19 Works

Megathrust shear force limits mountain height at convergent plate boundaries

Armin Dielforder , Ralf Hetzel & Onno Oncken
The shear force along convergent plate boundary faults (megathrusts) determines the height of mountain ranges that can be mechanically sustained. Whether the true height of mountain ranges corresponds to this tectonically supported elevation is, however, debated. In particular, climate-dependent erosional processes are often assumed to exert a major control on mountain height, although this assumption has remained difficult to validate. To address this issue, we first constrained the shear force along active megathrusts from their...

Palaeofloral response to base level changes in the late Permian Bowen and Galilee basins (Australia)

Alexander Wheeler , Joan Sharon Esterle & Annette Elizabeth Götz
A variety of depositional environments characterise the infill of the late Permian Bowen and Galilee basins. These range from proximal fluvial-floodplain sequences and significant coal deposits through to more distal paralic and marine sections. The uppermost Permian sequence in these basins features spatiotemporal facies shifts but the regionally pervasive nature of the coal seams allows for the examination of the palaeoflora in context of changing environments through time between these bounding surfaces. The predominant flora...

Tracing wedge-internal deformation by means of strontium isotope systematics of vein carbonate

Armin Dielforder , Igor M. Villa , Alfons Berger & Marco Herwegh
Radiogenic strontium isotopes (87Sr/86Sr) of vein carbonates play a crucial role in the tectono-metamorphic study of fold-and-thrust belts and accretionary wedges and have been used to document fluid sources and fluxes, for example, along major fault zones. Moreover, the 87Sr/86Sr ratios of vein carbonates can trace the diagenetic to metamorphic evolution of pore fluids entrapped in accreted sediments. Here we present 87Sr/86Sr ratios of vein carbonates from the paleo-accretionary complex of the central European Alps...

Force-balance changes at the subduction-to-collision transition and implications for mountain building

Armin Dielforder & Andrea Hampel
The elevation of mountain belts increases at the subduction-to-collision transition in response to crustal thickening and processes like slab breakoff, but the main parameters controlling how much mountain height increases remain poorly understood. Based on analytical and finite-element force-balance models, we show that the increase in mountain height depends mainly on the magnitude of the shear force along the plate boundary fault (megathrust) and the reduction of submarine margin relief. During oceanic subduction, the megathrust...

Postglacial slip distribution along the Teton normal fault, northeastern Basin-and-Range Province (Wyoming, USA) derived from tectonically offset geomorphological features

Andrea Hampel & Maria-Sophie Erdmann
Along the eastern front of the Teton Range, northeastern Basin-and-Range Province, well-preserved fault scarps that formed across moraines, river terraces and other geomorphological features indicate that multiple earthquakes ruptured the range-bounding Teton normal fault after the Last Glacial Maximum (LGM). Here we use high-resolution digital elevation models derived from Lidar data to determine the vertical slip distribution along-strike of the Teton fault from 54 topographic profiles across tectonically offset geomorphological features along the entire Teton...

2D finite-element modelling of the interaction between poroelastic effects and viscoelastic relaxation during the seismic cycle

Jill Peikert , Andrea Hampel & Meike Bagge
The analysis of Coulomb stress changes has become an important tool for seismic hazard evaluation because such stress changes may trigger or delay next earthquakes. Processes that can cause significant Coulomb stress changes include coseismic slip, earthquake-induced poroelastic effects and transient postseismic processes such as viscoelastic relaxation. In this study, we use 2D finite-element models for intracontinental normal and thrust faults to investigate the spatial and temporal evolution and the interaction of pore fluid pressure...

A profile through ancient fast-spreading oceanic crust in the Wadi Gideah, Oman ophiolite – reference frame for the crustal drillings within the ICDP Oman Drilling Project

Jürgen Koepke , Dieter Garbe-Schönberg , Dominik Mock & Samuel Müller
The Oman Ophiolite is the largest and best-investigated piece of ancient oceanic lithosphere on our planet. This ophiolite was target of the Oman Drilling Project (OmanDP) within the frame of ICDP (International Continental Scientific Drilling Program) which aimed to establish a comprehensive drilling program in order to understand essential processes related to the geodynamics of mid-ocean ridges, as magmatic formation, cooling/alteration by seawater-derived fluids, and the weathering with focus on the carbonatisation of peridotites. Over...

The compilation of the new Alpine gravity maps - from the work of the AlpArray Gravity Research Group

Pavol Zahorec , Juraj Papco , Roman Pasteka , Miroslav Bielik , Sylvain Bonvalot , Carla Braitenberg, Jörg Ebbing , Gerald Gabriel , Andrej Gosar , Adam Grand , Hans-Jürgen Götze & György Hetényi
The international networking initiative AlpArray Gravity Research Group (AAGRG) focused on the compiling homogeneous surface-based gravity datasets across the Alps and adjacent areas, on creating digital data sets for Bouguer and Free Air anomalies. In 2016/17 all ten countries around the Alps have agreed to contribute with point or gridded gravity data and data processing techniques to a recompilation of the Alpine gravity field in an area which is limited by 2° to 23° East...

Carbonate microfacies and transgressive-regressive cycles of Oxfordian shallow-water limestones (Korallenoolith, Lower Saxony Basin)

Deyan Zhang , Stefan Huck & Ulrich Heimhofer
During the Oxfordian stage, the Lower Saxony Basin (LSB) was covered by a shallow epicontinental sea (Ziegler 1990), in which a thick succession of marine limestones and marls was deposited. Unfortunately, the scarcity of open marine marker fossils and numerous sedimentary gaps make it diffcult to correlate strata from the LSB with Oxfordian deposits elsewhere in the world (Betzler et al. 2007; Zuo et al. 2017). In a first step, this study therefore aims at...

The ICDP Oman Drilling Project – Implications from drill core GT1 on magmatic processes beneath fast-spreading mid-ocean ridges

Dominik Mock , David Axford Neave , Samuel Müller , Dieter Garbe-Schönberg , Benoit Ildefonse , Jürgen Koepke & Oman Drilling Project Science Team
A key aim of the ICDP Oman Drilling Project is to constrain magmatic processes beneath fast-spreading mid-ocean ridges. Several drill cores from the Samail ophiolite (Oman), which is regarded as the best-preserved piece of ancient oceanic lithosphere on land, were obtained. Drill core GT1 covers about 400 m from the layered gabbro section between ~1200 and 800 m above the mantle transition zone (maM). The vast majority of the samples recovered are (olivine-) gabbros with...

Versorgungsgradprognosen als Baustein einer evidenzbasierten Versorgungsplanung

Stephan L. Thomsen, Kai Ingwersen & Insa Weilage
Hintergrund: Als Teil der Maßnahmen zur Bekämpfung des Hausärztemangels insbesondere im ländlichen Raum gewinnt die Versorgungsplanung an Bedeutung. Methode: Diese Arbeit zeigt auf, wie durch die Kombination von Bevölkerungsprognosen und Arztzahlprognosen auf Basis der Kohorten-Komponenten-Methode die Qualität der Versorgungsplanung verbessert werden kann. Auf Grundlage bereits verfügbarer Daten (Bevölkerungszahlen und Arztregister) können Entwicklungen der Versorgungsgrade kleinräumig vorhergesagt werden. Die regionale und temporale Differenzierung ermöglicht das frühzeitige Erkennen von spezifischen Handlungsbedarfen. Dabei ist es wichtig, Limitationen in...

Deepwater Systems Reloaded: Advances on our understanding on submarine lobe deposits

Yvonne T. Spychala , David M. Hodgson , Joris T. Eggenhuisen , Stephen Flint , Christopher Stevenson , Mike Tilston , Ian A. Kane , Amadine Prelat & Florian Pohl
Submarine lobes are high aspect ratio sand-rich deposits that are fed by turbidity currents and debris flows via channels in deep-marine settings. As a major component of submarine fans, they represent 1) an important archive of palaeo-environmental change, 2) sinks for organic carbon and pollutants, and 3) are also of economic interest. Classic models describe lobes as purely depositional tabular sheets that thin and fine from an apex. Over the last decade, outcrop studies, numerical...

Tetravalent uranium mobilization by complexation or oxidation and associated U isotope fractionation

Yvonne Roebbert , Chris Daniel Rosendahl , Ashley Brown , Axel Schippers , Rizlan Bernier-Latmani & Stefan Weyer
Uranium (U) isotopes are suggested to monitor the success of (bio)remediation relying on the reduction of soluble and mobile U(VI) to less soluble U(IV)1. However, the subsurface stability of U(IV), typically present as solid-phase non-crystalline U, may be affected by complexation or oxidation. Understanding these processes and their impact on U isotope fractionation is important to correctly interpret field U isotope signatures. We investigated U mobilization by complexation and oxidation and measured the associated U...

Exhumation and erosion rates in the flat-topped Nock Mountains in the Eastern Alps constrained by low-temperature and cosmogenic 10Be data

Andreas Wölfler , Andrea Hampel , Christoph Glotzbach & István Dunkl
Constraining rates of landscape evolution is a necessary pre-requisite for reconstructing the spatiotemporal evolution of the Earth´s surface. In our study, we present new zircon and apatite fission track and (U-Th)/He ages as well as catchment-wide 10Be-derived erosion rates to determine exhumation and erosion rates in the Nock Mountains, an elevated-low relief landscape in the Eastern Alps. Zircon fission track and zircon (U-Th)/He analyses yielded cooling ages of ~90 and ~80 Ma, respectively, which we...

Half-precession signals in Lake Ohrid and their spatial and temporal connection to proxy records in the European realmS

Arne Ulfers , Christian Zeeden , Silke Voigt & Wonik Thomas
Lake Ohrid (North Macedonia/Albania) is Europe’s oldest lake and thus is a valuable archive for changes of local (hydro)climate during the last 1.36 million years (e.g., Wagner et al. 2019). During an International Continental Scientific Drilling Program campaign in 2013, geophysical downhole logging by the Leibniz Institute for Applied Geophysics acquired continuous datasets of physical properties. Additionally, sediment cores from four sites were obtained, the deepest with a length of 570 m (Wagner et al....

X-ray absorption spectroscopy study of Mn reference compounds for the identification and quantification of Mn species in soils

Teresa Zahoransky , Anna V. Wegorzewski , Winnie Huong & Christian Mikutta
Chemical reactivity, mobility, and bioavailability of manganese (Mn) in the environment depend crucially on its speciation. Despite the broad application of X-ray absorption spectroscopy (XAS) to environmental samples, studies covering the identification and quantification of Mn species in soils are surprisingly scarce. In this study, we analyzed 32 organic and inorganic Mn reference compounds by Mn K-edge (6,539 eV) XAS to assess the potential of XAS to differentiate various Mn coordination environments in soils. X-ray...

Lernunterstützende Fachkraft-Kind-Interaktionen in Kitas. Mikroanalytische Untersuchung der Effekte der KoAkiK- Weiterqualifizierung mit B-LuKA

Theresa Johannsen & Lisa Keller
Im Rahmen der KoAkiK-Verbundprojekte wurden pädagogische Fachkräfte in Kindertages-einrichtungen (Kitas) hinsichtlich ihrer lernunterstützenden Interaktionsgestaltung weiterqualifiziert. Zur Evaluation der Maßnahme wurden Videografien von Fachkraft-Kind-Interaktionen mit dem Beobachtungssystem zur Erfassung der Lernunterstützung im Kita-Alltag (B-LuKA) mikroanalytisch ausgewertet. Anhand einer Stichprobe von 85 Fachkräften werden die Art und Häufigkeit lernunterstützender und potenziell kognitiv aktivierender Äußerungen in dyadischen Situationen im Kita-Alltag beschrieben und Effekte der Weiterqualifizierung diskutiert.

Slip rate of the Danghe Nan Shan thrust fault from 10Be exposure dating of folded river terraces: Implications for the strain distribution in northern Tibet

Qiang Xu , Ralf Hetzel , Andrea Hampel & Reinhard Wolff
The northeastward motion of the Tibetan Plateau along the Altyn Tagh strike-slip fault causes thrust faulting in three parallel mountain ranges (Qilian Shan, Daxue Shan, Danghe Nan Shan) in the plateau interior, and leads to NNE-directed crustal shortening and plateau growth. While slip rates at the plateau margin (i.e. along the Qilian Shan and the Altyn Tagh fault) are well constrained, rates of thrust faulting and the strain distribution in the plateau interior remain poorly...

Proximal to distal grain-size distribution of basin-floor lobes: A study from the Battfjellet Formation, Central Tertiary Basin, Svalbard

Yvonne T. Spychala , Thymen A.B. Ramaaker , Joris T. Eggenhuisen , Sten-Andreas Grundvåg , Florian Pohl & Sara Wroblewska
The grain-size distribution of sediment particles is an important aspect of the architecture of submarine fans and lobes. It governs depositional sand quality, and reflects distribution of particulate organic carbon and pollutants. Documenting the grain-size distribution of these deep-marine sedimentary bodies can also offer us an insight in the flows that deposited them. Submarine lobes are commonly assumed to linearly fine from an apex, meaning there should be a proportional relation between grain size and...

Registration Year

  • 2022
    19

Resource Types

  • Text
    19

Affiliations

  • Leibniz University Hannover
    17
  • University of Münster
    3
  • Kiel University
    3
  • Durham University
    2
  • University of Manchester
    2
  • Utrecht University
    2
  • Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences
    2
  • //ror.org/00rqy9422:The University of Queensland, Australia
    1
  • UiT The Arctic University of Norway
    1
  • University of Lausanne
    1