der Forschungsgrabung angefertigt wurde und die Gesteinsabfolge im Original dokumentiert. Daraus wird ein Exponat, das dem Publikum Einblicke geben soll, wie sedimentäre Abfolgen datiert und interpretiert werden. Der Steinbruch Ettling ist bekannt für seine außerordentlich gut erhaltenen Fische mit Farbmustern. Der einzige Ammonit, der als Altersanzeiger dienen kann, kommt aus einer Bank, die im Transferpräparat enthalten ist. So kann Biostratigraphie anschaulich vermittelt werden. Weitere Forschungsdatenwerden in Zukunft direkt auf das Transferpräparat übertragen. Derzeitige Analysenumfassen mineralogische Zusammensetzung, Nannofazies, Chemostratigraphie und quantitative Auswertungen aus der Forschungsgrabung. Die Ergebnisse, die allein sehr abstrakt wären, sind so anschaulich am Profil vermittelbar. Das Exponat dient somit zur Vermittlung vielfältiger geowissenschaftlicher Ansätze und Fragestellungen weit über den Fossilbestand hinaus und liefert direkte Einblicke in die Forschung.

9:00am - 9:15am
Topics: 4.13 Museen als Fenster in die Forschung

Was ist die Öffentlichkeit

Jonas Grutzpalk

HSPV NRW, Germany

Ein Museum will eine Öffentlichkeit erreichen. Doch das ist leichter gesagt als getan, denn aus soziologischer Sicht zeigt sich die Öffentlichkeit nicht als monolithischer Block, sondern als ein Konglomerat aus sozialen Milieus, die Informationen sehr unterschiedlich aufnehmen und verarbeiten. Das Wahlkapfteam Barack Obamas z.B. war dementsprechend auf über 80 solcher ÖffentlichkeitEN eingestellt und sprach sie jeweils unterschiedlich an. Wie kann die Soziologie mit ihren Modellen von dem, was man gemeinhin "Gesellschaft" nennt der Wissenschaft, die genau weiß, "wie man mit dem Hammer philosopirt" (Nietzsche) ggf. dabei helfen, ihre Öffentlichkeiten zu erkennen und erfolgreich mit ihnen zu kommunzieren? Dieser Frage würde ich gerne in meinem Beitrag diskutieren.

9:15am - 9:30am
Topics: 4.13 Museen als Fenster in die Forschung

Ohne „in die Kreide zu kommen“ in die Kreide kommen: Günstig produzierte Videos zur Ergänzung geologischer Ausstellungen

Ulrich Kotthoff1, Lioba Thaut1, Julia Pawlowski2

1Leibniz-Institut zur Analyse des Biodiversitätswandels, Germany; 2Universität Hamburg

Kleine Museen mit eingeschränkter Finanzierung können oft nur geringe Mittel aufbringen, um mit weiterführenden Material Vitrinen und Ausstellungsobjekte zu ergänzen, zum Beispiel englische Texte oder Tonmaterial für Sehbehinderte. Um spezielle Zielgruppen, wie z. B. Kinder und Schülerinnen und Schüler anzusprechen und ihnen Sammlungsobjekte zugänglich zu machen, bieten sich kurze Videos an, die wissenschaftliche Zusammenhänge erläutern. Ferner können Forschungsmethoden in solchen Videos erklärt werden. Die Einbindung von ergänzenden Visualisierungen kann u a. über QR-Codes oder an geeigneten Stellen mit Monitoren erfolgen.

Wir präsentieren anhand von Fallbeispielen Ansätze, wie mit geringem technischen Aufwand und weit verbreiteter, zum Teil frei verfügbarer Software ergänzendes Videomaterial erzeugt und in Ausstellungen eingesetzt werden kann. Das Poster bietet über QR-Codes Zugang zu auf diese Art generierte Videodateien.

8:30am - 10:00am1.01 Towards 'Net Zero' with negative emissions and sustainable landscapes
Location: Hall D (HFB)
Session Chair: Patrick Frings, GFZ Potsdam
Session Chair: Patricia Grasse, iDiv
Session Chair: Dirk Sachse, GFZ Potsdam
8:30am - 9:00am
Invited Session Keynote
Topics: 1.01 Towards 'Net Zero' with negative emissions and sustainable landscapes

Quantifying and optimising Enhanced Weathering as a CO2 removal tool

Patrick Frings

GFZ Potsdam, Germany

The application of finely ground silicate minerals to croplands and forests, with the aim of enhancing the rate of natural CO2 consuming weathering reactions, is receiving attention as a part of climate change mitigation strategies. Yet considerable uncertainty surrounds the quantification of CO2 removal associated with Enhanced Weathering, and its potential efficacy remains undemonstrated outside of the laboratory. Here, I discuss how the geochemical insights garnered from decades of natural weathering studies provide a pathway towards a strategy for ‘Monitoring, Reporting and Verification’ of CO2 sequestration. These natural weathering studies have also produced an understanding of what limits silicate weathering in different settings, which can be used to shed light on how deployment strategies, and specifically application sites, can be optimised.

9:00am - 9:15am
Topics: 1.01 Towards 'Net Zero' with negative emissions and sustainable landscapes

Limits and CO2 equilibration of near-coast alkalinity enhancement

Jing He2, Michael Tyka1

1Google Inc., United States of America; 2MIT-WHOI Joint Program in Oceanography and Applied Ocean Science and Engineering, Cambridge, MA, 02139, USA

In this work we study critical questions which determine the scale and viability of ocean alkalinity enhancement (OAE): Which coastal locations are able to sustain a large flux of alkalinity at minimal pH and aragonite saturation changes? What is the interference distance between adjacent OAE projects? How much CO2 is absorbed per unit of alkalinity added? How quickly does the induced CO2 deficiency equilibrate with the atmosphere?
Using the LLC270 (0.3deg) ECCO global circulation model we find that the steady-state OAE rate varies over 1–2 orders of magnitude between different coasts and exhibits complex patterns and non-local dependencies which vary from region to region. Neighboring OAE sites can exhibit dependencies as far as 400 km or more. We show that near-coastal OAE has the potential to scale globally to several GtCO2/yr of drawdown with conservative pH constraints, but only if the effort is spread over the majority of available coastlines.
Depending on the location, we find a diverse set of equilibration kinetics, determined by the interplay of gas exchange and surface residence time. Most locations reach an uptake-efficiency plateau of 0.6–0.8mol CO2 per mol of alkalinity after 3–4 years, after which there is little further CO2 uptake. Some locations (e.g. Hawaii) take significantly longer to equilibrate (up to 8–10 years), but can still eventually achieve high uptake. If the alkalinity released advects into regions of significant downwelling (e.g. around Iceland) up to half of the OAE potential can be lost to bottom waters.

9:15am - 9:30am
Topics: 1.01 Towards 'Net Zero' with negative emissions and sustainable landscapes

Human impacts on marine sedimentary carbon sequestration

Lucas Porz1, Wenyan Zhang1, Rümeysa Yilmaz1,2, Corinna Schrum1,2

1Helmhotz-Zentrum Hereon, Germany; 2Universität Hamburg, Germany

The seafloor functions as a substantial long-term (>100 yr) carbon sink and reservoir in the form of sedimentary organic particles. Human activities can modify the seafloor's natural carbon sequestration capacity by disturbing the upper sediment layers and thereby altering biogeochemical processes and releasing previously trapped carbon. Yet, the overall magnitudes of the changes in sedimentary carbon pools induced by these processes are not well known and could not be adequately considered in environmental impact assessments so far.

In this study, we quantify anthropogenic disturbances of sedimentary carbon sequestration in the North Sea using a combination of measurement data and numerical modeling. In particular, we examine the effects of bottom-contacting fisheries, sediment extraction, and material dumping. By resolving spatial and temporal patterns of both natural and anthropogenic drivers, we identify areas particularly vulnerable to degradation, representing the most detailed large-scale estimates of human impacts on North Sea sediments to date. Our results indicate that while the impacts of human activities on sedimentary carbon sequestration are comparable in magnitude to natural sedimentation processes, the resulting carbon benefits are considerably lower than previously estimated.

Although remaining uncertainties need to be further confined and missing processes such as ecosystem feedbacks considered, our findings can serve as a useful basis for the consideration of sedimentary carbon disturbance in the context of marine spatial management plans.

9:30am - 9:45am
Topics: 1.01 Towards 'Net Zero' with negative emissions and sustainable landscapes

Enhanced weathering of mafic rocks in tropical Colombia

Camilo Montes, Aymer Maturana, Maritza Duque, Jaime Escobar, Juan Andres Gil, Juan David Atencio

Universidad del Norte, Colombia

The tropics have the potential to capture large amounts of CO2 through enhanced weathering of mafic rocks. This negative emissions technology can be articulated with the needs of the agricultural sector, in particular the large irrigated tropical cropland in the tropics. High-yield agricultural soils in the tropics are acidic. Their acidity is traditionally controlled with lime, which in turn emits CO2. Crushed mafic rocks can be used instead of lime, with the added benefit of not only avoiding the lime emissions, but also capturing CO2. In tropical Colombia, there are extensive plantations of African oil palm, sugar cane, rice, banana, and corn. Nearby, there are large open-cast mining operations that produce massive volumes of mafic and ultramafic rocks as waste product. We are characterizing mafic and ultramafic rocks closest to the potential application sites, as well as the products of their weathering under natural conditions. We are also conducting field experiments with natural soils from areas of active afforestation, as well as in soils degraded by cattle ranching. Both were previously covered by rain forests. In these experiments we are evaluating the reaction rates and efficiencies of mafic and ultramafic rocks under tropical conditions in natural soils. We aim to establish the technical and scientific basis for a process by which the forestry, mining, agricultural, and energy industries in the tropics can reduce their operational carbon footprint, and eventually offer carbon capture bonds in the international market.

9:45am - 10:00am
Topics: 1.01 Towards 'Net Zero' with negative emissions and sustainable landscapes

Navigating the Uncertainty: Rethinking the Relationship of Law and Science

Tony Cabus

CAU Kiel, Germany

It is now well known that limiting the warming of the planet to 1,5°C by the end of the century will require some degree of carbon dioxide removal (CDR) and marine CDR technologies have emerged as a potential solution to mitigate climate change. While marine CDR can be piloted domestically, its maximum efficiency requires international coordination due to transboundary effects. However, the current international legal framework, including the UNFCCC and its descendants, lacks a dedicated regime for CDR, resulting in a plethora of potentially applicable sources of law with different answers on the legality of CDR. Emphasizing the challenges and necessities of coordinating CDR activities on a global level, this presentation addresses the unrealistic optimism of current law to over-rely on clear cut answers from natural sciences. It will explain how the traditional approach of the law needs to be revised to adapt to the scientific realities of climate action. This analysis should provide a reflection on the need for a wider societal debate to solve “trade-offs” issues that lawyers alone are not in a position to solve.

8:30am - 10:00am1.17-1 Marine mineral deposits: Formation, exploration, and environmental impacts of human activities
Location: Wiwi 101
Session Chair: Sebastian Fuchs, Bundesanstalt für Geowissenschaften und Rohstoffe
8:30am - 9:00am
Invited Session Keynote
Topics: 1.17 Marine mineral deposits: Formation, exploration, and environmental impacts of human activities

Advancements in Deep-Sea Mineral Exploration and Legal Aspects of Deep-Sea Mining

Carsten Rühlemann, Annemiek Vink, Thomas Kuhn

Bundesanstalt für Geowissenschaften und Rohstoffe, Germany

The presentation provides an overview of BGR's deep-sea mineral resource exploration and informs on recent developments in deep-sea mining. Metals such as copper, nickel and cobalt play a vital role in the production of regenerative energies and high-tech electronic products. Currently, these metals are solely extracted from land sources, but increasing global demand has spurred interest in deep-sea deposits located in areas beyond national jurisdiction. Polymetallic nodules, cobalt-rich manganese crusts and massive sulphides found at water depths of 1 to 5 kilometers are seen as potential sources of such raw materials. Germany, as an industrial country with high raw material demands, heavily relies on metal imports. As a potential measure to reduce dependence and secure supply, Germany has invested actively in the exploration of marine mineral deposits and their environment in the eastern Pacific and southwestern Indian Ocean during the last two decades. The International Seabed Authority (ISA) is currently negotiating regulations for the mining of these resources (“Mining Code”). At the moment, the focus is on adopting regulations for polymetallic nodule mining, possibly by 2024. However, companies could potentially already submit mining applications today, to be considered by the Council despite the absence of a full set of binding regulations. Significant progress has recently been made in overcoming the technical challenges of mining the deep sea. Several contractors have successfully tested mining systems and are currently monitoring the resultant impacts on the environment and the biodiversity.

9:15am - 9:30am
Topics: 1.17 Marine mineral deposits: Formation, exploration, and environmental impacts of human activities

Systematic variations in trace element composition of pyrites from the Xunmei hydrothermal field (26°S), Mid-Atlantic Ridge

Lei Fan1,2,3, Guozhi Wang2, Astrid Holzheid1, Basem Zoheir1,4, Xuefa Shi3, Matthias Frische5, Qing Lei2

1Kiel University, Germany; 2Chengdu University of Technology, China; 3First Institute of Oceanography - Qingdao, China; 4Benha University, Egypt; 5GEOMAR Helmholtz Centre for Ocean Research - Kiel, Germany

Two zoned inactive chimney samples from the SMAR 26°S (Xunmei) hydrothermal field were studied petrographically and by in-situ LA-ICP-MS analysis. Morphologically different pyrites precipitated with increasing temperatures from the outermost chimney wall to intermediate zone, then to the inner zone, and finally to interstice pore fillings which represents the late mature stage. The distribution of trace elements in pyrites across the chimney indicates a strong dependence on time, temperature, and associated sulfide minerals. The variation of trace elements in different paragenetic stages of pyrite reveals that the hydrothermal system most likely evolved from low-temperature low-chloride liquid-dominated fluids (enriched in Zn, Cd, Tl, Ag, Pb, Mn, Mo, and V) to higher temperature, vapor-dominated fluids (Cu, Au, Te, and Bi), probably representing magmatic volatiles, and then to high-temperature fluids (Co and Se). In the waning stage of the hydrothermal system, circulating hot fluids in auxiliary conduits were depleted in most trace elements. LA-ICP-MS time-depth profiles reveal that Co, Se, and Mo are present mainly in lattice substitution, whereas Cu, Zn, Cd, Tl, Ag, Te, and Bi are related to micro-/nano-inclusions. Profiles for As, Pb, Au, and Sb can be either smooth or irregular, indicating both lattice substitutions and inclusions. Adsorbed films on pyrites control the distribution of V and Mo. To conclude, the behavior of trace elements is strongly associated with the fluid evolution during chimney growth, where trapping of micro-/nano-inclusions and surface adsorption are seen more frequently at the low-temperature stage, whereas lattice substitutions are dominant at elevated temperature stages.

8:30am - 10:00am-
Location: Wiwi 104
8:30am - 10:00am3.11-1 Triassic Revolution
Location: Wiwi 104a
Session Chair: Emma Dunne, Friedrich-Alexander-Universität Erlangen-Nürnberg
8:30am - 8:45am
Topics: 3.11 Triassic Revolution

Prevailing deteriorated palaeoenvironments related to the hyperthermal Permian-Triassic mass extinction

Zhicai Zhu1,2,3, Yongqing Liu2, Hongwei Kuang2, Alex J. Farnsworth1, Andrew J. Newell4, Michael J. Benton1

1School of Earth Sciences, University of Bristol, Bristol, BS8 1RJ, UK; 2Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China; 3State Key Laboratory for Mineral Deposits Research, Nanjing University, Nanjing 210023, China; 4British Geological Survey, Maclean Building, Wallingford OX10 8BB, UK

The Permian-Triassic mass extinction, one of the most severe biotic crises in Earth's history, has been attributed to sharp heating (nearly 15°C in low-latitude areas) initially triggered by massive volcanic eruptions of the Siberian Traps in the latest Permian. Drastic environmental changes have been identified worldwide, both in the sea and on land. However, the connections of global palaeoclimate changes, particularly their detection in complex terrestrial systems, remain debatable. Here, based on sedimentological and geochemical data and state-of-the-art modelling from North China, we emphasise the drastically deteriorated palaeoenvironments (e.g. unstable, drought and intermittent heavy precipitation) under a regime of sharp heating, mass wasting and acid rain on land may be significant causes of the mass killing events near the end-Permian and the subsequent Early Triassic long-lasting stressed terrestrial palaeoclimate that delayed the recovery of life. Understanding the Permian-Triassic hyperthermal crisis may also provide critical insight into similar events of different magnitudes in Earth's history, and could inform our near future, in the context of anthropogenic warming and our rapidly changing planet.

8:45am - 9:00am
Topics: 3.11 Triassic Revolution

From the field to the synchrotron, investigating the early Triassic recovery fauna from Driefontein, South Africa

Kathleen Nina Dollman1, Chandele Montogomery2, Andy Heckert3, Vincent Fernandez1, John Hancox2

1European Synchrotron and Radiation Facility, France; 2Evolutionary Studies Institute, University of Witwatersrand, Johannesburg; 3Department of Geological and Environmental Sciences, Appalachian State University

The Karoo Supergroup of South Africa contains extremely rich palaeontological record, including evidence of the largest mass extinction in history, the end-Permian extinction (±251.9 Ma). The recovery of terrestrial ecosystems from this mass extinction is an active area of research and one of South Africa’s most important contributions to the field of palaeontology. The farm Driefontein 11 in the Free State Province preserves an Early Triassic (upper Olenekian) fossil lagerstattë in the Burgersdorp Formation of the Karoo’s Beaufort Group . Driefontein yields tens of thousands of body and trace fossils. These fossils range in size from sub-mm scale teeth and invertebrates to bones of large temnospondyls and archosauromorphs. Despite the importance of these fossils, the fauna of Driefontein remains incompletely known – reflecting the sheer numbers of specimens (+- 30 000 coprolites alone) as well as the fragmentary and/or fragile nature and microscopic size of many of the remains. Here, we use a multiresolution (42µm to 1.14µm) approach with propagation phase contrast X-ray synchrotron micro computed tomography on the newly installed beamline, BM18, at the European Synchrotron and Radiation Facility, to investigate all trophic levels of Driefontein. We use this large dataset of high-resolution scans to investigate various aspects of organismal biology, including growth history, functional morphology, and comparative anatomy. This study contributes to our knowledge of the recovery of terrestrial ecosystems after the largest mass extinction in history, the end-Permian extinction, and highlights the importance of Driefontein 11 as a site for future research in the field of palaeontology

9:00am - 9:15am
Topics: 3.11 Triassic Revolution


Rainer R Schoch, Hans-Dieter Sues

Staatlichse Museum fur Naturkunde Stuttgart, Germany

Following the end-Permian biotic crisis, reptiles rapidly diversified and dispersed across the globe at the beginning of the Triassic Period. Non-mammalian synapsids became much less abundant and had massive losses in diversity during the end-Permian event. To date, the fossil record of continental tetrapods has largely been restricted to the Karoo of South Africa and European Russia. In the Central European Basin, Early and early Middle Triassic continental red beds are collectively referred to as the Buntsandstein Group. Whereas the strata of the Lower Buntsandstein are largely unfossiliferous, those of the Middle and Upper Buntsandstein have yielded many tracks and trackways representing a great diversity of tetrapods and occasionally skeletal remains of tetrapods. Temnospondyl stem-amphibians were common with a variety of ecomorphs. A sandstone quarry at Rotfelden in the Black Forest region (Germany) exposed a 6-to-8-m-thick section within the top of the Röt 4 Subformation. Tetrapod remains have been recovered from several horizons in this section. Previously, Amotosaurus rotfeldensis, a tanystropheid archosauromorph and the temnospondyl Eocyclotosaurus lehmani have been reported from this locality. New discoveries include a new Euparkeria-grade archosauriform and a rhynchosaur. The latter is documented by a group of three juvenile skeletons. The absence of unambiguous records of non-mammalian synapsids in the Buntsandstein is possibly related to environmental factors. The growing number of tetrapod taxa from the Buntsandstein suggests that assemblages of continental tetrapods had already recovered to a considerable extent 6-7 million years after the end-Permian extinction.

9:15am - 9:30am
Topics: 3.11 Triassic Revolution

In a while it will be a crocodile: the early evolution of Crocodylomorpha in Europe

Stephan N.F. Spiekman

Naturkunde Museum Stuttgart, Germany

Crocodylomorpha, the crocodylian stem-lineage, is the only pseudosuchian clade that survived into the Jurassic. Its earliest members, the non-crocodyliform crocodylomorphs or ‘sphenosuchians’, were terrestrial and mostly small-bodied (<2 m long). A redescription of both known European ‘sphenosuchian’ taxa is provided, Terrestrisuchus gracilis from the Late Triassic (Norian-Rhaetian?) of southern Wales, and Saltoposuchus connectens from the Norian of southwestern Germany. Terrestrisuchus and Saltoposuchus can clearly be distinguished based on many character states, contrary to some previous hypotheses. A new phylogenetic analysis finds that both taxa form a clade of gracile, long-legged crocodylomorphs, identified as Saltoposuchidae, together with Litargosuchus leptorhynchus. Analysis of a µCT-scan provides a virtually complete threedimensional reconstruction of the Terrestrisuchus braincase. The quadrate only forms a small, unfused contact with the prootic, contrary to later crocodylomorphs in which the braincase is heavily fused to surrounding cranial elements. The posterior skull region is extensively pneumatised by, among others, large pre- and postcarotid recesses on the parabasisphenoid and a large pneumatic cavity within the articular of the mandible, revealing extensive braincase pneumatisation occurred early within Crocodylomorpha. Terrestrisuchus preserves an ossified basihyal and scleral ring, the latter representing the first occurrence among non-bird-line archosaurs. Based on phylogenetic flexible discriminant analysis (pFDA) of the relative dimensions of the sclerotic ring and orbit, Terrestrisuchus was likely active in a range of light levels. Histological long bone sections of both Terrestrisuchus and Saltoposuchus reveal highly vascularized fibrolamellar tissue, indicating sustained high growth rates and thus high resting metabolic rates and active lifestyles for saltoposuchids.

9:30am - 9:45am
Topics: 3.11 Triassic Revolution

A new pachypleurosaur (Reptilia: Sauropterygia) from the Middle Triassic of southwestern China and its phylogenetic and biogeographic implications

Yi-Wei Hu1, Qiang Li1,2, Jun Liu1

1School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, China; 2Institute of Geosciences, University of Bonn, Bonn 53115, Germany

After the devastating Permo-Triassic Mass Extinction, several new groups of large predators invaded the sea in the early part of the Triassic, including sauropterygians, ichthyosauromorphs and thalattosaurs. Among these predators, sauropterygians are the most abundant group in terms of the generic/species diversity. Here we report a new species of Pachypleurosauria (Sauropterygia: Eosauropterygia) from a recently discovered Lagerstätten in the Upper Member of Anisian Guanling Formation. The only known specimen of the new species was collected from Muta village, Luxi County, Yunnan Province, South China. Our new phylogenetic analysis based on a novel data matrix recovered the new taxon as a sister group to Dianmeisaurus. The new phylogenetic analysis also collapsed the monophyly of traditionally recgonized Eusauropterygia. Pistosauridea, Majiashanosaurus, and Hanosaurus comprise the consecutive sister groups to a new clade including Pachypleurosauria and Nothosauroidea. A monophyletic Pachypleurosauria, of which the clade consisting of Dianmeisaurus and Panzhousaurus occupy the basal-most position, is recovered by this study. The clade consisting of Dawazisaurus and Dianopachysaurus forms the sister group to remaining pachypleurosaurs included in this study. Since Dianmeisaurus, Panzhousaurus, Dawazisaurus and Dianopachysaurus are all exclusively known from South China, we suggest that pachypleurosaurs had a paleobiogeographic origin in the eastern Tethys.

9:45am - 10:00am
Topics: 3.11 Triassic Revolution

The Triassic Revolution on land

Michael J. Benton

University of Bristol, United Kingdom

The evolution of terrestrial life was as profoundly affected by the end-Permian mass extinction as life in the sea. The recovery of life in the Triassic represented much more than simply a return to pre-extinction conditions, but in fact an entirely new world was ushered in. The generalized replacement of synapsids by archosauromorph reptiles had long been recognized, together with the rise of the dinosaurs to ecological dominance and origins of many modern groups including lissamphibians, turtles, lizards, crocodilomorphs, and mammals. In addition, all the new larger tetrapods had switched from a sprawling posture before the crisis to an erect posture and parasagittal gait afterwards, and this hints at higher activity levels. This is confirmed by the more recent discovery that many of the Triassic archosauromorphs had indicators of endothermy (warm-bloodedness) in their bone histology, and that these Triassic tetrapods also had insulating dermal structures: hair in synapsids and feathers in dinosaurs, pterosaurs and their ancestors. All these indications of endothermy are debated and yet to be confirmed by further study, but they suggest an overall increase of energy in ecosystems, a general speeding up of life as competition and predation increased. Also, it means that these tetrapods were consuming more energy than their Permian forebears. In many ways, these discoveries suggest a macroevolutionary model equivalent to the Mesozoic Marine Revolution, in which Mesozoic marine life was more active and more meaty than much if Palaeozoic marine life.

8:30am - 10:00am3.24 Shaping divergent plate boundaries and associated georesources through tectonic, magmatic and hydrothermal processes
Location: Wiwi 105
Session Chair: Anne Glerum, GFZ German Research Centre for Geosciences, Potsdam, Germany
Session Chair: Marta Perez-Gussinye, MARUM/Bremen Universität
8:45am - 9:00am
Topics: 3.24 Shaping divergent plate boundaries and associated georesources through tectonic, magmatic and hydrothermal processes

Geodynamic modelling of the Wilson-cycle: investigating the interplay of structural and thermal inheritance

Zoltán Erdős1, Susanne Buiter1,2, Joya Tetreault3

1Helmholtz Centre Potsdam – GFZ German Research Centre for Geosciences, Potsdam, Germany; 2RWTH Aachen University, Tectonics and Geodynamics, Aachen, Germany; 3Geological Survey of Norway, Trondheim, Norway

Many rifted margins are thought to have formed in areas that have previously experienced subduction and orogenesis. Yet, our understanding of how structural and thermal inheritance from preceding convergence affects rifting is still incomplete. We use 2D thermo-mechanical numerical models to investigate how the size of a collisional orogen affects the style of subsequent continental rifting. Our models build an orogen through subduction and collision before the onset of rifting. We focus on the deformation style of the resulting rifted margins and the degree in which inheritance is utilized.

We find that the style of extension changes with the size of the orogen. A narrow orogen produces a narrow margin on the side of the overriding plate with core-complex-style reactivation of the subduction interface while a large amount of oceanic material is preserved in the conjugate margin. In contrast, wide orogens localize rifting away from the subduction interface: the subduction interface is temporarily reactivated, but deformation quickly shifts to the thick orogenic assembly resulting in wide rifted margins. Ductile deformation in the lower crust promotes localization of simultaneously active conjugate shear-zones in the brittle crust above. Rifting in these experiments occurs within the subducting plate.

Our results demonstrate a wide range of features that can form in the presence of inherited compressional structures and emphasise the importance of taking the deformation history into account when trying to understand the evolution of continental rifting.

9:00am - 9:15am
Topics: 3.24 Shaping divergent plate boundaries and associated georesources through tectonic, magmatic and hydrothermal processes

Inherited structures and their impact on rift evolution: A numerical study of the South China Sea

Kai Li1,2, Sascha Brune1,3, Zoltán Erdős1, Derek Neuharth4, Geoffroy Mohn5, Anne Glerum1

1The Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Germany; 2Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany; 3Institute of Geosciences, University of Potsdam, Potsdam-Golm, Germany; 4Department of Earth Sciences, ETH Zürich, Zurich, Switzerland; 5CY Cergy Paris Université, GEC, 95000 Neuville sur Oise, France

The South China Sea experienced Cenozoic rifting in a region that was previously part of a Mesozoic Andean-type orogeny, which presumably had resulted in structural, compositional, and thermal inheritance. Recent studies using seismic profiles, drill cores, and geochronological analysis have revealed evidence for such heterogeneous pre-rift lithosphere in the South China Sea (Fan et al., 2017). Here, we further investigate the impact of orogenic inheritance on rift evolution using a numerical forward model that integrates both geodynamic and landscape evolution software (Neuharth et al., 2022). By varying our velocity boundary conditions over time, the model encompasses first continental collision, followed by post-orogenic collapse, continental rifting, and final lithospheric breakup. The model is constrained by observed crustal thicknesses, cooling history, and lithosphere-asthenosphere boundary depth, and successfully reproduces realistic orogenic topography, thrust fault distribution, and rifted margin of the SCS.We find that during orogeny, crustal thickening leads to the development of inherited weaknesses in the modelled crust. From orogenic collapse to continental rifting, pre-existing thrust faults are reactivated and serve as nucleation sites for normal faults, which interact with later rift-related normal faults to modify the regional stress field. The modeling results demonstrate that pre-existing thrust faults and a ductile lower crust play a crucial role in shaping the wide rifted margin of the SCS. We infer from our results that the location of crustal breakup is often influenced by these inherited structures. These regions have typically undergone thermal weakening, which further facilitates the process of crustal breakup during rifting.

9:15am - 9:30am
Topics: 3.24 Shaping divergent plate boundaries and associated georesources through tectonic, magmatic and hydrothermal processes

Geodynamic controls on sediment-hosted metal deposits in continental rifts

Anne Glerum1, Sascha Brune1,2, Joseph Magnall1, Philipp Weis1,2, Sarah Gleeson1,3

1GFZ German Research Centre for Geosciences, Potsdam, Germany, Germany; 2University of Potsdam, Potsdam, Germany; 3Freie Universität, Berlin, Germany

Many large sediment-hosted clastic-dominated (CD) base metal deposits occur in failed continental rifts and the passive margins of successful rifts, e.g., in the MacArthur Basin, Australia, and in the Selwyn Basin in Canada. Continental rifts and their margins provide a specific mix of higher temperatures and heat flows, fault networks facilitating fluid flow, sediment input from the generated topography, and ocean water contributing pelagic sediments and sulfates. The large-scale geodynamics thus provide the necessary ingredients for metal leaching, with metal deposition then occurring on much smaller spatial and temporal scales.

To identify the specific geodynamic conditions conducive to large CD-type deposit formation, we numerically model 2D rift systems from inception to break-up with the geodynamic code ASPECT (Heister et al. 2017) coupled to the landscape evolution model FastScape (Braun and Willett 2013; Neuharth et al. 2022). With high-resolution (~300 m) simulations, we investigate how rift type (e.g., wide versus narrow), the presence of a craton, and the efficiency of erosional and depositional processes affect the formation of potential source and host rock domains. We subsequently analyse the optimal alignment of these regions where metals are leached and deposited, respectively, with faulting events providing fluid pathways between them. For these favorable co-occurrences, we estimate the potential size of metal deposits and identify those conditions that predict the largest deposits.

Braun and Willett. 2013. Geomorphology 180–181. 10.1016/j.geomorph.2012.10.008.

Heister et al. 2017. Geophys. J. Int. 210 (2): 833–51. 10.1093/gji/ggx195.

Neuharth et al. 2022. Tectonics 41 (3): e2021TC007166. 10.1029/2021TC007166.

9:30am - 9:45am
Topics: 3.24 Shaping divergent plate boundaries and associated georesources through tectonic, magmatic and hydrothermal processes

Spatio-temporal Dynamics of Hydrothermal Circulation over 10 million years of Ultraslow- Rifting and Spreading

Javier Garcia-Pintado, Marta Perez-Gussinye, Leila Mezri

MARUM/Bremen Universität, Germany

Present spatiotemporal variations of hydrothermal fluxes in the modern and recent ocean provide an observational snapshot of the dynamic interaction between the tectonics of ocean basins and submarine hydrothermal systems. In order to support the understanding of feedbacks between tectonics and the life cycle of hydrothermal systems, we discuss the mechanical, fluid flow and heat flux patterns in a coupled ThermoHydroMechanical model at the ocean basin scale. The case study is an ultra-slow spreading basin, evolving from the initial rifting stages up to the ridge formation. Heat release by plastic deformation at fractures and faults, exothermic serpentinization reactions, sensible and latent crystallization heat from magmatic emplacement and radiogenic heat provide different energy-source signatures promoting hydrothermal activity. The large basin-scale domain allows us to navigate through the evolution of the modelled concurrent hydrothermal systems, emerging and decaying in consonance with the tectonics and the energy-sources. We discuss how the evolving permeability field in crust and sediments exerts a strong control on the hydrothermal circulation, and describe the dynamics of reorganization patterns in fluid flow in response to the mechanical strains and heat sources.

9:45am - 10:00am
Topics: 3.24 Shaping divergent plate boundaries and associated georesources through tectonic, magmatic and hydrothermal processes

Quantitative analysis of normal fault network evolution

Sascha Brune1,2, Thilo Wrona1, Pauline Gayrin1,2, Derek Neuharth3, Anne Glerum1, John Naliboff4, Esther Heckenbach1,2

1Geodynamic Modelling Section, GFZ Potsdam, Germany; 2Institute of Geosciences, University of Potsdam, Germany; 3Department of Earth Sciences, ETH Zürich, Switzerland; 4Department of Earth and Environmental Science, New Mexico Institute of Mining and Technology, Socorro, NM, USA

Understanding how normal fault networks initiate and evolve is important for quantifying plate boundary deformation, assessing seismic hazard and finding natural resources. State-of-the-art numerical forward models treat faults as finite-width shear zones, not as discrete entities. To better understand fault system dynamics over geological scales, we develop workflows to isolate individual faults and their role in shaping the fault network.

We present 3D numerical rift models of moderately oblique extension using the ASPECT software. These models reproduce the thermo-mechanical behavior of Earth's lithosphere and simulate fault system dynamics from inception to breakup accounting for visco-plastic rheology, strain softening and surface processes. We extract surficial fault systems as a hierarchical, time-dependent 2D network of nodes, edges and components representing individual faults.

We find that the initial fault network forms through rapid fault growth and linkage, followed by competition between neighboring faults that leads to their coalescence into a stable network. At this point, modelled normal faults continue to accumulate displacement but do not grow any longer. As deformation localizes towards the center of the rift, the initial border faults shrink and disintegrate, being replaced by new faults in the center of the rift. The longevity of faulting is thereby controlled by crustal rheology and surface process efficiency. Quantitative analysis of fault evolution allows us to deduce fault growth and linkage as well as fault tip retreat and disintegration in unprecedented detail.

8:30am - 10:00am4.02-1 Within and Beyond - Research infrastructures that strengthen Open Science Practices in Geosciences
Location: Wiwi 107
Session Chair: Andrea Pörsch, Helmholtz Metadata Collaboration (HMC) at GFZ German Research Centre for Geosciences, Potsdam, Germany
Session Chair: Kirsten Elger, GFZ German Research Centre for Geosciences
8:30am - 9:00am
Invited Session Keynote
Topics: 4.02 Within and Beyond - Research infrastructures that strengthen Open Science Practices in Geosciences

Data Management for the App UmweltNAVI of the Federal State of Lower Saxony in Germany

Joachim Müller

wemove digital solutions GmbH, Germany

The App UmweltNAVI Niedersachsen (see the poster in session "4.10" or communicates geospatial data to a broad user community of education, individuals or experts. In order to adequately present the data in a mobile context, the data must be harmonized, transformed, and combined with other sources. To achieve this, an infrastructure was created that allows editors to integrate data sources and enrich them with information. For example, Web Feature Services, ESRI Shapefiles, SensorThings APIs (STA) are under the data sources. A GUI-guided transformation process enables the mapping of raw data to the harmonized data schema. For the presentation, complex data is simplified, data reconciliation with additional data sources (i.e. Wikipedia or is performed, and the resulting data is stored in a scalable backend. Currently, the database contains 1.8 million records from 57 regional and national data sources and 178,000 images.
Only open source or freely usable software components are used, such as Elasticsearch, Postgres/PostGIS, Airflow or Directus. The delivery layer is designed redundantly for high-performance, fail-safe operation.
A standards-compliant interface (OGC-API Feautures) is being planned to provide access to the data for further processing.
The project was initiated by the Lower Saxony Ministry for the Environment, Energy and Climate Protection in 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.

9:15am - 9:30am
Topics: 4.02 Within and Beyond - Research infrastructures that strengthen Open Science Practices in Geosciences an online application for disseminating the Global Heat Flow Database to the international heat flow community

Samuel Jennings1, Kirsten Elger1, Sven Fuchs1, Nikolas Ott2, Stephan Mäs2, Ben Norden1, Florian Neumann1, Simone Frenzel1

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

The Global Heat Flow Database serves as a valuable resource for researchers studying Earth's thermal regime. However, accessing and analyzing this vast collection of geothermal data is presently challenging and limits its widespread utilization. To address this, we present a new online application to the international heat flow community, facilitating seamless discovery, access and analysis of the data. Developed within the DFG-funded World Heat Flow Database Project, it complements the evaluation of existing data and development of a new, collaborative metadata schema for heat flow data.

Our application offers an intuitive interface, allowing researchers to efficiently search, retrieve, and visualize heat flow measurements worldwide. It supports advanced search functionalities that enable users to filter data based on geographical locations, geological parameters, measurement techniques, etc. Integration of powerful data visualization tools allow users to generate maps, plots, and graphs for visual exploration and interpretation. Furthermore, the application incorporates domain relevant statistical analysis functionalities, empowering researchers to perform trend analyses and other statistical assessments directly within the platform.

Our application also aims to foster collaboration within the international heat flow community. We incorporate features such as user profiles, discussion forums, and the ability to contribute new data or review existing records. Overall, we hope to bridge the gap between heat flow specialists and valuable geothermal data by providing an innovative and inclusive platform. We believe this tool will significantly enhance scientific investigations into the Earth's thermal regime and serve as a catalyst for further breakthroughs in the understanding of geothermal processes.

9:30am - 9:45am
Topics: 4.02 Within and Beyond - Research infrastructures that strengthen Open Science Practices in Geosciences

Seafloor geology and the European EMODnet data infrastructure: The challenge of integrating off-shore data across EEZ boundaries

Kristine Eva Charlotte Asch

Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Germany

Within the EMODnet Geology project BGR is leading the Workpackage Seafloor geology with the aim to compile and harmonise data of the pre-Quaternary and Quaternary off-shore geology and geomorphology of the European Seas, and finally publish the results according to FAIR data principles. The data are assembled from 36 EMODnet Geology partner organisations and derived mostly from geophysical surveys (e.g. echo soundings) and sampling (e.g. drilling or dredging). Major challenges pose the heterogeneity of the provided data regarding terminology, geometry, level of detail, age of datasets and technical conditions:

  • terminology. The participating partners use their own national or regional classification systems and description;
  • geometry: artificial discrepancies at EEZ-boundaries;
  • scale: some regions are investigated in comparatively high detail while others are mapped in overview scales;
  • age: often recently mapped units need to be integrated with data resulting from earlier mapping campaigns;
  • heterogeneous technical conditions within partner organisations.

In order to ensure data interoperability and create the maps layers in a largely harmonized, unified manner, the project requires common standards e.g.

  • controlled vocabularies, optimally based on existing standards such as INSPIRE or CGI-GeoSciML terminology,
  • a straightforward data model and
  • a pragmatic approach that takes into account the realities of the project partners.

This presentation will demonstrate the methodological approach to collate and combine data, information and knowledge from over 30 international partners and the challenge to develop, integrate and publish largely harmonized map layers of the off-shore geology of Europe and beyond.

9:45am - 10:00am
Topics: 4.02 Within and Beyond - Research infrastructures that strengthen Open Science Practices in Geosciences

Description of scientific metadata at the Federal Waterways Engineering and Research Institute (BAW)

Vikram Notay

Federal Waterways Engineering and Research Institute (BAW), Germany

The Federal Waterways Engineering and Research Institute acts as a consultant for and supports the Federal Ministry of Digital and Transport (BMDV) and the Federal Waterways and Shipping Administration (WSV) in navigation-related water engineering tasks. It creates and uses large volumes of scientific data like digital elevation models, simulation results, monitoring data, etc. as part of these activities. The description of this data with metadata is an essential prerequisite for its long-term storage, publication, retrieval and reuse. The requirements for metadata management were implemented with the INGRID software. INGRID offers various interfaces for capturing and processing metadata. It behaves format-agnostic, so different metadata formats can be processed.

The requirements for metadata processing at BAW are quite extensive and differ from the possibilities of usual geodata portals. As a result, custom fields and data classes have been defined in the metadata model. The ISO19139 metadata is used for transferring metadata to external geodata portals. A DOI data record can be generated from the metadata, which can in perspective also be registered automatically at To ensure the description of simulation results with metadata, the delivery of metadata together with data is firmly established in the workflows for data archival and publication.

The presentation describes the requirements for metadata processing, the basic structure of the application, and discusses the life cycle of metadata.

10:00amAusstellung Geoparke
Location: Wiwi 102
10:00am - 10:30amCoffee Break
Location: Foyer (Henry Ford Building)
10:30am - 12:00pmPlenary Discussion: Wie trifft uns die Klimakrise?
Location: Audimax
Session Chair: Anne Bernhardt, FU Berlin
Die Auswirkungen des Klimawandels sind allgegenwärtig: Gletscherschwund, Meeresspiegelanstieg, häufigere tropische Wirbelstürme, Überschwemmungen, aber auch Dürren und immer höhere Hitzerekorde. Damit verbunden sind massive Folgen für Gesellschaft und Wirtschaft, überall auf der Welt. In dieser Diskussionsrunde sprechen Wissenschaftler*innen und Aktivist*innen über die größten Herausforderungen, vor die uns die Klimakrise stellt. Wie unterscheiden sich kurzfristige und langfristige Folgen? Welche potenziellen Lösungswege müssen wir nun einschlagen und welche Chancen bringen diese für unsere Gesellschaft mit?
12:00pm - 1:30pmLunch Break | Exhibition
Location: Foyer (Henry Ford Building)
12:00pm - 1:30pmFS Sedimentologie Treffen
Location: Konferenzraum II HFB
Session Chair: Thomas Mann, Bundesanstalt für Geowissenschaften und Rohstoffe (BGR)
1:30pm - 2:00pmOpening Ceremony
Location: Audimax
Session Chair: Esther Martina Schwarzenbach, University of Fribourg
Session Chair: Dirk Scherler, GFZ Potsdam / Freie Universität Berlin
Introduction and opening by the organising committee of GeoBerlin2023, followed by opening speeched by
Prof. Günter Ziegler, FU President
Prof. Martin Meschede, President DGGV
Prof. Ralph Watzel, President BGR
2:00pm - 3:00pmPlenary Lecture by Isabel Montanez "Advances in reconstructing paleo-CO2 and ecosystem-climate-CO2 feedbacks through time"
Location: Audimax
Session Chair: Esther Martina Schwarzenbach, University of Fribourg
Topics: Plenary Talk

Advances in reconstructing paleo-CO2 and ecosystem-climate-CO2 feedbacks through time

Isabel Moñtanez

University of California, Davis, United States of America

Paleo-CO2 reconstructions are integral to understanding the evolution of Earth system processes and their interactions given that atmospheric CO2 concentrations are intrinsically linked to planetary function. Furthermore, past periods of major climate change provide unique insights into the response of land-atmosphere-ocean interactions to warming induced climate change, in particular for times of pCO2 comparable to those projected for our future. How well the past can inform the future, however, depends on how well paleo-CO2 estimates are constrained. In this talk, I will first discuss approaches to reconstructing paleo-CO2 concentrations, the challenges of constraining the uncertainty of these estimates, and the implications for constraining critical issues such as climate sensitivity. I will introduce a new community initiative, CO2PIP, focused on advancing the reconstruction of paleo-CO2 through modernizing of existing records and quantifying the representation of CO2 proxy sensitivities to environmental and ecophysiological conditions and processes that govern the CO2 signals. I will then focus on a deep-time glaciated period (the late Paleozoic Ice Age), characterized by pCO2 fluctuations within the range of Quaternary levels to those projected by socio-economic emission scenarios of this century, as well as defined by CO2-driven abrupt warmings that led to major changes in environmental conditions in the oceans and on land. An integrated multi-proxy data-modeling approach to investigating this deep-time icehouse provides a framework to evaluate the mechanistic linkages between processes and to conceptualize the collective data set. It further reveals the underlying processes linking pCO2 and environmental changes and documents the sensitivity of Earth System modeled atmospheric and oceanic circulation to changing pCO2. Application of paleo-CO2 and fossil plant morphologic and biogeochemical data to process-based ecosystem modeling documents physiological responses to CO2 and suggests ecosystem-scale vegetation-climate-CO2 feedbacks that would have influenced water cycling, surface runoff and weatherability, and led to major changes in organic carbon burial, and in turn atmospheric pCO2.

3:00pm - 3:30pmCoffee Break
Location: Foyer (Henry Ford Building)
3:30pm - 4:30pm30-Geotope³-Projektes
Location: Wiwi 103
Erlebniswelt Geoparks & Geotope
Präsentation spannender und beeindruckender geologischer Orte in Deutschland in einer Gemeinschaftsausstellung der Arbeitsgemeinschaft der Geoparks in Deutschland (AdG) und des Projektes 30 Geotope3 der DGGV. Gezeigt werden ganz unterschiedliche Methoden geologischer Erlebniswirkung: moderne fotorealistisch-dreidimensionale Geländeaufnahmen am Beispiel von 30 geologischen Objekten, geotouristische Angebote und Projekte der Geoparks, Ansätze für spielerisch-digitale Geotopwelten, Geoparks als außerschulische Lernorte mit BNE-Schwerpunkt sowie erdgeschichtliche Erlebniswelten im Film oder Podcast.
3:30pm - 5:00pm3.03-2 Advances in paleoclimate proxy development and application
Location: Hall A (HFB)
Session Chair: Amelia Jane Davies, Goethe University Frankfurt
Session Chair: David Bajnai, University of Göttingen
3:30pm - 4:00pm
Invited Session Keynote
Topics: 3.03 Advances in paleoclimate proxy development and application

Continental or oceanic weathering processes – What controlled the Late Cretaceous lithium cycle?

Sandra J. Huber1,2, Vanessa Schlidt1,2, Jorit F. Kniest1,2, H.-Michael Seitz1,2, Jacek Raddatz1,2, Horst R. Marschall1,2, Silke Voigt1,2

1Institute of Geosciences, Goethe University Frankfurt, Altenhöferallee 1, 60438 Frankfurt am Main, Germany; 2Frankfurt Isotope and Element Research Center (FIERCE), Goethe University Frankfurt, 60438 Frankfurt am Main, Germany

The lithium isotopic composition (δ7Li) of marine carbonates is known as a proxy for the chemical weathering intensity of silicate rocks. To evaluate the role of weathering as a sink for atmospheric CO2 during the Late Cretaceous, we generated a 20 Ma δ7Li record (86.3–66.0 Ma) using chalk from Northern Germany as an archive. The late Santonian to Maastrichtian record shows an overall increase of ~4.5‰ with superimposed increases in the late Santonian, early Campanian and across the Campanian–Maastrichtian transition.

The overall increase in δ7Li fits with the Late Cretaceous increase in seawater 87Sr/86Sr. Further, the δ7Li record strongly resembles both the evolution of deep-sea temperatures based on benthic oxygen isotopes and modeled changes in the rate of seafloor spreading. Thereby, increases of δ7Li in the early Campanian and across the Campanian–Maastrichtian transition correspond to major sea level falls, and the latter with a negative δ13C excursion.

These coherences allow three interpretative approaches: (1) Climate cooling controlled the weathering congruency and the magnitude of Li isotope fractionation by clay mineral formation on the continents. (2) Lowland exposure promoted erosion together with enhanced soil and clay formation after sea level falls. (3) A temperature-dependent fractionation during low-temperature basalt alteration affected the seawater δ7Li signal in a time, when more fresh oceanic basalts where available due to higher spreading rates. The best possible interpretation for the Late Cretaceous δ7Li record and the often-neglected aspects of basalt alteration and reverse weathering need to be further assessed and discussed.

4:00pm - 4:15pm
Topics: 3.03 Advances in paleoclimate proxy development and application

Lithium isotope compositions of various biogenic carbonates throughout the mid-Cretaceous – Challenges of reconstructing δ7LiSW in deep time

Vanessa Schlidt1,2, Sandra Janina Huber1,2, René Hoffmann3, Ulrich Heimhofer4, Elisabetta Erba5, Cinzia Bottini5, Stefan Huck4, Hans-Michael Seitz1,2, Silke Voigt1,2

1Goethe University Frankfurt, Institute for Geosciences, Altenhöferallee 1, 60438 Frankfurt (Germany); 2FIERCE - Frankfurt Isotope & Element Research Center, Altenhöferallee 1, 60438 Frankfurt, Germany; 3Ruhr-Universität Bochum, Institute for Geology, Mineralogy and Geophysics, Universitätsstraße 150, 44801 Bochum (Germany); 4Leibniz University Hannover, Institute of Geology, Callinstraße 30, 30167 Hannover (Germany); 5Università degli Studi di Milano, Dipartimento di Scienze della Terra Ardito Desio, Via Mangiagalli 34, 0039 02 Milan (Italy)

The evolution of the seawater Lithium isotope composition (δ7LiSW) depends on the prevalent weathering regime. To reconstruct δ7LiSW, and thus, weathering congruency, two main archives are widely used: calcareous fossils and bulk carbonate sediments. Either of these archives has its strong and weak points. While carbonate sediments are prone to diagenesis and clay contamination, biogenic skeletons may exhibit strong vital effects on δ7LiSW. Here, we present δ7LiSW data for the mid-Cretaceous derived from various biogenic carbonates such as bivalves (mainly rudists), cephalopods, and brachiopods from well-known sample sites across Europe.

Additionally, we assessed the extent of taxon-specific vital effects on δ7Li for well-preserved Albian molluscs from Madagascar (Mahajanga Basin, age 110.5 +/-0.5Ma) and compared them with data for modern taxonomic groups.

Our most complete data set derives from rudist shells (mainly requieniid rudists) from the mid-Barremian to early Aptian sample locations of Sausset (Urgonian Limestone Formation, France), Ericeira (Crismina Formation, Portugal), Kanfanar (Kanfanar unit, Croatia), and Miravete (Villarova de los Pinares Formation, Spain). We compare their δ7Li compositions and trends therein with that of cotemporaneous carbonate-rich sediments. We provide preliminary δ7LiSW for several time intervals which range between 22-25‰ on average with values exceeding 30‰ in the late Barremian.

Relative to published bulk carbonate data, we observe a systematic offset for rudist-shell δ7Li values of 3-8‰ towards heavier values. We assign this offset to vital effects similar to those known for modern calcitic molluscs.

4:15pm - 4:30pm
Topics: 3.03 Advances in paleoclimate proxy development and application

Temporal and spatial distribution of modern ostracod species of Lago Enriquillo (SW Dominican Republic)

Christopher Berndt1, Torsten Haberzettl1, Lilly Biedermann1, Michael Ernst Böttcher1,2,3, Berenice Matias Marte de Reyes4, Edwin Garcia Cocco4, Claudia Wrozyna1

1University Greifswald, Germany; 2Geochemistry & Isotope Biogeochemistry, Leibniz IOW, Germany; 3Interdisciplinary Faculty, University of Rostock, Germany,; 4Servicio Geológico Nacional, Santo Domingo, Dominican Republic

Understanding modern species´ ecological preferences and distribution are prerequisites for their application as proxies in paleoenvironmental reconstructions. This knowledge is, however, missing for the majority of tropical species. In order to contribute to close this gap we characterize the ostracod fauna of Lago Enriquillo in the Dominican Republic. Located in the Main Development Region of North Atlantic tropical storms it has experienced rapid water level fluctuations in the past that are assumed to be related to storm activities. This highlights the relevance of the lake for reconstructions of changes in precipitation and storm activity. Living ostracods inhabiting Lago Enriquillo were analyzed in March and September (dry and rainy season) 2022 with the aim to understand their temporal and spatial distribution and changes in morphological characteristics (valve size). Lago Enriquillo is a warm (27.8-33.8°C), mesohaline (43.7-46.3 psu) and generally slightly alkaline lake (pH: 7.5-8.1) with a max. water depth of 25 m. The spatially variable ostracod fauna is composed of Cyprideis similis, Perissocytheridea cribrosa and Thalassocypria sarbui. The three species reflect the lake’s seasonality differently in terms of their morphology and population structure. C. similis occurred continuously but is smaller in spring than in autumn. P. cribrosa inhabits the lake only in autumn and shows a distinct distribution dominating littoral areas with seasonal freshwater inflow. T. sarbui forms larger populations only in spring and forms only tentative size clusters. Their occurrence is restricted to water depths above (temporary) minima of oxygen (below 10 – 14 m).

4:30pm - 4:45pm
Topics: 3.03 Advances in paleoclimate proxy development and application

High resolution study of Glycymeris sp. shells from high energy event layers of the Cadiz Bay – a sclerochronological record for the onset of the Dark Ages Period

Alexandra Németh

Research Centre for Astronomy and Earth Sciences, Budapest, Hungary

Driving factors of shell growth of sub-fossil Glycymeris nummaria shells deposited by high energy events into layers at the Atlantic coast of the Iberian Peninsula were investigated by stable isotope analysis and analysing their growth patterns.

High energy events deposited layers of cockles along the coast of Cádiz Bay during the Roman Period (313 ± 114 AD) and the Dark Ages (648 ± 108 AD) (Gutiérrez-Mas, 2011). The climate fluctuation of the region between these two periods was largely investigated by analysing sediment cores from the pro-deltas on the Iberian margin (e.g. Bartels-Jónsdóttir et al., 2015), Glycymeris shells, however can provide seasonal data of temperature change and the seasonality in chemical characteristics of the marine ecosystems. Comparing the paleotemperature data reconstructed from oxygen isotope ratios of seasonally sampled shell carbonate indicates no significant cooling for the ‘Dark Ages Cold Period’ (DACP) for the Cádiz Bay. The seasonality of carbon isotope ratios however showed distinct changes between the Roman Period and the DACP. Seasonal maxima of δ13C values were twice as higher during the DACP which indicates seasonally intensified biological fractionation connected to enhanced primary productivity. This agrees with other studies implying intensified coastal upwelling during the DACP along the Iberian Peninsula, while they observe no significant cooling of the sea surface (Bartels-Jónsdottir et al. 2015). This case study adds to the growing number of evidence that the DACP can not be interpreted as a Europe-wide cooling event as it affected southern regions differently.

4:45pm - 5:00pm
Topics: 3.03 Advances in paleoclimate proxy development and application

Triple oxygen isotope measurements of air CO2 around Göttingen

David Bajnai, Tammo Freese, Andreas Pack

University of Göttingen, Germany

The triple oxygen isotope composition (δ18O and ∆’17O) of atmospheric CO2 provides valuable information about CO2 sources and carbon exchange fluxes between atmospheric reservoirs [1-2]. For example, stratospheric CO2 has a large positive 17O-anomaly due to photochemical processes. The ∆’17O of tropospheric CO2 is primarily influenced by carbonic anhydrase-catalyzed oxygen isotope exchange between air CO2 and water in vegetation, resulting in an air CO2 ∆’17O mainly governed by the isotope composition of local meteoric water. Additionally, CO2 from fossil fuel combustion processes shows a negative 17O-anomaly inherited from the isotope composition of atmospheric O2 [3].

Starting in April 2023, we conducted automated triple oxygen isotope measurements of air CO2 in Göttingen using tunable infrared laser direct absorption spectroscopy (TILDAS; Aerodyne, USA) coupled with a custom-built inlet system. The internal error of the ∆’17O measurements was < 10 ppm and of the δ18Omeasurements < 0.01‰.

In this report, we present our initial results and discuss the contribution of various reservoirs to the ∆’17O of atmospheric CO2 in Göttingen. We also examine daily and seasonal variations observed in our data.

[1] G. Koren et al., J. Geophys. Res. Atmos. 124, 8808–8836 (2019).

[2] M. E. G. Hofmann et al., Geochim. Cosmochim. Acta. 199, 143–163 (2017).

[3] B. Horváth, M. E. G. Hofmann, A. Pack, Geochim. Cosmochim. Acta. 95, 160–168 (2012).

3:30pm - 5:00pm3.20-2 Metamorphism and Deformation across scales
Location: Hall B (HFB)
Session Chair: Vasiliki Mouslopoulou, National Observatory of Athens
Session Chair: Marcel Thielmann, Universität Bayreuth
Session Chair: Gareth James Crutchley, GEOMAR Helmholtz Centre for Ocean Research Kiel
3:30pm - 4:00pm
Invited Session Keynote
Topics: 3.20 Multiscale Investigations of Convergent Margins: Unraveling Subduction Dynamics from Kinematic Transitions to Metamorphic Reactions

Subduction and collisional orogenesis: comparison of model predictions and observations with application to the Alpine orogeny and Tibetan plateau

Stefan Markus Schmalholz

University of Lausanne, Switzerland

The Alps are one of the best studied orogens, but arguably also one of the most disputed ones. Several major geodynamic processes remain unclear, such as the mechanism of (U)HP rock exhumation, for example exhumation during plate divergence or syn-convergent exhumation, or the mechanism of subduction initiation, for example vertically forced initiation by gravitational sinking or horizontally forced initiation due to plate convergence. The Tibetan plateau is currently the highest continental plateau and its first-order geometry is well constrained. Spatial variations in topography and crustal thickness can be used to estimate horizontal forces per unit length from spatial variations in gravitational potential energy per unit area. Knowledge of forces and stresses is essential to understand geodynamic processes. However, maximal magnitudes of differential stresses occuring locally within the crust remain disputed and range from ca. 10 MPa to several hundreds of MPa. Deterministic mathematical modelling based on the fundamental laws of physics is one method to test different geodynamic hypotheses and quantify potential stress magnitudes. Here, we employ 2D petrological-thermo-mechanical numerical simulations to the Alpine orogeny to test the two hypotheses of horizontally forced subduction initiation and syn-convergent exhumation with a single simulation and with petrological and geochronological data. We use 3D mechanical numerical calculations for the Tibetan plateau, to quantify the impact of (i) a realistic double curvature of the Earth’s crust, (ii) the effective viscosity of the crust, (iii) the stress exponent of a power-law flow law and (iv) the plateau’s corner regions on the 3D crustal stress field.

4:00pm - 4:15pm
Topics: 3.20 Multiscale Investigations of Convergent Margins: Unraveling Subduction Dynamics from Kinematic Transitions to Metamorphic Reactions

Rocks under stress: How dramatic the effect of stress on metamorphic reactions really is?

Lucie Tajcmanova

Heidelberg university, Germany

Recent decades have been connected with an impressively accelerating pace in the development and availability of new analytical techniques to earth scientists. Interestingly, the smaller the scale considered, the more heterogeneous an apparently uniform rock sample is. This heterogeneity is not only characterized by variation in chemical composition but also in mechanical properties. The mechanical effects may influence element transport and mineral assemblage in rocks which can, in turn, significantly control the mechanical-chemical coupling rates and mechanisms of various processes in the Earth’s interior.

Considering the interplay of metamorphic reaction and mechanical properties in our quantification approaches is critical for correct interpretation of observations in metamorphic rocks. In my contribution, I will show major applications of the new quantification approaches, the accompanying obstacles and the consequences for our petrological interpretations. New findings from coupled experimental and numerical studies emphasize the necessity of quantifying the stress/pressure distribution before any complex thermodynamic interpretations. In fact, any thermodynamic interpretation of a stressed system must take into account the locally-resolved state of stress during sample deformation.

4:15pm - 4:30pm
Topics: 3.20 Multiscale Investigations of Convergent Margins: Unraveling Subduction Dynamics from Kinematic Transitions to Metamorphic Reactions

Combining Observations and Reactive Flow Modeling to Investigate Lower Crustal Hydration - Insights from the Hustad Igneous Complex, Western Norway

Jasper M. Engelmann, Johannes C. Vrijmoed, Timm John

Freie Universitaet Berlin, Germany

The grain-scale mechanisms of hydration of mafic lower crustal rocks are investigated on chemical maps of continuous rock sections (20 x 2 cm) of partially amphibolitized samples from the Hustad Igneous Complex in the Western Gneiss Region, Norway. The Proterozoic pyroxenite body and crosscutting dolerite dike enclosed in felsic gneiss that underwent (U)-HP metamorphism show different responses to the exposure to hydrous fluids along fractures formed during late Caledonian extension and exhumation. While the dolerite reaches full amphibolitization in a cm-scale reaction halo with a dm-scale transition zone, the pyroxenite has experienced previous metamorphism and is less affected by this event. Dissolution-precipitation reactions and slightly faster grain boundary assisted flow are identified as the main mechanisms of fluid flow through the rock. Limited element mobility is documented by grain-scale compositional gradients in forming amphibole from magnesiohornblende (Si6.8, Al1.6, Mg3.0) to tschermakite (Si6.4, Al2.0, Mg2.6) at boundaries with plagioclase. Phase diagram calculations yield a P/T-window between 650 – 730°C and 0.4 – 0.6 GPa for amphibolite formation. To better understand the mechanism of hydration, a numerical model of Darcy flow coupled to amphibolitization reactions was formulated based on mass conservation and local equilibrium. The simulations suggest the observed difference in front propagation distance is controlled by the main lithologies. A simple 2D model is employed to demonstrate that the gradual transition from dolerite to amphibolite can be achieved by implementing higher permeability along grain boundaries, supported by the observation that flow along boundaries continues before individual grains are fully replaced.

4:30pm - 4:45pm
Topics: 3.20 Multiscale Investigations of Convergent Margins: Unraveling Subduction Dynamics from Kinematic Transitions to Metamorphic Reactions

Monazite and zircon petrochronology of granulites and migmatites as remnants of a magmatic arc on the West Gondwana margin (Socorro Nappe, south-eastern Brazil)

Mikaella Balis1, Bernhard Schulz1, Mario da Costa Campos Neto2

1TU Bergakademie Freiberg, Germany; 2University of São Paulo, Brazil

In the Southern Brasília Orogen (south-eastern Brazil), a nappe system that represents the roots of a magmatic arc records HT-UHT metamorphic conditions in lower to mid-crustal rocks. It is divided into two segments by a major shear zone, of which the northern nappe hosts the most extreme metamorphism and has been targeted for most petrochronological studies. These rocks carry insights into the stages of orogeny, as well as the first direct evidence of the paleo-active margin basement, and time-constraint (1) a metamorphism related to the magmatic arc consolidation on the active margin at 670-640 Ma and (2) an enduring UHT event related to collision and decompression at 630-590 Ma. The southern nappe (Socorro Nappe) hosts felsic and mafic granulites, and migmatites that apparently describe a less extreme pressure-temperature setting and relatively younger ages. We found distinctive patterns pertaining the inner nappe and its outward boundaries (Embu Terrane and São Roque Domain). We present new U-Th-PbC monazite data and LA-ICPMS U-Pb and Lu-Hf systematics in zircon retrieved from granulites, migmatites and paragneisses, and partial results on conventional thermobarometry and thermodynamic modelling. Our data plot within the P-T range of upper amphibolite to granulite facies and describe mostly post-peak retrograde clockwise trajectories, with lesser conditions at the nappe boundaries. Temperature, textural context and anatexis are major controls on the preservation of monazite versus zircon records. The outer nappe tends to host prominent 750 Ma-old monazite, whereas in the inner nappe such ages are scarce and most prevalent in the zircon records.

3:30pm - 5:00pm1.12 Innovative concepts and sustainability with hydrogen: ...
Location: Hall C (HFB)
Session Chair: Chaojie Cheng, Karlsruhe Institute of Technology
Session Chair: Marcel Schulz, Karlsruhe Institute of Technology
Session Chair: Christoph Hilgers, Karlsruhe Institut Für Technologie - Kit
3:30pm - 4:00pm
Invited Session Keynote
Topics: 1.12 Innovative concepts and sustainability with hydrogen: from underground hydrogen storage to business concepts

Geological storage of Hydrogen for Net Zero

Katriona Edlmann, Ali Hassanpouryouzband, Tim Armitage, Eike Thaysen, Niklas Heinemann

The University of Edinburgh, United Kingdom

To meet the global commitments for net zero carbon emissions our energy mix must transition from fossil fuels. Hydrogen is gaining increasing recognition as a low carbon energy option to support this energy transition. Hydrogen is considered a low-carbon substitute for fossil fuels to decarbonise domestic and industrial heat, power generation and heavy-duty transport. It can also promote increased renewable energy uptake by acting as an energy store to balance supply and demand.

For hydrogen to be deployed at the scales required for net zero, we will need access to large-scale geological storage. This talk will present an overview of the most recent findings from research working to establish the feasibility of storing hydrogen in underground porous reservoirs. The talk will cover the results of research into the key biological and chemical reactions between the reservoir rocks, formation fluids and injected hydrogen that could compromise the storage complex and the key flow processes that influence hydrogen migration and trapping during injection and withdrawal. It will also consider the role of hydrogen storage within an integrated energy system.

4:00pm - 4:15pm
Topics: 1.12 Innovative concepts and sustainability with hydrogen: from underground hydrogen storage to business concepts

Subsidence monitoring above the gas storage cavern field Epe (North Rhine-Westphalia) with Interferometric SAR displacement time series

Alison Seidel, Malte Westerhaus, Markus Even, Hansjörg Kutterer

Karlsruher Institut für Technologie (KIT), Germany

The first Hydrogen storage caverns of Germany are planned to be constructed at the salt cavern field Epe in NRW, where 114 caverns, of which more than 50 are currently used for natural gas storage, are located. Since gas filled caverns experience convergence over time and thus cause subsidence at the surface, it is important to have a monitoring concept with high spatial and temporal resolution, to predict future subsidence and potential damage to infrastructure, but also to detect unexpected subsidence quickly and assist in identifying the cause.

Epe displays a complex surface deformation field, consisting of cavern convergence caused linear trends, as well as precipitation dependent seasonal and cavern pressure dependent contributions as shown in previous studies of the area.

As part of the SAMUH2-Project, funded by the German Federal Ministry of Economics and Climate Protection, we are working on a monitoring concept to incorporate the already established methods of yearly levelling and GNSS measurements into our approach of using Interferometric SAR (InSAR) time series, which provide not only high spatial, but also good temporal resolution. Here, we use Sentinel-1 SAR data from 2015 to 2022, and process time series by using a joint approach of persistent scatterer (PS) and distributed scatterer (DS) techniques.

Our results show good agreement of the InSAR time series with other geodetic measuring methods. We can distinguish the signals of the different source mechanisms well and can even model varying cavern convergence rates, depending on the extent of the yearly cavern depletion and filling.

4:15pm - 4:30pm
Topics: 1.12 Innovative concepts and sustainability with hydrogen: from underground hydrogen storage to business concepts

Hydrogen storage in depleted gas fields – THM modelling strategy and preliminary case study results

Sonu Roy, Daniel von Reinicke Laredo, Andreas Henk

Technische Universität Darmstadt, Germany

In the current global race towards achieving self-sufficiency and sustainability in meeting energy demands with net-zero emissions, hydrogen has emerged as a promising solution. However, hydrogen's volumetric energy density is lower compared to conventional energy sources, and the storage conditions (pressure and temperature) for hydrogen on the surface are expensive and technically challenging.

To overcome the challenge of large-scale hydrogen storage, researchers around the world have proposed storing hydrogen in subsurface geological structures, such as salt caverns and porous reservoir rocks. While hydrogen storage in salt caverns is a more advanced concept, storing hydrogen in porous rocks such as depleted reservoirs and aquifers requires further research attention. This paper outlines a preliminary workflow for a feasibility study on the use of depleted gas reservoirs for hydrogen storage. Two different fields in Germany are used as examples to illustrate the process. One of the case study fields is still producing from the carbonates of the Zechstein Group, while the other is a decommissioned field that previously produced from unconsolidated Neogene sands. The workflow involves creating a static geological model and populating it with petrophysical parameters, followed by dynamic flow simulation for history matching. Hydrodynamical parameters for hydrogen are then introduced to simulate hypothetical storage cycles. A geomechanical model is then created incorporating the pore pressure data and material properties, to assess storage integrity, fault activity, and surface deflection in response to hydrogen filling. Overall, this workflow provides a comprehensive approach to evaluate the potential for hydrogen storage in depleted reservoirs.

4:30pm - 4:45pm
Topics: 1.12 Innovative concepts and sustainability with hydrogen: from underground hydrogen storage to business concepts

Hydrogen storage in geological systems – potential for biological methanation

Hilke Würdemann1, Christoph Otten1, Anja Striegel1, Vladislava Schulz1, Gion Strobel2

1Hochschule Merseburg, Germany; 2Uniper Energy, Germany

In the frame of the SAMUH2 project water samples were taken at a geological pore gas storage. In the course of the abandonment of a natural gas storage, deep fluids could be recovered from a depth of 500 - 600 meters. A total of eight boreholes were sampled from injection and observation wells. The focus of the investigations was on the analysis of the chemical composition of the fluids as well as the characterization of the microbial biocoenosis and partly also their metabolic activity.

Organic acids were detected in varying concentrations and compositions in both the fluid samples taken at the injection and observation wells. Organic acid concentrations ranged from 0.1 to 730 mg/L. Gen copies of Bacteria, sulfate reducers (SRB) and methanogenic archaea were detected in all fluids by qPCR. A detailed characterization of the microbial community was carried out by microbiome analysis. A diverse microbial community was detected on fermenters and methanogenic archea. Sulfate reducers, on the other hand, were identified predominantly in the observation wells.

Several laboratory experiments demonstrated that the fluids of injection wells contained an active biocenosis capable of hydrogenotrophic methanogenesis. In contrast, only one observation well fluid demonstrated the activity of hydrogenotrophic methanogenic archaea. The capability of underground storage facilities for producing eco- ("green") methane is a further topic of this study.

4:45pm - 5:00pm
Topics: 1.12 Innovative concepts and sustainability with hydrogen: from underground hydrogen storage to business concepts

Pore-scale study of cyclic injection and microbial activity on H2 recovery and loss mechanisms during underground H2 storage

Na LIU1, Maksim Lysyy1, Nicole Dopffel2, Martin Fernø1,2

1Department of Physics and Technology, University of Bergen, Bergen, Norway; 2Energy & Technology, NORCE Norwegian Research Centre AS, Bergen, Norway

Underground H2 storage (UHS) in salt caverns, deep saline formations, and depleted oil/gas reservoirs has emerged as a reliable and safe technology for storing renewable energy and reducing carbon dioxide emissions. H2 gas, however, is one of the most important electron donors for many subsurface microorganisms. During the multiple cycles of H2 injection and withdrawal operations, a certain amount of H2 is permanently lost due to various physical, chemical, and biological mechanisms. Although research in UHS in porous media is evolving, our understanding of the impacts of cyclic loading and microbial activity on H2 recovery and loss mechanisms remains inadequate.

In this study, we present recent findings from a quantitative investigation of H2 reconnection and recovery mechanisms in repeated injection-withdrawal cycles using a microfluidic pore network simulating shallow reservoir storage conditions (30 barg). Our results reveal that H2 storage capacities increase with higher injection rates, ranging between approximately 10% and 60%. Additionally, we observed the growth of a typical halophilic sulfate-reducing bacterium in the hydrogen-saturated pore network for 9 days. Significant H2 loss occurred due to microbial consumption within 2 days following injection into the microfluidic device. These results may have significant implications for hydrogen recovery and gas injectivity. Microvisual experiments provide critical observations of bubble-liquid interfacial area and reaction rate that are essential to the modeling that is needed to make long-term predictions. Our results contribute to improving the selection criteria for future storage sites, ensuring optimized and efficient H2 storage and utilization.

3:30pm - 5:00pm1.28 From research to impact on people – how can geosciences be applied in development cooperation?
Location: Hall D (HFB)
Session Chair: Manuel Hublitz, BGR
3:45pm - 4:00pm
Topics: 1.28 From research to impact on people – how can geosciences be applied in development cooperation?

A Collaborative Approach to Sustainable Mining Governance in the Andes: Insights from BGR's MinSus Project

Achim Constantin, Jacob Mai

BGR, Germany

The Andean region possess a wealth of mineral resources, such as copper and lithium, which are increasingly in demand by various industries and sectors, including renewable energy, electronics, and transportation. The mining industry has the potential to contribute significantly to its growth and social development, desirably in line with the Sustainable Development Goals (SDGs) of the UN Agenda 2030. At the same time, the sector also creates complex socio-economic and environmental challenges in the region.
In this context, the German Federal Ministry for Economic Cooperation and Development (BMZ) has commissioned the Federal Institute for Geoscience and Natural Resources (BGR) to carry out the MinSus project in cooperation with its regional counterpart, the United Nations Economic Commission for Latin America and the Caribbean (ECLAC).
The presentation will showcase how the MinSus project has promoted responsible and sustainable mining in the Andean countries over the past seven years, highlighting how the project has worked through building capacity for sustainable mining practices, improving governance frameworks, and fostering partnerships between stakeholders.
The presentation will also feature examples of dealing with abandoned mining sites. It will be illustrated how the investigation of these sites with regard to environmental and health hazards can be carried out, as well as how the potential for tailings reprocessing can be determined (“secondary mining”), demonstrating concrete approaches and applied geoscientific methodologies to managing mining legacies in a responsible and sustainable way.

4:00pm - 4:15pm
Topics: 1.28 From research to impact on people – how can geosciences be applied in development cooperation?

Well measured environmental interventions

Franziska Wende, Tim Gottschlag

Physikalisch-Technische Bundesanstalt (PTB), Germany

For 60 years, Germany’s National Metrology Institute Physikalisch-Technische Bundesanstalt (PTB) has been promoting the improvement of metrology systems and quality infrastructure within its partner countries in the Global South. Metrology and quality infrastructure are fundamental for the reliable measurement of all environmental parameters. Thus, geoscientific research heavily relies on them as a basis for comparable and accurate data.

Quality infrastructure includes metrology, standardization, testing, quality management, certification, and accreditation. PTB endeavours to strengthen all these components in its technical cooperation projects. For example, PTB works with its partner institutions in the Global South on the adaptation and development of environmental standards. These include, among others, standards concerning soil and water quality. Furthermore, PTB supports the process of accreditation of analytical test laboratories to increase credibility of environmental data on water, air, and soil.
All environmental data relies on the conformity of units. Accredited laboratories need to proof the traceability of their measurements up to the highest metrological authorities. PTB therefore strengthens National Metrology Institutes in its partner countries with regards to environmental services.

In the presentation, the components of quality infrastructure and their importance for geosciences will be introduced. Highlights from PTB projects in India and Guatemala will showcase success stories of improved quality infrastructure in the context of international cooperation for geoscientific applications.

4:15pm - 4:30pm
Topics: 1.28 From research to impact on people – how can geosciences be applied in development cooperation?

Chances and challenges of digitization in the mineral resources management in developing countries, examples from Mongolia

Thekla Abel1, Otgonbaatar Altanbasan2, Batbayar Jargalsaikhan2, Thomas Spehs3

1BGR, Germany; 2German-Mongolian Cooperation Project "Advisory Services for Sustainable Mineral Resources in Mongolia"; 3Spehs GbR

Mongolia is a sparsely populated, resource-rich country with a wide range of different mineral deposits and mining activities in size and quality of operation, distributed over a vast area of the territory. The wealth of mineral resources already being mined or developed for future exploitation, provide the country with a huge opportunity for its economic progress but also present challenges for a sustainable and effective state management of the mining sector.

Since the political change in Germany and Mongolia in the 1990s, the BGR (Federal Institute for Geosciences and Natural Resources) has carried out various projects within the framework of the German-Mongolian development cooperation, together with different Mongolian government institutions responsible for the mineral resources sector. To support a transparent and efficient governance of a responsible and sustainable mining sector, the BGR-projects focused mainly on capacity development and elaboration of professional information and data at the geology and mining authorities. In recent years, the focus has been increasingly on supporting digital transformation processes in connection with more efficient mining inspection and supervision works, digital mining cadastre, the digital management of geological maps, as well as enhancing the digital data exchange between institutions. These digital instruments support a more transparent and efficient state management of the mining sector and, during the Covid-pandemic, enabled the continuation of administrative processes (licensing, permits, reporting). Yet, the continuous need for further refinement and maintenance of these digital systems presents a challenge for human and financial capacities of state authorities in developing countries

4:30pm - 4:45pm
Topics: 1.28 From research to impact on people – how can geosciences be applied in development cooperation?


Elisa Gabriela Pineda Mejia1, Miguel Angel Garcia Wiliams1, Cindy Posas2


Honduras, located in Central America at the convergence of the North American tectonic plate with the Caribbean plate in the northwestern part and the Cocos plate with the Caribbean plate in the southern part, has geothermal potential not only related to power production but also for direct use application. A special strategic approach in the Central America is the geoscientific exploration of the over 1500 hot springs in the region. Only in Honduras, there are over 200 hot springs identified, from which over 40% have a superficial temperature of over 50°C and over 10% have temperatures of even more then 80°C.

This abstract presents the case of geochemical investigation in in Namasigüe and El Triunfo districts, located near the border to Nicaragua, in order to proceed in the identification of a deep geothermal reservoir but also identify the opportunity to delineate the potential of geothermal direct use for the community. Important elements of the geoscientific exploration in this socially conflictive area is the preparation of geoscientific information to raise awareness regarding the thermal waters among the local community but also to enhance the acceptance for the geothermal exploration taken out by the National Electric Power Company (ENEE).

The activities are part of Yacimientos II project, implemented by the Federal Institute for Geosciences and Natural Resources (BGR) from Germany and are supported by the National Secretary of Energy (SEN), who has an operative involvement with local communication concepts to prepare geoscientific findings for the community.

4:45pm - 5:00pm
Topics: 1.28 From research to impact on people – how can geosciences be applied in development cooperation?

Protection of a shallow karst aquifer in Zambia - Approach and challenges

Svenja Henrike Rau, Owen Micho, Douglas Lubaba, Pasca Mwila

Bundesanstalt für Geowissenschaften und Rohstoffe, Germany

BGR and the Zambian government jointly develop and protect the groundwater resources in the country’s capital Lusaka. As one of the fastest growing cities in southern Africa, Lusaka has been facing a sharp increase in the demand for water in recent years.

Sustainable abstraction of groundwater and the protection of the vulnerable karst aquifer supplying Lusaka are two key elements for future urban planning in the face of population growth, annual outbreaks of waterborne diseases and climate change. Geoscientific experts have to ensure that decisions are based on scientific results and technical recommendations and that the importance of protecting the natural resource is being communicated as a priority to the government, industries and society.

Potential new well fields were identified and one objective of the BGR project is the delineation of groundwater protection zones as a case study for Zambia. The development of statutory instruments to make groundwater protection an integral part of the Zambian law secures the resources for the future. The delineation of the zones is based on the approach from Botswana, as the various Western approaches cannot simply be transferred to southern Africa as soil structure, geology, climate and urban areas are often drastically different.

Protecting a karst aquifer with a thin soil cover is scientifically challenging. The population growth and limited urban planning structures combined with insufficient data increase the risk of groundwater contamination in Lusaka. A high level of cooperation between geoscientists, decision-makers, environmental regulators and the society is required to face the various challenges.

3:30pm - 5:00pm1.17-2 Marine mineral deposits: Formation, exploration, and environmental impacts of human activities
Location: Wiwi 101
Session Chair: Sebastian Fuchs, Bundesanstalt für Geowissenschaften und Rohstoffe
3:30pm - 3:45pm
Topics: 1.17 Marine mineral deposits: Formation, exploration, and environmental impacts of human activities

Passive sampling of labile dissolved trace metals in the deep sea: a suitable monitoring tool for marine mining activities?

Katja Schmidt1, Sophie Anna Luise Paul2

1BGR Federal Institute for Geosciences and Natural Resources, Stilleweg 2, 30655 Hannover, Germany; 2GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstrasse 1-3, 24148 Kiel, Germany

Analytical challenges such as low concentrations and a saline matrix, contamination risks during sampling and analysis, and the accessibility of remote ocean areas limit available methodologies for the investigation of trace elements in the open ocean and call for innovative, easy to use and robust investigation tools. Furthermore, the application of methodologies for the monitoring of e.g., deep-sea mining activities as part of environmental impact assessments will become of increasing importance for future marine research. We here evaluate an in situ passive sampling method using the technique of diffusive gradients in thin films (DGT), focussing on Mn, Cu, Ni, V, Cd, As, Sb, and rare earth elements and yttrium. Sampling was performed in bottom seawater above the BGR contract area for polymetallic nodule exploration in the Clarion Clipperton Zone in the NE Pacific. We present data from different passive sampling setups at depths between 0.3 m and 550 m above the seafloor accumulating trace metals for periods of 3 days up to 2 years, and discuss the effects of deployment time and the binding membrane type. Derived concentrations represent the labile fraction of the metals and hence that fraction that is (bio)available for an uptake through cell membranes. Results are compared to point sampling of seawater providing trace metal concentrations for different size fractions, which allows to constrain the degree of lability of dissolved trace metals. We further present results from the monitoring of a collector mining test of polymetallic nodules with respect to trace metal mobilization at the seafloor.

3:30pm - 5:00pm4.06 From Unoccupied Aerial Vehicles (UAVs) to Mixed-Reality Visualizations: Expanding Frontiers in Field Data Acquisition, 3D-Model-Design and Geo-Visualization
Location: Wiwi 104
Session Chair: Robert Jackisch, Technische Universität Berlin
Session Chair: Gerd Winterleitner, VFG-Lab GmbH
Session Chair: Anika Braun, Technische Universität Berlin
Session Chair: Felina Schütz, VFG-Lab
Session Chair: Christoph Grützner, FSU Jena
Session Chair: Gerold Zeilinger, University of Potsdam
3:30pm - 4:00pm
Invited Session Keynote
Topics: 4.06 From Unoccupied Aerial Vehicles (UAVs) to Mixed-Reality Visualizations: Expanding Frontiers in Field Data Acquisition, 3D-Model-Design and Geo-Visualization

Celebrating thirty years of virtual outcrops: status and perspectives

Simon J Buckley1, John A Howell2, Nicole Naumann1, Kari Ringdal1, Joris Vanbiervliet1, Conor Lewis1, Magda Chmielewska2

1Virtual Outcrop Geology Group, Bergen, Norway; 2University of Aberdeen, UK

Thirty years ago, scientists from the Technical University of Denmark and University of Bergen published 3D outcrop acquisition and processing methods for large-scale vertical cliff sections in Greenland (Dueholm & Olsen, 1993), thus laying out a pathway to today’s state-of-the-art in high resolution virtual outcrop modelling. Although the photogrammetric methods employed were based on film cameras and early digital processing, the authors successfully created stereoscopic outcrop models that could be used for accurate measurement of cross sections, channel bodies, and derived parameters such as net-to-gross ratio. Fast forward to today, and virtual outcrop modelling has evolved rapidly, spanning early work using laser scanning, integration with hyperspectral imaging, and the full-circle return to photogrammetry. The latter has brought about a paradigm shift in field geoscience, driven by lightweight digital cameras, drone platforms, and powerful computing hardware combined with automated image matching and point cloud generation algorithms. This has empowered geologists and geoscientists to quickly – and at low cost – acquire and process high resolution, accurate 3D models for detailed analysis. Over the last five years, and particularly through the COVID-19 pandemic, virtual outcrop models have been increasingly used for “soft” purposes, in education and training, for introducing a wide range of different geological features and concepts that may be difficult to access in a single field area, or as the basis for integrating a range of geospatial, field and subsurface data. In this contribution we will explore the status and impact of virtual outcrops and offer thoughts on future perspectives.

4:00pm - 4:15pm
Topics: 4.06 From Unoccupied Aerial Vehicles (UAVs) to Mixed-Reality Visualizations: Expanding Frontiers in Field Data Acquisition, 3D-Model-Design and Geo-Visualization

LiquidEarth: Integrating Rapid 3D Geological Modeling in Cross-Platform Mixed Reality

Fabian A. Stamm1, Simon Virgo1, Miguel De la Varga1,2, Florian Wellmann1,2

1Terranigma Solutions GmbH, Germany; 2Computational Geoscience, Geothermics and Reservoir Geophysics, RWTH Aachen University, Germany

Virtual and mixed reality technologies are reaching maturity for both professional and consumer applications, offering not only stereoscopic 3D visualization environments but also novel user interfaces with more immersive experiences of interacting with 3D content. Geosciences, which inherently deal with 3D complexities, can greatly benefit from these advancements. However, the potential benefits remain largely untapped for professional applications. Recent developments are bringing 3D geodata visualization with collaboration into virtual spaces. Nonetheless, the actual steps of 3D geological model creation and modification remain predominantly limited to workstation computers and 2D displays.

Addressing these limitations, we present LiquidEarth, a software solution that integrates rapid geomodeling with immersive mixed-reality environments. Utilizing a cloud-accelerated implicit modeling algorithm, LiquidEarth offers a dynamic experience of creating and updating 3D geological models in virtual spaces with real-time feedback. Cross-platform compatibility makes the solution device-agnostic, facilitating adoption in various geoscience applications and scenarios, including fieldwork.

The software combines features such as immersive visualization, real-time collaboration, field connectivity, workflow connectors, and flexible export options to create an integrated and versatile tool, making it ideal for geoscientific work in industry, research, and education. This holistic approach bridges the gap between immersive visualization of geological data and geological modeling, enabling geoscientists to harness the full potential of mixed reality technologies.

LiquidEarth signifies a substantial, yet initial, step towards the future of geomodeling by transcending traditional constraints. Its objective is to augment the geoscientific expert's ability to analyze and comprehend intricate geological 3D complexities while promoting the development of insightful conclusions.

4:15pm - 4:30pm
Topics: 4.06 From Unoccupied Aerial Vehicles (UAVs) to Mixed-Reality Visualizations: Expanding Frontiers in Field Data Acquisition, 3D-Model-Design and Geo-Visualization

Investigating the impact of differential biogenic carbonate production on carbonate system geometries through stratigraphic forward modelling: The Llucmajor example.

Timothy Oluwatobi Tella1, Gerd Winterleitner2, Maria Mutti1

1University of Potsdam; 2Fraunhofer IEG

The geometry of carbonate systems reflects the interaction of several factors. Although efforts have been made at investigating the controls on biogenic carbonate system evolution, the impact of the interaction of different carbonate producing biotas is still not fully understood. In this study, we developed a 4D stratigraphic forward models (SFM) of the Miocene Llucmajor platform coupled with sensitivity analysis to examine the effect on platform geometry of changes of the dominant biotic production in the oligophotic and euphotic zones. Our results indicate that the geometry of the platform is impacted by a complex interaction between carbonate production rates, variations in bathymetry, and changes in accommodation. Progradation in the platform model is mainly controlled by oligophotic production of rhodalgal sediments during the lowstands. This study also shows that platform geometry and internal architecture is significantly impacted by the interaction of the predominant carbonate producing biotas. The input parameters for this study are based on well-understood Miocene carbonate biotas with characteristic euphotic, oligophotic and photo-independent carbonate production in which it is essential to explicitly model each carbonate producing class within the simulation run and not averaged with a single carbonate production-depth profile. This distinction is particularly crucial for subsurface exploration studies that rely on stratigraphic forward models, where the overall platform geometry may be approximated through calibration runs and constrained by seismic surveys and wellbores. However, the internal architecture could be over-simplified, without an in-depth understanding of the target carbonate system such as is provided by this study.

4:30pm - 4:45pm
Topics: 4.06 From Unoccupied Aerial Vehicles (UAVs) to Mixed-Reality Visualizations: Expanding Frontiers in Field Data Acquisition, 3D-Model-Design and Geo-Visualization

Digital methods for the planning and construction of geothermal plants

Holger Kaiser

Bauer AG, Germany

Digitalisation helps to improve planning, make processes more transparent, save resources and counteract the staff shortages that will become even greater in the future.

BAUER Resources GmbH has been using the BIM methodology for over a decade, and for some years now processes in construction site operations and planning have been digitally supported.

With the help of drones, apps on mobile devices and sensors, linked with intelligent systems, execution and planning are being taken to a new level of detail, transparency and speed.

The detailed planning and execution of geothermal projects including geologie and hydrologie with digital support will be presented. Implementations in BIM with automation and other digital techniques (including real-time data from the construction site) which leads to a digital twin will be presented.

3:30pm - 5:00pm3.11-2 Triassic Revolution
Location: Wiwi 104a
Session Chair: Michael J. Benton, University of Bristol
3:30pm - 3:45pm
Topics: 3.11 Triassic Revolution

New insights into the Dinocephalosauridae, a recently recognised clade of Triassic marine archosauromorphs, including the identification of its first European member

Stephan N.F. Spiekman

Naturkunde Museum Stuttgart, Germany

The diversification of marine reptiles played a major part in the Triassic Revolution and represented the first large-scale return of tetrapods to an aquatic environment. Recently, a new marine archosauromorph clade, Dinocephalosauridae, was recognised, considerably increasing the known diversity of Triassic marine reptiles, particularly among the generally terrestrial Archosauromorpha. Its best-known member, Dinocephalosaurus orientalis, superficially resembles plesiosaurs, possessing a hyperelongate neck composed of many cervical vertebrae, an elongate torso, and flipper-like limbs. The osteology of Dinocephalosaurus is virtually completely described based on newly discovered specimens. Up to six metres long, it is characterised by its long tail and even longer neck. The appendicular skeleton exhibits a high degree of skeletal paedomorphosis recalling that of many sauropterygians, but the skull and neck are completely inconsistent with sauropterygian affinities. Its cranial morphology, including the presence of narial fossae, is very similar to that seen in another long-necked archosauromorph, Tanystropheus hydroides, which largely represents a convergence related to an aquatic piscivorous lifestyle. Chinese discoveries such as Dinocephalosaurus merit a re-evaluation of historical European collections. Based on such a revision, we also redescribe Trachelosaurus fischeri, known from a single, disarticulated specimen collected in the 1800s from the Solling Formation (Buntsandstein) of Bernburg, Germany. It possesses short, bifurcating cervical ribs, which are unique among archosauromorphs. Trachelosaurus is confidently recognised as the first European dinocephalosaurid based on a wide range of character states, including its highly presacral vertebral count, wide dorsal transverse processes, holocephalous dorsal ribs, an ilium lacking a preacetabular process, and a rod-like femur.

3:45pm - 4:00pm
Topics: 3.11 Triassic Revolution



Hefei University of Technology

Sauropterygia was a taxonomically and ecomorphologically diverse clade of Mesozoic marine reptiles spanning the Early Triassic to the Late Cretaceous. Sauropterygians are traditionally divided into two groups representing two markedly different body plans – the short-necked, durophagous Placodontia and the long-necked Eosauropterygia – whereas Saurosphargidae, a small clade of armoured marine reptiles, is considered as the sauropterygian sister-group. However, the early evolutionary history of sauropterygians and their phylogenetic relationships with other groups within Diapsida are still incompletely understood. Here, we report a new saurosphargid from the Early Triassic of South China, representing the earliest known occurrence of the clade. An updated phylogenetic analysis focussing on the interrelationships within diapsid reptiles recovers saurosphargids as nested within sauropterygians, forming a clade with eosauropterygians to the exclusion of placodonts. Furthermore, a clade comprising Eusaurosphargis and Palatodonta is recovered as the sauropterygian sister-group. The phylogenetic position of several Early and Middle Triassic sauropterygians of previously uncertain phylogenetic affinity, such as Atopodentatus, Hanosaurus, Majiashanosaurus and Corosaurus, is also clarified, elucidating the early evolutionary assembly of the sauropterygian body plan. Finally, our phylogenetic analysis recovers Testudinata and Archosauromorpha within Archelosauria, a result strongly supported by molecular data, but until now rarely recovered by any phylogenetic analysis using a morphology-only data set. Our study provides evidence for the rapid diversification of sauropterygians in the aftermath of the Permo-Triassic mass extinction event and emphasises the importance of broad taxonomic sampling in reconstructing phylogenetic relationships among extinct taxa.

4:15pm - 4:30pm
Topics: 3.11 Triassic Revolution

Puberty in a Mesozoic reptile

Qiang Li1,2, Jun Liu1,2, Nicole Klein2, Yasuhisa Nakajima3, P. Martin Sander1,2,4

1Division of Geology, School of Resources and Environmental Engineering, Hefei University of Technology, 230009 Hefei, China; 2Section Paleontology, Institute of Geosciences, University of Bonn, 53115 Bonn, Germany; 3Department of Natural Sciences, Faculty of Science and Engineering, Tokyo City University, 1588557 Tokyo, Japan; 4The Dinosaur Institute, Natural History Museum of Los Angeles County, Los Angeles, 90007 CA, USA

The histology of bone can be preserved virtually unaltered for hundreds of millions of years in fossils from all environments and all vertebrate taxa, giving rise to the flourishing field of paleohistology. The shafts of long bones are formed by the apposition of periosteal bone tissue, similar to the growth of wood, and preserve (an often cyclical) record of the growth of the individual and events in its life history. One such event is sexual maturation or puberty, during which hormonal changes transform the juvenile into a sexually mature adult. Puberty has been well studied in humans and some other living vertebrates. Here we describe puberty in Keichousaurus, a small sexually dimorphic and live-bearing marine reptile from Middle Triassic rocks of SW China, about 240 million years old. Using a combination of bone histology and morphology, we detected puberty as one of four life stages (the others being foetus, juvenile, and adult). Adult Keichousaurus males have a more robust humerus than females with pronounced muscle attachment sites and a triangular shaft cross section. Mid-shaft sections of the humeri of the males show the transition from the rounded juvenile cross section to the triangular adult cross section, as reflected in the contour of the growth marks. This shape change is produced by differential bone apposition of the periosteum, presumably triggered by sex hormones, as in humans, and influenced by changes in loading regime during puberty. This is the first report of puberty in a fossil amniote.

4:30pm - 5:00pm
Invited Session Keynote
Topics: 3.11 Triassic Revolution

Novel insights into the end-Triassic extinction from contemporaneous southern African sedimentary basins

Kimberley Chapelle

University of the Witwatersrand, South Africa

The end-Triassic Extinction Event (ETE) lead to the demise of ~76% of species, as well as major biotic transitions in terrestrial vertebrate faunas. These include the shift from a mainly synapsid- and pseudosuchian-dominated ecosystem in the Triassic (e.g. dicynodont and cynodont therapsids) to dinosaur-dominated ecosystem in the Jurassic. Our understanding of this crucial time in Earth’s history is hindered by the lack of sedimentary deposits that record the Triassic–Jurassic boundary and bear informative vertebrate fossils across this interval. Several southern African basins are infilled by uninterrupted Carnian–Pliensbachian sediments. These include the Stormberg Group of the main Karoo Basin of southern Africa, as well as the Mid-Zambezi and Tuli basins of Zimbabwe. Surprisingly, the paucity of the current known fossil record recovered from these southern African deposits limits their use in understanding the ETE. This is in part because, to date, the Late Triassic vertebrates known to pertain from these units are much less abundant and diverse than those from the Early Jurassic units. Over the last decade, increased field work targeting these areas, combining excavations with high-resolution dating and biostratigraphy, has yielded multiple new fossil-bearing localities that add crucial new data to our understanding of ETE faunal change. Here, I present an overview of these novel sites. One notable location includes the late Norian quarries from near the village of Qhemegha in the Eastern Cape of South Africa which preserve a diversity of vertebrates such as: large-bodied late-branching pseudosuchians; large- and small-bodied sauropodomorphs and theropods; non-dinosaurian avemetatarsalians; and synapsids.

3:30pm - 5:00pm1.24 Reclamation and transformation of post-mining landscapes:...
Location: Wiwi 105
Session Chair: Irina Engelhardt, TU Berlin
Session Chair: Martin Schultze, Helmholtz Cetre for Environmental Research - UFZ
3:30pm - 4:00pm
Invited Session Keynote
Topics: 1.24 Reclamation and transformation of post-mining landscapes: Biogeochemical processes, ecological and geochemical remediation strategies for open-cast mining lakes and sustainable water management

(How) does the water management work in connection with the lignite phase-out in the Rhenish mining area?

Nils Cremer

Erftverband, Germany

Der Braunkohleausstieg führt zu Veränderungen in allen Bereichen der Wasserwirtschaft. Im Rheinischen Revier werden sich nach dem Ende des Bergbaus einige der größten deutschen Seen bilden. Der Grundwasserspiegel steigt und die Fließrichtung des Grundwassers ändert sich. Einige Oberflächengewässer führen mehr Wasser, andere weniger. Wasser wird ein wichtiger Faktor in der gesamten Region sein, aber es wird auch einen Wettbewerb um Wasser auf lokaler Ebene geben. Die Veränderungen in der Wasserwirtschaft sind wesentliche Randbedingungen im Strukturwandel im Bergbaugebiet.

Im Rheinischen Revier verursachten die Entwässerungsmaßnahmen rund um die Tagebaue ein Defizit von mehr als 20 Milliarden Kubikmetern Wasser. Beim Ausgleich dieses Defizits spielt die Nutzung von Wasser aus dem Rhein, das durch große Wasserleitungen gepumpt wird, eine wichtige Rolle. Die Befüllung der Seen wird etwa 40 Jahre dauern. Die Auswirkungen des Klimawandels werden in diese Planung einbezogen.

Eine der Kernaufgaben im Rahmen des Braunkohleausstiegs ist die Sicherstellung der Trinkwasserversorgung. Der Zufluss von Grundwasser aus den Abraumdeponien, das aufgrund von Pyritoxidationseffekten etwa 1.500 mg/l Sulfat enthält, wird die Schließung von mindestens vier Wasserwerken erzwingen. Darüber hinaus werden ca. 12 Wasserwerke von infiltriertem Rheinwasser betroffen sein, das verschiedene organische Spurenstoffe enthält. Ein flächendeckendes Wasserversorgungskonzept wird die Trinkwasserversorgung von mehr als 2,5 Millionen Einwohnern sicherstellen.

4:00pm - 4:15pm
Topics: 1.24 Reclamation and transformation of post-mining landscapes: Biogeochemical processes, ecological and geochemical remediation strategies for open-cast mining lakes and sustainable water management

A workflow for investigating the subsurface of post-mining landscapes in Lusatia (Germany)

Silvio Janetz, Olaf Josafat Cortés Arroyo, Marcus Fahle, Anne Gädeke, Jörg Giese, Mark Gropius, Erik Nixdorf, Benedikt Preugschat, Elisabeth Schönfeldt, Bernhard Siemon

Federal Institute for Geosciences and Natural Resources, Germany

The largest contiguous former opencast lignite mining district in the EU is located in Lusatia (Germany). Hydrochemical contaminations such as acid mine drainage from opencast mines as well as increased susceptibility to soil instabilities pose major challenges for the reclamation of the Lusatian mining district in the coming decades. Therefore, time- and cost-efficient methods investigating former opencast lignite mines are vital for a sustainable remediation and reclamation.

In Lusatia, loose Cenozoic sediments (sands, silts, clays, and glacial tills) form several tens of metres of heterogeneous lithological successions in extensive opencast dumps. However, the effects of newly formed depositional structures, spatial heterogeneities and pore water mineralisation of the opencast dumps on groundwater flow and mass transport remain largely unknown in the post-mining areas of Lusatia.

In this study, we developed a workflow that makes use of spatially variable and heterogeneous input data ranging from airborne geophysics, geological maps and drilling logs. In a first step, we created 3D-representations of an exemplary post-mining area in Lusatia by using both classical geological interpretations as well as machine learning approaches. In a second step, the 3D representations are compared to each other and are used as input data for numerical groundwater modelling in order to analyse the effect on the simulated groundwater flow. This approach allows us to optimise the 3D-modelling workflow and to refine our understanding of the flow and mass transport processes between groundwater and pit lakes in the subsurface of post-mining areas.

4:15pm - 4:30pm
Topics: 1.24 Reclamation and transformation of post-mining landscapes: Biogeochemical processes, ecological and geochemical remediation strategies for open-cast mining lakes and sustainable water management

Microbially induced iron retention in the Central German coalfield using the example of the Witznitz mine dump: results of a feasibility study

Christian Hildmann, Sarah Kruber

Research Institute for Post-Mining Landscapes, Germany

As a result of the rearrangement of tertiary sediments and the groundwater lowering during open pit lignite mining, the formerly stable iron sulfide compounds oxidize to iron and sulfate ions and acidity. With the end of mining operations and the resulting rise in groundwater levels, these substances are transported into surface water, causing negative effects on the ecosystem and water management.
Sulfate reduction reverses the preceding oxidation process. By adding a carbon source, sulfate-reducing bacteria are activated in the aquifer. These metabolize the added carbon, producing sulfide which combines with the iron present in the groundwater to form iron sulfide and is fixed in the subsurface.
The process has already been tested as a pilot project in the Lusatian coalfield. For the transfer to the Central German mining district, adjustments had to be made to the plant design due to the cohesive soils and higher concentrations of iron and sulfate.
The plant configuration provides for a modular structure consisting of six self-sufficient sections. In each module, 86 individually controllable lances are provided for both lifting and infiltration of the water. Infiltration takes place in one lance at a time, while water is being lifted from other lances or these are paused so that water flows in. In this way, the problem of groundwater surface drawdown caused by upstream wells or the disadvantages of using external water are avoided. The lifted water is mixed with glycerine as a carbon source and then infiltrated again.

4:30pm - 4:45pm
Topics: 1.24 Reclamation and transformation of post-mining landscapes: Biogeochemical processes, ecological and geochemical remediation strategies for open-cast mining lakes and sustainable water management

Biogeochemical influence on water quality by efficient phosphorus retention in pH-neutral open-cast mining lakes

Björn Grüneberg1, Brigitte Nixdorf2, Jacqueline Rücker2, Thomas Gonsiorczyk3, Michael Hupfer3, Wilfried Uhlmann4, Dirk Sailer4, Yvonne Hillecke4, David Kneis5, Thomas Petzoldt5, Ina Hildebrandt6, Adrian Horn6

1Landeslabor Berlin-Brandenburg; 2BTU Cottbus Senftenberg, Germany; 3Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB); 4Institut für Wasser und Boden Dr. Uhlmann, Dresden; 5Technische Universität Dresden, Institut für Hydrobiologie; 6BGD ECOSAX GmbH, Dresden

Empirical trophic models (Vollenweider-type) are one of the basic "tools of the trade" in management of natural and artificial lakes. They are not applicable to open-cast mining lakes (PML) because they underestimate their resilience to phosphorus (P) inputs. The high iron availability causes an efficient binding for phosphorus (P) in water and sediment of PML. The main objective was use hydrogeochemical modelling to assess the risks of eutrophication in the following way:

i) to develop conceptual (empirical) models (Vollenweider type) that can be used to more accurately estimate tolerable P loading to PMLs

ii) to represent the transition range from conditions with Fe excess to natural conditions in a model structure

iii) to identify specific indicators and tipping points for different P retention.

We analysed hydrological data, loads, and sediment properties to derive a closed P balance for 29 neutral mining lakes. The latter cover a range of water retention times and external P inputs. We distinguished three phases of PML development or maturation and the relevance of P-binding processes or binding forms. The Fe:P ratio in sediment was found to be the most important predictor of P retention. By integrating this ratio into conceptual models it is now possible to predict in-lake P-concentration from P inputs for PMLs and even for lakes with decreasing Fe import at the transition to “natural lake” conditions. We conclude that processes such as Fe~P adsorption and vivianite formation under anoxic conditions most likely ensure high P retention in the long term.

4:45pm - 5:00pm
Topics: 1.24 Reclamation and transformation of post-mining landscapes: Biogeochemical processes, ecological and geochemical remediation strategies for open-cast mining lakes and sustainable water management

Lake Runstedt – a pit lake for treating polluted water and protecting groundwater

Martin Schultze1, Tina Endrulat2, Anne Weber2, Andreas Schroeter3, Petra Wolf4

1Helmholtz Cetre for Environmental Research - UFZ, Germany; 2Lausitzer und Mitteldeutsche Bergbau-Verwaltungsgesellschaft mbH, Germany; 3IHU Gesellschaft für Ingenieur-, Hydro- und Umweltgeologie mbH, Germany; 4FCB Fachbüro für Consulting und Bodenmechanik GmbH, Germany

Lake Runstedt (near Merseburg, Germany; area 2.3 km², volume 53x106 m³, max. depth 32.8 m) is an artificial lake resulting from lignite mining. The lower part of the former mine void was filled by industrial wastes consisting mainly of ashes but also containing waste from nitrogen fertilizer production rich in ammonium. Ammonium concentrations exceed 300 mgL-1 in the pore water in the deposited wastes and constitute a threat for the regional groundwater resources. For protecting the groundwater, Lake Runstedt was created by filling the remaining space of the mine void above the waste with water from Saale River. The neighbouring pit lakes are managed in a way that groundwater flows into Lake Runstedt from all directions and that there is no outflow except evaporation. Hypolimnetic aerators provide the hypolimnion with oxygen needed for nitrification and reed was established in the littoral as habitat for denitrification. Since completion of the filling in 2003, the system has worked well as documented by monitoring. Usually, limnologists look at lakes as valuable ecosystems that have to be protected. In case of Lake Runstedt, the lake is used as a reactor. This unusual approach should not be a common preference but considered as exceptional option in applied limnology. The presentation will report on the creation of Lake Runstedt, the results of monitoring and research, and discuss the use of lakes as reactors protecting other compartments of the environment.

3:30pm - 5:00pm4.02-2 Within and Beyond - Research infrastructures that strengthen Open Science Practices in Geosciences
Location: Wiwi 107
Session Chair: Melanie Lorenz, GFZ German Research Centre for Geosciences
Session Chair: Andrea Pörsch, Helmholtz Metadata Collaboration (HMC) at GFZ German Research Centre for Geosciences, Potsdam, Germany
3:30pm - 3:45pm
Topics: 4.02 Within and Beyond - Research infrastructures that strengthen Open Science Practices in Geosciences

Strengthening Open Science Practices Through re3data, the Global Registry of Research Data Repositories

Nina Leonie Weisweiler1, Kirsten Elger2, Heinz Pampel1,4, Alexandra Axtmann3, Roland Bertelmann1, Thanh Binh Nguyen3, Edeltraud Schnepf3, Vivien Petras4, Angelika Semrau3, Dorothea Strecker4, Robert Ulrich3, Arne Upmeier3, Paul Vierkant5, Gabriele Weickert3, Michael Witt6

1Helmholtz Association, Helmholtz Open Science Office, Germany; 2GFZ German Research Centre for Geosciences, Germany; 3Karlsruhe Institute of Technology (KIT), Germany; 4Humboldt-Universität zu Berlin, Germany; 5DataCite - International Data Citation Initiative e.V., Germany; 6Purdue University, United States

For more than a decade, re3data (, the global registry of research data repositories, has helped researchers, funding agencies, libraries, and other research data services to find, identify, and reference research data repositories. As the world's largest directory of data repositories, re3data describes over 3100 infrastructures on the basis of its comprehensive metadata schema in May 2023. The service allows searching for research data repositories of any type and from all disciplines, and users can filter results based on a wide range of characteristics. The re3data descriptions are openly accessible via an API and are reused by numerous open science services, including DataCite Commons. re3data is engaged in various initiatives and projects concerning data management and is mentioned in the policies of scientific institutions, funding organizations, and publishers.

The presentation will focus on the growth, development, and accomplishments of re3data over more than 10 years that have resulted in re3data becoming the most comprehensive information and metadata resource on research data repositories. Further, the presentation will address how re3data’s activities can support the establishment of best practices, support open science, and facilitate networking within different research communities. With over 850 entries the field of geosciences is one of the most strongly represented subject groups in the registry.

3:45pm - 4:00pm
Topics: 4.02 Within and Beyond - Research infrastructures that strengthen Open Science Practices in Geosciences

LabInfrastructure@Geo.X – A Laboratory Infrastructure Search Portal for the Geo.X Network

Manja Luzi-Helbing1,2, Marc Hanisch1, Hannes Fuchs1, Hildegard Gödde1,2, Lutz Hecht3,4

1Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany; 2Geo.X - Research Network for Geosciences in Berlin and Potsdam, Telegrafenberg, 14473 Potsdam, Germany; 3Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Invalidenstraße 43, 10115 Berlin, Germany; 4Institute of Geological Sciences, Freie Universität Berlin, Malteserstr. 74-100, 12249 Berlin, Germany

LI@Geo.X is a search portal for the laboratory infrastructure in the Geo.X network, jointly developed by the network partners. It supports collaborations and joint projects by providing information on instruments, analytical methods, contact persons, location of the laboratories, and links to their websites. LI@Geo.X is undergoing further development as LabInfrastructure@Geo.X in the framework of the Helmholtz DataHub Initiative. We extend the metadata scheme by adding, e.g., access information to the laboratories, user regulations, key and data publications. As technical improvements we implement:

  • a web-based user interface (change request form) for submitting new or modified laboratory metadata. This change request form is also equipped with a vocabulary tool for keywording instruments and analytical methods. For this we use the controlled vocabularies of the NASA GCMD instrument keywords and a vocabulary adapted for the Geo.X network.
  • a management interface which facilitates the decentralised editing and maintenance of the laboratory metadata.
  • semantic search options and filter functions which are aligned with the needs of the scientific target groups.

Including over 220 entries, LabInfrastructure@Geo.X cooperates with various Helmholtz initiatives and is embedded into the NFDI4Earth landscape.

4:00pm - 4:15pm
Topics: 4.02 Within and Beyond - Research infrastructures that strengthen Open Science Practices in Geosciences

The BGR GeoPortal: Enabling Access and Integration of Geoscientific Data

Christoph Schettler, Gerd Arns-Krogmann

Federal Institute for Geosciences and Natural Resources, Germany

The BGR GeoPortal is a comprehensive platform that facilitates seamless access to geoscientific data, fostering data exploration and integration. In this abstract, we highlight several key features of the GeoPortal and discuss our ongoing efforts to address challenges in consolidating data sources and promoting data sharing.

To enhance the integration of geoscientific data with existing literature, the GeoPortal incorporates a linkage to the Geological Literature Linked Data (ZSN). This integration allows users to seamlessly connect relevant scientific publications with associated geospatial data, promoting a more holistic understanding of geological phenomena.

The inclusion of an RDF interface within the GeoPortal further supports data integration and interlinking. By providing a standard semantic web interface, the GeoPortal enables users to connect and exchange data with other systems, fostering a networked environment for collaborative research and data sharing.

4:15pm - 4:30pm
Topics: 4.02 Within and Beyond - Research infrastructures that strengthen Open Science Practices in Geosciences

The Geometadatenplattform METAVER and its application in the state Brandenburg/Germany

Beate Lukas

Ministry of Agriculture, Environment and Climate Protection of the State of Brandenburg, Germany

METAVER ( is the central platform for recording and publishing (INSPIRE) geospatial metadata from various federal states of Germany. It offers various interfaces for recording and further processing metadata. An editor tailored to the requirements in the institutional area supports standard-compliant recording, according to various aspects of metadata rules in Germany. A web application enables comfortable research and visualization of data sources and providing services. METAVER was implemented with the INGRID software, which is being developed as part of an administrative cooperation of all federal states of Germany.
In the state of Brandenburg, and here specifically in the environmental sector, various requirements are covered by the application. The requirements result, for example, from the Environmental Information Act, the INSPIRE Directive and the OpenData Act.
The talk describes the framework conditions of the application and its basic structure and discusses the synergy effects of the application throughout the METAVER partners.. It also describes the integration of data interfaces of the state of Brandenburg and their integration into processes such as the Opendata strategy and provision of metadata according to the INSPIRE Directive.

4:30pm - 4:45pm
Topics: 4.02 Within and Beyond - Research infrastructures that strengthen Open Science Practices in Geosciences

Open Data and more in the Geosciences – an introduction to GFZ Data Services

Kirsten Elger, Simone Frenzel, Florian Ott

GFZ German Research Centre for Geosciences, Potsdam, Germany

For more than a decade, there is an increasing international demand for free and open access to publicly funded scientific research products. These include “classical” text manuscripts, data and software underlying scholarly publications, raw and curated observational data, and many more. Essential for the long-term preservation and re-use of these scientific datasets is the storage in appropriate, ideally domain specific repositories, accompanied by comprehensive data description and sufficient metadata for data discovery. These should include a licence for data re-use and sharing. Scientific datasets should be published using citable Digital Object Identifier (DOI).

GFZ Data Services is a repository for research data and scientific software across the Earth System Sciences, hosted at GFZ. The curated data are archived, persistently accessible and published with DOI. They range from large dynamic datasets from global monitoring networks with real-time acquisition, to international services in geodesy and geophysics, to the full suite of small and highly heterogeneous datasets collected by individual researchers or small teams ("long-tail data"). In addition to the DOI registration and data archiving itself, GFZ Data Services team offers comprehensive consultation by domain scientists and IT specialists.

This presentation will introduce to the broad service portfolio of GFZ Data Services, including project-specific DOI landing pages for our national and international partners, data curation practices, supporting tools like the online metadata editor, data description templates and extensive data publication guidelines. It will further show examples of how metadata exchange with other data portals is increasing the visibility of our data publications.

4:00pm - 6:00pmDMG Vorstands- und Beiratssitzung
Location: Konferenzraum II HFB
Session Chair: Friedhelm von Blanckenburg, GFZ Potsdam
5:30pm - 7:00pmPoster social - Themes: 1.01 | 1.04 | 1.12 | 1.17 | 1.24 | 1.28 | 3.03 | 3.11 | 3.20 | 3.24 | 4.06 | 4.13 | Others
Location: Foyer (Henry Ford Building)
Mon: 1
Topics: 1.01 Towards 'Net Zero' with negative emissions and sustainable landscapes

Capturing CO2 by olivine weathering in facade plaster

Maximilian Berndsen1,2, Rauno Baese3, Katharina Alms1

1Fraunhofer IEG, Fraunhofer Research Institution for Energy Infrastructures and Geothermal Systems, Bochum, Germany; 2Institute of Geology, Mineralogy, and Geophysics, Ruhr-University Bochum, Bochum, Germany; 3Knauf Gips KG, Iphofen, Germany

The building and construction sector accounts for a significant proportion of current anthropogenic CO2 emissions. Reducing the carbon footprint of building materials is difficult because some process-related CO2 emissions cannot be avoided. While the industry is developing methods to reduce its emissions by capturing CO2 from flue gas streams, this study investigates an alternative mechanism to reduce the carbon footprint of building materials, namely the incorporation of olivine into building materials such as façade plaster. Olivine is susceptible to weathering and reacts with CO2 to form magnesium carbonate and silica.

In collaboration with the company Knauf Gips KG, an outdoor test facility will be built to monitor the mineralogical changes in olivine façade plaster under natural weathering conditions over a period of 18 months. In parallel, laboratory experiments will be carried out to accelerate the weathering process by continuous artificial weathering of the plaster samples. Fluids will be regularly sampled and analysed to detect potential environmental hazards, such as the release of nickel and chromium into the environment. All plaster samples will be analysed by X-ray diffraction (XRD) and scanning electron microscopy (SEM) to identify mineralogical and structural changes during the experiments. The extent of CO2 mineralisation will be assessed based on mass balance calculations with the experimental reactants and their products. A sustainability assessment of the whole value chain will be carried out to determine whether olivine in building materials can effectively contribute to offsetting the CO2 emissions of the construction industry.

Mon: 2
Topics: 1.01 Towards 'Net Zero' with negative emissions and sustainable landscapes

Benthic sources for dissolved inorganic carbon in the North Sea: A stable isotope perspective

Michael E. Böttcher1, Cátia M. Ehlert von Ahn1, Carla K.M. Nantke1, Antonia Schell1, Donald E. Canfield2, Andreas Neumann3, Abdul M. Al-Raei4, Vera Winde1, Iris Schmiedinger1

1Leibniz IOW, Germany; 2Institute of Biology, University of Southern Denmark, Odense M, Denmark; 3Hereon, Geesthacht, Germany; 4Max Planck Institute for Marine Microbiology, Bremen, Germany

Marine sediments may act as a sink for carbon. Substrate and electron donor availabilities, sedimentology, as well as biological activity may influence the carbon cycling, impacting the release of TA and DIC. The North Sea is a highly dynamic system with shallow tidal areas and fresh water tributaries delivering nutrients and dissolved carbon. For the southern part, benthic DIC sources have been identified [1], with tidal areas being further hot spots [2], some being impacted by submarine fresh water discharge [3]. The Skagerrak provides the unique opportunity of studying benthic DIC production under the impact of different dominant electron acceptors [4]. Potential transformation of carbonates may impact release of TA and DIC.

Here, we investigated the role of different sediments from the North Sea, including tidal areas, for their DIC source function and carbon storage capacity. Water column, pore water, and sediment samples were investigated to understand the processes controlling the benthic production and release of TA and DIC. The carbon isotope composition of dissolved and solid phases were investigated to understand the specific biogeochemical processes dominating benthic mineralization and carbonate dissolution.

[1] Burt et al. (2016) Limnol. Oceanogr. 61, 666-683. [2] Schwichtenberg et al. (2020) Biogeosciences, 17, 4223-4245. [3] Winde V. et al. (2014) J. Mar. Sys. 129, 394-402. [4] Canfield D.E. et al. (1993) Geochim Cosmochim Acta 57, 3867-2883.

The investigations are carried out within the BMBF project COOLSTYLE/CARBOSTORE. The Sylt part also contributes to the DFG project KiSNet, and investigations are further supported by Leibniz IOW.

Mon: 3
Topics: 1.01 Towards 'Net Zero' with negative emissions and sustainable landscapes

Quantifying and optimising Enhanced Weathering as a CO2 removal tool

Patrick Frings

GFZ Potsdam, Germany

The application of finely ground silicate minerals to croplands and forests, with the aim of enhancing the rate of natural CO2 consuming weathering reactions, is receiving attention as a part of climate change mitigation strategies. Yet considerable uncertainty surrounds the quantification of CO2 removal associated with Enhanced Weathering, and its potential efficacy remains undemonstrated outside of the laboratory. Here, I discuss how the geochemical insights garnered from decades of natural weathering studies provide a pathway towards a strategy for ‘Monitoring, Reporting and Verification’ of CO2 sequestration. These natural weathering studies have also produced an understanding of what limits silicate weathering in different settings, which can be used to shed light on how deployment strategies, and specifically application sites, can be optimised.

Mon: 4
Topics: 1.01 Towards 'Net Zero' with negative emissions and sustainable landscapes

Biogenic processes of methane production and oxidation along thermokarst lake to lagoon transitions

Susanne Liebner1,2, Sara E Anthony3,4, Knoblauch Christian5, Kallmeyer Jens1, Strauss Jens6, Yang Sizhong1

1GFZ German Research Centre for Geosciences, Germany; 2University of Potsdam, Institute for Biochemistry and Biology, Potsdam, Germany; 3University of Cologne, Institute of Geology and Mineralogy, Cologne, Germany; 4Landscape Ecology, Faculty of Agricultural and Environmental Sciences, University of Rostock, 18059 Rostock, Germany; 5Universität Hamburg, Institute of Soil Science, Center for Earth System Research and Sustainability, Hamburg, Germany; 6Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Permafrost Research Unit, Potsdam, Germany,

Thermokarst lagoons form at the terrestrial-marine interface when thermokarst lakes, hotspots for Arctic methane emissions, erode onto the Arctic shelf. Thermokarst lagoons are dynamic environments with seasonal ice build-up and potential alternations between freshwater and marine discharge. Aiming to understand how microbial methane cycling changes along thermokarst lake to lagoon transitions we have investigated the sediment geochemistry and microbiota of the Polar Fox lagoon, a thermokarst lagoon in north-eastern Siberia, relative to that of two adjacent thermokarst lakes. In-situ methane concentrations, methane-carbon isotopic signatures, analysis of amplicon sequencing variants (ASVs), metagenomics, and pore-water geochemistry point towards efficient communities of anaerobic methane oxidizers (AOM) in a sulfate-methane transition zone 2-3 meters below the sediment surface of the lagoon. The lagoon’s in-situ methane concentration in the sulfate zone was only 0.4 – 5% that of the deeper sediment and of the two adjacent thermokarst lakes which have no connection to the Arctic Ocean. In the lakes, methane concentrations reached values up to 2.2 µmol per gram pointing towards oversaturation with methane in the sediment. Based on the analysis of general microbiome composition, we suggest that deterministic process triggered a substantial overall shift of microbial assemblages and a loss in spatial dissimilarity and diversity. Our study shows that thermokarst lake to lagoon transitions are associated with the formation of novel sediment microbiomes and that Arctic thermokarst lagoons can host efficient AOM communities with the potential to substantially mitigate methane concentrations in coastal thermokarst sediments.

Mon: 5
Topics: 1.01 Towards 'Net Zero' with negative emissions and sustainable landscapes

Monitoring alkalinity enhancement in intertidal environments - A field study -

Julia Anne-Elise Lübbers1, Isabel Mendes1, Alexandra Cravo1, Joachim Schönfeld2, Patricia Grasse3

1Centre for Marine and Environmental Research (CIMA) - Infrastructure Network in Aquatic Research (ARNET), Universidade do Algarve, Faro, Portugal; 2Helmoltz Centre for Ocean Research Kiel (GEOMAR), Germany; 3German Centre for Integrative Biodiversity Research Halle-Jena-Leipzig (iDiv), Germany

Global warming is the greatest threat for humankind today. Despite all efforts to reduce CO2 emissions, the undertaken measures are not sufficient to stop the temperature rise. One recently proposed and promising approach to actively remove CO2 from the atmosphere is carbon dioxide removal through marine alkalinity enhancement. This technique increase the natural CO2 uptake capacity of seawater through weathering of fine-grained alkaline minerals in marine environments. Even through this method has been extensively tested and verified by numerical models, field experiments scaling the CO2 uptake under natural conditions and assessing the impact on the environment and biota are still lacking. To bridge this gap of knowledge a monitored 2-year in-situ experiment was established in September 2022 at the Ria Formosa Coastal Lagoon, southern Portugal.

The experiment was installed in the pioneer vegetation zone of the saltmarsh with three replicate plots. Each plot contain deployments of coarse olivine, fine olivine, coarse basalt and fine basalt and an unchanged area as control. Supernatant and porewater from each treatment are analysed monthly for temperature, salinity, oxygen concentration, pH, total alkalinity, nutrients, and trace metals. Sediment samples are analysed quarterly for faunal and floral composition to evaluate the impact on the biota.

The first months of the experiment showed an increase in total alkalinity in the supernatant and porewater of the treatments. Other environmental parameters remained stable among the different treatments and control. The total alkalinity decreased through time although remained on higher levels as compared to the natural background level.

Acknowledgment. Research supported by the Portuguese Science Foundation, with the projects PTDC/CTA-CLI/1065/2021, UID/00350/2020CIMA and contracts DL57/2016/CP1361/CT0009.

Mon: 6
Topics: 1.01 Towards 'Net Zero' with negative emissions and sustainable landscapes

PERBAS: An International Project to Study Potential Sites for the Permanent Offshore Storage of CO2 in Marine Basalts

Sebastian Hölz1, Jörg Bialas1, Jyotirmoy Mallik5, Viktoriya Yarushina4, Stephane Polteau4, Manika Prasad3, Nimisha Vedanti2, Sverre Planke6, Ravi Sharma7, Gerald Klein8, Markus Krieger9

1GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany; 2CSIR - National Geophysical Research Institute, Hyderabad, India; 3Colorado School of Mines - CCUS Innovation Center, Golden, USA; 4IFE, Institute for Energy Technology, Kjeller, Norway; 5IISER Bhopal, Bhopal, India; 6Volcanic Basin Petroleum Research AS, Oslo, Norway; 7Indian Institute of Technology Roorkee, India; 8TEEC, Isernhagen, Germany; 9TERRASYS Geophysics, Hamburg, Germany

CO2 neutrality by 2045 requires increasing the currently worldwide achieved CO2 storage volume (40 Mt/y) to the order of tens of Gt/y. With current storage techniques, CO2 often remains in the gaseous phase, thus, free to spread underground risking unwanted leakage in the distant future. As an alternative, the mineralization of CO2 in basalts, where the vast majority (>90%) of the carbon is mineralized and fixed in carbonates within two years, offers a permanent safe storage as a solid (e.g. CarbFix, Iceland).
The international joint project PERBAS (ACT4) with partners from Norway, USA and India aims to pave the way for the commercialization of large-scale, permanent CO2 sequestration into marine basalt complexes off the coast of Norway and India. The project seeks solutions for reservoir selection, CO2 transport, injection and monitoring. PERBAS will investigate the feasibility of supercritical CO2 injection, using water in the pore space, in order to avoid the requirement to inject 20 t of water for 1 t of CO2. This would have the additional advantage that supercritical CO2 would be associated with a free gas phase, which allows the application of geophysical remote sensing for monitoring thereby reducing the number of monitoring wells required.
Within the German sub-project CO2PR, geophysical field data (seismics and electromagnetics) will be collected during a research cruise offshore Norway currently planned for 2024. The resolution and efficiency of associated inversion techniques will be made usable for large-volume (Gt) reservoirs and complemented with new AI methods to identify signals suitable for monitoring.

Mon: 7
Topics: 1.01 Towards 'Net Zero' with negative emissions and sustainable landscapes

Formation of fully carbonated/silicified peridotite (listwaenite) during shallow-crustal extension (Eastern Oman Mountains)

Andreas Scharf1, Frank Mattern1, Ivan Callegari2, Christopher Bailey3, Uwe Ring4

1Sultan Qaboos University, Oman; 2German University of technology in Oman; 3William & Mary, Virginia, USA; 4Stockholm University, Sweden

Oman’s listwaenite formed when carbonate-rich fluids reacted with peridotite, reducing the atmosphere’s carbon. Listwaenite provides clues regarding natural global carbon flux and sequestration. Oman contains the world's largest exposure of oceanic lithosphere. Obduction of the peridotite-bearing Semail Ophiolite onto Arabia occurred during the Late Cretaceous. The ophiolite’s hot base exerted contact metamorphism onto tectonically underlying rocks (“metamorphic sole”). Post-obductional doming, extension and E/W-shortening overprinted the rocks. In the Fanja area, (par-)autochthonous platform rocks are in contact with allochthonous rocks, and numerous listwaenite bodies several kilometers long and tens of meters wide are exposed. Mapping of the Fanja area at the scale of 1:10,000, determined the listwaenite’s tectogenesis. Two models exist. Listwaenite formed either during Late Cretaceous convergence and subduction or during shallow post-obductional extension. Mapping confirms: (i) Two listwaenite generations exist: an early gently dipping and a more common late steeply dipping generation. (ii) Listwaenite contacts of both generations with the ambient rocks are always a non-contractional fault. (iii) The listwaenite-metamorphic sole contact of the older listwaenite bodies is discordant and faulted. (iv) Both listwaenite generations are typically tabular, while the metamorphic sole may be intensely folded. (v) Drag folds and Riedel faults indicate extensional and/or WNW-striking sinistral shear of the late listwaenite. (vi) The late-generation bodies cut different sections of the allochthonous. (vii) At the Fanja Half-Graben, listwaenite is in extensional fault contact with post-obductional sediments (uppermost Cretaceous Al-Khod Fm.). No listwaenite clasts are found within this formation. Our observations demonstrate that all listwaenite bodies formed during extension.

Mon: 9
Topics: 1.01 Towards 'Net Zero' with negative emissions and sustainable landscapes

The Earth Science Box Modeling Toolkit (ESBMTK)

Ulrich Wortmann

University of Toronto, Canada

Box modeling is a versatile tool to explore earth systems processes, ranging from transient changes in the marine carbonate system to the long-term evolution of biogeochemical cycles. The Earth Science Box Modeling Toolkit is a python based toolkit that allows for the rapid creation and deployment of box models. It abstracts typical modeling tasks, e.g., air-sea gas exchange, weathering, seafloor carbonate precipitation/dissolution, kinetic isotope fractionation, etc., to python classes. Class instances can then simply be combined to build a model. While there is no graphical interface, this approach significantly reduces coding complexity and model development time. Crucially, the model structure is independent of the numerical implementation. Instead the model is parsed to dynamically create the necessary equation systems that can be passed to ode solver libraries like ODEPACK. Separating model description from numerical implementation results in well-documented model code, and combines the computational efficiency of state-of-the-art numerical libraries with the ease of use of python. The efficiency of this process is demonstrated by a 12-box model with air-sea gas exchange, tracers for carbon isotopes, and water column carbonate chemistry that requires about 1 CPU second to calculate the model evolution over 30 million years.

Mon: 10
Topics: 1.04 Hydrogen: energy carrier in nature and for society – from natural hydrogen occurrences to large-scale hydrogen storage

Natural hydrogen: What we know about its genesis and its geological occurrences

Maximilian Hasch, Peter Klitzke, Dieter Franke, Andreas Bahr, Rüdiger Lutz, Philipp Weniger, Christian Ostertag-Henning

Bundesanstalt für Geowissenschaften und Rohstoffe, Germany

Recently, interest in hydrogen as an emission free fuel has increased. So far, hydrogen is produced by steam methane reforming (SMR), water electrolysis or methane pyrolysis. These processes are energy consuming and SMR emits carbon dioxide. Naturally occurring hydrogen might represent an alternative to technologically produced hydrogen. It is therefore worthwhile to explore whether economically viable amounts of hydrogen are present in the earth.

Whereas a wealth of hydrogen on earth is considered to be trapped in the earth’s core and lower mantle and mostly inaccessible to humans, natural hydrogen also occurs in the crust and upper mantle where it is formed from biogenic and abiogenic sources. Important processes for the generation of natural hydrogen include: water-rock interactions involving ferrous iron, e.g. serpentinization, equilibrium reactions associated with volcanic activity and hydrothermal vents, water radiolysis, mechanochemical reactions in cataclastic rocks associated with fault zones and thermal decomposition of organic matter to form graphite at high temperatures in deep sedimentary basins or crystalline basement.

The presence of hydrogen-rich gas was documented at Mid-Ocean-Ridges, ophiolites, sedimentary basins, and Precambrian cratons. A multitude of studies on natural hydrogen exists, but the relationship between generation, fluid migration and potential occurrence of economic accumulations of natural hydrogen is still a matter of debate.

We present an overview of the current published knowledge on natural hydrogen showing selected study locations of previous works and the amount of naturally occurring hydrogen inferred at each site. The methods used to estimate the amount of occurring hydrogen are reviewed.

Mon: 12
Topics: 1.12 Innovative concepts and sustainability with hydrogen: from underground hydrogen storage to business concepts

Visualisation of microbial growth and distribution in real rock pores during underground hydrogen storage

Chaojie Cheng1, Benjamin Busch1, Martin Krueger2, Anja Dohrmann2, Martin von Dollen1, Christoph Hilgers1

1Institute of Applied Geosciences, Karlsruhe Institute of Technology, Karlsruhe, Germany; 2Geo-microbiology, BGR, Hannover, Germany

Hydrogen, converted from renewable energy sources, provides a feasible road map to balance the daily up to seasonally fluctuation between renewable energy supply and consumer demand. Underground hydrogen storage (UHS) in porous formations is promising since depleted hydrocarbon reservoirs and aquifers are widespread worldwide, and have a large capacity to meet the G-TWh storage demand. However, unlike underground natural gas (mainly methane) storage, hydrogen is highly susceptible to microbial metabolisms, which can consume and convert hydrogen into other molecules such as methane through methanogenesis. This poses a risk of hydrogen loss and contamination. Another concept is geo-bio-methanation directly in the subsurface, enabling stable long-term storage. Both concepts require a thorough understanding of microbial activities within porous rocks. The key questions, including, 1) does microbial growth reduce reservoir performance? 2) is there any effect of minerals and pore microstructures on microbial activities? 3) how do static and flow conditions affect microbe distribution? need to be better elucidated. To tackle these questions, we develop an unconventional real-rock micromodel configured with a thin rock layer in a transparent microfluidic chip. This innovative setup allows us to visualise microbial growth in rocks under a fluorescence microscope. By employing real-rock micromodels, we can overcome limitations related to mineral homogeneity and artificial pore structures. Consequently, this workflow and platform may hence offer new possibilities for studying microbial metabolism in geo-materials and the potential interactions.

Mon: 13
Topics: 1.12 Innovative concepts and sustainability with hydrogen: from underground hydrogen storage to business concepts

Hydrogen storage in a saline aquifer in Ketzin (Brandenburg, Germany) – a numerical pre-feasibility study in the context of the regional hydrogen economy

Lea Döpp1,2, Márton Pal Farkas1, Anna-Maria Eckel1, Cornelia Schmidt-Hattenberger1, Ingo Sass1,2

1GFZ Potsdam, Germany; 2TU Darmstadt, Germany

Geological hydrogen storage in saline aquifers is necessary due to their large capacities, enabling long-term and short-term storage and providing a secure and cost-effective option for integrating hydrogen into the energy system. Currently, there are no operational saline aquifer storages for hydrogen in Germany. However, there is an urgent need for investigating the desired capacity and performance of hydrogen underground storage facilities in deep saline aquifers as one of the most promising geological environments.

In this study, the sedimentary Stuttgart formation at the Ketzin site in Brandenburg, Germany, is assessed for geological hydrogen storage using an open-source reservoir simulator. The site has already been used for town gas and natural gas as well as for pilot CO2 storage in the past decades. The experience from these storage operations can be transferred to a potential hydrogen storage system.

The goal of the investigation is to evaluate the influence of geological parameters of the heterogeneous formation such as porosity, permeability, salinity, and capillary pressure on flow rates, quantities as well as on the recovery rate. The range of each parameter agrees with the measured uncertainty of petrophysical data. The results of the pre-feasibility study are then considered in the context of the regional hydrogen economy.

Overall, this multidisciplinary approach combines numerical simulations, geological parameters, and regional economic considerations. Future studies will focus on optimizing the operational parameter to minimize well-head pressure difference between charge and discharge cycles, to maximize production rates, and to achieve net-zero cumulative injection of hydrogen over time.

Mon: 14
Topics: 1.12 Innovative concepts and sustainability with hydrogen: from underground hydrogen storage to business concepts

Experimental large scale salt cavern methanation simulation

Marcel Schulz, Birgit Müller, Frank Schilling

Karlsruhe Institute of Technology, Germany

Despite the high salinity, biological processes could be used in salt caverns for methanation if suitable conditions are created. With suitable backfill materials, growth areas for the formation of biofilms could be created and the availability of sulfate could be reduced. These backfill materials can also be used in the course of cavern containment to reduce convergence.

Large scale experiments enable the simulation of cavern filling with suitable porous materials and the testing of growth material to promote biofilm formation. The aim is to develop an underground methanation reactor that also minimizes the convergence of the cavern. Therefore, it has to be tested if methanogenic archaea can survive under the given conditions.

We use an autoclave system with a volume of ca. 35 liters. Pressures of up to 100 bar and temperatures of up to 100 °C are possible. The autoclave consists of two chambers and a 2.5 m long casing in between. For safety reasons, the gas will contain 95 % N2, 4 % H2 and 1 % CO2. The bottom of the autoclave will be filled with brine and salt. As filling materials, expanded clay and construction waste are foreseen.

Mon: 15
Topics: 1.17 Marine mineral deposits: Formation, exploration, and environmental impacts of human activities

Europe’s marine minerals: EMODnet geology and Geological Service for Europe (GSEU)

Xavier Monteys1, Charise McKeon1, Teresa Medialdea2, Francisco Javier González2, Egidio Marino2, Luis Somoza2, Ana Lobato2

1Geological Survey Ireland, Ireland; 2Geological Survey of Spain (IGME-CSIC)

The European Marine Observation and Data Network (EMODnet) is a long-term marine data initiative funded by the European Maritime, Fisheries and Aquaculture Fund (EMFAF) and supported by the EU’s integrated maritime policy. The EMODnet Geology team released in 2023 a series of pan-European products related to marine themes including Seafloor geology, geological events, submerged landscapes, and Marine Minerals. Data products are available through the integrated EMODnet Central Portal: Collated marine mineral types and energy resources are: aggregates; hydrocarbons; gas hydrates; sapropel, marine placers; phosphorites; evaporites; polymetallic sulphides; polymetallic nodules; cobalt-rich ferromanganese crust; metal-rich sediments; rock, pegmatite and vein hosted mineralisation. The marine minerals theme is also connected to the five-year EU Coordination and Support Action, GSEU, (EuroGeoSurveys) that will deliver a plan for a sustainable Geological Service for Europe to be implemented beyond the 2027 project end, including assessing Europe’s offshore CRM resources improving the knowledge of underexplored areas and their mineral resources harmonizing datasets and cartographic products with a focus on European strategic and CRM for power generation and energy storage. With Earth’s population growth, efforts to meet our needs for resources with indigenous supplies continue. Many minerals and critical raw materials form important components in low-carbon and resource-efficient technologies such as electric car batteries, wind turbines and solar panels. Information on the types of minerals has relevance to engineering disciplines including extractive industries, beach nourishment and reclamation projects, and more general in Marine Spatial Planning. Environmental and marine EU policies are benefiting from the project’s outcomes.

Mon: 16
Topics: 1.17 Marine mineral deposits: Formation, exploration, and environmental impacts of human activities

New approach to ferromanganese nodules from the Baltic Sea

Michał Pilaszkiewicz1, Karol Zglinicki2, Agnieszka Wrzosek1, Krzysztof Szamałek1

1University of Warsaw, Poland; 2National Atomic Energy Agency, Poland

Polymetallic nodules (including ferromanganese) are one the major metal-bearing sources, those admitted as strategic and critical raw materials (CRMs) by the European Commission. Their widespread on seas’ and oceans’ bottoms entail interests in economic use of them.

Ferromanganese (Fe-Mn) nodules occur on the seabedof most areas of the Baltic Sea. Those from the Polish Exclusive Economic Zone (PEEZ) are ones of least explored elements of the marine environment. Since 2020 there have been 3 research cruises on the area of the PEEZ - on 3 selected areas, 25 km2 each (near Baltic Beta oil rig, Slupsk Furrow and Gdansk’s Basin). Almost 100 sediment samples from the seabed were collected by Van Veen sampler and box-corer. So far, more than 2000 samples of nodules have been described and analyzed.

The main assumptions of the project are to determine:

  • mineralogical and chemical compositions, genesis, age;

  • geochemical variability of Fe-Mn nodules and their relation to bottom sediments and the morphology of the bottom surface;

  • directions for depositional potential based on chemical composition for averaged samples of the areas in the PEEZ.

The chemical investigation (by using of ICP-MS) performed on the new nodule samples from the Słupsk Furrow and the edge of the Gotland Basin showed the average REE content at the level of 164.33 ppm (from 118.40 ppm to 202.74 ppm). There is a visible small positive Li anomaly (from 60.40 ppm to 444.60 ppm).

Further research investigations may redound more data in the context of economic potential.

Mon: 17
Topics: 1.24 Reclamation and transformation of post-mining landscapes: Biogeochemical processes, ecological and geochemical remediation strategies for open-cast mining lakes and sustainable water management

Airborne geophysical investigation of former opencast lignite mining areas using machine learning and other techniques

Olaf Josafat Cortes Arroyo, Bernhard Siemon, Silvio Janetz, Marcus Fahle, Elisabeth Schönfeldt

Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Germany

As part of project D-AERO Finsterwalde, the “Bundesanstalt für Geowissenschaften und Rohstoffe” (BGR) carried out an airborne geophysical study in a former opencast lignite mining area in summer 2021. The area (260 km², 1742 line-km) surveyed using BGR’s helicopter-borne geophysical system (electromagnetics (EM), magnetics and radiometrics) is located about 60 km southwest of the city of Cottbus. The project was conducted in cooperation with “Lausitzer und Mitteldeutsche Bergbau-Verwaltungsgesellschaft” (LMBV) and in consultation with “Landesamt für Bergbau, Geologie und Rohstoffe Brandenburg“ (LBGR). The results (Siemon et al., 2022) include a comparison of the resistivity models derived from EM data with a geological database provided by LMBV and corroborates the validity of the resistivity models.

We present here the first results of “FINA”, a new project by BGR´s „Forschungs- und Entwicklungszentrum Bergbaufolgen” (FEZB) that, among several other goals, aims to make use of the collected helicopter-borne EM information to complement the previous analysis. Using machine-learning algorithms, the EM models are analyzed searching for patterns previously not seen. An in-depth analysis is performed based on geological and geophysical databases, now complemented with geophysical logs and further geological borehole information provided by LBGR. These results will be used in the near future to refine a new 3D geological model of Lusatia currently in development, in order to obtain a better understanding of the water distribution and flow patterns in that region.

Mon: 18
Topics: 1.24 Reclamation and transformation of post-mining landscapes: Biogeochemical processes, ecological and geochemical remediation strategies for open-cast mining lakes and sustainable water management

Application of isotopes to study groundwater surface water interactions in the German Lusatian mining district – a first characterization

Paul Königer, Anne Gaedeke, Maike Gröschke, Silvio Janetz

BGR Bundesanstalt für Geowissenschaften, Germany

The hydrology and hydrogeology of the German Lusatian mining district has strongly been impacted by open pit lignite mining. During active mining, mines are dewatered to lower the groundwater tables below the coal-bearing layers (up to 100 m below the surface). Following the phase-out of current mining activities, groundwater levels will rise and groundwater will reconnect with surface water. The groundwater-surface water interactions strongly influence flow patterns and dynamics as well as hydrochemistry and water quality, and are still largely unknown.

It is therefore planned to systematically select up to five representative post-mining lakes to conduct detailed measurement of climatological parameters and stable isotopes (deuterium, oxygen-18, and sulphur-34). The overall goal of this work (IsoGon project) is the characterization of surface water-groundwater interactions and the quantification of evaporation losses from the post-mining lakes in Lusatia. In this contribution, we summarize our planned project activities, state of the project, current understanding of the subject and our objectives of further planned work.

Mon: 19
Topics: 1.24 Reclamation and transformation of post-mining landscapes: Biogeochemical processes, ecological and geochemical remediation strategies for open-cast mining lakes and sustainable water management

Overview of the ecological situation of open pit lakes of the lignite mining in Germany

Jessica Ramm1, Brigitte Nixdorf2, Klaus van de Weyer3

1Landkreis Cuxhaven - Amt Wasser und Abfallwirtschaft; 2BTU Cottbus Senftenberg, Germany; 3Lanaplan GbR, Landschafts- und Gewässerökologie

The EU Water Framework Directive (WFD) demands a good ecological status or ecological potential for natural and artificial lakes larger than 50 ha until 2027. More than 100 artificial mining lakes originate from lignite mining activities in Germany. The specific chemistry of mining lakes with their high phosphorus retention capacity is a chance for the development of clear lakes that are poor in nutrients. For neutral mining lakes, the existing typology for natural lakes which is based on the biological quality elements was adapted. For acidic lakes, the phytoplankton assessment was modified by including the diversity of the phytoplankton. In total, 36 of the largest existing mining lakes in Germany were assessed and description of the limnological lake characteristics were elaborated. Some of the relevant lakes could not be sampled because they are still in filling process and under surveillance of the mining authorities or safety demands for sampling are not given. So far, 53 % of lakes considered in this study reach the good or better ecological potential. Three lakes fail this state because environmental quality standards for river basin-specific chemical pollutants are not complied. Only one lake shows too high trophic conditions. The currently applied assessment tools especially those for macrophytes and microphytobenthos do not meet the requirements for the specific ecological situation in acidic mining lakes. Therefore, these results can only be regarded as an intermediate status of assessment for mining lakes. A revision of the assessment process of macrophytes and microphytobenthos in acidic lakes is recommended.

Mon: 20
Topics: 3.03 Advances in paleoclimate proxy development and application

A historical record of combustion pollution in lake sediments during medieval and early modern times in Bad Waldsee (southern Germany)

Kristin Haas1, Sara Saeidi ghavi andam2, Matthias Hinderer1, Thomas Schiedek1, Elena Marinova2

1Institute of Geosciences, Department of Applied Sediment Geology- Technical University of Darmstadt, Darmstadt, Germany; 2Archeobotany Lab, Baden-Wuerttemberg State Office for Cultural Heritage- Regierungspräsidium Stuttgart, Gaienhofen-Hemmenhofen, Germany

Laminated sediments of lake Stadtsee, located next to the city Bad Waldsee, provide a unique archive of socio-economic and environmental history since Medieval times. In this study we explored the composition patterns of PAHs and DMP together with the sedimentary charcoal influx records as indicators of variations in natural and anthropogenic fire activity from 1200-1800.

Charcoal particles and organic pollutants are emitted from incomplete combustion in the surrounding area as well as in the city and thus deposited in sediments. Pyrogenic Polycyclic aromatic hydrocarbons (PAHs) can be linked to vegetation types, householdburnings or pre-industrial production. In particular, the co-occurrence of charcoal and PAHs including dimethyl-phenanthrene (DMP) isomers can be used as a proxy to distinguish natural- and human-related historical fire activity. However, this proxy has rarely been applied for the time period before 1800.

Macro charcoal results show 15 screened charcoal peaks, which group into two phases of biomass burning. The first phase in the late Medieval period show high proportions of burned grass and monocot leaves, whereas in the second phase in the early Modern Times wood was the main fire fuel. The obtained PAH patterns, in particular the DMP isomers ratio (1.7-DMP/1.2-DMP), support the change in fuel source. High perylene values in late Medieval time indicate biogenic processes under anoxic conditions and suggests delivery of terrestrial organic material by water.

Mon: 21
Topics: 3.03 Advances in paleoclimate proxy development and application

Mg isotope fractionation in the bivalve Glycymeris

Niklas Keller1, Eric Otto Walliser2, Melita Peharda3, Michael Tatzel1

1Georg-August Universität Göttingen, Germany; 2Hessisches Landesmuseum für Kunst und Natur, Wiesbaden, Germany; 3Institute of Oceanography and Fisheries, Split, Croatia

The Cenozoic cooling that occurred over the past 50 Ma is accompanied by an increase of Mg/Ca ratio in seawater. How this change in seawater chemistry is linked to climate change is still disputed. Mg isotope ratios of seawater could distinguish several possible causes including dolomitization, authigenic clay formation and changes in rates of silicate- and carbonate weathering. Former reconstructions of Mg isotope ratios of paleo-seawater are based on foraminifera, corals or carbonate muds, which however yield conflicting results. Here we assess the suitability of the bivalve Glycymeris as an archive for paleo-seawater δ26Mg (the standardized 26Mg/24Mg ratio). Their potential as geochemical archive advantage arises from their strong evolutionary conservatism, thick shells and a fossil record dating back to the Early Cretaceous. We report Mg isotope signatures of shells of three recent Glycymeris species from the Adriatic Sea that show an increasing fractionation with increasing ontogenetic age, a property that we use to determine δ26Mg of paleo-seawater from fossil Glycymeris specimens.

Mon: 22
Topics: 3.03 Advances in paleoclimate proxy development and application

Seasonal changes of ambient environment reflected in Glycymeris shells from the Iberian Shelf

Alexandra Németh, Zoltán Kern

Research Centre for Astronomy and Earth Sciences, Budapest, Hungary

The aim of our study was to investigate the driving factors for shell growth in G. glycymeris bivalves by analysing the growth patterns and stable oxygen and carbon isotope compositions of shells collected from the Atlantic coast of the Iberian Peninsula.

An increment chronology, covering the 1985-2001 period, was established from the shells and was used to explore longevity and growth responses to environmental parameters. The inter-annual fluctuation of increment widths displayed a positive correlation (r=0.49, p < 0.05) with the regional March sea surface temperature (SST), suggesting that at this collection site, late winter SST is limiting the growth of the studied bivalve species. Significant negative correlations were observed with precipitation (r=-0.69 p<0.05) and also with sea surface salinity (r=-0.59 p<0.05) in February associated with complex hydrological processes of the Iberian Shelf. Intensive regional precipitation in June seems to have a positive effect on shell growth.

Comparing sub-annually resolved oxygen isotope ratios from three specimens with overlapping lifespans (1984-1993) to satellite-derived temperature data proved that summer SST maxima were recorded within the shell carbonate, whereas annual minima are not reflected.

Our results imply that annual growth rates of G. glycymeris shells collected near Aveiro are affected by summer runoff events and late winter SSTs. The latter connection is more difficult to explain as Glycymeris shell growth usually slows down or ceases during this period. Late winter stages of Glycymeris reproduction may affect their sensitivity to late winter SSTs and may have possible consequences for the overall annual shell growth.

Mon: 23
Topics: 3.03 Advances in paleoclimate proxy development and application

Seasonal variances in the palaeolake of Tayma (Saudi Arabia) seen in microfossils during the Early Holocene Humid Period

Anna Pint1, Ella Quante1,2, Peter Frenzel1, Eilyn Becher1, Max Engel3

1Friedrich Schiller Universität Jena, Germany; 2Department of Archaeology, Max Planck Institute for Geoanthropology, Jena; 3Institute of Geography, Ruprecht Karl University of Heidelberg

During the Early Holocene Humid Period (EHHP), a perennial lake was located in the endorheic depression north of the modern settlement of Tayma in Saudi Arabia. While the climate in this area is arid to hyperarid today, it was arid to semiarid during the EHHP. A deep lake phase occurred around the 8.2 ka BP climate deterioration that led to general cooling and drying on the Arabian Peninsula. Foraminifers and ostracods in the sediments of the sabkha basin represent a brackish to hypersaline inland water fauna, which provides valuable information on the past precipitation/evaporation balance. In the lower part of an analysed core section from the deepest part of the basin, they reflect the beginning of the EHHP with a transition to a more humid phase and the development from slightly saline wetlands to a shallow brackish lake, shown by increasing microfossil abundances, a decreasing adult/juvenile-ratio in ostracods, and an increase of δ13C. This culminated in a deep lake phase at ca. 8.3 cal. BP. Varved sediments from two sections contain ostracods and foraminifers which are more abundant in the dark layers, indicating more favorable living conditions during deposition of these layers. This is also indicated by higher frequencies of juvenile carapaces in the light layers, suggesting possibly higher juvenile mortality rates. A sieve pore analysis in ostracods valves proposes distinctly higher salinities during deposition of the light layers. The seasonal variances in the microfossil assemblages may reflect generally dry summers and more humid winters.

Mon: 24
Topics: 3.03 Advances in paleoclimate proxy development and application

Are molluscs a reliable archive for stable isotope paleo-temperature reconstructions? Implications from dual clumped isotope thermometry

Vanessa Schlidt1, David Evans2,1, Niels de Winter3, Miguel Bernecker1, Amelia Jane Davies1, Iris Arndt1, Philip Tauxe Staudigel1, Mattia Tagliavento1, Wolfgang Müller1, Jens Fiebig1

1Institute for Geosciences, Goethe University Frankfurt, Altenhöferallee 1, 60438 Frankfurt, Germany; 2School of Ocean and Earth Science, University of Southampton, Southampton, UK; 3Department of Earth Sciences, Faculty of Geosciences, Utrecht University, the Netherlands

Shell carbonates of marine molluscs are a widely used archive for paleo-environmental reconstructions. However, their use for temperature reconstructions may be impeded by species-specific vital effects and/or a lack of knowledge of the chemical and isotopic composition of paleo-seawater. Clumped isotope (∆47) thermometry of marine carbonates enables temperature reconstructions independent of seawater composition provided the carbonate formed in thermodynamic equilibrium. Dual clumped isotope thermometry, i.e. simultaneous analysis of ∆48 alongside ∆47, offers the opportunity to determine if a carbonate formed in isotopic equilibrium and to account for kinetic effects taking place prior to and/or during precipitation. Here, we present dual clumped isotope data for several modern mollusc specimens (including bivalves and gastropods) with average growth temperatures ranging from 5-27°C. We find that most specimens analysed in this study exhibit dual clumped isotope compositions which are indistinguishable from equilibrium. Moreover, their ∆47-derived temperatures agree within errors with their growth temperatures. We interpret the apparent equilibrium calcification of mollusc shell carbonates to be a possible consequence of a relatively low pH at the site of calcification. The absence of any resolvable kinetic isotope effects makes molluscs a reliable archive for highly precise (95CI of <2.2°C) temperature reconstructions via ∆47-analysis. Based on previous ∆47 investigations of molluscs grown at known seawater oxygen isotope compositions (δ18OSW), we also determine the temperature dependencies of the oxygen isotope fractionation between seawater and molluscan aragonite/calcite.

47 and δ18O values of fossil molluscs may be used in conjunction with these calibrations to reconstruct both - seawater-δ18O and temperature.

Mon: 25
Topics: 3.03 Advances in paleoclimate proxy development and application

Isotope hydrogeochemistry and physico-chemistry of Lago Enriquillo (Dominican Republic) and its tributaries

Christopher Berndt1, Michael Ernst Böttcher1,2,3, Torsten Haberzettl1, Lilly Biedermann1, Berenice Matias Marte de Reyes4, Edwin Garcia Cocco4, Claudia Wrozyna1

1University Greifswald, Germany; 2Geochemistry & Isotope Biogeochemistry, Leibniz IOW, Germany; 3Interdisciplinary Faculty, University of Rostock, Germany,; 4Servicio Geológico Nacional, Santo Domingo, Dominican Republic

Tropical cyclones (TCs) such as hurricanes are amongst the most devastating natural disasters of the modern world causing massive humanitarian, ecological, and economic damage every year. A better understanding of timing and frequency of TCs must, therefore, be a key priority for building resilience of affected countries. Within this project, we investigate a stable isotope-based approach for the reconstruction of paleo-TCs through the integration of ecological and morphological data with isotope geochemical signatures of modern ostracodes in relation to the hydrochemistry from a tropical lake located within the Main Development Region of TCs (Lago Enriquillo, Dominican Republic). Water samples were taken during two seasons in 2022 on different vertical profiles through the lake, associated tributaries and closed-by water bodies. Besides in-situ characterization, samples were taken for major, minor, and trace elements using different analytical approaches, and the stable isotope signatures of water (2H, 18O; CRDS spectroscopy), dissolved inorganic carbon (13C; gas mass spectrometry), and sulfate (34S, 18O; gas mass spectrometry). Hydrochemical data were further evaluated using the speciation model PHREEQC.

Substantial changes in the lake composition were observed between the two campaigns. Together with an evaluation of element stoichiometries, the water isotopes allow for an evaluation of sources and evapotranspiration. Carbon and sulfur isotopes allow to deduce the role of microbial activity and solution-atmosphere exchange on the modulation of the dissolved carbon system, in contact with solid phase carbonates, like ostracod shells

Mon: 27
Topics: 3.11 Triassic Revolution

Testing Triassic S2S models using simple grain-size analysis

James Michael Lovell-Kennedy, Emma Dobromylskyj, Pete Burgess

University of Liverpool, United Kingdom

Outcrop and sub-crop evidence from the Lower Triassic Sherwood Sandstone Group (SSG) suggests a northerly flowing braided river deposited pebble-rich red sandstones through several UK basins. Previous workers assume the sole source of this ‘Budleigh Salterton River System’ to be the Armorican Massif, based on dominantly metaquartzite pebble composition, paleoflow orientations and lithostratigraphy trend. However, a proximal to distal facies trend northwards from an Armorican Massif source should mean pebble-sized clasts decrease in abundance northwards, yet pebble-rich sandstones and conglomerates are seen through several basins with slight variations in composition, perhaps indicating that other topographic high areas adjacent to the river system also provide a source for the pebble clasts via tributary drainage systems. This study conducted fieldwork to collect data specifically surrounding clast inclusions pebble clasts, including clast size, abundance, and orientation, to determine if/where possible tributaries occur. Pebble abundance was plotted against distance using Matlab software, with a simple model inversion used to assess the distance from the source. Our results indicate a three source-model is most likely, suggesting local sources are present and significant contributors to the overall sediment budget. Using spatial distributions of pebble abundance, one tributary was likely located from the Welsh Massif and a second from a potential basin margin fault. These results contrast previous models, which suggest the majority of sediment was sourced from the Armorican Massif, and raise several questions about the distribution of Triassic sediment fairways across the UK.

Mon: 28
Topics: 3.20 Multiscale Investigations of Convergent Margins: Unraveling Subduction Dynamics from Kinematic Transitions to Metamorphic Reactions

Alpine and Variscan peak pressures of different rock types from the Adula Nappe (Central Alps) determined by Raman spectroscopy of quartz inclusions in garnet

Olga Brunsmann1, Marisa Germer1, Alexandra Pohl2, Victoria Kohn3, Vincent Könemann1, Xin Zhong1, Timm John1, Jan Pleuger1

1Institute of Geological Sciences, FU Berlin, Germany; 2Geologischer Dienst Nordrhein-Westfalen; 3Department of Lithospheric Research, Vienna University

The Adula nappe in the Swiss-Italian Central Alps is a continental basement nappe from the former European margin that was subducted to depths indicating (ultra)-high-pressure conditions. Many studies were performed to understand the pressure-temperature-time evolution of the Adula nappe. The Adula nappe underwent eclogite-facies metamorphism during the Variscan and Alpine orogenic cycles but the Variscan and Alpine parageneses are hard to distinguish.

For this study, around fifty samples were collected from different lithologies on a N-S transect through the Adula nappe parallel to the direction of subduction. Raman spectroscopy on quartz inclusions in garnet was used as a geobarometer to measure minimum peak pressures. This method is independent of chemical equilibria and yields reliable pressure constraints even if the high-pressure mineral assemblage has been retrogressed. Variscan and Alpine garnet domains were identified using the Electron Microprobe and Scanning Electron Microscopy.

The Variscan peak pressure was at least 2.3 GPa. For the Alpine metamorphism, the Zr-in-rutile temperatures exhibit a gradient increasing from ca. 500-550 oC in the north to around 700 oC in the south. The minimum peak pressures in the northern and central Adula nappe are 2.1-2.2 GPa for metasediments, 1.4-2.0 GPa for metabasites, and 1.5 GPa for an orthogneiss. Lower pressures of 1.1-1.3 GPa in the southern Adula nappe were potentially caused by viscous relaxation of the quartz inclusions during the high-temperature Lepontine metamorphism.

Mon: 29
Topics: 3.20 Multiscale Investigations of Convergent Margins: Unraveling Subduction Dynamics from Kinematic Transitions to Metamorphic Reactions

Exhumation related crystallographic preferred orientations in Cretaceous high pressure rocks of the Eastern Alps

Ruth Keppler, Niko Froitzheim

Universität Bonn, Germany

The Saualpe-Koralpe high pressure (HP) complex as well as the HP units of the Pohorje mountains formed during the Cretaceous orogenic cycle in the Eastern Alps. Within these units eclogite bodies can be found, which were probably emplaced along the rift zone that led to the opening of the Meliata ocean. After closure of the ocean ongoing convergence led to underplating within the lower plate, which led to the formation of the Austroalpine nappe stack. During subduction, the Saualpe, Koralpe and Pohorje units reached peak pressure conditions of 2.2-2.4 GPa/630-690°C, 1.8-1.9 GPa/670°C and 3.0–3.7 GPa/710–940 °C, respectively. PT-analyses, microstructural investigations and dating predict different contrasting models for the subsequent exhumation of these units.

Here, we investigate the deformational history of these units during their exhumation. We sampled sets of pristine eclogites, retrograde amphibolite facies shear zones as well as neighboring gneisses surrounding the eclogite lenses. The samples were analyzed by electron backscatter diffraction (EBSD) to determine their crystallographic preferred orientation (CPO) and deformation mechanisms. Both omphacite in pristine eclogites and hornblende in the amphibolite facies shear zones show a pronounced CPO. Hornblende yields distinct signs of dynamic recrystallization by subgrain rotation within the shear zones. Quartz CPO was analyzed in both the eclogites and the surrounding gneiss matrix. Results indicate a shear sense reversal during the exhumation of the Pohorje eclogites.

In this study we show CPO data that recorded the deformational path of these rocks from eclogite facies conditions up to the exhumation to crustal levels.

Mon: 30
Topics: 3.20 Multiscale Investigations of Convergent Margins: Unraveling Subduction Dynamics from Kinematic Transitions to Metamorphic Reactions

Numerical Thermo-Mechanical Modeling of Collision Zones: Investigating Anisotropy Effects using MDOODZ Software

Roman Kulakov1, Irina Medved2, Thibault Duretz1, William Halter3, Stefan Schmalholz3

1Goethe-Universität Frankfurt, Germany; 2Trofimuk Institute of Petroleum Geology and Geophysics​ of Siberian Branch Russian Academy of Sciences (IPGG SB RAS); 3UNIL | Université de Lausanne

Understanding collision zones and their geodynamic processes is crucial for comprehending plate tectonics, mountain building, and seismic activities. This study employs the software MDOODZ for numerical thermo-mechanical modelling, specifically designed to simulate the mechanical behaviour and thermal evolution of rocks in 2D complex geological settings.

Focusing on a collision zone, we investigate the influence of anisotropy on geodynamic processes. Anisotropy, resulting from preferred orientations of minerals or rock structures, plays a significant role in the deformation behaviour and mechanical response of stressed rocks. By incorporating anisotropy effects using the director vector and transformation matrix approaches proposed by Mühlhaus (2002) and Fletcher (2005), respectively, we explore its impact on the overall geodynamic evolution of the collision zone.

Our 2D thermo-mechanical numerical model captures the essential dynamics of the collision zone, considering the coupling of mechanical and thermal processes, including rock rheology, heat transfer, and their interactions. Accounting for anisotropic properties enables us to investigate the implications of various orientations and strengths of anisotropy on geodynamic processes within the collision zone.

Our findings contribute to understanding collision zone dynamics, highlighting the significance of anisotropy effects in shaping geological processes. The utilisation of MDOODZ, in conjunction with anisotropy incorporation, facilitates exploring the intricate interplay between anisotropy and thermo-mechanical interactions in collision zones.

Mon: 31
Topics: 3.20 Multiscale Investigations of Convergent Margins: Unraveling Subduction Dynamics from Kinematic Transitions to Metamorphic Reactions

Effects of upper mantle drag on slab detachment dynamics: insights from 0D and 3D experiments

Andrea Piccolo, Marcel Thielmann, Arne Spang

Bayreuth Universität, BGI, Bayreuth, Germany

Slab detachment is a process that has been invoked to explain rapid uplift, deep seismicity, and magmatic activity in several active orogens (e.g., Alps, Himalaya). However, it is not yet clear to which extent slab detachment is the primary cause of these phenomena. Thus, deciphering the physical processes controlling the slab break-off is important to understand its impact on the post-collisional evolution of orogens.

Here, we employ numerical models to investigate the nonlinear coupling between mantle flow and slab detachment. Due to the three-dimensional nature of slab detachment and the variety of involved processes, it is daunting to pinpoint the first order controls on the time scale of this process. We, therefore, started to investigate this issue by developing a 0D necking model that describes the temporal evolution of the thickness of a detaching slab. We accounted for the effects of the nonlinear coupling between upper mantle and detaching slab and derived a set of nondimensional numbers that control the slab detachment process.

Based on these findings, we, then, used 2D and 3D numerical models to further determine higher dimensional geometrical effects on slab detachment. Results show that the predictions from the 0D experiments predict simple 2D and 3D experiments sufficiently well. For more complex slab geometries, higher dimensional results deviate from the 0D predictions. Nevertheless, the combination of 0D and 2D/3D numerical models allows to determine first order controls on slab detachment and thus also on specific geological observations such as seismicity and surface response.

Mon: 33
Topics: 3.20 Multiscale Investigations of Convergent Margins: Unraveling Subduction Dynamics from Kinematic Transitions to Metamorphic Reactions

First results of quartz inclusion elastic barometry and insitu U/Pb dating in garnet for Koralpe-Saualpe-Pohorje (KSP) Complex

Iris Wannhoff1, Jan Pleuger1, Xin Zhong1, Timm John1, Leo J. Millonig2, Axel Gerdes2

1Freie Universität, 12249 Berlin, Germany; 2Goethe Universität, 60438 Frankfurt am Main, Germany

The KSP Complex in the Eastern Alps is a lithologically heterogenous (U)HP nappe with eclogite lenses embedded in gneisses and metasediments. The formation history of the KSP Complex is still debated. Here, we investigate in detail the pressure and temperature conditions during the formation of the complex along a NW-SE transect following the direction of subduction. This is the first study where quartz inclusions in garnet elastic barometry was conducted to determine the entrapment pressures, which correspond to the minimum pressure conditions present during the entrapment of quartz inside garnet. The eclogites yield pressures of max. 1.9 GPa across the KSP complex, indicating no pressure increase from the NW to SE. The metasediments and gneisses show overall lower pressures with ca. 1.4 GPa. Temperatures based on Zr-in-rutile thermometry do not indicate a temperature increase from NW to SE, with ca. 640 (±30)°C across the whole KSP Complex, based on very similar Zr content of ca. 270 ppm. U/Pb dating on garnets in metasediments provide the following ages for the Koralpe 101.3 ± 6.6 Ma (throughout garnet); Saualpe 224.6 ± 31 Ma (core) and 95.43 ± 5.6 Ma (rim); Pohorje 99.83 ± 5.85 to 104.2 ± 7.1 Ma (throughout garnet). Garnet in eclogite from Koralpe is 112.8 ± 9.9 Ma. Combined with results of previous studies of eclogite ages, we suggest, that the eclogites are former (probably Permian) gabbro intrusions that experienced HP conditions during the Eo-Alpine orogeny. Whereas garnet ages of metasediments from Saualpe provide evidence for a polymetamorphic history.

Mon: 34
Topics: 3.20 Multiscale Investigations of Convergent Margins: Unraveling Subduction Dynamics from Kinematic Transitions to Metamorphic Reactions

The effect of aqueous fluid on viscous relaxation of garnet and modification of inclusion pressures after entrapment

Xin Zhong1, David Wallis2, Phillip Kingsbery1, Timm John1

1Freie Universitat Berlin, Germany; 2Cambridge University, UK

The elastic interaction between an inclusion and its host is often employed to study the entrapment conditions during metamorphism on the assumption that the host is not affected by creep. However, it is not well understood how fast creep-induced relaxation may occur and under what conditions the elastic regime holds for each crystalline inclusion-host system. In this study, we performed heating experiments on eclogite and spessartine garnets under 1) graphite, 2) N2+H2 and 3) H2O+Ar fluxed conditions at different temperatures. Raman spectroscopy is used to measure the same quartz and zircon inclusions after different heating times. The Raman-band wavenumber undergoes a time-dependent decrease in quartz inclusions and increase in zircon inclusions under H2O+Ar and H2+N2 conditions, but stabilises after the first heating step under graphite-buffered conditions. EBSD results reveal greater misorientation around the heated inclusions compared to unheated inclusions. Raman mapping reveals that stress heterogeneity in the garnet host develops first and fades away afterward, indicating dispersal of dislocations into the host. A visco-elastic model fit to the measured Raman data provides estimates of flow-law parameters for garnet. These results demonstrate the efficiency of H migration and its weakening effect on garnet. The data also indicate that the garnet can be stronger than previously thought under a dry and reduced environment, which is consistent with the high activation energy of Si diffusion in dry garnet. This study provides a critical temperature and water limit for elastic thermobarometry and criteria of determining whether an inclusion has been reset or not.

Mon: 35
Topics: 4.06 From Unoccupied Aerial Vehicles (UAVs) to Mixed-Reality Visualizations: Expanding Frontiers in Field Data Acquisition, 3D-Model-Design and Geo-Visualization

The internal structure of the Asse salt diapir – new insights from 3D geological modelling

York Fischer, Evelyn Suchi

Federal Institute For Geosciences And Natural Resources, Germany

As part of the retrieval planning of radioactive waste from the ASSE II salt mine, located in the western part of the Asse-Heesberg salt structure south-east of the city of Braunschweig in northern Germany, a detailed and consistent 3D geological model of the internal structure is required. It’s used as a planning tool for the construction of a recovery mine and includes the Zechstein units from the Staßfurt to the Aller-formations (z2-z4). The data basis consists of a multitude of prospecting data such as drill cores, georadar reflectors, 3D seismic and dip values, for instance.

3D geological modelling of salt rock which has been highly deformed by salt migration and tectonical stress as well, faces some challenges. The various layers within the salt rock are strongly folded and overturned in parts. Lithologically different salt bodies often intertwine. The visualization of such complex structures often cannot be realized using conventional 3D modelling software that bases on fixed mathematical algorithms. Thus, details of the internal structure remain disregarded in many cases. Salt model surfaces can be shaped more precisely considering not only the input data, but also the geologic evolution of the salt structure. Therefore, in this project, we use a software (OpenGeo7) that requests complete manual drawing of the isobaths of the model surfaces. In the present study, we present some challenges and results of this type of 3D geological modelling.

Mon: 37
Topics: 4.06 From Unoccupied Aerial Vehicles (UAVs) to Mixed-Reality Visualizations: Expanding Frontiers in Field Data Acquisition, 3D-Model-Design and Geo-Visualization

Automatisation of sparse cloud cleaning in Agisoft Metashape Professional (ver. 2.x)

Joel Mohren, Maximilian Schulze

Institute of Geology and Mineralogy, University of Cologne, Germany

The U.S. Geological Survey (USGS) has recently published a guideline for processing coastal imagery acquired by unmanned aerial vehicles (UAVs) based on the widely used Agisoft Metashape Professional software (USGS Open-File Report 2021-1039; Over et al. 2021). The guideline aims to improve the quality of photogrammetric reconstructions by iteratively removing low-quality tie points based on different cleaning parameters. However, the improvement procedure is iteratively performed and requires permanent attendance of the operator. Furthermore, the different cleaning steps are executed on a trial-and-error basis, adding up to the overall attentiveness required.

To minimise the time expenditure necessary for conducting the cleaning procedure and to provide a frame for the reproducibility of photogrammetric product derivations, we have compiled a python script to automate the tie point cloud optimisation as detailed in the USGS report. The graphical user interface of the script allows non-expert users to adjust important cleaning parameters, such as maximum reconstruction uncertainty, minimum projection accuracy and/or maximum reprojection error thresholds, and number of iterations to be performed. Furthermore, main tie point cloud quality measures can be directly assessed. We will demonstrate that the time required to clean tie point clouds (using a computer equipped with a 3.60 GHz processor, 64 GB Ram, and NVIDIA Quadro M4000) can be significantly reduced, such that cleaning of a (unprocessed) ~8 million tie point cloud is achieved unattended in about 30 minutes (default cleaning threshold values used), with ~7 million tie points being automatically removed while significantly increasing point cloud quality measures.

Mon: 38
Topics: 4.06 From Unoccupied Aerial Vehicles (UAVs) to Mixed-Reality Visualizations: Expanding Frontiers in Field Data Acquisition, 3D-Model-Design and Geo-Visualization

GIS-based geological 3D modeling of the Paleozoic rocks of the Halle-Wittenberg-block in the urban area of Halle (Saale) and surroundings

Benedykt Vincent Pasek, Wolfgang Gossel

Institute of Geosciences, Martin-Luther-University Halle-Wittenberg, Halle, Germany

The Halle Fault in central Germany is a major tectonic fault that separates the lower permian rocks (Rotliegend) in the north from triassic rocks in the south. While geological modeling of the Cenozoic and Mesozoic rocks on both sides of the fault has been carried out frequently in the last two decades, the Paleozoic volcanics and sediments of the Permo-Carboniferous rocks in the Halle-Wittenberg-Scholle that outcrop in the urban area have not been modeled in 3D. This study aims to fill this gap by proposing a 3D GIS-based modeling approach to model the geometric and stratigraphic relationship of the volcanic rocks and host-sediments of the Halle-Wittenberg-Scholle.

The approach relies on standard geological data, such as geological maps, boreholes, and digital terrain models, from which geological cross sections are generated and used for further modeling. Existing profiles and seismic data are desired and can bring advantages in the modeling process. While attempts to develop an open-source modeling tool have already been made, they require programming skills, making this GIS-based approach more accessible to a wider audience.

For this purpose this research aims to make the proposed method publicly available, enabling anyone to create a 3D geological model without the need for specialized and costly modeling programs. This approach facilitates an ideal exchange between students and scientists, promoting further understanding and exploration of the possibilities of geological 3D modeling, and also advancing the understanding of the geological features of the Halle Fault.

Mon: 40
Topics: 4.13 Museen als Fenster in die Forschung

Besucher aktiv werden lassen: Angewandte Paläontologie zur Wissenschaftskommunikation

Ulrich Kotthoff1, Lioba Thaut1, Julia Pawlowski2

1Leibniz-Institut zur Analyse des Biodiversitätswandels, Germany; 2Universität Hamburg

Ökosystem- und Klimaänderungen sind äußerst aktuelle und brisante Themen, die bei einem großen Teil der Bevölkerung auf breites Interesse stoßen. Bei der Unterscheidung zwischen anthropogen beeinflussten und rein natürlichen Änderungen spielen paläoklimatologische Untersuchungen eine wichtige Rolle. Die Ergebnisse solcher Untersuchungen geben populäre Medien jedoch zum Teil missverständlich oder gar verfälscht wieder. Oft veröffentlichen Medien Ökosystem- und Klimadaten und diskutieren diese, doch die Ansätze zur Ermittlung der präsentierten Daten, ihre Verlässlichkeit sowie ihre Anwendbarkeit bleiben NichtwissenschaftlerInnen oft verschlossen.

Ein guter Weg, interessierten Laien natürliche Klimaänderungen zu erläutern und generell das Verständnis für wissenschaftliche Forschung zu stärken, sind vereinfachte Fallstudien z. B. anhand von synthetischen Pollenpräparaten. Wir stellen solche Studien vor und diskutieren ihre Umsetzbarkeit in Museen, Schulen und der universitären Lehre anhand des Beispiels eines Kurses zur Pollen-basierten Paläoklimaanalyse mit Grundschulkindern, bei dem theoretische Fragen mit Analysen und haptischen Arbeiten verknüpft wurden. Wir legen weiterhin dar, wie solche Kurse in verkleinertem Umfang auch bei öffentlichen Veranstaltungen umgesetzt werden können.

Mon: 41
Topics: 4.13 Museen als Fenster in die Forschung

Geoparks – Connecting geology, nature and society for a sustainable future

Anna Mareis, Fabian Weiß

Geopark Ries e.V., Germany

Geoparks serve as an important link between science and the public. Through the lens of geotourism, they not only strengthen regional development and sustainable economics but also offer an interesting encounter with geology and the profound story of our planet’s past. Geoparks provide universal access to the habitat Earth and thereby enhance the respect for nature within society. Since last year the Geopark Ries has been labeled UNESCO Global Geopark, highlighting its remarkable geological heritage on the global stage. The concept of the Geopark Ries is designed to captivate, interest and educate individuals from diverse backgrounds. Even from a very young age, visitors are able to dive into Earth’s history via child-firendly educational programs. Numerous geosites, expert-led tours and thematic hiking trails not only deepen the understanding for the environment and geology of interested locals and tourists but also grant researches and students access to the type locality of Suevite and Riesite.

Therefore, Geoparks play a significant role in raising public awareness regarding the relationship between geology, nature and humanity, thus laying a solid foundation for a sustainable future.

Mon: 42
Topics: Others

Das Natürlich Geschlossene System (NGS) eine axiomatische Triade der Geologie

Hans Eckhard Offhaus

Geologie, Germany

Neben geologischen besitzen Gesteinsgrenzen auch die mathematische Eigenschaft der Gleichheit oder der Kongruenz. Im Einheitskubus des NGS können durch die Mittelsenkrechte vier kongruente Dreiecke in der lotrechten Ebene und vier kongruente Prismen dargestellt werden. Der geometrische Zusammenhang ist begründet durch das mathematische Axiom der Kongruenz. Die Kongruenz der Gesteinsschichtung ist ein rein geologisch begründetes Faktum der Geologie, die Erklärung desselben Bedarfs keiner weiteren Entität.

Der Einheitskubus des NGS erklärt die Verknüpfung des Kongruenzaxioms mit dem Parallelenaxiom in der Geologie. Das Parallelenaxiom ermöglicht den Ansatz der Messtechnik im geologischen Bau, die Einbeziehung des Zahlensystems und somit die axiomatisch begründete Komplexität in der Geologie. Die Veränderung der räumlichen Lage von Gesteinen aus einer ursprünglich horizontalen Lagerung in alle möglichen Schrägstellungen desselben verursachen Schnitte von unterschiedlichsten Flächen und Ebenen im geologischen Bau. In diesen Schnittlinien inzidieren unterschiedliche geologische Flächen und Ebenen miteinander. Die Spuren dieser Schnitte sind Linien der Inzidenz. Auswirkungen geologischer Schrägstellungen der Gesteine können durch das Axiom der Inzidenz erklärt werden.

Die Triade ist ein vollständiges, widerspruchsfreies und kategorisches System von Axiomen.Das NGS, ein mathematisches Objekt der Geologie, erklärt die Zusammenhänge der axiomatischen Triade in der Geologie. I.S. des Mathematikers David Hilbert (1862 – 1943) wird die Geologie durch ein System miteinander verknüpfter Axiome erklärt, das aus den Axiomen der Kongruenz, der Parallelität und der Inzidenz besteht. Die axiomatische Triade ermöglicht die Entwicklung einer "Theoretischen Geologie".

Mon: 43
Topics: Others

Precision, accuracy, and trueness: Bursting myths on portable XRF

Kathrin P. Schneider, Mareike Gerken, Roald Tagle, Falk Reinhardt, Nigel Kelly, Andrew Menzies, Christian Hirschle

Bruker Nano GmbH, Germany

Handheld and portable X-ray fluorescence (XRF) spectrometers have evolved in recent years from being primarily used as metal sorting tools in scrap yards to becoming instruments of high analytical performance. However, this trend has not been fully embraced by the academic and research community, and there are multiple reasons for this. In this presentation we will provide a comprehensive description of the capabilities of these devices, particularly in the context in geo-analysis and archeometric research. We will cover typical analytical performance indicators, including instrument stability, limits of detection, precision and accuracy, as well as reproducibility in quantification. Furthermore, we will discuss how the hardware concept of the instrument influences its performance, allowing for a better understanding of the instrument's capabilities and limitations.

As a practical example, we will focus on the analysis of archaeological ceramics using the TRACER 5g. Ceramic analysis is a common research field in archaeometry that presents additional complexities for accurate elemental characterization. For this application, we will discuss strategies for optimizing measurement time and analytical parameters, tuning existing calibrations for the samples, validating results for publication requirements, and address the challenges of non-invasive analysis of precious artifacts. Additionally, we will explore how the combination of sample characteristics, analytical questions, and XRF physics are directly connected in this context. The presentation will provide a realistic assessment of the analytical performance of portable XRF instruments by offering a robust analytical evaluation that dispels existing myths surrounding this technique.

Mon: 46
Topics: 1.01 Towards 'Net Zero' with negative emissions and sustainable landscapes

Depositional conditions controlling organic carbon burial in fine-grained sediments of the North Sea – The Helgoland Mud Area as a test field

Daniel Mueller1,2, Bo Liu1, Walter Geibert1, Elda Miramontes2,3, Heidi Taubner2,3, Lasse Sander4, Moritz Holtappelsa1,3, Susann Henkel1,3, Ingrid Dohrmann1, Denise Bethke1, Jessica Volz1, Kai-Uwe Hinrichsb Hinrichs2, Sabine Kasten1,2,3

1Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Germany; 2University of Bremen, Faculty of Geosciences, Germany; 3MARUM – Center for Marine Environmental Sciences, University of Bremen, Germany; 4Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Wadden Sea Research Station, List/Sylt, Germany

Fine-grained marine sediments are the largest permanent carbon sink on our planet. We chose the Helgoland Mud Area (HMA) as it represents the most important depocenter of such sediments in the German Bight and hosts a variety of sedimentary habitats that differ in key depositional factors – including water depth, sedimentation rates, grain size and origin of organic matter (OM). The HMA serves as a natural model area to (1) identify the main depositional drivers controlling the burial of organic carbon and (2) assess the efficiency of different sedimentary habitats as natural long-term carbon sinks. During two expeditions with RV Heincke, we collected a total of 16 MUC-cores from different areas of the HMA. Pore-water and solid-phase sampling and analyses were performed - including 210Pbxs to assess sedimentation rates and bioturbation depths, grain-size distribution, TOC contents and pore-water concentrations and stable carbon isotopic composition of DIC to determine the origin of the degrading OM. Sedimentation rates for the past ~200 years range from <0.5 to 6 mm yr-1 with highest rates in the southern and central part of the HMA. TOC contents typically vary from 1 to 2 wt% with highest values in areas of highest sedimentation rates. The source and reactivity of the degraded OM show large variations, ranging from marine origin in the NW to terrestrial sources in the S of the HMA. The obtained data set will be subject to statistical analysis to determine the key factors controlling the burial of organic carbon in fine-grained North Sea sediments.

7:00pmÖffentliche Abend-Diskussion "Das Anthropozän - Wie Menschen geologisch tätig wurden – und in Zukunft handeln sollten"
Location: Audimax
Session Chair: Georg Feulner, PIK
Seit der Industrialisierung sind die Menschen zu einer der wichtigsten Kräfte auf unserem Planeten geworden und haben das Erdklima, Landschaften und Ökosysteme tiefgreifend verändert. Wie können wir leben, ohne die planetaren Belastbarkeitsgrenzen der Erde zu überschreiten? Welchen Beitrag können die Geowissenschaften dafür leisten? Was können wir aus der Erdgeschichte lernen? Und wie können wir eine nachhaltige Zukunft gestalten? Darüber diskutieren die Klimaforscherin Ricarda Winkelmann und der Geochemiker Friedhelm von Blanckenburg.

Moderation: Georg Feulner | Potsdam-Institut für Klimafolgenforschung (PIK) e. V.
7:00pmStudent and Early Career Researcher EvenT (SECRET)
Location: Senatssaal