
GeoBerlin 2023
Geosciences Beyond Boundaries - Research, Society, Future
150th PGLA (BGR) Anniversary and 175th DGGV Anniversary
Berlin | 3 – 8 September 2023
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).
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Session Overview |
Date: Thursday, 07/Sept/2023 | |
Ausstellung Geoparke Location: Wiwi 102 | |
Exhibition "Life conquers a planet: Example Earth" | Gesteins-Ausstellung: Leben übernimmt die planetare Steuerung: Beispiel Erde Location: Foyer (Henry Ford Building) Session Chair: Christoph Heubeck, Friedrich-Schiller universität Jena | |
8:30am - 9:20am | Plenary Lecture by Lesley Wyborn "OneGeoscience: Providing FAIR global access to all geoscience data - are we there yet?" Location: Audimax Session Chair: Kirsten Elger, GFZ German Research Centre for Geosciences |
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Topics: Plenary Talk
OneGeoscience: Providing FAIR global access to all geoscience data - are we there yet? Australian National University, Australia Geoscience deals with all fields of natural science related to understanding past, current and future states of the Earth and the terrestrial bodies. Geoscience has many sub-disciplines that have strong roots in other sciences such as chemistry, physics, geography, biology and mathematics. Each sub-discipline generally works in isolation and is governed by different science unions, societies and associations. Datasets generated by each are diverse, complex and heterogeneous: few fully comply with the FAIR principles. Hence it is hard to integrate datasets both within and across each sub-discipline. To enable efficient integration of geoscience data to effectively contribute to societal grand challenges will require conformance to agreed international standards and compliance with FAIR. The first attempt at international digital integration of data within one of these sub-disciplines was OneGeology, which in 2008 harmonised geological map data globally. More recently, OneGeochemistry is emerging as a fledgling effort to unify geochemical data across multiple sample types and analytical techniques in the geochemical domain. Geophysicists have not yet taken up the call for OneGeophysics but the potential is there. Rather than developing standards completely within each sub-discipline, a more holistic approach is to leverage the Observation, Measurement and Samples (OMS) Standard (IS0 19156: 2003) and break down the standards and vocabularies required into modules based around the feature of interest, instrument, procedures, event, place, properties value, result, etc. This presentation will highlight potential ways to use OMS to accelerate development and convergence of standards and vocabularies required to enable OneGeoscience to become a reality. |
9:20am - 9:40am | Awards: Hermann-Credner-Preis: Stefanie Tofelde, Uni. Potsdam | Hans-Cloos-Preis: Michaela Falkenroth, TU Darmstadt | 2x Rendel-Awards DFG: Felix Augustin, Tübingen & Jonas Preine, Hamburg Location: Audimax |
9:40am - 10:00am | Coffee Break Location: Foyer (Henry Ford Building) |
10:00am - 11:15am | 3.05-1 „Geomorphology and Sedimentology Beyond Boundaries“ - towards integrating geomorphology and sedimentary system science Location: Hall A (HFB) Session Chair: Anne Bernhardt, FU Berlin |
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10:00am - 10:30am
Invited Session Keynote Topics: 3.05 „Geomorphology and Sedimentology Beyond Boundaries“ - towards integrating geomorphology and sedimentary system science Linking source to sink in active rifts: Insights from the Gulf of Corinth, Greece Imperial College, United Kingdom The volume and grain-size of sediment supplied from catchments fundamentally control basin stratigraphy. Despite this, few studies have constrained sediment budgets and grain-size exported into an active rift and compared this to the characteristics of depositional stratigraphy. Here, we use the Gulf of Corinth as a natural laboratory to quantify the controls on sediment export within an active rift. We measured the hydraulic geometries, surface grain-sizes of channel bars and full-weighted grain-size distributions of river sediment at the mouths of multiple catchments draining the rift, which constitute 83% the Gulf’s drainage area. Results show that grain-size increases westward along the southern coast of the Gulf and that median and coarse-fraction of the sieved grain-size distribution are primarily controlled by bedrock lithology, with late Quaternary uplift rates exerting a secondary control. We also demonstrate that the median and coarse-fraction of the grain-size distribution are predominantly transported in bedload; however, typical sand-grade particles are transported as suspended load at bankfull conditions, suggesting disparate source-to-sink transit timescales for sand and gravel. Using this data, we derive both a Holocene sediment budget and a grain-size specific bedload discharged into the Gulf of Corinth using the grain-size measurements and previously published estimates of sediment fluxes and volumes. Finally, we demonstrate that at the scale of individual fault blocks, these sedimentary signals fundamentally control the nature of basin deposition, including the characteristics and architectures of hangingwall Gilbert deltas. Our results therefore highlight the importance of linking geomorphic and stratigraphic approaches in areas of active extension. 10:30am - 10:45am
Topics: 3.05 „Geomorphology and Sedimentology Beyond Boundaries“ - towards integrating geomorphology and sedimentary system science Sediment transfer and recycling in segmented sedimentary systems: An example from the Aare river (Switzerland) 1University of Münster, Germany; 2Technical University of Darmstadt, Germany; 3University of Bern, Switzerland; 4Bayerisches Landesamt für Umwelt, Germany Environmental signals produced by changes in climate or tectonic regime are transferred and modified through sedimentary systems from source to sink. Sediment (and therefore signal) transfer in segmented systems is interrupted through sediment storage in e.g. lacustrine sinks. The Alpine orogen is a mountain chain characterized by high denudation rates that sources important rivers such as the Rhine river. This study focuses on the Aare river, a tributary to the Rhine, that originates in the Swiss High Alps. The course of the present-day Aare river is controlled by an overdeepened valley carved during the Pleistocene glaciations, and segmented by several lakes. We present a provenance dataset based on detrital garnet geochemistry from modern river sands, Pleistocene deposits from drill core samples and river terraces, a Pliocene river terrace, and the Miocene Molasse bedrock. We show that before the Pleistocene, i.e. before valley incision, detritus was transferred directly from the High Alps to the Rhine river plain. After the incision in the Pleistocene, the Aare river recycled the incised local Molasse bedrock. Today, the Aare river is in turn recycling those Pleistocene river terraces as well as the local bedrock. First-cycle detritus from the High Alps is instead stored in man-made and natural lakes. Our data shows that the “erosional engine” of sedimentary systems changes drastically in response to geomorphic reorganizations, and that provenance analysis is a prerequisite to locate the sediment source, as well as the origin of any environmental signal produced in that source. 10:45am - 11:00am
Topics: 3.05 „Geomorphology and Sedimentology Beyond Boundaries“ - towards integrating geomorphology and sedimentary system science Sedimentological record of a river mouth in Northern Lebanon during the Holocene 1Catholic University Eichstaett-Ingolstadt, Germany; 2Austrian Archaeological Institute Vienna, Austria; 3American University of Beirut, Lebanon Within the framework of a geoarchaeological project to reconstruct the environmental conditions in the hinterland of an archaeological excavation in Northern Lebanon a drilling core near to the Nahr-El-Jaouz river mouth was taken in 2022. The core exhibits a 10,50m thick succession of Holocene fluvial deposits. Sampling comprised more than 100 samples. Sedimentological techniques using grain size distributions and textural parameters were applied for the assessment of facies type and the conditions of sediment transport and deposition. At a drilled depth of 10,00-10,50m gravelly sediments occurred representing the deltaic foreset followed by an alternating sequence of muds and sandy muds deposited directly at the river mouth or somewhat upstream (deltaic topset). The section above consisting of sandy to muddy sediments was formed by temporarily floods or stagnant water showing mainly suspension transport of the particles. The facial interpretation indicates a transition between a lagoonal environment of the topset and a distal floodplain far from the main river. Most of the upper core (9,35m to the surface) shows sediments formed within a wetland environment. Frequent facial changes from distal to proximate floodplain positions with muddy and sandy deposits can be observed. Gravelly layers occur as occasional intercalations deposited by more turbulent floods of different reach and force. The drill core indicates a former sea arm of several kilometres in length for the Nahr-El-Jaouz river mouth. Unfortunately, at present no age data from 14C analyses of taken charcoals or from OSL dating are available. These analyses are still in progress. 11:00am - 11:15am
Topics: 3.05 „Geomorphology and Sedimentology Beyond Boundaries“ - towards integrating geomorphology and sedimentary system science Using Laser-Diffraction Grain-Size Analysis and End-Member Modelling Analysis (EMMA) to understand laminar to turbulent flow transitions in deep-water systems 1RWTH Aachen, Germany; 2Leibniz University Hannover, Germany; 3Queen's University, Ontario, Canada Hybrid beds or linked debrites are deposits that form under bi- or tri-partite flow conditions, involving transitions from turbulent to laminar flow conditions. Often, hybrid beds occur with distal or lateral flow transformation following significant entrainment of a muddy substrate and/or declining turbulent energy. Hybrid beds have been noted to make up significant proportions of deposits within basin-floor setting worldwide, most commonly within the distal fringes of lobe systems. The stratigraphic distribution of hybrid beds has been linked to the character of the supply slope and seafloor relief, where hybrid beds are invoked to develop during periods of disequilibrium in out-of-grade slopes. The mechanisms of formation and evolution of flows that deposit hybrid beds have been significantly studied and debated over the past decades. The aim of this study is to utilize techniques not commonly used in this area, namely Laser-Diffraction Grain-Size Analysis and End-Member Modelling Analysis (EMMA) to undertake a detailed study of lateral and down-dip changes within targeted deposits, to interpret more accurately how and when turbulent to laminar fluctuations occur, as well as adding quantitative analysis to previously established qualitative models. Samples were taken from the Marnoso-Arenacea Formation, the Castagnola Formation, and the Gottero Formation. Initial findings show significant correlation between grain-size distribution from similar facies across different formations. Despite variability in the median grain-size between formations, similar end members can be extracted from each, indicating deposition under similar flow conditions. |
10:00am - 11:15am | 3.02-1 Mineralogical, Geochemical and Biogenic Transformations in the Critical Zone: what, where, when and how? Location: Hall B (HFB) Session Chair: Georg H Grathoff, University of Greifswald Session Chair: Friedhelm von Blanckenburg, GFZ Potsdam |
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10:00am - 10:30am
Invited Session Keynote Topics: 3.02 Mineralogical, Geochemical and Biogenic Transformations in the Critical Zone: what, where, when and how? Clay Mineral Reactions and Transport in the Critical Zone University of Georgia, United States of America The expression “Rock+Acid+Water -> Clays+Ions+Bicarbonate” may seem simple, but it encompasses many complex processes working in the Earth’s Critical Zone (CZ). The SE United States Calhoun CZ Observatory (O) has been observing the CZ for decades, leading to new understanding of how geological and human factors impact landscape evolution and management. The distribution of clays in the CZO is linked to the response of land to various factors that influence soil formation. These factors include vegetative cover (such as crops, regenerative pines, and old-growth hardwoods), interfluve order (old ridge-crests versus young legacy sediments), underlying geology (felsic versus mafic rocks), climate change (wetter versus dryer seasons), and denudation rates (erosion rates ranging from 1 to 1000 m/Ma). Through observations, we have found that plant cover and rooting depth affect soil gas (CO2 and O2) distributions, which in turn affect clay mineral hydrolysis and redox reactions. We have also found that clay mineral signatures show increasing indices of chemical alteration along increasing interfluve orders. Additionally, felsic rocks weather more deeply into the CZ than mafic rocks under similar biota, climate, relief, and time conditions. Furthermore, we have found that the chemical signatures captured in clays may not reflect average conditions, but rather specific points in soil moisture states. Finally, we have observed that rates of material transport within the CZ vary greatly depending on the chronometer used. The CZ constitutes a small volume of the Earth’s clay budget however it is an important clay factory in exogenic cycles. 10:30am - 10:45am
Topics: 3.02 Mineralogical, Geochemical and Biogenic Transformations in the Critical Zone: what, where, when and how? Do pseudo-sands' internal structures determine biogeochemistry of tropicals' critical zone? 1iES Landau, RPTU Kaiserslautern-Landau, Germany; 2Department of Geology, University of Georgia, Athens, GA, USA; 3Institute of Soil Science, Leibniz Universität Hannover, Germany Deeply weathered soils are iconic components of the tropical critical zone. Being short of exchangeable nutrients, physical features beyond sheer depth determine more than elsewhere the provision of life-sustaining resources. Biogeochemical models can hardly capture tropical fluxes, due to them being mainly developed and validated for temperate zones, focusing more on topsoil processes. To overcome this systematic bias, pedotransfer functions are regionally adapted for modeling soil water movements and then used for tropical biogeochemical modeling. However, soil texture based on single grain size distribution neglects the impact of actual soil structures in the field and leads to pronounced discrepancies between field measurements and model predictions for tropical soils. A prominent example of this mismatch is overestimated N2O emissions. Now, scientific efforts are being made to correct this systematic bias in predicting soil functioning. A well-known characteristic of tropical soils, potentially responsible for the systematic error, are water-stable aggregates called pseudo-sands. In the field, they are perceived as sand, but in the lab measured as clay and silt. The simple assumption that pseudo-sands act just like sands in the field seems to work satisfactorily for certain hydrological predictions. We pursue the hypothesis that, biogeochemically, pseudo-sands do not simply act like sands. We provide evidences why pseudo-sands cannot be simply treated neither like “regular sand” nor like the sum of its units. The long-term goal is to develop tropical biogeochemical model versions related to the properties of pseudo-sands that will lead to improved models of the critical zone of the tropics. 10:45am - 11:00am
Topics: 3.02 Mineralogical, Geochemical and Biogenic Transformations in the Critical Zone: what, where, when and how? Clay minerals in the critical zone and links to climate change University of Greifswald, Germany This contribution uses a recently published global clay mineral inventory of the critical zone to assess how well clay mineral assemblages reflect climate. The relative abundance of the main clay mineral groups (the 1:1, 2:1 and 2:1:1 hydrous phyllosilicates are used to evaluate a Clay Mineral Alteration Index (CMAI), which is compared with current latitudes and the Köppen-Geiger climatic zones. This CMAI relationship is defined as: CMAI = (2:1LE + 2:1:1LE) – (1:1LE + 2:1HE) (physically weathered – newly formed) where, LE = Low to no expandability, HE = high expandability and CMAI values range between -100 (warm tropical) and +100 (cold polar). For selected soil types, such as the alfisols, some general correlations exist between CMAI values and distance from the equator. However, the database indicates that lithological controls on clay mineral assemblages introduce a large degree of heterogeneity to the system. This makes a direct interpretation based on numerical indices difficult to implement. Improved correlations can be achieved by selecting consistent soil types developed on the same host lithologies (e.g. soils on Silurian shales). Following this procedure, very good correlations can be attained as long as the climatic parameters of temperatures and rainfall are both considered. A refined correlation between the CMAI and current climatic conditions is put to the test on palaeosols and shales from the geological record. 11:00am - 11:15am
Topics: 3.02 Mineralogical, Geochemical and Biogenic Transformations in the Critical Zone: what, where, when and how? How deep is the critical zone? 1Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum GFZ, Germany; 2Freie Universität Berlin, Germany The depth of the critical zone, the zone that spans from the canopy to the weathering front in the subsurface, is mostly unknown due to its inaccessible nature. To identify the depth of the critical zone and infer its assumed control by water flow we conducted four drilling campaigns in granitoid rock along a climate gradient in the Chilean Coastal Cordillera. The drilled cores differ in the depth of the weathering front between arid, semi-arid, mediterranean, and humid climate. The arid study site is located at the southern end of the Atacama Desert and the drill core is hydrothermally overprinted. No chemical top-down weathering or physical disintegration of the granitic rock is found. The semi-arid drill core reveals multiple weathering fronts along fractures and shows top-down chemical weathering in the uppermost 10 m. In the mediterranean study site, we found the deepest weathering front with saprolite to a depth of ~45 m, followed by bedrock with wide fractures. The physical disintegration is stronger than chemical mass losses due to weathering. The humid study site is characterised by a shallow weathering front at ~10 m depth. Even though sufficient water is available to form a deep weathering zone, the formation of clay and other secondary minerals inhibits further advance of the weathering front by clogging pore space thus preventing water flow. We conclude while the of degree of (chemical) weathering is set by climate, the depth of the weathering front depends on the abundance and width of tectonic fractures. |
10:00am - 11:15am | 1.15-1 Mineralogy of complex ore deposits – from exploration to ore processing Location: Hall C (HFB) Session Chair: Maximilian Korges, University of Potsdam Session Chair: Benjamin Florian Walter, Karlsruhe Institute of Technology |
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10:00am - 10:15am
Topics: 1.15 Mineralogy of complex ore deposits – from exploration to ore processing Carbonate replacement sulfide mineralization in the Kupferschiefer district (Saale subbasin, Eastern Germany) 1GFZ German Research Centre for Geosciences, 14473 Potsdam, Germany; 2Institute of Geological Sciences, Freie Universität Berlin, Malteserstrasse, 74-100, Berlin 12249, Germany; 3Landesamt für Geologie und Bergwesen, Sachsen-Anhalt, Köthener Straße 38, D-06118 Halle, Germany The Kupferschiefer districts in Central Europe contain some of the world’s largest sediment-hosted stratiform Cu deposits. The fine-grained sulfides are hosted by the Rotliegend sandstone (S1), organic matter-rich Kupferschiefer (T1) mudstones and Zechstein Limestone (Ca1). In this study, standard and high-resolution microscopy techniques (reflected-transmitted light, SEM, FIB-TEM) are combined with quantitative mineralogical data (X-ray diffraction, QXRD) to characterize the key mineral assemblages and styles of sulfide mineralization in drill core samples from different localities (Sangerhausen, Allstedt, Wallendorf) of the Saale subbasin, Eastern Germany. Our QXRD data show a progressive decrease in calcite abundance from the underlying S1 into the T1 in the Sangerhausen and Allstedt drill cores and an upward increase in calcite in the Wallendorf drill core. Petrographic data show extensive in situ alteration of rock fragments and detrital feldspar in the S1. Diagenetic calcite has formed intergranular pore-filling cement that occludes primary porosity in the S1 and T1. The ore-stage sulfides (bornite, sphalerite, galena, ± pyrite) in the S1 and T1 are mostly formed as a replacement of calcite cement and, to a lesser extent, feldspar. High-resolution TEM data has helped to identify hematite and magnetite within particular calcite growth zones in the S1, which likely corresponds with the “Rote Fäule” alteration associated with the Cu sulfide mineralization. Nanoscale Cu-chloride complexes have also been identified, intergrown with pore-filling illite in the T1. In summary, the distribution and dissolution of calcite cement were critical to the secondary porosity development and migration of the mineralizing fluids in the Saale subbasin. 10:15am - 10:30am
Topics: 1.15 Mineralogy of complex ore deposits – from exploration to ore processing Quantitative mineralogical analysis for the development of new exploration vectors at the Spremberg-Graustein-Schleife Cu-Ag Kupferschiefer deposit, Lusatia, Germany Helmholtz Institute Freiberg for Resource Technology, Helmholtz-Zentrum Dresden-Rossendorf, Germany. The Spremberg-Graustein-Schleife deposit is part of the Kupferschiefer district in the southern Permian Basin and comprises copper and silver mineralized rocks hosted by pre-Zechstein sandstones, Kupferschiefer, and Zechstein carbonates. As there is still significant exploration potential across the southern Permian basin, the goal of the present study is to identify mineralogical signatures, which may be usable as exploration vectors. The specific focus in this study is on the gangue mineralogy, since it is more likely to provide a larger detectable footprint in the mineralizing system. Multiple analytical methods were combined to investigate samples from three mineralized and non-mineralized drill-cores. Scanning Electron Microscope (SEM) based image analysis (MLA) was carried out to obtain quantitative data on mineralogy as well as major-element carbonate chemistry of each stratigraphic unit. Quantitative bulk-powder XRD was performed as an external validation. In addition, the SEM-MLA data are being integrated with hyperspectral core-scans for upscaling observations. Zechstein carbonate rocks in the well-mineralized drill-hole are dominantly composed of dolomite, in contrast to the weakly-mineralized drill-hole that contains more calcite. In the mineralized sandstones, three successive generations of carbonate cement have been identified from backscatter electron imaging and semi-quantitative EDX measurements, comprising i) dolomite to ii) Mn-Fe dolomite, and finally the deposition of iii) ankerite rims. Kaolinite, one of the main cement minerals in the sandstones, appears more abundantly in the mineralized than in the barren sandstones. The occurrence of ankerite and kaolinite may indicate overprinting by the mineralizing fluids and may thus be useable vectors towards mineralization. 10:30am - 10:45am
Topics: 1.15 Mineralogy of complex ore deposits – from exploration to ore processing Minor and trace elements in the Spremberg-Graustein-Schleife Kupferschiefer deposit: A deportment study Helmholtz-Zentrum Dresden Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Chemnitzer Str. 40, 09599 Freiberg, Germany The sediment-hosted Spremberg-Graustein-Schleife deposit is located in Lusatia, eastern Germany. Mineralization occurs in the lower Zechstein units, extending from the Grauliegend conglomerates and sandstones into the overlying organic-rich Kupferschiefer black shales and Zechstein carbonates. Around 100 Mt of Cu-Ag ore is present within the deposit. The ore is also enriched in Pb, Zn, Co, Ni, Au, Bi, Se, Re, and Ge (in addition to Cu and Ag). Despite the metal endowment, detailed quantitative metal deportment studies have not been carried out for this deposit, or indeed any other Kupferschiefer deposit. This study aims to bridge the gap. Core samples representing the complete mineralization interval (31 m in total) at three different sites within the deposit were mineralogically and geochemically analyzed. To ensure a comprehensive, high-quality and internally consistent dataset, various analytical methods including X-ray fluorescence (XRF), ICP-OES, ICP-MS, X-ray diffraction (XRD), Mineral Liberation Analysis (MLA), electron probe micro-analysis (EPMA) and laser ablation ICP-MS (LA-ICP-MS) were performed. The results reveal that the concentration and main hosts of copper and potential by-products vary vertically between the stratigraphical units, and spatially at different locations of the deposit. Such information will eventually help to predict deportments across the deposit, track each element within the minerals processing plants and also to get an idea of expected recoveries and thus optimizing the procedure. 10:45am - 11:00am
Topics: 1.15 Mineralogy of complex ore deposits – from exploration to ore processing Fluid and chemical constraints on sphalerite precipitation in the Boundary Zone Zn-Pb prospect, Yukon, Canada 1GFZ German Research Centre for Geosciences, Potsdam, Germany, Germany; 2Institute of Geological Sciences, Freie Universität Berlin, Germany; 3Fireweed Metals, British Columbia, Canada; 4Paul Scherrer Institut, Villigen, Switzerland Sphalerite (ZnS) is the main ore mineral in clastic-dominant (CD-type) massive sulfide deposits. However, the precise physicochemical conditions of ore formation are often poorly constrained. This study uses sphalerite mineral chemistry and fluid inclusion microthermometry to constrain conditions of Zn mineralization at the Boundary Zone prospect of Macmillan Pass district, Canada. The sulfide mineralization comprises pyrite, sphalerite, galena, and minor chalcopyrite. Sphalerite with contrasting trace element compositions is hosted in Late Ordovician-Early Silurian (Duo Lake Formation) and Late Devonian (Portrait Lake Formation) black mudstones. Different paragenetic stages of sphalerite formation preserve distinct trace element patterns within and between host rock intervals, and overall, Ge, Ga, Cu, and Cd, are relatively enriched compared to In. Trace element incorporation mechanisms vary, with both direct and coupled substitution (e.g., 3Zn2+ ↔ (Ge)4+ + 2Cu+) pathways suggestive of compositional and fluid temperature differences during sphalerite precipitation. Homogenization temperatures (Th) of CO2-N2-bearing, 2-phase primary aqueous fluid inclusions in Portrait Lake sphalerite range between 154 – 249°C (median= 179°C). The Th values of quartz-hosted CO2-N2-H2S-CH4-bearing aqueous inclusions from late veins are in the range of 207 – 236°C (median= 223°C). These temperatures are consistent with sphalerite trace element geothermometry (GGIMFis; 163 – 279°C) and are comparable to nearby Tom and Jason CD-type deposits in the Macmillan Pass district. 11:15am - 11:30am
Topics: 1.15 Mineralogy of complex ore deposits – from exploration to ore processing Numerical modeling unravels differences in greisenization processes Freie Universität Berlin, Germany The Zinnwald/Cinovec Sn-W-Li greisen deposit on the border between Germany and Czech Republic in the eastern part of Krušné Hory/Erzgebirge represents a fluorine-rich hydrothermal alteration of a granite-rhyolite association. We investigated the effects of fluid-rock interaction on distal rhyolites of the deposit, using petrological and mineralogical data to constrain the process of greisenization in detail. The samples were selected from the contact between granite and rhyolite. Three distinct zones of high- and low-degree topaz-greisenization and albitization developed with different textures, mineral assemblages and mineral compositions. Beyond the albitization zone, a continuous transition to the least altered rhyolite was observed. In the greisen part, the predominant minerals are quartz (~80 vol%) and topaz (~10 vol%) with minor mica (~5 vol%). We employed a reactive transport model based on mass conservation and local equilibrium to unravel the detailed process of greisenization. We integrated solution models and endmember thermodynamic data for topaz in recent thermodynamic datasets. The model accounts for fluid flow, porosity and density evolution. The model is used to emulated the sequence of observed petrological zones as obtained with automated mineralogy to constrain the original fluid chemistry and reconstruct elements redistribution during greisenization. By comparing fluid-rock interaction models producing topaz greisen and topaz-free mica greisen, we quantify the F-content necessary to form the greisen at Zinnwald/Cínovec. The comparison implies that F content has a great influence on the greisenization types, which may be related to different metallogenic processes and give insights into W-Sn ore deposits. |
10:00am - 11:15am | 1.13-1 Site selection for a nuclear waste repository – Data acquisition, host rock characterisation and analogue studies Location: Hall D (HFB) Session Chair: Lisa Richter, Federal Institute for Geosciences and Natural Resources Session Chair: Lisa Winhausen, RWTH Aachen |
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10:00am - 10:30am
Invited Session Keynote Topics: 1.13 Site selection for a nuclear waste repository – Data acquisition, host rock characterisation and analogue studies Geological Reasoning for the Site of the Swiss Nuclear Waste Repository Nagra, Switzerland The site selection process for the deep geological repository for Swiss radioactive waste is in its final phase. Using 3D-seismics and deep boreholes, Nagra has collected the data for selecting the most suitable site. In autumn 2022, Nagra announced that a general license application would be prepared for a combined repository for high- and low-/intermediate-level waste in the Nördlich Lägern region. The 13 technical criteria used for site comparison comprise safety-related aspects including barrier properties and their long-term stability, as well as the constructability of the repository and access facilities. Phases 1 and 2 of the process resulted in the selection of three potential sites in the external Alpine Foreland of Northern Switzerland, all with the ~100 m thick Jurassic Opalinus Clay as host rock. The sites fulfill the requirements for repositories for low- and intermediate-level waste as well as for high-level waste and spent fuel. In the final Phase 3 of site selection, the remaining sites were investigated by means of 3D-seismics and 9 deep boreholes. The boreholes aimed at assessing the barrier properties of the clay-mineral rich rock sequence, including the bounding aquifers. To address the long-term stability of the geological barrier, the Quaternary erosion history was investigated with 11 cored boreholes. In our contribution, we provide an overview of key results from the seismic surveying and the boreholes in the three siting regions. Based on these investigations, we present and discuss the geological differences between the regions that have led to the proposed site. 10:30am - 10:45am
Topics: 1.13 Site selection for a nuclear waste repository – Data acquisition, host rock characterisation and analogue studies Site selection process for the deep geological repository in the Czech Republic SÚRAO, Czech Republic The main criterion concerning the planned deep geological repository comprises its long-term safety, which must be ensured for a period of hundreds of thousands of years. Therefore, particular attention is being devoted to the selection of a suitable site for the facility. As far as the Czech Republic is concerned, it is planned that the DGR will be constructed in a suitable crystalline rock mass. Nine potential sites were originally selected for consideration, all of which were subjected to detailed geological survey assessment. The DGR site selection process was preceded by the extensive collection and evaluation of the relevant data covering the detailed site description and assessment of local conditions. Recently, SÚRAO has conducted a huge amount of research at the sites via e.g. field research, terrain reconnaissance, geological mapping, hydrogeological mapping and sampling, geophysical surveys, the measurement of seismic phenomena, etc. As a result of the research, 3D geoscientific models of the rock conditions were created, which allowed for the assessment of the sites. The nine sites were compared based on safety, feasibility and environmental impact studies following which, on 21 December 2020, the government approved the selection of the four sites recommended by SÚRAO – Březový potok, Horka, Hrádek and Janoch. Further research and exploration work aimed at the eventual selection of the final and backup sites will be conducted up to 2028. The result of this complex characterization will be compiled into a set of site descriptive models describing both – geological setting and long-term evolution of the sites. 10:45am - 11:00am
Topics: 1.13 Site selection for a nuclear waste repository – Data acquisition, host rock characterisation and analogue studies Geological characterisation for deep geological repository site selection: an example of Hrádek site, Czech Republic Czech Geological Survey, Czech Republic The site selection process for deep geological repository is a long-term project based on numerous disciplines. In the Czech Republic the geological characterisation was performed on nine selected sites in crystalline rocks, from which four were taken into account for ongoing geological survey and detailed site description. This contribution will present the approach to the geological characterisation, which was, is and will be used for selection of final deep geological repository site on an example of Hrádek locality. The Hrádek locality is based in Moldanubian granitoid and metamorphic rocks of Bohemian massif in the central part of Czech Republic. In the previous phase, mostly archive data were used in combination with local field studies, in order to present a 3D geological model as an input for other models (e.g. hydraulic, transport, discrete fracture network model). The ongoing phase of geological characterisation includes mainly field studies, geological and hydrogeological mapping in combination with geophysical research and future borehole research, geophysical profiling and hydrogeological monitoring. All the data collected will be included in 3D geological model with uncertainty assessment with the aim to compare and evaluate the best site for future deep geological repository. 11:00am - 11:15am
Topics: 1.13 Site selection for a nuclear waste repository – Data acquisition, host rock characterisation and analogue studies Stress state estimation – variability assessment of model results 1TU Darmstadt, Institute of Applied Geosciences, Schnittspahnstraße 9, 64287 Darmstadt, Germany; 2Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany; 3TU Berlin, Ernst-Reuter-Platz 1, 10587 Berlin, Germany; 4Nationale Genossenschaft für die Lagerung radioaktiver Abfälle, Hardstraße 73, 5430 Wettingen, Switzerland; 5Rocks Expert SARL, 244 chemin de Bertine, 04300 St. Maime, France; 6SINTEF Industry, S.P. Andersens veg 15b, 7031 Trondheim, Norway The upper crust of the Earth is used more and more to transport and extract raw materials and energy. It is also used for the final disposal of radioactive waste in deep geological repositories. An accurate knowledge of the hosting rock and surrounding formation coupled to comprehensive modelling are fundamental to demonstrate the geological site has the required properties for safe and long-term underground storage. Besides other criteria, geomechanics plays an important role. Especially, the estimation of the contemporary stress state in the upper crust is a challenge. In-situ data of maximum and minimum horizontal stress magnitudes (SHmax and Shmin) are required to calibrate 3-D geomechanical models. During the recent exploration phase for a deep geological repository for radioactive waste in Switzerland, a unique dataset of stress magnitude data has been acquired from eight cored boreholes. Rock mechanical properties were constrained from geophysical logging and laboratory testing. The empirically correlated rock properties were not simply averaged, but a probability distribution was provided. The stress field was explored by conducting more than 120 tests in different stratigraphic units, to estimate the magnitudes of SHmax and Shmin. We present the results of a 3‑D geomechanical-numerical model that shows the best-fit with respect to the measured stress magnitudes. Considering the uncertainties of the tests and the ones resulting from rock property variability, the model can reproduce most of the measurements. However, we do show not only the best-fit result, but a bandwidth of individual stress components within a P05-P95 probability range. |
10:00am - 11:15am | 1.06-1 Deep geothermal resources and projects Location: Wiwi 101 Session Chair: Jasmaria Wojatschke, Bundesanstalt für Geowissenschaften und Rohstoffe (BGR) Session Chair: Nora Koltzer, Fraunhofer IEG |
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10:00am - 10:15am
Topics: 1.06 Deep geothermal resources and projects Geothermal Project Potsdam 1UGS GmbH, Germany; 2EWP Potsdam Potsdam the provincial capital of the German state Brandenburg started with an ambitious program to reduce its climate impact about 10 years ago. The program includes the substitution of fossil energy sources for district heating by renewable energy. The investigation of the geothermal potential of the urban area forms an important component of this strategy. Several deep saline aquifers in the closer surrounding of Potsdam show a potential for a geothermal utilization. They are used for different purposes like natural gas storage (Buntsandstein), underground heat storage (Jurassic), balneology (Rhaetian) or injection of process water (Muschelkalk, Jurassic). The exploration campaign started with 2D seismic measurements which were focused on the investigation of the Mesozoic succession up to a depth of about 2,500 m bgl. Based on the seismic results a drill site was determined where a vertical borehole was drilled into a depth of 2,157 m bgl. The exploration well encountered the succession down to the Muschelkalk formation with partly surprising results. The investigation of the encountered aquifers favoured the further exploitation of the Middle Jurassic Aalenian sandstone as a geothermal reservoir. Accordingly, the second well was deviated to reach this horizon in a deeper situated part of the structure. Hydraulic tests of the aquifer show promising results with respect to a future use in a local heating system of the surrounding residential buildings. The overrun could be feed into the nearby district heating network. Besides, the results will be used for the development of further locations for a geothermal utilization. 10:15am - 10:30am
Topics: 1.06 Deep geothermal resources and projects Opportunities for hydrogeothermal uses in NE Germany: from site evaluation to project realization 1Geologischer Dienst, LUNG Mecklenburg-Vorpommern, Germany; 2Geowissenschaftliches Zentrum der Georg-August-Universität Göttingen, Abteilung Angewandte Geologie, Germany; 3Ministerium für Klimaschutz, Landwirtschaft, ländliche Räume und Natur Mecklenburg-Vorpommern, Germany Low enthalpy geothermal systems are well established in north-eastern Germany. The first German hydrothermal doublet started heat production in Waren/Müritz in 1984. Since then other sites in Mecklenburg-Western Pomerania and Brandenburg were explored and realized. Very recently the geothermal heating plant of Schwerin-Lankow has officially started operations and will substitute about 20 percent of fossil energy use in this town. In most of these projects deep saline aquifers of Mesozoic age were used, which formed in the eastern part of the North German Basin. The well suited reservoir sandstones were often deposited in fluvial and deltaic systems within up to 15 km wide distributary channel belts. The porosity and permeability of channel facies sandstones reach very high values up to 30 % and >6 Darcy, respectively. On basis of integrated sedimentological-palaeontological investigation and facies analyses using cores and wire logs of numerous deep wells, 15 different stratigraphic channel systems could be detected and mapped (www.sandsteinfazies.de). The results can be used together with temperature distribution data for a first site evaluation. Estimations of productivity and temperature have to be combined with numbers of potential users and existing or planned heat distribution infrastructure in larger communities. The Geological Survey and ministries of Mecklenburg-Western Pomerania will encourage politicians and decision makers to think about geothermal energy use in their field of responsibility but also support investors to claim for financial support to realize renewable energy projects. This includes open access to available geological and geophysical data according to the Geological Data Act (GeolDG). 10:30am - 10:45am
Topics: 1.06 Deep geothermal resources and projects Remaining opportunities in medium-deep reservoirs of the North German Basin – lessons learned from the new development in Schwerin 1Geowissenschaftliches Zentrum Georg-August-Universität Göttingen, Germany; 2Schwerin The North German Basin yields enormous resources of heat in place bound to the Palaeozoic–Mesozoic succession and to fault systems. Early exploration campaigns have identified highly permeable Mesozoic sandstones at depth of <2,300 m with temperatures of <100°C. Despite the fundamental knowledge established by these campaigns, the development of hydrothermal reservoirs remained limited due to considerable pre-drilling risks resulting from uncertainties in reservoir predictions at individual localities. To minimise risks associated to subsurface uncertainties, an interdisciplinary work flow integrating sedimentological, geophysical, and petrophysical methods was designed to re-evaluate the six Mesozoic reservoir complexes of the North German Basin. Within the projects Sandsteinfazies, GeoPoNDD and mesoTherm this work flow was applied to an extensive database of cores and wireline logs leading to high-resolution maps depicting facies, thickness and quality of individual hydrothermal reservoirs. These maps enable reliable predictions of key parameters, i.e. net-thickness and permeability, on regional to local scales and, thus, make a significant contribution to the reduction of subsurface uncertainties. The potential of these subsurface reservoir maps to increase the utilisation of geothermal energy is demonstrated on the example of the reservoir development at Schwerin, a previously underexplored locality. There, reservoir predictions enabled targeting a highly productive sandstone at 1,250 m depth. The operation combines a conventional doublet system with industrial heat pumps to supply 7 MWth to the local heating grid. The lessons learned from Schwerin demonstrate significant opportunities in medium-deep reservoirs enabling a sustained increase of developments for heat supply in North Germany. 10:45am - 11:00am
Topics: 1.06 Deep geothermal resources and projects Lower Cretaceous Sandstones in the Lower Saxony Basin – a potential geothermal play Landesamt für Bergbau, Energie und Geologie, Germany This study focusses on Lower Cretaceous sandstone units of Valanginian and Berriasian age in Lower Saxony. The understanding of the distribution and the hydraulic properties of these aquifers is essential to identify suitable areas for geothermal applications. Relevant aquifer units were defined in this study by a significant regional distribution, a thickness of more than 5 m and suitable hydraulic properties. Three sandstone units can be mapped for the Valanginian stage: The Bentheim Sandstone, the Dichotomiten Sandstone and the so called Hauptsandstein. For the Berriasian stage, the most important sandstone units are the so-called Kopf-Sandstein (Fuhse Formation) and the sandstones of the Basinghausen Subformation. All of these sandstones are located in depths between several hundreds of meters up to 1500 m with a resulting temperature between 30°C to around 50°C. Aquifers of Valanginian age have the best transmissivities and could be a target for geothermal application. Sandstone units of Berriasian age barely meet the minimum requirements for geothermal use on a regional scale. Nevertheless, suitable aquifer conditions may be developed locally. All maps of the Lower Cretaceous sandstones can be found at the NIBIS mapserver and the data compilation is free to download. A base map with the relevant sandstone units and all analyzed data points such as well logs, cores and outcrops are available for each geological unit. Parameters for geothermal applications (e.g. depths of the formation, total thickness, sandstone thickness, porosity, permeability and transmissivity) are available as individual layers. 11:00am - 11:15am
Topics: 1.06 Deep geothermal resources and projects Geothermal potential of Mesozoic carbonates on the example of the Rüdersdorf Formation (North German Basin): opportunity or not? University of Göttingen, Germany The Mesozoic succession of the North German Basin (NGB) yields enormous resources of heat in place bound to Mesozoic sandstone reservoirs located at depths of up to 2.500 m. Compared to highly-permeable sandstone reservoirs, which are exploited for heat production since the 1980s, carbonate reservoirs are underexplored so far. This study evaluates the potential of Mesozoic carbonates on the example of the Rüdersdorf Formation (“Schaumkalk”) in the subsurface of Berlin/Brandenburg. The data are based on an extensive bed-by-bed outcrop study in the Rüdersdorf open-pit mine to the East of Berlin, and examination of well cores from Berlin-Spandau and Potsdam. The vertical succession exposed in outcrop and well cores shows gradual transitions from marly limestone background facies (“Wellenkalk”) to thick cross-bedded oolitic grain- to packstone reservoir facies (“Schaumkalk”). Based on analyses of carbonate microfacies and reservoir properties, oolitic reservoir facies exhibit high secondary porosities but low permeabilities. The late-diagenetic dissolution of oolites contributed to oomoldic porosity volumes of up to 27,4 % resulting in the typical foamy texture. But due to matrix-supported grain fabrics, the pore connectivity remained low as emphasized by the permeability range of 0.004–7.7 mD. The potential of the reservoir facies is further limited as fluid circulation along open fractures and faults did obviously not contribute to an enhanced matrix permeability. Accounting for this and the limited lateral extent of thick oomoldic reservoir facies, proven in regional well-to-well correlations, the opportunities for reservoir developments in the Rüdersdorf Formation seem to be very limited. |
10:00am - 11:15am | 2.01-1 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) |
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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 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 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 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 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. |
10:00am - 11:15am | 3.12-3 Past climates and environments inform our future Location: Wiwi 104a Session Chair: Cécile Blanchet, GFZ Potsdam Session Chair: Stefanie Kaboth-Bahr, Free University Berlin |
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10:00am - 10:15am
Topics: 3.12 Past climates and environments inform our future Effects of CO2 and Ocean Mixing on Miocene and Pliocene Temperature Gradients: Strongly reduced seasonality Alfred Wegener Institute, Germany Cenozoic climate changes have been linked to tectonic activity and variations in atmospheric CO2 concentrations. Here, we present Miocene and Pliocene sensitivity experiments performed with the climate model COSMOS. The experiments contain changes with respect to paleogeography, ocean gateway configuration, and atmospheric CO2 concentrations, as well as a range of vertical mixing coefficients in the ocean. For the mid-Miocene, we show that the impact of ocean mixing on surface temperature is comparable to the effect of the possible range in reconstructed CO2 concentrations. In combination with stronger vertical mixing, relatively moderate CO2 concentrations of 450 ppmv enable global-mean surface, deep-water, and meridional temperature characteristics representative of mid-Miocene Climatic Optimum (MMCO) reconstructions. The Miocene climate shows a reduced meridional temperature gradient and reduced seasonality. In the case of enhanced mixing, surface and deep ocean temperatures show significant warming of up to 5–10°C and an Arctic temperature anomaly of >12°C. In the Pliocene simulations, the impact of vertical mixing and CO2 is less important for the deep ocean, which we interpret as a different sensitivity dependence on the background state and mixed layer dynamics. We find a significant reduction in surface albedo and effective emissivity for either a high level of atmospheric CO2 or increased vertical mixing. Our mixing sensitivity experiments provide a warm deep ocean via ocean heat uptake. We propose that the mixing hypothesis can be tested by reconstructions of the thermocline and seasonal paleoclimate data indicating a lower seasonality relative to today. 10:15am - 10:30am
Topics: 3.12 Past climates and environments inform our future Aquatic biomonitors and biomarkers reveal temperature and environmental changes during the Thirty Years' War: A case study from Bad Waldsee, Germany 1Institute of Geosystems and Bioindication, Technische Universität Braunschweig, Braunschweig, Germany; 2lnstitute of Earth Sciences, Ruprecht-Karls-University Heidelberg, Heidelberg, Germany; 3Institute of Applied Geosciences, Technische Universität Darmstadt, Darmstadt, Germany The Thirty Years' War (1618-1648) had significant consequences for both human populations and natural ecosystems in Europe. To gain a better understanding of its impact on the local aquatic environment, we analyzed a sediment core from Stadtsee, a lake located in the city of Bad Waldsee, Upper Swabia, using a variety of aquatic biotic and abiotic proxies, including bioindicators, biomarkers, and sedimentological data. Through this multi-proxy approach, we infer changes in aquatic communities and their environment during this tumultuous period. Our findings indicate that this war had a marked impact on the lake ecosystem, as evidenced by changes in diatom assemblages, with declining diatom concentrations and progressively decreasing contributions of hypereutrophic species. These changes suggest a lowering in nutrient supply, possibly due to a reduced load of human and animal waste. This is supported by decreasing productivity (low Si/Ti) and declining δ13Corg values. It appears that the war led to a lake recovery and an improvement in water quality, as suggested by the presence of three bryozoans Plumatella species and the absence of Cristatella mucedo, indicating reduced nutrient levels and a well-oxygenated environment, in agreement with high Mn/Fe ratios. Additionally, the presence of chironomids, such as Corynoneura arctica-type and C. intersectus-type, point to a concomitant decline in temperature. This is consistent with preliminary results obtained by the lipid paleothermometer HDI26. Our study thus highlights the valuable insights provided by bioindicators, biomarkers and sediment geochemistry in a concerted approach about water quality and the health of the Stadtsee ecosystem during the Thirty Years' War. 10:45am - 11:00am
Topics: 3.12 Past climates and environments inform our future Changes in precipitation during the last 420 kyr in northern Central America as recorded by Lake Petén Itzá, Guatemala 1Institut für Geosysteme und Bioindikation, Technische Universität Braunschweig, Germany; 2Institute of Earth Sciences, Organic Environmental Geochemistry Group, Heidelberg University, Germany; 3Centro de Geociencias Juriquilla, Universidad Nacional Autónoma de México, Mexico; 4GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany; 5Department of Geological Sciences and Bolin Centre for Climate Research, Stockholm University, Sweden Lake Petén Itzá, Guatemala, is one of the oldest lakes in northern Central America. Its sedimentary record contains the signal in precipitation variability of the last four interglacial-glacial cycles (420-14 cal ka BP). Changes in rainfall during the last 80 kyr have been widely described in the lake’s record and associated with shifts in the Intertropical Convergence Zone (ITCZ) and the Atlantic Meridional Oceanic Circulation (AMOC). However, there is limited knowledge regarding the hydrological responses of Petén Itzá prior to this time interval due to a poorly constrained chronology. Here, we provide a significantly improved chronology allowing a more detailed analysis of changes in runoff, evaporation, and vegetation throughout the last 420 kyr. Magnetic susceptibility, bulk density, elemental geochemistry and pollen data indicate that glacial periods were characterized by dry conditions, generally associated with low runoff, high evaporation and temperate environments. On the contrary, interglacial periods suggest wetter conditions with high runoff, low evaporation and dominance of tropical vegetation. Our results are consistent with other paleo-precipitation records in the region, such as the marine records ODP 1239 from the eastern equatorial Pacific and the ODP 1002 from Cariaco Basin, suggesting that the runoff variability at Petén Itzá may be associated with the long-term latitudinal migration of the ITCZ. Frequency analyses of our data show the presence of 100, 40 and 21 kyr periodicities and thus an orbital control. Our study serves as a first reference point in the transregional study of the late Quaternary climate in northern Central America. |
10:00am - 11:15am | 3.23-1 Mountain Building in the Alpine-Mediterranean domain – from mantle imaging to crustal and surface processes back in time - AlpArray and AdriaArray Location: Wiwi 105 Session Chair: Sabrina Metzger, GFZ Potsdam Session Chair: Mark R. Handy, Freie Universität |
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10:00am - 10:30am
Invited Session Keynote Topics: 3.23 Mountain Building in the Alpine-Mediterranean domain – from mantle imaging to crustal and surface processes back in time - AlpArray and AdriaArray How AlpArray is guiding us to a new model of Alpine orogenesis and status report of the AdriaArray initiative Freie Universität, Germany AlpArray is changing notions of lithospheric subduction along the Alps and its effects on orogeninc lithosphere. Teleseismic Vp tomography reveals a slab of European lithosphere that is largely detached at and below 150 km in the Western Alps. Only in part of the Central Alps is the slab still attached, possibly reaching down to the mantle transition zone, where it appears connected to subducted remains of Alpine Tethys. SKS directions beneath the Alps suggest that asthenosphere not only flowed passively around the sinking slab, but may have induced the anomalous northward dip of the detached slab segment beneath the Eastern Alps. The structure of the orogenic lithosphere differs profoundly along strike of the Alps, as revealed by local earthquake tomography, ambient-noise studies, as well as S-to-P receiver-functions and gravity studies: In the Central Alps where the slab is still attached, the exhumed retro-wedge of the orogen overrides a wedge of Adriatic lower crust. In the Eastern Alps where the slab has detached, exhumation is focused in the orogenic core (Tauern Window) north of and above bulged lower crust of presumed Adriatic origin. This indicates decoupling at the base of qtz-rich, presumably hydrous intermediate crust to accommodate coeval Miocene N-S shortening, orogen-parallel thinning and eastward extrusion of orogenic lithosphere. We propose a new model for Alpine orogenesis that invokes changing wedge stability and migrating subduction singularities above the delaminating and detaching Alpine slab in the east to explain east-west differences in Oligo-Miocene structure, magmatism, erosion and sedimentation in peripheral Alpine basins. 10:30am - 10:45am
Topics: 3.23 Mountain Building in the Alpine-Mediterranean domain – from mantle imaging to crustal and surface processes back in time - AlpArray and AdriaArray Role of lithospheric-scale geological inheritance in the continental lithosphere dynamics 1GFZ German Research Centre for Geosciences, Potsdam Germany; 2Faculty of Georesources and Materials Engineering, RWTH Aachen University, Aachen, Germany Orogens in the Alpine-Himalayan collision zone (AHCZ) exhibit characteristic diffused seismicity compared to the stable continental interiors. Interestingly, they also have a thicker-than-average silica-rich upper crust and total crustal thickness, while their lithosphere thickness is similar to that of stable continental interiors (e.g., Tibet, Zagros). These observations provide a metric for the lithospheric-scale geological inheritance, the role of which we aim to understand in continental lithosphere dynamics over seismic and geologic timescales. To achieve this understanding, we use data-driven modelling to compute the present-day thermomechanical state of the AHCZ lithosphere. Our results indicate the existence of a critical crustal thickness, which is thermodynamically controlled by the internal energy and chemical composition of the crust and is similar to the global average of continental crust thickness. Orogenic lithospheres with thicknesses above this critical value possess higher potential energy and are weakened by the internal energy from heat-producing elements, whereas continental interior lithospheres with thicknesses close to the critical crustal thickness are stronger. Weaker orogenic lithospheres respond via dissipating this energy in a diffused deformation mode, leading to zones of deformation in contrast to focused deformation at the plate-boundaries. The observed crustal differentiation in the AHCZ could be understood as perturbations to the critical crustal thickness caused by plate-boundary forces. The dynamic evolution of these perturbations indicates that the critical crustal thickness is a stable fixed-point attractor in the evolutionary phase-space. 10:45am - 11:00am
Topics: 3.23 Mountain Building in the Alpine-Mediterranean domain – from mantle imaging to crustal and surface processes back in time - AlpArray and AdriaArray Shallow Asthenospheric Volumes Beneath Cenozoic Volcanic Provinces in the Circum-Mediterranean: Evidence from Seismic Tomography, Magmatic Geochemistry and Integrated Geophysical-Petrological Thermochemical Modelling 1Kiel Univeristy, Germany; 2GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany; 3Departamento de Física de la Tierra y Astrofísica, Universidad Complutense de Madrid (UCM) Spain; 4Department of Earth Sciences, University of Cambridge, Cambridge, United Kingdom To relate Intraplate volcanism to upper mantle structure, we investigate small-scale structural-variations of the lithosphere-asthenosphere beneath the Circum-Mediterranean using regional high-resolution 3-D surface-wave tomography. The imaged low shear-wave velocities (Vs<4.2 km/s) between depths of ~70-300 km indicate the presence of nine shallow asthenospheric volumes (SAVs) across the Circum-Mediterranean upper mantle forming a partly interconnected belt and separated only by high velocity slabs and thickened lithosphere. Integrated geophysical-petrological modelling for 14 representative locations, yields estimates of the lithospheric thickness and the upper mantle geotherm and confirms the presence of thin lithosphere (<80 km) above areas of anomalously warm SAVs (>1300°C). We distinguish between Intraplate, Mixed-origin and Subduction-related volcanism in the Circum-Mediterranean during the last 70 Ma and find a remarkable colocation between the SAVs and Cenozoic Intraplate and Mixed-origin volcanic provinces (IMVPs). Moreover, the lateral distance from any shallow asthenosphere to the closest neighboring volcanic province is, on average, as low as 100 km, with a maximum distance of 350 km, indicating a dense network of IMVPs above SAVs. By contrast, IMVPs are completely absent in areas of thick mantle lithosphere. We relate origin of the SAVs either to asthenospheric upwelling caused by slab-rollback and back-arc extension (Aegean-Anatolian, Pannonian, Moesian, Western Mediterranean SAVs) or to thermal erosion of the lithosphere partly coupled with continental rifting (Adriatic, Central European, North African, Middle East SAVs), respectively. The oldest ages of the IMVPs in the Circum-Mediterranean indicate that the development of the current SAVs started at about ~60-70 Ma ago and accelerated in Neogene. 11:00am - 11:15am
Topics: 3.23 Mountain Building in the Alpine-Mediterranean domain – from mantle imaging to crustal and surface processes back in time - AlpArray and AdriaArray Mapping the mantle transition zone discontinuities across South-Central Europe using body waves from seismic noise 1University of Vienna, Austria; 2ETH-Zürich, Switzerland; 3Massachusetts Institute of Technology, USA. Imaging the deep Earth structures is conventionally carried out using earthquake recordings. However, the resolving capability of such techniques (e.g., SS precursors and receiver function analysis) is often limited by the uneven spatial distribution of earthquake events and the high complexity of earthquake rupture processes. Recent advances in passive noise interferometry demonstrated the possibilities of recovering body waves from noise correlations, opening up new prospects for imaging the deep earth. In this study, we map the mantle transition zone (MTZ) discontinuities beneath South- Central Europe using P-wave reflection phases recovered from noise correlations. We analyze up to four years of seismic noise recordings from 900 broadband stations in the study area. By stacking noise correlations in selected summer months, we significantly improved the retrieval of typically low-amplitude body-wave reflection phases in the light of a quiet surface-wave environment and sufficient noise body-wave illumination from deep paths. We obtain reliable P-wave reflections associated with the 410-km and 660-km discontinuities in the period band of 4-10 s. These short-period reflections reveal clear lateral depth variations of the two discontinuities, indicating a complex MTZ arrangement in the greater Alpine region that is related to both present and past tectonic regimes. Our imaging method shows its potential for general applications in studying deep-earth discontinuities. |
10:00am - 11:15am | CANCELED: 1.31 Bergbau in Deutschland Location: Wiwi 108 |
11:15am - 11:30am | Break Location: Foyer (Henry Ford Building) |
11:30am - 1:00pm | Plenary Discussion: Mehr Erdsystemwissen in die Schule Location: Audimax Session Chair: Martin Meschede, Universität Greifswald Session Chair: Kirsten Elger, GFZ German Research Centre for Geosciences Session Chair: Tamara Fahry-Seelig, DVGeo Der Globale Klimawandel und die Ausrottung vieler Tierarten zeigen uns heute ganz deutlich wie der Mensch das System Erde beeinflusst. Die Gesellschaft wünscht sich einen Übergang zu umweltfreundlichen und klimaneutralen Technologien und die Jugend setzt sich engagiert dafür ein. Doch gleichzeitig werden geowissenschaftliche Themen im Lehrplan marginalisiert und vielerorts wird Erdkunde mit anderen Schulfächern, wie z.B. Geschichte, zusammengelegt. |
1:00pm - 1:30pm | Lunch Break | Exhibition Location: Foyer (Henry Ford Building) |
1:30pm - 3:00pm | 3.05-2 „Geomorphology and Sedimentology Beyond Boundaries“ - towards integrating geomorphology and sedimentary system science Location: Hall A (HFB) |
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1:30pm - 1:45pm
Topics: 3.05 „Geomorphology and Sedimentology Beyond Boundaries“ - towards integrating geomorphology and sedimentary system science Responses of alluvial river networks to environmental change: Integrating geomorphic and stratigraphic archives 1Helmholtz Centre Potsdam, GFZ German Centre for Geoscience Research, Germany; 2Institute for Geosciences, University of Potsdam, Germany; 3Saint Anthony Falls Laboratory, University of Minnesota, USA; 4Department of Earth & Environmental Sciences, University of Minnesota, USA Alluvial river networks are key components of sedimentary systems. They transport sediment, supplied from eroding source regions, to downstream depositional sinks. Their slopes and the rates at which they transport sediment are controlled by their water and sediment supplies, which are sensitive to environmental conditions: temperature and precipitation rates influence erosion rates, and hence sediment supply; precipitation rates are also a first order control on water supply. Changes in sediment and water supply therefore drive changes in channel slope, which may be preserved in fluvial terrace sequences, and sediment-transport rates, which may be preserved in downstream stratigraphic records. Consequently, if we can understand this behaviour, we may be able to use geomorphic and stratigraphic archives to reconstruct past environmental change and its influence on landscapes. Here, we apply a physically based model describing the coupled evolution of sediment transport and slope along alluvial rivers. We show that aggradation, incision, and variation in sediment-transport rates can be damped and lag significantly behind environmental change, depending on the forcing timescale, and on network geometry and hydrology. When water supply is varied, variation in sediment output can in some cases be amplified and appear to lead the imposed forcing. These effects should be taken into account when interpreting fluvial terrace and sedimentary records. Contrasting patterns of aggradation and incision compared with sediment-transport rates implies that integrating information from geomorphic and stratigraphic archives will provide deeper paleo-climatic insights and a powerful test of our understanding of sedimentary systems. 1:45pm - 2:00pm
Topics: 3.05 „Geomorphology and Sedimentology Beyond Boundaries“ - towards integrating geomorphology and sedimentary system science Headward drainage basin expansion drives Miocene incision along the Yangtze River, China 1Freie Universität Berlin, Berlin, Germany; 2University of North Carolina, Chapel Hill, NC, USA; 3Universität Potsdam, Potsdam, Germany Along the southeastern margin of the Tibetan Plateau, the onset of rapid fluvial incision during the Miocene is commonly attributed to growth of high topography. Recent recognition of lacustrine strata preserved atop interfluves, however, suggest that headward expansion of river networks drove migration of the topographic divide. Here, we explore the impact of this process on fluvial incision and sediment transport along the Yangtze River. Landscape evolution simulations using TopoToolbox (TTLEM and TVD-FVM) demonstrate that expansion of the Yangtze watershed into previously internally-drained basins since the Late Miocene could be responsible for 1-2 km of fluvial incision. The distribution of modern knickpoints and river profiles are consistent with this hypothesis. We suggest that increased erosive power associated with capture and basin integration drove accelerated incision and sediment transport during the Late Miocene. Progressive captures and integration of sub-basins could have driven punctuated episodes of rapid incision as drainage divides were progressively breached. Our results support the notion that the low-relief landscape atop the eastern Tibetan Plateau was elevated prior to Miocene time, and that basin integration and headward incision into this high-standing plateau drive rapid incision downstream of this former topographic divide. 2:00pm - 2:15pm
Topics: 3.05 „Geomorphology and Sedimentology Beyond Boundaries“ - towards integrating geomorphology and sedimentary system science Modelling the detrital signals of cosmogenic nuclides concentrations coupled with landscape evolution Geosciences Environnement Toulouse, GET, CNRS, IRD, CNES, Universite de Toulouse, 14 avenue E. Belin, F-31400, Toulouse, France The measurement of cosmogenic nuclide (CN) concentrations in riverine sediment has provided breakthroughs in our understanding of landscape evolution. Yet, the link between this detrital CN signal and landscape evolution is based on hypotheses that are not easy to verify in the field. New applications could arise from a better understanding of the statistics of CN concentrations in sediment grains. In this work, we present the coupling between the landscape evolution model Cidre and a model of the CN concentration in distinct grains. These grains are exhumed and detached from the bedrock and then transported in the sediment to the catchment outlet with temporary burials and travels according to the erosion-deposition rates calculated spatially in Cidre. The concentration in the various CN can be monitored in these grains. Because the CN concentrations are calculated in a limited number of grains, they provide an approximation of the whole CN flux. Thus, this approach is limited by the number of grains that can be handled in a reasonable computing time. On the other hand, part of the variability in the erosion-deposition processes can be recorded in the grain-by-grain distribution of the CN concentrations by monitoring the CN concentrations in distinct grains using a Lagrangian approach. We illustrate the robustness, the perspective and the limits of this approach by deriving the catchment-mean erosion from the 10Be mean concentration of the grains leaving a synthetic catchment uplifting at different rates and by comparing this derived erosion rate to the actual one calculated by Cidre. 2:15pm - 2:30pm
Topics: 3.05 „Geomorphology and Sedimentology Beyond Boundaries“ - towards integrating geomorphology and sedimentary system science Late Quaternary deformation, strain partitioning, and growth of the fold and thrust belt of The Western Himalaya 1IIT Gandhinagar, Gandhinagar, Gujarat, India; 2Christian Albrecht Universität zu Kiel, Germany; 3Universität Potsdam, Germany; 4Arizona State University, Tempe, U.S.A.; 5Physical Research Laboratory, Ahmedabad, India Constraining millennial-scale fault slip rates and understanding the related structural architecture in active orogenic wedges might provide important assessment of future seismic risk evaluations. An increasing number of Holocene and Late Pleistocene deformation rates have been reported throughout the Western Himalayan frontal fold-and-thrust belt (FTB), which have illustrated that the deformation is divided along several arc-parallel fault splays rooted to the Main Himalayan Thrust décollement. Studies also report complex pattern of out of sequence faulting, as well as spatiotemporal variations in fault growth and lateral heterogeneity of the FTB. However, what drives this lateral heterogeneity is debated until now. Late Pleistocene – Holocene deformed fluvial strath terraces across active faults in western Himalayan provide a measure of time-averaged fault slip rates along the Himalayan Frontal Thrust (HFT) and the Medlicott Wadia Thrust (MWT). While the Quaternary slip rates along the HFT varies from 3 – 12 mm/y, the slip rates from the ~700 km- long MWT is steadily high (7 – 9 mm/y).In contrast, previously published balanced cross-sections proposed slip rates of ~1 – 2 mm/y along the MWT. So from million-year to millennial timescale, there exists a significant temporal variation in fault activity. Single fault system like the MWT accommodate up to 50 - 60% of the total measured geodetic rates on Holocene/Late Quaternary timescales. These results document significant strain partitioning within the Sub-Himalaya and steady - high slip on the MWT which, beside the HFT could host the next big seismic event and damage the human-infested north India. 2:30pm - 2:45pm
Topics: 3.05 „Geomorphology and Sedimentology Beyond Boundaries“ - towards integrating geomorphology and sedimentary system science Middle to Late Pleistocene alluvial surface ages recorded by their spectral reflectance in Patagonia. 1German Research Centre for Geosciences (GFZ) Helmholtz Centre, Potsdam, Germany; 2Institute for Geosciences, Potsdam University, Potsdam, Germany; 3Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, Canada The age of alluvial surfaces can play a key role in deciphering surface processes and landscape evolution. However, the most common dating methods (e.g. with cosmogenic nuclides like 10Be) are expensive and time-consuming. We propose an approach that utilizes a limited number of 10Be samples in combination with hyperspectral data to estimate surface ages. Specifically, we make use of known alterations of the spectral reflectance of geochemical surfaces caused by weathering processes, e.g., clay mineral and iron oxide formation. Changes consist of an overall increase in reflection, but mainly the development of characteristic absorption features. Our aim is to detect these weathering features via hyperspectral satellite imagery to build a ground-truthed spectral-age model for estimating alluvial surface ages over large regions. To test this approach along the Río Santa Cruz in southern Patagonia, we dated 7 out of 13 fluvial terrace levels that yielded exposure ages up to 1.5 My, and we conducted in situ spectral measurements using a field spectrometer. By comparing these observations to satellite data (Landsat 8 and EnMAP), we can estimate ages and make better correlations of undated surfaces along the 250-km length of the river. Surprisingly, the age range of the model indicates slower than expected weathering rates and a major methodological advance in the detection of weathering processes via hyperspectral satellite. 2:45pm - 3:00pm
Topics: 3.05 „Geomorphology and Sedimentology Beyond Boundaries“ - towards integrating geomorphology and sedimentary system science The temperature control on the intensity of silicate weathering 1GFZ German Research Centre for Geosciences, Earth Surface Geochemistry, Telegrafenberg, 14473 Potsdam, Germany; 2State Key Laboratory of Marine Geology, Tongji University, 200092 Shanghai, China; 3Institute of Geochemistry and Petrology, Department of Earth Sciences, ETH Zürich, Clausiusstrasse 25, 8092 Zürich, Switzerland Chemical weathering of silicate minerals plays a vital role in maintaining the long-term habitability of Earth’s climate over geological timescales via a negative feedback mechanism. But much debate concerns the response strength of silicate weathering to each climatic factor and its evolution with land surface reorganisation. Such discrepancy arises from lacking weathering proxy validation and scarce quantitative paleo-constraints on individual forcing factors. Here we examine the catchment-scale link of silicate weathering intensity with various environmental parameters using a global compilation of modern sediment dataset for calculation of weathering intensity proxies, including chemical index of alteration (CIA) and weathering index of Parker (WIP). We show the primary control of temperature on silicate weathering given the monotonic increase of feldspar dissolution (constrained by CIA) with it at 0-30 oC, while controls of precipitation or topographic-lithological factors are regional and subordinate1. We interpret the non-linear forcing of temperature on feldspar dissolution as depletion of more reactive plagioclase (relative to orthoclase) at higher temperature. Accordingly, the surface temperature decrease could be accompanied with a higher proportion of more reactive plagioclase available for weathering, supporting the hypothesis that land surface reactivity has increased during the late Cenozoic cooling2. We also propose a first-order quantitative relationship between surface temperature, feldspar dissolution and CO2 consumption that will be of great potential for deep-time temperature reconstruction and carbon cycle modeling. References 1. Deng, K., Yang, S. & Guo, Y. (2022) Nat Commun 13, 1781. 2. Caves Rugenstein, J.K., Ibarra, D.E. & von Blanckenburg, F. (2019) Nature 571, 99–102. |
1:30pm - 3:00pm | 3.02-2 Mineralogical, Geochemical and Biogenic Transformations in the Critical Zone: what, where, when and how? Location: Hall B (HFB) Session Chair: Friedhelm von Blanckenburg, GFZ Potsdam Session Chair: Georg H Grathoff, University of Greifswald |
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1:30pm - 2:00pm
Invited Session Keynote Topics: 3.02 Mineralogical, Geochemical and Biogenic Transformations in the Critical Zone: what, where, when and how? Ecohydrological partitioning through the critical zone drives groundwater recharge: an isotopic approach 1HU Berlin, Germany; 2IGB Leibniz-Institute of Freshwater Ecology and Inland Fisheries Berlin, Germany; 3School of Geosciences, -- University of Aberdeen, Scotland, UK In times of accelerated global change, integrated tools are urgently needed that allow process-based, quantitative assessment of how climatic drivers interact with land cover, soil water conditions and hydrogeology to control the inter-relationships between water fluxes and storage in the Critical Zone (CZ). These dynamic relationships determine the availability and quality of water resources during droughts at multiple spatial and temporal scales. This talk will present approaches to investigate the relationships between water fluxes through and storage in the CZ, together with the associated water ages and residence times. The focus will be on groundwater recharge, as groundwater levels have been dramatically affected by the recent extreme droughts in large parts of Central Europe. Multiple ecohydrological processes and transformations within the CZ are influencing groundwater recharge by partitioning incoming precipitation into green (i.e. evaporation and transpiration) and blue (i.e. groundwater recharge and streamflow generation) water fluxes. Water stable isotopes help to constrain ecohydrological process understanding in the CZ. Incorporating isotopes into tracer-aided ecohydrological models allows water flux, storage and age dynamics to be quantified in both plot und catchment scale modelling. Using such novel analysis of the spatio-temporal interactions of water flux-storage-ages in the CZ improves understanding of the sensitivity and resilience of catchment functionality to hydroclimatic perturbations, and provides science-based evidence on which land management techniques have the potential to modify green water fluxes and to conserve soil water storage, to guide decision-making and build resilience to future droughts. 2:00pm - 2:15pm
Topics: 3.02 Mineralogical, Geochemical and Biogenic Transformations in the Critical Zone: what, where, when and how? Imbalances in dissolved elemental export fluxes disclose “hidden” Critical Zone pathways 1GFZ German Research Centre for Geosciences, Section Earth Surface Geochemistry, Telegrafenberg, 14473 Potsdam, Germany; 2Freie Universität Berlin, Institute of Geological Sciences, Malteserstr. 74-100, 12249 Berlin, Germany; 3Chair of Hydrology, Albert Ludwigs University of Freiburg, Friedrichstraße 39, 79098 Freiburg, Germany Streams are integrators over all biogeochemical reactions taking place in the Critical Zone. The resulting export of dissolved elements from a watershed is commonly used to infer chemical weathering fluxes. Yet, this approach rests on the assumption that the mass of a given element released from primary minerals that was not incorporated into secondary solids is quantitatively transferred into the stream in the dissolved form. The comparison of element-specific solute stream fluxes with chemical weathering fluxes determined in the residual solids shows that this is often not the case. An imbalance persists even after correcting for a bias potentially introduced by changes in water flow over these entirely different timescales. To explore causes for imbalances between short-term and long-term weathering fluxes, described by their ratio in form of a “Dissolved Export Efficiency” (DEE), we sampled six Critical Zone water compartments for one year in the Conventwald (Black Forest, Germany). We found deficits in the dissolved load, which emerged in the deep saprolite. For Si, Al, and Fe the deficit can be attributed to an export pathway that includes a “hidden” Critical Zone compartment or pool of unsampled colloids that are exported preferentially during flushing events. In contrast, deficits found for nutritive elements (Ca, K, Mg, P) can be explained by deep nutrient uptake followed by nutrient retainment in re-growing forest biomass or export in form of biogenic particulates. Given the collective evidence for these imbalances the deep Critical Zone warrants attention towards a complete budget of element cycles. 2:15pm - 2:30pm
Topics: 3.02 Mineralogical, Geochemical and Biogenic Transformations in the Critical Zone: what, where, when and how? Non-linear sensitivity of mineral weathering to erosion implies a maximum of CO2 drawdown at moderate erosion rates 1Ludwig Maximilian University of Munich, Germany; 2Department of Geosciences, Colorado State University, Fort Collins, USA; 3GFZ German Research Center for Geosciences, Potsdam, Germany Silicate weathering sequesters CO2 from the atmosphere and stabilizes Earth’s climate over geologic timescales. In turn, weathering of accessory carbonate and sulfide minerals is a geologically relevant CO2 source. Rock-uplift and -erosion is the primary mechanism by which fresh minerals are exposed to weathering at Earth’s surface. Therefore, the global inorganic carbon cycle is sensitive to mountain uplift and erosion. However, quantifying this sensitivity is complex, because existing data do not consider weathering of all relevant mineral phases, and because co-variation of multiple environmental factors obscures the role of erosion. Here, we analyze the sensitivity of silicate, carbonate, and sulfide weathering fluxes to erosion in solute chemistry from four small mountain streams that span well-defined erosion-rate gradients in relatively uniform metasedimentary lithologies. Across all datasets and 2-3 orders of magnitude of erosion rate, we find that silicate weathering fluxes are almost insensitive to erosion at rates >10-2 mm yr-1. In contrast, weathering fluxes from sulfide and carbonate minerals increase sub-linearly with erosion. By fitting a weathering model to these data, we show that the contrasting sensitivities of silicate, carbonate, and sulfide weathering produce a distinct CO2-drawdown maximum at moderate erosion rates of ~0.1 mm/y. Below this maximum, mineral supply limits silicate weathering. Above the maximum, silicate weathering fluxes plateau and CO2 emissions from coupled sulfide oxidation and carbonate weathering increasingly dominate the carbon budget. Overall, uplift of metasedimentary lithologies to moderate relief can substantially bolster Earth’s CO2 sink whereas further uplift may decrease, or even reverse, CO2 sequestration rates. 2:30pm - 2:45pm
Topics: 3.02 Mineralogical, Geochemical and Biogenic Transformations in the Critical Zone: what, where, when and how? A Numerical Laterisation Formation Model for Ferricretes 1Helmholtz-Zentrum GFZ Potsdam; 2Université Rennes 1 Géosciences Rennes Ferricretes are hard iron layers forming in semi-arid to subtropical environments. We can observe them in i.e. Africa, Australia or Brazil. They are an important part of regional geomorphology, capping hills and protecting landscapes. Climatic dependance is very high. Ferricrete formation occurs under strongly seasonally contrasting climates with precipitation and dry cycles. During wet seasons, transport and accumulation of elements happens while during dry seasons, precipitation and hardening dominate. It is also known that ferricretes form in tectonically “quiet” environments, and approximately need 1 Myr to form meter thick layers. There are two ferricrete formation hypotheses, the hydrological hypothesis and the laterite hypothesis. Recently, we developed a numerical model for ferricrete formation based on the laterisation hypothesis. 33% of land surfaces are covered by laterites today. The thickest lateritic profiles evolved for millions of years and are found in the centre of tectonically inactive areas. Weathering is the main process responsible for laterisation, transforming bedrock into regolith. A typical lateritic profile is divided into multiple stages from the weathering front to the surface, starting with a coarse grained and then fine grained saprolite, a mottled zone and at the top, a ferricrete. In our model, we assume that as the regolith ages, it undergoes a process of transformation that leads to hardening and compaction. Material is constantly eroded away from the regolith, thus making the model dependant on a constant material input for example through uplift. This is necessary to reach sufficient laterisation levels for ferricrete formation. 2:45pm - 3:00pm
Topics: 3.02 Mineralogical, Geochemical and Biogenic Transformations in the Critical Zone: what, where, when and how? Storms cause peatland flooding and paint it black: Sulfur biogeochemistry of a rewetting temperate coastal area 1Leibniz IOW, Germany; 2AUF, University of Rostock Land-ocean interactions in the coastal zone are of particular interest regarding the exchange of substances, like nutrients, carbon, sulfur, metals, and water. The rising sea level is and will enhance the pressure of salty solutions on previously fresh water ecosystems. Currently coastal areas in the North Eastern part of Germany under increasingly rewetted by the connection with the brackish Baltic Sea. We present results on the isotope biogeochemistry of a modern rewetted wetland, at the southern Baltic Sea, the Huetelmoor, that is under impact by event-type flooding by brackish seawater. These events lead to an enhancement of sulfate availability for microbial carbon transformations. Sediment cores on transects within the wetland were investigated for the pore water and soil composition, together with selected ground water wells and surface waters from the channeling system. Different fractions of the soils were analyzed for the elemental composition, mineral micro-textures, and the stable sulfur (and oxygen) isotope composition of different sulfur fractions to understand the water and biogeochemical carbon-sulfur-metal cycles and the geochemical signatures in authigenic mineral phases and organic matter. Adding sulfate creates space for mineral authigenesis and organic matter sulfurization. The soils are impacted by different intensities in sulfur cycling as reflected by isotope and textural signals. Further mechanistic investigations consider the role of DOS upon changing sulfur substrate availability. Results allow for a transfer of proxy information to other modern and past coastal organic-rich peatlands. Acknowledgement for support by DFG Research Training Group BALTIC TRANSCOAST, ERASMUS, and DAAD |
1:30pm - 3:00pm | 1.15-2 Mineralogy of complex ore deposits – from exploration to ore processing Location: Hall C (HFB) Session Chair: Max Frenzel, Helmholtz-Zentrum Dresden-Rossendorf e.V. Session Chair: Jochen Kolb, KIT |
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1:30pm - 1:45pm
Topics: 1.15 Mineralogy of complex ore deposits – from exploration to ore processing Constraining the interplay of magmatic and hydrothermal processes during ore formation with numerical models 1GFZ, Germany; 2University of Potsdam Future exploration for mineral resources will target greater depths and submarine settings, which is costly and technically challenging. For this development, numerical modeling can be used to identify the governing processes within entire ore-forming systems. Capturing the dynamics of magmatic-hydrothermal interface processes requires to resolve mass and energy fluxes as a continuum that extends beyond the roots of hydrothermal systems and bridges the gaps between fluid flow and magma dynamics. Magma is mobile during intrusion events and can convect until it reaches a crystal lockup due to cooling and crystallization. During this process, the magma reservoir reaches fluid saturation and exsolves metal-bearing magmatic volatiles to the host rock. We developed a consistent formulation for fluid generation and transport in a coupled model for viscous flow according to the Navier-Stokes-Equations and porous flow with Darcy’s Law, using an up-scaled description of volatile release from reservoir to host rock and realistic magma properties from published experimental and modelling works. We explore the consequences of exsolved volatile phases on magma dynamics and its implications on fluid release and ore formation within the host rock. We distinguish three distinct stages during the evolution of magmatic bodies and their associated porphyry copper deposits with a preparation, a brecciation-stockwork-veining and an ore-formation stage. 1:45pm - 2:00pm
Topics: 1.15 Mineralogy of complex ore deposits – from exploration to ore processing Pedras: Modal mineralogy approximations from assay data using Bayesian inference 1Monash University, Australia; 2Mineral Mapping Pty; 3University of Tasmania Mineralogy evaluation is critical to understand a deposit’s mineralogical variability, and inform decisions associated with ore beneficiation. Elemental-to-mineral conversion techniques (EMC) are a popular method to rapidly estimate a sample’s modal mineralogy from an assay dataset. EMC techniques are based in the principle that the bulk chemistry of a sample is proportional to the product of its modal mineralogy and the mineral’s elemental composition. In this work, we present a Baeysian framework to infer modal mineralogy from compositional data, Pedras. It builds upon the works of Escolme et al. (2019) and Berry et al. (2011), an EMC method that uses linear programming to minimize coefficients representing the energy required to generate a given mineral assemblage. The minimization process implies thermodynamic equilibrium, which is rarely the case for hydrothermal environments. Instead, the thermodynamic coefficients are defined as a logistic probability distribution function, centred at the mineral assemblage’s equilibrium, which relaxes the thermodynamic coefficient’s minimization. The framework is tested on synthetic alteration assemblages within a porphyry copper deposit and applied to a geochemical dataset from the Wainaulo porphyry copper deposit (Fiji). The results show that by relaxing thermodynamic minimization constraint, accurate modal mineralogy can be approximated at different stages of hydrothermal alteration in porphyry copper deposit systems. Major mineralogical domains are obtained from mineral approximations, reflecting different lithotypes, alteration and mineralization patterns. The modal mineralogy outputs also provide invaluable insights of mineral associations that vector towards mineralization, The method’s accuracy is enhanced when prior knowledge is objectively included in the modelling stage. 2:00pm - 2:15pm
Topics: 1.15 Mineralogy of complex ore deposits – from exploration to ore processing Deportment study of critical elements – The Ruwai Pb-Zn-Ag skarn deposit in Central Kalimantan, Indonesia, as a case study 1Helmholtz-Zentrum Dresden-Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Germany; 2School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, Australia; 3Department of Geology and Geological Engineering, Colorado School of Mines, USA; 4Gadjah Mada University, Yogyakarta, Indonesia The Ruwai Pb-Zn-Ag skarn deposit is located within the Schwaner Mountain Complex in Central Kalimantan, Indonesia. It is the largest polymetallic skarn deposit in Kalimantan with the resources is estimated up to 14.43 Mt. at 4.94 wt.% Zn, 3.28 wt.% Pb, 108.11 g/t Ag which hosted by Jurassic limestones of the Ketapang Complex and Cretaceous granitoids of Sukadana Complex. In order to study the complex mineralogy and deportment of critical-elements (Ag, Bi, Sb, In, Te, Cd) pulp samples from the main stages of the processing plant (Ball mill/feed, Pb concentrate, Zn concentrate, Pb scavenger, Zn scavenger, Fe screw, and tailings) as well as 66 core samples of Pb-Zn-Ag mineralization were obtained. Preliminary results on the pulp samples from X-ray diffraction (XRD), X-ray fluorescence (XRF) and mineral liberation analysis (MLA) agree within analytical uncertainties. The data allows a preliminary assessment of the deportment and distribution of Ag and Bi in the skarn ores and processing products. Particularly, acanthite (Ag2S) and freibergite ((Ag,Cu,Fe)12(Sb,As)4S13) are likely to be important hosts of Ag, while Bi occurs within bismuthinite (Bi2S3) and native bismuth (Bi). For the core samples, µ-XRF measurements of slabs have so far provided a broad overview of elemental distribution within the samples, while XRD results indicate more complex mineralogical compositions than the pulp samples. Further analytical work including electron probe microanalysis (EPMA) and laser ablation ICP-MS are planned for all samples to be also able to evaluate the resource potential of other critical elements of interest such as Sb, In, Te, Cd. 2:15pm - 2:30pm
Topics: 1.15 Mineralogy of complex ore deposits – from exploration to ore processing Ore mineralogy and metal deportment of Fe-Ni-Co laterite deposits from Sebuku Island, SE Kalimantan, Indonesia 1Helmholtz-Zentrum Dresden-Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Freiberg, Germany; 2School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, QLD, Australia; 3National Research and Innovation Agency, Banten, Indonesia; 4Sebuku Iron Lateritic Ore, Sebuku, Indonesia Indonesian laterite deposits are a major source of Ni and Co. Here, we present new geological data on the Sebuku laterites (SE Kalimantan, Indonesia), with a resource of ~390 Mt at 42.5 wt.% Fe, 0.9 wt.% Ni, and 0.15 wt.% Co. The deposits are mostly limonitic, oxide-dominated Fe-Ni-Co-rich horizons, which formed by weathering of Jurassic-Cretaceous ophiolitic units. Although the Fe ore has been mined since 2006, little mineralogical and geochemical data are available, which would allow optimizing beneficiation and recovery of Ni and Co. Typical laterite profiles at Sebuku consist of: 1) weathered bedrock composed of serpentinized dunites and harzburgites overlain by 2) a 0.2-7 m-thick saprolite zone, 3) a 2-8.5 m-thick yellow limonite zone, and 4) a 1-3.5 m-thick red-limonite zone. Preliminary XRF, XRD, and mineral liberation analysis (MLA) data show a decrease in Mg and Si and an increase in Fe moving upwards through the laterite profile, corresponding to a transition from silicate- to oxide-rich mineralogy. Oxides and (oxy)-hydroxides comprise goethite, maghemite, hematite, magnetite, chromium spinel, gibbsite/bayerite, and various Mn-minerals, whereas silicates consist of serpentine, chlorite, talc, quartz, pyroxene, olivine, and clay minerals. Ni is hosted by various minerals, which include goethite, Mn-oxides, serpentine, and clays, whereas Co is mainly hosted by Mn-oxides. Mineral chemical analyses (EPMA) are planned to further understand critical metal variability and distribution within the host minerals and throughout the deposits. Our ultimate goal is to characterize and quantify the distribution of Ni and Co in order to develop more efficient beneficiation processes. 2:30pm - 2:45pm
Topics: 1.15 Mineralogy of complex ore deposits – from exploration to ore processing Economic challenges of Fe, Co, Ni, Sc processing from complex ore deposits on the example of Sebuku Fe-(Ni)-Laterite (Indonesia) UIT GmbH, Germany Securing a predictable and affordable supply of critical metals for the high-tech industry, coupled with tightening supplies and augmented competition for available resources, leads to increasing exploration of complex and/or unconventional deposits. Complex ores often require extensive metallurgical processing and thus suffer from high capital and/or operational expenditures (CAPEX and OPEX). The Fe, Co, Ni, and Sc extraction from Sebuku Fe-(Ni)-Laterite was studied. The study compares conventional and alternative extraction methods, considering both the metal value of the deposit and the operational expenditures involved. Conventional methods, such as roasting, stirred leaching, and pressure leaching, showed high extraction efficiencies for the target elements but also a significant demand in energy and chemicals. Alternative reducing agents in combination with conventional methods benefit faster leaching times and reduced energy demand at similar extraction efficiencies and might result in a more cost-effective and environmentally friendly process chain. Unconventional approaches, such as ionic liquids and deep eutectic solvents, report lower recovery rates necessitating further basic investigations to optimize the leaching agents and/or to develop efficient process designs with respect to the specific requirements. Independent on the approach used, a basic process design including the implementation of potential recycling processes and waste/wastewater streams is mandatory for a first economic assessment of the individual routes. Based on this evaluation, the study highlights the need for further optimization to make beneficiation approaches feasible and attractive for potential investors especially viewing the current market prices for metals and chemicals. This study is part of the StratOre Project (Client II). |
1:30pm - 3:00pm | 1.13-2 Site selection for a nuclear waste repository – Data acquisition, host rock characterisation and analogue studies Location: Hall D (HFB) Session Chair: Michael Kühn, Deutsches GeoForschungsZentrum (GFZ) Session Chair: Bernhard Schuck, Bundesanstalt für Geowissenschaften und Rohstoffe |
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1:30pm - 1:45pm
Topics: 1.13 Site selection for a nuclear waste repository – Data acquisition, host rock characterisation and analogue studies Geochemical, Petrophysical and Rock Mechanical Characterization of Crystalline Rocks in Germany for High-level Radioactive Waste Disposal – First Results of the AMPEDEK Project TU Darmstadt, Germany The safe disposal of radioactive waste is a critical and frequently discussed topic in society. The Bundesgesellschaft für Endlagerung (BGE) was assigned with the selection of a suitable site for the disposal of high-level radioactive waste in Germany and, in the first phase of the selection procedure, has defined various selection criteria and sub-areas, seven of which cover the crystalline basement in Germany. For most of these sub-areas, little or no information is available on the crystalline host rocks and their properties, which would allow a narrowing of the site selection and identification of a suitable repository. Therefore, the AMPEDEK project establishes a reference database for the characterization of crystalline rocks in Germany. For this purpose, the database will contain information on the mineralogical, geochemical, petrophysical, and rock mechanical properties of predominantly igneous and metamorphic rocks of the Variscan basement. In the first phase, existing data from the literature or state geological offices were compiled and the structure of the database was established. In the second phase, ~500 drill cores and rock samples from quarries were analyzed in the laboratory to close existing data gaps. The goal was to sample as many different lithologies as possible to create a database that covers the majority of the relevant areas. The database currently contains ~8600 data points from 8 states and will be used to select smaller areas for Phase 2 of the site selection process and thus for detailed surface geological exploration campaigns. 1:45pm - 2:00pm
Topics: 1.13 Site selection for a nuclear waste repository – Data acquisition, host rock characterisation and analogue studies The anisotropy of granites - First results of a systematic study of German felsic plutonites 1Technische Universität Bergakademie Freiberg, Institut für Geologie, Bernhard-von-Cotta Str. 2, 09599 Freiberg, Germany; 2Thüringer Landesamt für Umwelt, Bergbau und Naturschutz, Außenstelle Weimar, Dienstgebäude 2, Carl-August-Allee 8 – 10, 99423 Weimar, Germany Granites represent suitable crystalline host rocks for nuclear waste repositories because of their mechanical strength and apparent isotropy. However, all granites have a primary structural and petrophysical anisotropy that developed during the emplacement and crystallization of the melt. The primary anisotropy likely controls the orientation of post-magmatic structural features such as extensional fractures. This secondary anisotropy controls potential fluid pathways. Thus, a causal relationship between primary and secondary anisotropies could be an important constraint in terms of the site selection process. We present the first results of a systematic study of German felsic plutonites. We focus on samples of syn-variscan peraluminous granite plutons from two localities, namely the Fichtelgebirge and the Erzgebirge. These areas represent different tectonic settings during intrusion, i.e., compression and transtension, respectively. To estimate their primary anisotropy, we analyzed the crystallographic preferred orientation (CPO) of the rock-forming minerals. CPOs were measured using the neutron time-of-flight (ToF) texture diffractometer “SKAT” and electron backscatter diffraction (EBSD). Based on this data intrinsic bulk rock elastic properties are modeled. All granites show weak but distinct preferred orientations of the rock-forming minerals, which are coherent on a local scale. The quartz textures, for example, show similar CPOs, with point maxima of the positive rhombs combined with small-circle to crossed-girdle c-axis distributions. However, the orientation with respect to the geographic reference system strongly varies on a regional scale. We will discuss the CPOs regarding their tectonic setting and correlate the primary anisotropy with the post-magmatic fracture patterns of the particular granites. 2:00pm - 2:15pm
Topics: 1.13 Site selection for a nuclear waste repository – Data acquisition, host rock characterisation and analogue studies 3D-architecture of a high-grade metamorphic gneiss terrain – How suitable are these rocks for of a deep geological repository site in Germany? BGE Bundesgesellschaft für Endlagerung mbH Most high-grade metamorphic gneiss units in Germany exhibit a strong late-Variscan thermal imprint recorded by the presence of migmatites and granitic intrusions. A nuclear waste repository in this setting is challenging because the amalgamation of various gneisses and magmatic rocks must be predicted and assessed to a search depth of 1500 m. Understanding the 3D-architecture of such basement units relies on better exposed regions than found in Germany. In this contribution, we use selected field areas to show the difficulty to predict the variability of high-grade metamorphic rock types at depth. The Argentera Massif in the western Alps represents an ideal field analogue as it displays a variety of para- and orthogneisses and their equivalent migmatites along continuous surface outcrops. Detailed field observations from this area help to constrain the structural and lithological anisotropy of a typical Moldanubian crustal segment. Except for the occurrence of large amphibolite lenses, gneisses and migmatites exhibit textural gradients at various scales rather than distinct lithological boundaries. Sharp boundaries on the other hand result from cross-cutting shear-zones that developed under retrograde greenshist facies conditions and discordant intrusions. Whereas the overall 3D-geometry and anisotropy of the gneiss terrane may be described with the help of 3D models it is generally not possible to predict the spatial distribution of lithotypes and dominant textures for a given rock volume. This contribution indicates why foliated gneisses and migmatites are less suitable as host rocks for a high-level radioactive waste repository compared with late granitoid intrusions that are more homogeneous. 2:15pm - 2:30pm
Topics: 1.13 Site selection for a nuclear waste repository – Data acquisition, host rock characterisation and analogue studies Trace element mobility in hydrothermal calcite during low temperature alteration - implications for radionuclide retention Technische Universität Berlin, Germany The recent exploration for nuclear waste repositories includes the evaluation of safety mechanisms in case of a leakage of radiotoxic material. Possible retention mechanisms like the uptake of these elements from the conducting aquifer into ubiquitous fracture minerals like calcite have drawn much attention. In laboratory experiments, it has been shown that especially actinides are efficiently scavenged by (re)crystallization of calcite1. To assess the long-term immobilization potential of calcite and the effect of low temperature alteration, element mobility in natural analogues needs to be studied. A suitable study site is the Wenzel ore mine in the Black Forest (S-Germany), which was actively mined until 1823. Here, hydrothermal calcite veins are exposed at the tunnel wall. After it´s shut down the mine was naturally flooded and calcite remained in contact to groundwater for approx. 175 years until the mine was drained and reopened to the public in 1999. Elemental distributions of La and Sr, which are considered as analogue elements for actinides and Ra are revealed by µXRF and LA-ICP-MS maps at high spatial resolution of 2 µm. First results show a complex pattern of Sr-enriched and depleted layers at the calcite-groundwater interface, which alternate at the 10 – 200 µm scale. In addition, localized enrichments of La appear, exceeding the pristine calcite concentrations by a factor of 4. Both features are interpreted as a result of secondary element mobility and discussed with respect of the retention potential of calcite during low temperature alteration. 1Curti E. (1999) Applied Geochemistry 14: 433-445 |
1:30pm - 3:00pm | 1.06-2 Deep geothermal resources and projects Location: Wiwi 101 Session Chair: Nora Koltzer, Fraunhofer IEG Session Chair: Torsten Tischner, Federal Institute for Geosciences and Natural Resources |
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1:30pm - 1:45pm
Topics: 1.06 Deep geothermal resources and projects Finding the geothermal sweet spots of Germany by integrating the subsurface geological heterogeneity with process simulations 1GFZ German Research Centre for Geosciences, Potsdam Germany; 2Faculty of Georesources and Materials Engineering, RWTH Aachen University, Aachen, Germany In Germany the heat demand distribution and operational geothermal production show limited spatial overlap and this is related to the geology in the subsurface. Most of the geothermal energy projects are located in the sedimentary areas of the Molasse Basin, the Upper Rhine Graben and the North German Basin. All these areas have in common that a thermal blanketing effect of young shallow sediments with high porosity keep the heat trapped beneath the insulating porous layer. The North German Basin has an additional heat controlling element - the mobilized Zechstein salt. Salt is thermally twice as conductive as clastic sediments and acts as a chimney for heat transport. The third controlling factor is the basal heat input that depends on the depth to the thermal LAB and the thickness of the upper crystalline crust producing ragiogenic heat, thus adding up to a half to the heat budget in the basins. Finally, the coupled transport of heat and fluid and the composition of the moving fluids add a last layer of complexity in defining geothermal sweet spots. As the fluids can move fast, they can take along their heat/cold, but also may transport solved material that can precipitate and destroy permeability if the PT-regime of the solution changes. The meanwhile increasing resolution of data and structural models of the subsurface open new opposrtunities to simulate heat transport considering the heterogenous physical property distribution as well as physical processes , thus enabling predictions far beyond the interpolation of a few temperatures measurements. 1:45pm - 2:00pm
Topics: 1.06 Deep geothermal resources and projects The World Heat Flow Database project: a new research data infrastructure for a community-driven Global Heat Flow Database 1Helmholtz Zentrum Potsdam Deutsches GeoForschungsZentrum GFZ; 2Technische Universität Dresden, FB Geowissenschaften, Geoinformatik The Global Heat Flow Database (GHFDB) is fostered and maintained by the International Heat Flow Commission (IHFC) for nearly 60 years. During these decades, the technological database concepts and storing capabilities evolved, allowing to add entries in the heat-flow database and underlying scientific methods according to the state of the art and database technology. In 2019, a collaborative database revision process started to provide a quality-assured and authenticated database. The community-driven approach, called the Global Heat Flow Data Assessment Project, started with a discussion of a new database structure to substitute the former database structure from 1976. It was designed to scrutinize and reassess the stored heat flow data according to the new structure. In parallel, the DFG-funded World Heat Flow Database project is developing a modern research data infrastructure for the new global compilation of heat flow data. It will offer comprehensive information on heat-flow related data, publications, projects, and researchers. It is designed to reflect the criteria of FAIR and OPEN data policy and to support the interoperability with other geoscientific data services 2:00pm - 2:15pm
Topics: 1.06 Deep geothermal resources and projects Roll-out of Deep Geothermal Energy in North-West Europe (DGE-ROLLOUT): Geothermal Energy Potential of Lower Carboniferous Carbonate Rocks 1Geological Survey of North Rhine-Westphalia, De-Greiff-Straße 195, 47803 Krefeld, Germany; 2Royal Belgian Institute for Natural Sciences, Geological Survey of Belgium, Rue Jenner, 13, 1000-Brussels, Belgium; 3Energie Beheer Nederland B.V., Daalsesingel 1, 3511 SV Utrecht, The Netherlands; 4Flemish Institute for Technological Research, Boeretang 200, 2400 Mol, Belgium; 5Fraunhofer Institution for Energy Infrastructures and Geothermal Systems IEG, Lennershofstrasse 140, 44801 Bochum, Germany Deep geothermal energy (DGE) may play a crucial role in the future energy production considering its base load capacity and ubiquitous availability. The EU Interreg North-West Europe (NWE) funded project DGE-ROLLOUT aims to promote the hydrothermal potential of Lower Carboniferous carbonate rocks, which is investigated following a multi-disciplinary geoscientific approach. Besides the Geological Survey of North Rhine-Westphalia as lead partner, project partners include the national geological surveys of Belgium, France and the Netherlands, as well as industry partners (DMT GmbH & Co. KG; Energie Beheer Nederland B.V.; RWE Power AG) and research institutions (Fraunhofer Institution for Energy Infrastructures and Geothermal Systems; Technical University Darmstadt; Flemish Institute for Technological Research). Sub- and associated partners include the national geological surveys of Great Britain and Ireland and the European Geothermal Energy Council, amongst others. DGE-ROLLOUT comprises three administrative, one investment and three implementation work packages (WP T1-T3): T1 provides a reconciled knowledge baseline for the DGE market development in NWE, including a transnationally harmonised depth and thickness map of the Lower Carboniferous. T2 fills information gaps through the acquisition of 2D seismic surveys, drillings, reprocessing vintage seismic data, and developing 3D subsurface models. T3 increases the efficiency of existing geothermal systems, implementing new or improved production techniques regarding reservoir behaviour, cascading systems and thermal energy storage. As DGE-ROLLOUT comes to an end in October 2023, we are keen on presenting our final results and evaluating the extent to which we succeeded in promoting the DGE potential of Lower Carboniferous carbonate rocks in NWE. 2:15pm - 2:30pm
Topics: 1.06 Deep geothermal resources and projects Geological and geophysical data integration and modeling approach for subsurface characterization; Northern Bavaria case study Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany Characterizing the subsurface structural and stratigraphic configuration is critical to address current global environmental challenges such as green energy transition and underground storage. Northern Bavaria, as our case study, is mainly covered by Permo-Mesozoic sedimentary units. Local and regional thickness changes are mainly attributed to the partly exposed structural complexity. To the east, the exposed crystalline rocks consist mainly of metamorphic rocks of Variscan affinity and late to post- orogenic intrusions. The presence and extent of granitic intrusions as a source of heat production and the estimation of the depth to the base of Permo-Mesozoic sedimentary cover are the main objectives of this study. In this study, we integrate the information from wells and exposed basement geology with reprocessed DEKORP seismic reflection, recently acquired 230 km 2D seismic reflection, Bouguer gravity anomaly and magnetic data to improve our understanding of the structural and stratigraphic configuration of the subsurface in northern Bavaria. Our first results confirm the presence of a granitic body (Hassfurt Granite) as the main source of thermal anomaly observed in northern Bavaria. We also show Permian (Rotliegend) grabens and half grabens storing 1-1.5 km thick sedimentary units. Rotliegend units are covered by relatively tabular Mesozoic cover. In structural point of view, we show that some of the Permian basin bounding normal faults are reactivated as reverse faults during the Cretaceous inversion event. Our observations and models contribute to reservoir characterization (buried fault zones and associated brittle deformation) and reduce exploration and potential future development risks. |
1:30pm - 3:00pm | 2.01-2 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) |
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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 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 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 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). |
1:30pm - 3:00pm | 4.11 Geo-scientific methods in Archaeology, Archaeometry and Experimental Archaeology Location: Wiwi 104a Session Chair: Rafael Ferreiro Mählmann, Technische Universität Darmstadt |
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1:30pm - 2:00pm
Invited Session Keynote Topics: 4.11 Geo-scientific methods in Archaeology, Archaeometry and Experimental Archaeology Investigating material culture (dis)continuities of Iron Age insular communities of Eastern Adriatic at the time of Greek settlement 1Texas Tech University, Department of Geosciences, Lubbock TX 79409, United States of America; 2Institute of Archaeology, 10000 Zagreb, Croatia The Adriatic seascape, as the Mediterranean’s northernmost extension, has long been an important crossroad of cultural exchanges between the East and the West. Here, connectivity and insularity served to link diverse peoples and cultures, with regional connectivity reaching its peak during the Iron Age. Concurrently, the Greeks embarked on extensive overseas journeys and established numerous settlements across the Mediterranean. One fascinating example to explore the dynamics between the locals and Greek colonists is the island of Hvar in central Dalmatia, which offers valuable insights through the examination of ceramic material culture. Using a range of traditional and state-of-the-art microscopic and spectroscopic analyses, a wide range of Greek and local Iron Age coarseware from the Greek colony of Pharos and local indigenous settlements was examined, with a particular emphasis on the practices involved in raw materials selection. A novel method for collecting elemental concentration data was implemented, which concentrates exclusively on the clayey substrate. This approach effectively mitigates any potential bias arising from the tempering of clay paste. Additionally, we conducted a geological survey of the island to identify plausible raw material deposits, considering that coarseware was predominantly produced locally. The findings of our study provide fresh perspectives on the lives of protohistoric local communities and their interactions with Greek settlers for whom the island of Hvar served as a hub from which Hellenistic culture spread throughout the insular and coastal Adriatic regions and beyond. 2:00pm - 2:15pm
Topics: 4.11 Geo-scientific methods in Archaeology, Archaeometry and Experimental Archaeology Which tools did stonemasons from the Late Bronze Age use to carve stelae of hard rocks from the Iberian Peninsula? 1Technische Universität Darmstadt, Germany; 2University of Freiburg , Germany; 3Labor für Archäometallurgie, Kenzingen, Germany; 4Instituto de Arqueología, Mérida; Universidad Autónoma, Madrid, Spain; 5Fragua Fuirio, Sevilla, Spain; 6University of Coimbra, Portugal This research will put emphasis on a multidisciplinary approach to examine the Iberian stelae of the Late Bronze Age (c. 1200-800 BC) involving petrographic, geochemical, and metallurgic analyses, complemented by experimental archaeology. The petrographic determination of the rock composition of 16 stelae provided evidence that hard magmatic, sedimentary, and meta-sedimentary rocks were used. The rocks were classified as quartz rich granite, leucocratic syenogranite-aplite, meta-arkose, quarzitic wacke, and silicate quartz-sandstone. Regarding the magmatic rocks, the finest available grain size was preferred. The sedimentary and meta-sedimentary rocks were carved on surfaces with a hard ground, a silicate – ferruginous cemented bed or on a joint wall. For the archaeological experiment, a variety of lithic tools and bronze chisels with various alloys were replicated, based on original Late Bronze Age tools from Portugal and Spain. Some lithic tools were completely inapplicable, while others, for example an amoeboid diablastic and equigranular quartzite (99 % quartz), provided acceptable results. The carving results with bronze chisels were disillusioning, regardless of the alloy composition. A long-ignored iron chisel from the Late Bronze Age site of Rocha do Vigio (Portugal) was studied with metallography. It revealed a medium-high carbon content steel and the replication of this chisel resulted as the only effective tool, provided the edge was hardened. This would establish the introduction of iron technology as a terminus post quem for the group of silicate quartz-sandstone stelae in Extremadura. Indeed, many of Europe´s earliest irons were found in nearby Portugal. *(DFG-project AR 1305/2-1), https://www.experimentalarchaeology.uni-freiburg.de/ 2:15pm - 2:30pm
Topics: 4.11 Geo-scientific methods in Archaeology, Archaeometry and Experimental Archaeology Petrographic, mineralogic, geochemical and geo-morphological provenience study on granite stelae from the Beira Alta (Beira Interior, Portugal) 1Technische Universität Darmstadt, Germany; 2University of Freiburg, Germany; 3University of Coimbra, Portugal; 4Museum of Sabugal, Portugal Of twelve stelae from the Late Bronze Age (c. 1200-800 BC) that are exhibited in five museums in the Beira Interior (Portugal), ten are carved in granitoid rocks of mainly leucocratic composition. Between the Serra da Estrela and the river Tejo, 70 % of the area is covered by granitoid intrusions of pre-, syn- and post-orogenic Variscan age. Plutons intruded in metamorphic and meta-sedimentary rocks older than Late-Carboniferous. Only one stele each was extracted from the largest intrusions of the area, from the Guarda biotite-monzogranite, and one from the pre-orogenic Fundão hornblende bearing biotite-granodiorite to monzogranite. A precise provenience study is thus not possible. Eight stelae where isotropic fine to medium grained granitoids with predominantly muscovite and rarely containing biotite. Microstructures, mineralogy, textural characteristics and geochemical analyses points to highly differentiated micro-plutonic rocks or dykes. Having realized that all twelve large granitoid intrusions in the Beira are less differentiated and porphyry, 16 aplite dykes and apophyses could be detected in a field study. Some aplite dykes in the northern part of the study area show the same composition variations as the Malhada Sorda pluton and its apophyses. But some dykes cannot be related with a late or post-orogenic intrusion. Seven syenogranite aplite rocks and apophyses could be related with a stelae rock type. Remarkably, all potential extraction sites are close to the place of stelae discovery, at the border of old communication routes, or near Late Bronze Age sites. *(DFG-project AR 1305/2-1), https://www.experimentalarchaeology.uni-freiburg.de/ 2:30pm - 2:45pm
Topics: 4.11 Geo-scientific methods in Archaeology, Archaeometry and Experimental Archaeology Metamorphic mapping and geo-morphologic considerations to locate the extraction sites of meta-psammite Late Bronze Age stelae from the Beira Interior (Portugal) 1Technische Universität Darmstadt, Germany; 2Museum of Sabugal, Portugal; 3Vila Velha de Ródão, Portugal; 4University of Freiburg, Germany; 5University of Coimbra, Portugal; 6B2R Institut UniLaSalle Beauvais, France A petrographic and geochemical provenience analysis of meta-psammite Iberian Stelae from the Final Bronze Age will be presented. A provenience analysis of archaeological objects is a Sisyphean task or impossible when dealing with uniform rock composition and structure along strike as they occur in sedimentary formations. If there are no observable singularities along vertical and horizontal inter-digitations of facies, the specification of a possible extraction site is like searching a needle in a haystack. Geo-morphologic consideration helps to enhance the probability to find the outcrop if strike of formation is perpendicular to valleys or mountain ranges. Furthermore, post metamorphic folding and tectonic dismembering reduces the possible areas, and increases the probability to find appropriate outcrops. The Beira Interior was metamorphosed during the Variscan Orogeny showing a metamorphic field gradient from amphibolite to sub-greenschist facies. The orogenic tectono-metamorphic pattern is disturbed by pluton intrusions and by aplite dykes. Metamorphic aureole zonation crosscuts formation strike and the orogenic metamorphic facies zonation. Therefore, areas with the same sedimentary lithotype (educt) and transformed to meta-sedimentary and metamorphic rocks (product) of a specific contact-metamorphic grade often postdates orogenic metamorphism and deformation. All these observations allow to drastically reduce the potential raw-material areas and to find outcrops showing the same educt-product genetic history as found in the rock-types of stelae. The very first application of metamorphic mapping techniques in combination with geo-morphology will be presented to clarify the provenience of archaeological objects. *(DFG-project AR 1305/2-1), https://www.experimentalarchaeology.uni-freiburg.de/ 2:45pm - 3:00pm
Topics: 4.11 Geo-scientific methods in Archaeology, Archaeometry and Experimental Archaeology Geophysical Prospection in Archaeology EASTERN ATLAS, Germany In recent decades, Applied Geophysics has become firmly established among geoscientific methods in archaeology for the non-destructive prospection of archaeological remains in the subsurface. Significant contributions have been made by technical developments towards mobile multi-channel platforms that can survey even very large areas of Hundreds of hectares with high spatial resolution and positioning accuracy in cm-range. Today, magnetometry and ground penetrating radar are not only used in research projects targeting known archaeological sites, but also as a professional commercial service in linear and urban planning projects. In the presentation an overview of the current state of the art will be given. The application of the available prospection techniques will be presented with examples, including archaeo-geophysical surveys done along the power lines SuedLink and SuedOstLink in Germany. An essential point in the presentation of the results arises from the interdisciplinary cooperation between geophysics and archaeology. A deeper understanding from the point of view of the user, in this case archaeology, is necessary to properly evaluate the geophysical data in terms of their archaeological significance. |
1:30pm - 3:00pm | 3.23-2 Mountain Building in the Alpine-Mediterranean domain – from mantle imaging to crustal and surface processes back in time - AlpArray and AdriaArray Location: Wiwi 105 Session Chair: Mark R. Handy, Freie Universität Session Chair: Sabrina Metzger, GFZ Potsdam |
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1:30pm - 1:45pm
Topics: 3.23 Mountain Building in the Alpine-Mediterranean domain – from mantle imaging to crustal and surface processes back in time - AlpArray and AdriaArray High resolution image of the Moho in the Eastern Alpine–Dinaric transition and implications for Alpine tectonic history 1GFZ German Research Centre for Geosciences (GFZ), Potsdam, Germany; 2Freie Universität Berlin, Institute for Geological Sciences, Berlin, Germany; 3See https://doi.org/10.14470/MF7562601148 for full memberlist; 4See https://alparray.ethz.ch for full member list The tectonic structure of the Eastern Alps is heavily debated with successive geophysical studies that are unable to resolve areas of ambiguity (e.g., the presence of a switch in subduction polarity and differing crustal models). In order to better understand this area, we produce a high resolution Moho map of the Eastern Alps based on a dense seismic broadband array deployment. Moho depths were derived from joint analysis of receiver function images of direct conversions and multiple reflections for both the SV (radial) and SH (transverse) components, which enables us to map overlapping and inclined discontinuities. We observe the European Moho to be underlying the Adriatic Moho from the west up to the eastern edge of the Tauern Window. East of the Tauern Window, a sharp transition from underthrusting European to a flat and thinned crust associated with Pannonian extension tectonics occurs, which is underthrust by both European crust in the north and by Adriatic crust in the south. The Adriatic lithosphere underthrusts northward below the Southern Alps and becomes steeper and deeper towards the Dinarides where it dips towards the north-east. Our results suggest that the steep high velocity region in the mantle below the Eastern Alps, observed in tomographic studies, is likely to be of European origin. 1:45pm - 2:00pm
Topics: 3.23 Mountain Building in the Alpine-Mediterranean domain – from mantle imaging to crustal and surface processes back in time - AlpArray and AdriaArray Paleogene deformation pattern and Neogene post-collisional reorganization of the Dinarides fold and thrust belt 1Friedrich-Schiller-Universität Jena, Germany; 2Institute of Geology & Geological Engineering, University of Zagreb, Croatia,; 3Utrecht University, Netherlands; 4Faculty of Science, University of Zagreb, Croatia The Late Cretaceous collision of the Adriatic microplate with Eurasia resulted in an overall SW-vergent and in-sequence structural architecture of the Dinarides. In the Paleogene the deformation propagated from the Internal towards the External Dinarides, associated with ca. 130 km of crustal shortening. Fault kinematic data and balanced cross-sections across the External Dinarides suggest contrasting styles along-strike the orogen, separated by a ca. 250 km long dextral transpressive fault. This fault delimits the southern, SW-vergent nappe stack segment from a northern, NE-vergent backthrust-dominated Velebit segment. Based on the distribution of the flexural foreland basin sediments, it is known that these two domains deformed contemporaneously, which marked the end of the Paleogene Dinaric orogeny. Within these Eo- to early Oligocene syntectonic and older Mesozoic carbonate platform rocks horizontal marine terraces are preserved at elevations of up to 600 m. We extracted terrace surfaces along the entire Adriatic coast from DEMs. All these flat surfaces are degradational, not related to bedding or faults, and they are located on the western side of the main drainage divide facing the Adriatic Sea. Their spatial correlation is in agreement with the position of a reported negative P-wave tomography anomaly, which in turn correlates with the thinned part of the Adriatic lithosphere. Our findings suggest an orogen-wide surface uplift affecting the Dinarides in the Neogene due to mantle delamination. Our overarching results show that the Paleogene Dinaric orogeny was related to high crustal shorten- and thickening, whereas the Neogene was related mainly to surface uplift. 2:00pm - 2:15pm
Topics: 3.23 Mountain Building in the Alpine-Mediterranean domain – from mantle imaging to crustal and surface processes back in time - AlpArray and AdriaArray Active tectonics of the eastern Southern Alps 1Institute for Geosciences, Friedrich-Schiller University Jena, Germany; 2School of Geography, Earth and Environmental Sciences, University of Plymouth, UK; 3Neotectonics and Natural Hazards Group, RWTH Aachen University, Aachen, Germany; 4Leibniz Institute for Applied Geophysics (LIAG) Hanover, Hanover, Germany; 5Department of Geology, University of Ljubljana, Ljubljana, Slovenia Current tectonic activity in the eastern Southern Alps is driven by the ongoing collision of Adria with Europe at a rate of ca. 2-3 mm/yr. While the South Alpine Front is well-studied, the deformation in the hinterland of the orogenic front is still not well-understood. Structurally, this area is characterised by dominantly E-W-trending, south-vergent thrusts and dextral strike-slip faults of the eastern Periadriatic fault system and the Dinaric system in Slovenia. Here we present new data on active faulting from tectonic geomorphology studies, field mapping, paleoseismology, and Quaternary dating techniques. We show that in Slovenia, crustal deformation is accommodated by a system of NW-SE striking right-lateral strike slip faults in a more than 60 km-wide zone. While the largest of those faults might be capable of magnitude M≥7 earthquakes, there is no historical or geological record for such large events. Several shorter faults with lengths of less than 15 km also show postglacial activity, but very little is known about their earthquake history. In Italy, most of the deformation is accommodated by thrusting at the South Alpine orogenic front and in the Friulian Plain. However, historical reports and our geomorphological observations indicate that strong earthquakes (M>6) occurred in the interior of the mountain chain, but these events are probably very rare. In Austria, the geological record of active faulting is sparse, although damaging historical quakes are known. New dating results from undisturbed geomorphic markers allow us to place constraints on the maximum amount of deformation that is accommodated here. 2:15pm - 2:30pm
Topics: 3.23 Mountain Building in the Alpine-Mediterranean domain – from mantle imaging to crustal and surface processes back in time - AlpArray and AdriaArray Geomorphologic evidence for postglacial activity of the Fella-Sava Fault, eastern Southern Alps, Italy Friedrich-Schiller-Universität Jena, Germany The eastern Southern Alps are a seismically active region. Research has been conducted to identify seismically active faults, with the sources of several catastrophic earthquakes still unknown. In this study, we conducted a paleoseismological investigation around the Fella-Sava Fault in the trijunction of Austria, Italy, and Slovenia, within the epicentral area of the destructive 1348 earthquake (MW 6.6-7.0). The Fella-Sava Fault is a ca. 100 km long, E-W- to WNW-ESE trending dextrally transpressive fault related to the Periadriatic fault system. Using digital elevation models (DEMs), we tried to identify direct evidence for surface rupturing earthquakes like fault scarps or offset geomorphic markers. Additionally, we put a special emphasis on sackungen. Sackungen are created by the gravitational collapse of mountain flanks, both aseismically and coseismically. Hillshades and aspect-maps derived from the DEMs proved suitable for mapping sackungen on a regional scale covering an area of ca. 1500 km2. A systematic remote sensing-based mapping of sackungen (of which several were subsequently ground-proven) in an area 15 km to both sides of the western segment of the Fella-Sava Fault revealed their clustering within 5 km on either side of the fault. The sackungen correlate neither with lithology nor valley depth. A directional analysis shows that the preferred trend of the sackungen is parallel to the Fella-Sava Fault and doesn’t correlate with the distribution of regional slope orientations. Thus, we suspect that the higher number sackungen in proximity of the Fella-Sava-Fault provides geomorphological evidence for its postglacial seismic activity, including the 1348 earthquake. 2:30pm - 2:45pm
Topics: 3.23 Mountain Building in the Alpine-Mediterranean domain – from mantle imaging to crustal and surface processes back in time - AlpArray and AdriaArray Finding Quaternary Seismic Slip Along the Eastern Periadriatic Fault System: Dating Fault Gouges by combined means of Electron Spin Resonance and Optically Stimulated Luminescence 1Friedrich-Schiller University Jena, Germany; 2Leibniz-Institut für Angewandte Geophysik LIAG Hannover, Germany; 3University of Ljubljana, Slovemia The Periadriatic Fault System (PAF) is among the largest post-collisional structures of the Alps. Recent studies using GPS velocities suggest that Adria-Europe convergence is still being accommodated in the Eastern Alps. However, according to instrumental and historical seismicity records, earthquake activity is mostly concentrated along structures in the adjacent Southern Alps. This is also the case for the PAF, which except for ambiguous historical events presents little to no earthquake record. Electron spin resonance (ESR) and Optically Stimulated Luminescence (OSL) are ultra-low temperature thermochronometers (closing temperature below 100 °C), with a Quaternary dating range (a few decades up to ~2 Ma). Both have the potential to date shear heating episodes. In this contribution, we present a first approach to narrow down earthquake activity during the Quaternary in the Eastern Alps by combining the application of ESR and OSL. Specifically, we aim to show which segments of the PAF system accommodated seismotectonic deformation by directly dating quartz and feldspar from fault gouges. For ESR, we measure the signals from the Al center in quartz following the single aliquot additive (SAAD) and single aliquot regenerative (SAR) protocols, focusing on the 4-11 µm and 100-150 µm grain size fractions. For OSL, we measure the IR50 and pIRIR225 signals on K-feldspar aliquots of the 100-150 µm grain size fraction. Our ESR results indicate the PAF accommodated seismic slip during the Quaternary with a maximum age ranging from 1-0.5 Ma, and OSL minimum ages of around 0.3 Ma. 2:45pm - 3:00pm
Topics: 3.23 Mountain Building in the Alpine-Mediterranean domain – from mantle imaging to crustal and surface processes back in time - AlpArray and AdriaArray The 2019 Mw6.4 Durres, Albania earthquake – anatomy of a thrust fault from high-resolution aftershock relocations 1Deutsches GeoForschungsZentrum, Germany; 2Utrecht University, The Netherlands; 3Karlsruhe Institute of Technology, Germany; 4Polytechnic University of Tirana, Albania The 2019, Mw 6.4 earthquake struck Albania at the Adriatic port city of Durres, 30 km away from the capital Tirana. It caused significant destruction and more than 50 deaths. The mainshock had thrust mechanism typical for the western Balkan margin along which the Adriatic micro plate collides with Europe. A dense temporary network of 30 seismic stations was deployed for 9 months to record the aftershock sequence. We applied a fully automated, machine learning-based detection and phase-picking routine to analyse the seismic data. This way more than 19,000 events were detected and located. Deriving cross-correlation-based differential travel times and relocating the entire catalogue of events with the HypoDD algorithm and a newly derived 1D velocity model reveals the fine-scale structure of the thrust fault. The rupture occurred on a ~30° NE dipping fault between approx. 10 and 20 km depth. The aftershocks collapse to several additional synthetic and antithetic structures highlighting a complex fault network. |
1:30pm - 3:00pm | 4.12 Geoethics – fostering ethical perspectives in the Geosciences Location: Wiwi 108 Session Chair: Dominic Hildebrandt, ETH Zurich Session Chair: Martin Bohle, Ronin Institute Session Chair: Barbara Zambelli, TU Bergakademie Freiberg |
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1:30pm - 2:00pm
Invited Session Keynote Topics: 4.12 Geoethics – fostering ethical perspectives in the Geosciences Geoethics and Transgenerational Climate Crimes - four examples to hold States and corporations accountable AIC Agencia de Iniciativas Cidadas, Brazil Is it possible to hold States and corporations accountable for the extractive industry’s transgenerational climate crimes? Answering this question implies the definition of climate crimes in time and space and, for this reason, four case studies will be analyzed to substantiate the critical analysis proposed: the Coalbrook mine disaster in South Africa (1960), the Amoco Cadiz oil spill in France (1978), the Performance Coal Company explosion in the United States (2010), and the Vale-BHP tailing dam collapse in Brazil (2015). Actions that cause climate catastrophe affect individuals and ecosystems beyond jurisdictions in an uncontrolled and incalculable way. The real purpose of the extractive industry must be observed from a geoethical perspective, that is, the extractive industry’s capacity of producing and reproducing life. States and corporations have historically managed the extractive industrial complex regardless and to the detriment of the existence of life in explored territories. This means that States and corporations are accomplices in actions that not only cause the worsening of life conditions in the present time, but also prevent life on the planet to be fostered and preserved. By comparing the alleged benefits and the real harm arising from a geopolitical developmental agenda of global endless industrial extractivism, this paper develops the geoethical possibilities of definition of transgenerational climate crimes departing from four case scenarios and their devastating consequences. 2:00pm - 2:15pm
Topics: 4.12 Geoethics – fostering ethical perspectives in the Geosciences Responsible Geosciences, or Geoscience Literacy for Urbanites 1Ronin Institute, Montclair (NJ), USA; 2International Association for Promoting Geoethics (IAPG), Rome, Italy Urbanites, i.e., people living in urban environments, should be geoscience-literate. Them living under a ‘veil of geo-ignorance’ is not a valid option for responsible geosciences. The urban realm is a social-ecological system on a planetary scale. Its complex-adaptive dynamics couple human practices and the geosphere1 2 (e.g., buildings, mines, shipping), causing massive fluxes (e.g., energy, water, materials), implies extensive civil-engineering works (e.g., housing, transport, infrastructure), and applies geoscience expertise. (e.g., foundations, drainage, position) A well-functioning urban realm requires professionals, who design, build and govern it, to apply geoscience expertise. Urban environments emphasise socio-economic interactions of people sheltered from everyday geosphere phenomena (e.g., weather, climate, slope-stability) and many disasters (e.g. floods, storms, heatwaves). However, most people have little insight into how much urban lifestyles depend on geosphere functions. That ignorance is a systemic risk for modern societies, which geoscience professionals should mitigate3, and meteorology gives an example of ‘how’. Modern meteorologists combine weather forecasts with information on meteorological phenomena, climate change, and impacts on economic and social activities. They show how forecasts determine people's work and life, demonstrating the wealth of geoscientific information and professional practices. The yet-to-answere question: How to do alike? 1. Otto, I. M. et al. Human agency in the Anthropocene. Ecol. Econ. 167, 106463 (2020). 2. Rosol, C., Nelson, S. & Renn, J. Introduction: In the machine room of the Anthropocene. Anthr. Rev. 4, 2–8 (2017). 3. Bohle, M., Sibilla, A. & Casals I Graells, R. A Concept of Society-Earth-Centric Narratives. Ann. Geophys. 60, (2017). 2:15pm - 2:30pm
Topics: 4.12 Geoethics – fostering ethical perspectives in the Geosciences Let us synchronize watches HSPV NRW, Germany “The mind seemed to grow giddy by looking so far into the abyss of time,“ noted John Playfair after having been introduced to geology by James Hutton. Deep time is in fact one of the main intellectual tools one must be ready to work with when wanting to do geology. Marcia Bjornerud describes how tedious the communication between geologists and people who think that the earth was created after the domestication of the dog can be. But it is not only religious people – almost everyone else finds it hard to grasp a duration of a million, 100 Million or a billion years too. This is because time is not only an objective parameter of the fourth dimension – it is also dependent on social factors. We all know that because time passes by more quickly when we a are older and / or in company and it goes slow when we are waiting for Father Christmas to show up or when we are bored. This social dimension of time will be looked at in my presentation. I will make use of the writings of religious scientist Mircea Eliade on time and will – with the help of the writings of geologist Marcia Bjornerud – try to describe the social implications the geological vision of time has or could and should have. Bjornerud (and I with her) is sure that geological “deep time” is not only a specific way of thinking for geologists but also a tool for social integration. |
1:30pm - 5:00pm | LEHRERFORT- BILDUNG Location: Wiwi 103 Session Chair: Sylke Hlawatsch, Richard Hallmann Schule |
2:00pm - 4:00pm | Stadtexkursion "Weltkulturerbe Museumsinsel" | 14:00 - 16:00 h Start: 14:00 Uhr Museumsinsel // Granitschale vor dem Alten Museum (Nähe U Museumsinsel, Bus Lustgarten) Anreise organisiert jeder selbst! Ende: 16:00 Uhr Exursionsleiterin: Gerda Schirrmeister |
3:10pm - 3:40pm | Closing Ceremony Location: Audimax Session Chair: Esther Martina Schwarzenbach, University of Fribourg Session Chair: Dirk Scherler, GFZ Potsdam / Freie Universität Berlin |
