589 Works

A new approach for 3d temperatur modelling in areas with sparse data - an example from northern Saxony-Anhalt (Germany)

Jacob Wächter, Christian Olaf Müller, Alexander Malz & Klaus-Jörg Hartmann
Landesamt für Geologie und Bergwesen Sachsen-Anhalt, Germany

Modelling of subsurface temperatures is based on various approaches, which typically focus on interpolation or numerical simulation procedures. Mostly, they are based on few single measurements and do not take into account the geological structure or lithological and thermal conductivity conditions of the subsurface. Herein, we present a new approach for the parameterization and modelling of subsurface temperatures for areas with sparse available data. We used temperature...

Raw Material Potential from Historic Mine Sites

Henrike Sievers , Petr Rambousek , Monica Serra, Antje Wittenberg & Daniel Oliveira
Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Hannover, Germany (1); Česká geologická služba, prac. Geologická 6, Praha 5–Barrandov, Czech Republic (2); ISPRA - Dipartimento per il Servizio Geologico d'Italia, Roma, Italy (3); Laboratório Nacional de Energia e Geologia, Amadora, Portugal (4)

The raw materials required by the European industry, especially metallic raw materials, are largely imported into the EU. Thus, Europe’s economic and social wellbeing relies on supplies from international sources and depends on secure...

Orbital forcing of Triassic megamonsoon activity documented in lacustrinesediments from Ordos Basin, China

Runjian Chu, Huaichun Wu, Rukai Zhu & Qiang Fang
China University of Geosciences (Beijing), China (1); Research Institute of Petroleum Exploration Development, PetroChina, Beijing, China (2)

The “hothouse” Triassic climate provides a key window to study megamonsoon systems. However, high-quality paleoclimate proxy records are rarely reported from the Tethys realm, where the seasonal meridional migration of the intertropical convergence zone (ITCZ) should be the most remarkable. Here, continuous and well-dated proxy records are used to study monsoon activity in the northeastern Tethys from the...

Applications of virtual reality to Geoscience

Claudia Ruiz-Graham
Imaged Reality

Field trips are essential for geologists and engineers to develop interpretation skills and to get a sense of scale. Unfortunately, attendance to field trips has become less frequent due to cost, with only a handful of team members attending a field trip once or twice a year. Sometimes access to key outcrop analogues can be difficult or too hazardous. COVID-19 has made attendance to field trips even more challenging. An alternative solution...

Wall rock contamination and mineralogical modifications in carbonatite dykes of the Palabora Complex, South Africa

R. Johannes Giebel , Benjamin F. Walter , Michael A.W. Marks & Gregor Markl
Contamination of carbonatite melts is often neglected due to a fast magma ascent and low liquidus temperatures. However, increased silicate mineral formation observed in numerous carbonatite occurrences world-wide requires an external Si introduction. Our study demonstrates that carbonatite dykes penetrating different lithologies of Palabora (South Africa) shows different modes of mineralogical modification. In particular Al and Si-rich lithologies show the most significant effects. Besides silicate mineral formation Si introduction may cause directly and indirectly variations...

µ-EDXRF based classification of chromites. A quick approach for testing hand specimen and drill cores.

Dieter Rammlmair & Wilhelm Nikonow
Chromites from ophiolites and layered intrusions show a wide variety in Cr#, Mg# and Cr/Fe ratios. These ratios provide information on the genesis of the chromite deposits e.g. the place of formation. By means of µ-EDXRF this information can be obtained in a very quick way from cut hand specimen. Unfortunately, chromites show a number of very intensive diffraction signals due to the polychromatic beam of the µ-EDXRF system, which even after calculating the minimum...

FloodRisk: Earthquakes, uplift, and long-term liabilities – risk minimisation during mine flooding

Dennis Quandt , Michael Alber , Felix Allgaier , Benjamin Busch , Even Markus , Kasper Fischer , Wolfgang Friederich , Jonas Greve , Mathias Knaak , Birgit Müller , Thomas Niederhuber , Detlev Rettenmaier , Martina Rische , Thomas Röckel , Frank Schilling , Daniel Schröder , Olaf Ukelis , Malte Westerhaus , Roman Zorn & Benjamin Busch
Due to the cessation of coal mining in Germany, mine water management in the former coal districts is subject to change and of environmental and economic significance. Since there is no technical need to drain the abandoned coal mines, mine water levels rise. As a result, subsurface rock pore pressures rise changing the subsurface effective stress regime. This may induce local ground movements and activate mining-related and natural fault zones. In order to develop a...

Critical Minerals in US Geothermal Brines: Opportunities and Challenges for their Extraction

Ghanashyam Neupane
Geothermal power plants produce a large volume of brine for power generation. Since these brines are the product of long-term water-rock interactions at elevated temperatures at depth, they contain dissolved chemical components including critical and strategic mineral commodities at various concentrations. Despite the low concentrations for many of these minerals, significant quantities of select minerals could be recovered due to the large volumes of brine utilized by geothermal power plants. Over the years, the U.S....

Thermo-compositional models of the West Gondwana cratons

Nils-Peter Finger , Mikhail K. Kaban , Magdala Tesauro , Walter D. Mooney & Maik Thomas
When Western Gondwana broke apart into the South American and African continents ca.120 Ma ago, some of its cratons were broken apart as well. Following the isopycnic hypothesis, their long-term stability and often neutral to positive buoyancy can be explained by the counteracting effects of cooling (density increase) and iron depletion (density decrease). To separate these effects, we created the presented models following an iterative integrated approach using mainly seismic and gravity data. In the...

Fracture network characterization and DFN modelling of the Upper Carboniferous, Ruhr Area, Germany

Felix Allgaier, Benjamin Busch , Dennis Quandt , Thomas Niederhuber , Birgit Müller & Christoph Hilgers
Since coal mining in the Ruhr Area has been ceased, mine water drainage is gradually reduced leading to the rise of formation water and groundwater levels. Rising mine water levels increase the pore pressure and induce stress changes in the subsurface, which may reactivate natural and/or mining-related faults and fractures. As part of the interdisciplinary FloodRisk project, which aims to enhance the understanding of the geomechanical coupling of increased pore pressure and heterogeneous ground movements,...

Mine water rebound in German hard coal mines – geochemical and petrophysical data support for an integrative monitoring plan

Henning Jasnowski-Peters, Barbara M.A. Teichert , Till Genth , Lisa Rose & Christian Melchers
Research Center of Post Mining, Technische Hochschule Georg Agricola University, Germany(1);Mine water rebound in German hard coal mine areas operated by RAG AG under the leadership of RAG Foundation is a showcase for post-mining associated research. It is a long-term, cost intensive and multidisciplinary project affecting highly populated urban areas like the Ruhr District. RAG is facing long-term liabilities as regulatory framework for the rebound process. Currently, mine water is pumped from levels down to...

Volcanites of MORB and WPB character in the evaporitic Permian Haselgebirge Formation (Eastern Alps, Austria) and possible tectonic implications

Christoph Leitner, Friedrich Finger & Albert Gilg
The evaporitic Haselgebirge Formation hosts in many places small occurrences of basaltic rocks. The geochemistry of these basalts can potentially provide information about the tectonic setting of the Haselgebirge Formation and the evolution of the Meliata ocean, respectively. XRD analysis and thin sections give hints to the original geochemistry, however the basalts altered significantly in contact with brines. Therefore, we present here 70 new XRF analyses of these basaltic rocks from various localities (Pfennigwiese, Annaberg,...

Implementation of the Geological Data Act (Geologiedatengesetz): A digital approach of the Geological Survey of Lower Saxony

Robert Schöner, Jan Sbresny , Jörg Elbracht , Nicole Engel & Hans-Jürgen Brauner
State Authority for Mining, Energy and Geology (LBEG), Hannover, Germany(1);Public access to geological data, especially to data from commercial subsurface geological investigations, was claimed for a long time in the German geoscience community. Since June 30th 2020, the Geological Data Act (Geologiedatengesetz, GeolDG) regulates the public availability of this data and replaces the Mineral Act (Lagerstättengesetz) from 1934. The GeolDG implicates both duties for persons who carry out or commission geological investigations and for the...

Collecting, sharing, and visualising harmonised data on European raw materials occurrences and mines – success or failure?

Špela Kumelj , Lisbeth Flindt Jørgensen , Frands Schjøth , Andrej Vihtelič , Blaž Bahar & Katarina Hribernik
Geological Survey of Slovenia, Slovenia(1);Geological Survey of Denmark and Greenland, Denmark(2);Easy web access to useful and reliable mineral information for the whole of Europe is the main objective of the extension of the M4EU base in the GeoERA project Mineral Intelligence for Europe (MINTELL4EU). The foundation has been laid by previous projects such as Minerals4EU, ProSUM, SCRREEN, EuRare, ORAMA, and new ones have been added in collaboration with ongoing projects such as RESEERVE. Europe's geological...

Reasons for extreme Th/U zoning of zircon in magmatic rocks: examples from the Bushveld Complex

Armin Zeh , Dominik Gudelius & Allan H Wilson
Zircons of magmatic rocks can show enormous variations in Th/U ratios (0.2 to 100) and extreme Th/U zoning. We present data from felsic and mafic rocks of the Bushveld Complex in South Africa. Zircon grains in mafic cumulate rocks reveal Th/U ratios up to 70, those in felsic rocks barely exceed 1.0. In mafic rocks zircon mostly occur together with Rt-Bt-Kfs-Qtz in intercumulus domains, and crystallized during final magma cooling between 900 and 700°C, after...

Time-dependent fracture permeability induced by fluid-rock interactions under intermittent and continuous flow

Chaojie Cheng & Harald Milsch
Fractures are the predominant flow pathways in low-permeability rocks. Understanding the fluid-rock interactions that occur in rock fractures and their effects on fracture aperture variations is important for assessing the sustainability of reservoir productivity. This study presents two long-term flow-through experiments with fractured pure quartz sandstones to investigate how fluid composition affects fracture changes over time. One sample was continuously flowed through with fluids (DI or Si-rich fluid), while the other sample was subjected to...

Inverse modelling of transport distance to reduce ambiguities of microbial and chemical source tracking in karst catchments

Johannes Zirlewagen, Ferry Schiperski , Tobias Licha & Traugott Scheytt
The identification of contamination sources is vital for water protection, especially in highly vulnerable karst aquifers. Contamination sources might be distinguished by host-specific DNA markers of bacteria (Microbial Source Tracking, MST) or source-specific indicator compounds (Chemical Source Tracking, CST). These methods can help to identify a type of contamination source but fail to distinguish similar contaminant signals from different origins, e.g. multiple points of wastewater infiltration. Transport modelling can reduce these ambiguities by considering the...

Subduction initiation and arc evolution from a rear-arc perspective – A synthesis of results from IODP Exp. 351

Philipp A. Brandl
Subduction is a key process for the plate tectonic cycle and is responsible for the bimodal composition of the Earth’ crust. Whereas active subduction zones can be directly observed at many places, their initiation and the early evolution of the associated volcanic arc can only be studied from the geological record. One key location to study the geological processes related to subduction initiation and subsequent arc emergence and maturation is the Izu-Bonin-Mariana (IBM) subduction zone...

Groundwater exploration and production in arid Jordan

Falk Lindenmaier , Gerhard Kapinos , Mark Gropius , Klaus Holzner , Florian Brückner , Daniel van Rooijen , Rebecca Bahls & Mathias Toll
The water providers of Jordan are constantly seeking to find new water resources to supply the public. Water table depths of up to 250 m, dry aquifers and saline waters make it increasingly difficult to successfully strike exploitable groundwater. We provided geoelectrical measurements for the exploration of a new well field area and set up a preliminary a-priori model for the interpretation of the geoelectrical results. Borehole geophysical logs, data on salinity content and subsurface...

Petrology and Geochronology of foidites and melilitites in SW Germany and E France

Thomas Binder , Benjamin F. Walter & Michael A. W. Marks
Foidites and melilitites are strongly SiO2-undersaturated rocks that form by extremely low degrees of partial melting of the metasomatically overprinted lithospheric mantle. In Central Europe, they occur in volcanic fields, dike swarms or as isolated stocks and diatremes. Our detailed study on foidites from SW Germany indicates two distinct age groups with marked differences in mineralogy and mineral chemistry: Based on in-situ U Pb age data (apatite, perovskite, zircon) a Miocene cohort (~ 9–19 Ma)...

Hydro-thermal modeling of geothermal energy extraction from Soultz-sous-Forêts, France using supercritical CO2

Mrityunjay Singh , Saeed Mahmoodpour , Kristian Bär & Claire Bossennec
Climate change requires immediate action, and for sustainable development, and uninterrupted energy supply is necessary. Since anthropogenic emission of CO2 in the atmosphere has a major role in climate change, carbon negative energy solutions are the necessity of the time. Geothermal energy is one such renewable source that can assist in achieving an economic solution to low carbon energy. Engineered geothermal systems or enhanced geothermal systems (EGS) are more suitable from an industrial perspective and...

Recent case studies and advances of the magnetotelluric method in geothermal exploration

Friedemann Samrock
The magnetotelluric (MT) method is a well-established tool in geothermal exploration. Case studies from all over the world and from different geothermal settings have proven its effectiveness, when it comes to subsurface reservoir characterization and the successful siting of geothermal wells. A reason for MT being a popular tool in geothermal exploration is that the bulk electrical conductivity of the subsurface, as recovered by MT, can be used as a proxy for key geothermal parameters....

The Eocene-Oligocene Transition in intra-continental basins: A perspective from the Upper Rhine Graben

Emile Simon , Hendrik Vogel & Mathieu Schuster
The Eocene-Oligocene Transition (EOT) marks a turning point from the Eocene greenhouse paleoclimate to near-modern icehouse conditions. This ~790 kyr long interval is associated with major shifts in geochemical and sedimentological proxies, biological extinctions, and evolutionary turnovers, in both the marine and continental realms. These various archives provide strong evidence for a rapid global cooling, an oceanic reorganization, and the onset of a continental-scale icesheet over Antarctica. The two main causes invoked for this climatic...

Petrography and geochemistry of the Middle–Upper Jurassic Banik section, northernmost Iraq – Implications for palaeoredox, evaporitic and diagenetic conditions

Nagham Omar, Tom McCann & Ali I. Al-Juboury
Lithological, petrographic, and geochemical analysis of the Middle to Upper Jurassic succession (i.e. Sargelu and Naokelekan formations) from northernmost Iraq were undertaken. The aim was to provide an updated discussion for their sedimentary and diagenetic histories, as well as examine the evaporation proxies and palaeoredox conditions under which the Sargelu and Naokelekan formations were deposited. Lithologically, the Sargelu Formation comprises massive dolomites, interbedded with shales, rare cherts and one single limestone bed, whilst the Naokelekan...

Sedimentology of the Bromacker (Thuringian Forest Basin, Germany; early Permian): Classification of sedimentary structures

Frank Scholze
The Thuringian Forest Basin (southern Thuringia, central Germany) is composed of volcanic and sedimentary rocks belonging to the Gehren Subgroup and the Rotliegend Group of late Carboniferous–early Permian age. The ~8x10 km wide main part of the Tambach-Dietharz (sub-)basin contains the Tambach Formation, which is characterized by red-bed deposits of early Permian (Artinskian) age. Lithostratigraphically, the Tambach Formation can be subdivided into three members, in ascending stratigraphic order: Bielstein Conglomerate, Tambach Sandstone, Finsterbergen Conglomerate. So...

Registration Year

  • 2022
    436
  • 2021
    150
  • 2020
    3

Resource Types

  • Text
    586
  • Other
    2
  • Conference Paper
    1

Affiliations

  • Karlsruhe Institute of Technology
    54
  • Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences
    44
  • Federal Institute for Geosciences and Natural Resources
    31
  • Technical University of Darmstadt
    20
  • University of Bremen
    18
  • Leibniz University Hannover
    16
  • University of Tübingen
    16
  • RWTH Aachen University
    16
  • University of Göttingen
    14
  • Utrecht University
    12