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
Location: Wiwi 104
Date: Monday, 04/Sept/2023
8:30am - 10:00am-
Location: Wiwi 104
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.


Date: Tuesday, 05/Sept/2023
10:00am - 11:15am2.03-1 Setting the stage for a habitable planet: Solid earth processes through time
Location: Wiwi 104
Session Chair: Sara Vulpius, Freie Universität Berlin
Session Chair: Liam Hoare, Ruhr-Universität Bochum
10:00am - 10:15am
Topics: 2.03 Setting the stage for a habitable planet: Solid Earth processes through time

Experimental and isotopic constraints on the formation of Archean continental crust

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

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

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

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

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

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

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

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

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

Metamorphism and the tectonic evolution of the Archean

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Craig Storey1, Hugo Moreira1,2

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

1Freie Universität Berlin, Germany; 2Universität zu Köln

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Sven Merseburger, Felix Marxer, Francois Holtz, Jürgen Koepke

Leibniz Universität Hannover, Germany

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


Date: Wednesday, 06/Sept/2023
10:00am - 11:15am-
Location: Wiwi 104
2:00pm - 3:30pm3.25 The links between deep-seated mechanisms, surface processes and landscape evolution
Location: Wiwi 104
Session Chair: Lorenzo Gemignani, Freie Universität Berlin
Session Chair: Riccardo Reitano, Univeristy of Rome "Roma Tre"
Session Chair: Silvia Crosetto, GFZ Potsdam
Session Chair: Alexander Rohrmann, Freie Universität Berlin
Session Chair: Richard F Ott, GFZ Potsdam
Session Chair: Romano Clementucci, ETH Zurich
2:00pm - 2:30pm
Invited Session Keynote
Topics: 3.25 The links between deep-seated mechanisms, surface processes and landscape evolution

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Controls on Island morphologic evolution

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

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

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

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

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

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

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

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

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

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

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

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

Christian Masurenko

ECTerra GEO Consult GBR, Germany

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

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

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

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

UNECE Resource Management Young Member Group (RMYMG), Germany

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

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

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

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

Meta Dobnikar1, Snježana Miletić1, Zoltán Horváth2

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

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

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

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


UNECE, 2020: Criteria for ICE-SRM Designation

UNECE, 2023: What is UNFC?

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

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

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

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

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

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

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

UNFC – a tool the scientific community should be aware of

Antje Wittenberg1, Sören Henning1, Jochen Kolb2

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

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

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

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

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

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


Date: Thursday, 07/Sept/2023
10:00am - 11:15am2.01-1 Late accretion processes from impacts to planetary differentiation - a multidisciplinary approach
Location: Wiwi 104
Session Chair: Laetitia Allibert, Natural History Museum, Berlin
Session Chair: Sabrina Schwinger, German Aerospace Center (DLR)
10:00am - 10:30am
Invited Session Keynote
Topics: 2.01 Late accretion processes from impacts to planetary differentiation - a multidisciplinary approach

Late veneer on the terrestrial planets: dynamics perspective

Alessandro Morbidelli1, David Nesvorny2, Zhu Meng-Hua3

1CNRS, France; 2SWRI, Co., USA; 3University of Macao, China

The origin of the late veneer of the terrestrial planets and of the lunar bombardment has been the subject of numerous studies in the field of cosmochemistry and in the field of planet formation and dynamical evolution of the early solar system. In the last years, we have studied [1,..,5] the dynamical and collisional evolution of the population of planetesimals originally in the terrestrial planet region and still “alive” at the time of the Moon-forming event. We have shown that this population of leftover planetesimals can explain the late veneer of Earth, Mars and Vesta as constrained by the amount of highly siderophile elements (HSE) in their mantles as well as the number of late impact basins on the Moon. The low concentration of HSE in the lunar mantle can be explained by a late sequestration of lunar mantle HSEs into the core at the time of the lunar mantle overturn. The origin of the late veneer carrier from the terrestrial planet region is consistent with the isotopic constraints on the source of the late veneer, indicating a non-carbonaceous source. This suggests that the carbonaceous projectiles that delivered part of the terrestrial volatile elements had already decayed by the time the late veneer started.

[5]Nesvorný, D., et al. 2023, Icarus, 399, 115545.

[4]Nesvorný, D., et al. 2022, ApJL, 941, L9.

[3]Zhu, M.-H. et al. 2021, Nature Astronomy, 5, 1286.

[2]Zhu, M.-H. et al. 2019, Nature Astronomy, 571, 226.

[1]Morbidelli, A., et al. 2018, Icarus, 305, 262.

10:30am - 10:45am
Topics: 2.01 Late accretion processes from impacts to planetary differentiation - a multidisciplinary approach

Giant impacts onto magma ocean: metal-silicate mixing constrained by coupling analogue laboratory experiments and numerical modelling

Laetitia Allibert1, Maylis Landeau2, Miki Nakajima3, Randolph Röhlen1, Augustin Maller2, Kai Wünnemann1

1Natural History Museum, Berlin, Germany; 2Institut de physique du Globe de Paris, Paris, France; 3University of Rochester, Department of Earth and Environmental Sciences, Rochester, NY, United States

Planetary formation models suggest that Earth experienced multiple high-energy impacts. Among those, the Moon-forming event is thought to be responsible for melting a large fraction of proto-Earth’s silicate mantle. Mixing of the impactor’s metallic core into Earth's silicate mantle controlled the chemical equilibration between metal and silicates, and hence the respective compositions of Earth's core and mantle. The extent of this mixing is, however, still debated. Previous studies explore mixing upon large impacts either with numerical modelling or with analog laboratory experiments. Numerical simulations are efficient in that they reproduce the shock physics of hypervelocity impacts. However, their spatial resolution is too limited to produce the turbulent features responsible for metal-silicate mixing in a magma ocean. Liquid impact experiments on the other hand are subsonic and hence neglect compressibility effects. However, they produce small-scale mixing and turbulence, which is crucial in estimating metal-silicate equilibration. Recent simulations and experiments disagree on the degree of mixing between the impactor and target materials. The origin of these differences is still unclear and requires further investigation. We present a scaling-law developed to extend the laboratory experiments results to hypervelocity cases and its further application the the metal-silicate mixing upon impact. We find that the Mach number (impact velocity to sound speed ratio) affects the metal-silicate mixing upon impacts, but that its effect depends on the other impact parameters such as the impactor size.

10:45am - 11:00am
Topics: 2.01 Late accretion processes from impacts to planetary differentiation - a multidisciplinary approach

Impactor Core Fragmentation During Impacts in the Late Accretion Phase

Randolph Röhlen1, Kai Wünnemann1,2, Laetitia Allibert1, Lukas Manske1, Christian Maas3, Ulrich Hansen3

1Museum für Naturkunde Berlin, Germany; 2Freie Universität Berlin, Institute for Geological Science, Germany; 3Institut für Geophysik, Westfälische Wilhelms-Universität Münster, Germany

The influence of asteroid impacts during the late accretion phase on Earth’s present day composition is still not fully understood. One important question here is if the mixing of metal cores from differentiated impactors into an existing magma ocean could explain the relatively high concentrations of highly siderophile elements observed in Earth’s mantle. For this it is essential to know how much the impactor cores break apart during the impact process, since a more fragmented body will allow more mixing with the surrounding material.

We simulate the impacts of differentiated impactors into magma oceans using the grid-based Eulerian shock physics code iSALE. We developed and implemented a new method to improve the fragmentation behavior in such Eulerian codes and used it to study the fragmentation and dispersion of the metal core of the differentiated impactor. We vary the size and velocity of the impactor as well as target properties like the depth of the magma ocean and its viscosity.

We see significant fragmentation of the impactor core under most tested parameters. Higher impact velocity and greater magma ocean depth show an especially pronounced increase in core fragmentation.

Acknowledgments: We gratefully acknowledge the developers of iSALE-2D, including Gareth Collins, Kai Wünnemann, Dirk Elbeshausen, Tom Davison, Boris Ivanov and Jay Melosh. This work was funded by the Deutsche Forschungsgemeinschaft (SFB-TRR170, subproject C2 and C4).

11:00am - 11:15am
Topics: 2.01 Late accretion processes from impacts to planetary differentiation - a multidisciplinary approach

The ongoing homogenization of primordial and late-accreted components in ocean island basalt mantle sources

Bradley James Peters1, Andrea Mundl-Petermeier2, Valerie A. Finlayson3

1Institute of Geochemistry and Petrology, ETH Zürich, 8092 Zürich, Switzerland; 2Department of Lithospheric Research, University of Vienna, 1090 Vienna, Austria; 3Department of Geology, University of Maryland, College Park, MD 20742, United States

The formation of a segregated metallic core is viewed as an inevitable consequence of the growth of larger protoplanets. However, the effect of this process on the distribution of siderophile elements is hugely variable depending on the physiochemical nature of the protoplanet and the pressure and temperature at which metal-silicate equilibration occurs. On Earth, study of this process can be complicated by the overprinting effect of late accretion, which delivered additional siderophile element mass to the Earth. Along with Precambrian-aged mantle-derived rocks, ocean island basalts (OIB) are now recognized as an important source of information about the early siderophile evolution of the deep Earth. We demonstrate that the combined W isotopic and highly siderophile element (HSE) characteristics of major global hotspots (Hawaiʻi, Iceland, Réunion) preserve geochemical signatures secondary to Hadean metal-silicate equilibration that have not been overprinted by late accretion. Further, some OIB preserve Ru/Ir ratios that are higher than expected, either for chondritic material delivered by late accretion or for the more highly processed primitive mantle. These elevated Ru/Ir signatures are not always easily explained by partial melting and/or magma differentiation processes and must in part reflect elevated Ru/Ir ratios in the deep mantle sources of OIB. Ruthenium has previously been investigated for its unique behavior among HSE during metal-silicate equilibration and heterogeneous, pre-late accretion Ru isotopic signatures have been recognized in some Archean-aged mantle-derived rocks. This implies that OIB may be an untapped source of information about the state of Earth’s interior during and after core formation.

1:30pm - 3:00pm2.01-2 Late accretion processes from impacts to planetary differentiation - a multidisciplinary approach
Location: Wiwi 104
Session Chair: Laetitia Allibert, Natural History Museum, Berlin
Session Chair: Sabrina Schwinger, German Aerospace Center (DLR)
1:30pm - 1:45pm
Topics: 2.01 Late accretion processes from impacts to planetary differentiation - a multidisciplinary approach

The origin of the lunar volatile depletion inferred from zinc and copper isotopic compositions of mare basalts

Guillaume Florin, Philipp Gleißner, Harry Becker

Freie Universität, Germany

Although the giant impact hypothesis is the most accepted model for the formation of the Moon the origin of its volatile depletion is still matter of debate. The heavy isotopic composition of moderately volatile elements like K, Rb or Zn is often interpreted as supporting evidence for a large-scale volatile depletion event. On the other hand, elevated abundances of water and other volatile elements in some lunar rocks are interpreted in favour for a less volatile depleted interior and more local volatile-loss processes like magmatic degassing. In the latter model, the heavy stable isotope composition of lunar rocks would be a result of late stage magmatic degassing into vacuum. Here we explore the processes affecting volatile elements in mare basalts through the scope of copper and zinc isotopes.

We report new data for mass-dependent stable isotopes of copper and zinc determined from the same rock aliquot of low- and high-Ti mare basalts. Thanks to the combine data set and the high quality of double spike Zn isotopic data, we resolve the effects of fractional crystallization and late magmatic degassing. Based on these results, fractional crystallization and late-stage magmatic degassing cannot explain volatile depletion and the heavy isotopic composition of most mare basalts and their mantle sources. The homogeneous Zn isotopic composition of low and high-Ti basalt mantle sources suggest that volatile loss and mass-dependent isotope fractionation occurred before the formation of these lunar mantle reservoirs, likely during or briefly after the giant impact.

1:45pm - 2:00pm
Topics: 2.01 Late accretion processes from impacts to planetary differentiation - a multidisciplinary approach

Siderophile volatile element inventory of lunar mare basalts: Constraints on magmatic processes and mantle sources

Philipp Gleißner, Niklas Kallnik, Harry Becker

Freie Universität Berlin, Germany

Elevated contents of water and moderately volatile elements in some lunar materials have invigorated the discussion on the volatile content of the lunar interior and on the extent to which the volatile element inventory of lunar magmatic rocks is controlled by element volatility and degassing. In order to constrain magmatic processes and mantle source compositions, we obtained a comprehensive data set for mass fractions of the moderately to highly volatile elements Cu, Se, Ag, S, Te, Cd, In, and Tl in various low- and high-Ti mare basalts. Mass fractions of Cu, S, Se, and Ag in each suite are mainly controlled by fractional crystallization. In contrast, Te, Cd, In, and Tl display disturbed fractional crystallization trends, most likely due to late magmatic degassing and recondensation of volatile species of these elements. Low-Ti mare basalt suites display constant ratios of specific siderophile volatile elements (e.g. Cu/Ag, Cu/S, S/Se), which we interpret as characteristics of their mantle sources. High-Ti mare basalt suites differ from low-Ti mare basalts by their significantly lower Cu/S, but higher S/Se ratios. Fractional crystallization modeling reveals that these differences are inherited mainly from their source regions in the lunar mantle. Despite the systematically different element ratios, low- and high-Ti mare basalt source compositions are characterized by consistently low mass fractions of siderophile volatile elements. Our new data support the hypothesis of volatile loss prior to formation of the lunar mantle sources and reveal element ratios in the lunar mantle that are significantly different from the terrestrial mantle.

2:00pm - 2:15pm
Topics: 2.01 Late accretion processes from impacts to planetary differentiation - a multidisciplinary approach

Precise Pb-Pb ages derived from lunar impact breccias: the key to dating large lunar basins

Harry Becker1, Thomas Haber2, Dennis Vanderliek1, Wajiha Iqbal2, Tiantian Liu3, Erik Scherer2, Winfried Schwarz4, Martin Whitehouse5, Carolyn H. van der Bogert2, Harald Hiesinger2

1Freie Universität Berlin, Germany; 2Universität Münster; 3Museum für Naturkunde Berlin; 4Universität Heidelberg; 5Swedish Museum of Natural History

Understanding the early lunar bombardment history hinges on reliable formation ages of the large lunar basins. Recent studies have shown that Zr minerals and Ca phosphates in petrographically, chemically, and microstructurally well-characterized lunar impactites can yield easily reproducible U-Pb ages that can be related to impacts. Geological, textural, and chemical arguments, plus impact melt distribution models, suggest that the widespread 3.92 Ga and 4.21 ages in breccias at the Apollo 14-17 landing sites likely reflect the Imbrium and Serenitatis impacts, respectively. However, the ages of other basins are more uncertain. Lunar granulites – impactites that were thermally metamorphosed by impact melt sheets – also should record basin-forming events. We have combined precise in situ Pb-Pb dates with Pb-Pb isochron dating to constrain the early history of the Apollo 17 granulite 77017. The rock contains annealed anorthositic gabbro clasts with relict igneous textures and a finer, thermally annealed matrix. High Ir abundances and the presence of metal indicate that the gabbro crystallized from impact melt. Baddeleyites define a homogeneous Pb-Pb age distribution (4175±3 Ma, n = 5), which is interpreted to date the crystallization of this impact melt. The phosphate Pb-Pb ages range between 4.18 and 4.13 Ga and are consistent with variable resetting by the metamorphic heating event. A Pb-Pb isochron yields a precise date for the granulite facies metamorphism (4143±1 Ma). The heating event may either relate to the impact that formed the Crisium basin or to another nearby basin-forming impact on the feldspathic highland terrane (Nectaris or Smythii).