10 Works

Permeability available for VMS source fluids in altered and fractured lavas in the oceanic crust, Semail ophiolite, Oman

Alannah C. Brett & Larryn W. Diamond
The distribution of permeability in the upper oceanic crust controls hydrothermal circulation and the water–rock interactions that feed seafloor mineralization. A prevailing view is that lavas behave as fractured aquifers whose permeability is dominated by major extensional faults flanked by damage zones. Comparatively little is known about the permeability of the km-wide blocks of crust that lie between major faults, yet such blocks constitute huge sources of leachable metals. Our field mapping of hydrothermal veins...

Decoupled dust deposition and ocean productivity in the Antarctic Zone of the Southern Ocean over the past 1.5 million years

Michael E. Weber , Ian Bailey , Sidney R. Hemming , Yasmina M. Martos , Brendan T. Reilly , Thomas A. Ronge , Stefanie Brachfeld , Trevor Williams , Maureen Raymo , Simon T. Belt , Hendrik Vogel , Victoria Peck , Linda Armbrecht , Alix Cage , Fabricio G. Cardillo , Zhiheng Du , Gerson Fauth , Christopher J. Fogwill , Marga Garcia , Marlo Garnsworthy , Anna Glüder , Michelle Guitard , Marcus Gutjahr , Iván Hernández-Almeida , Frida S. Hoem … & Xufeng Zheng
Southern Ocean paleoceanography provides key insights into how iron fertilization and oceanic productivity developed through Pleistocene ice-ages and their role in influencing the carbon cycle. We report the first high-resolution record of dust deposition and ocean productivity for the Antarctic Zone, close to the main dust source, Patagonia. Our deep-ocean records cover the last 1.5 Ma, thus doubling that from Antarctic ice-cores. We find a ≥10-fold increase in dust deposition during glacials and a ≤5-fold...

Magnetic pore fabrics and how they predict preferred fluid migration paths in porous rocks

Andrea Regina Biedermann
The shape preferred orientation and connectivity of pores in reservoir rocks largely controls fluid migration properties, for example, by defining preferred flow directions. An accurate determination of preferred flow directions, observed as permeability anisotropy, is an integral part of reservoir characterization, due to profound effects on fluid migration. Numerous research fields, including groundwater studies, hydrocarbon exploitation, contamination mitigation, and CO2 sequestration, therefore seek methods to reliably characterize pore fabrics and permeability anisotropy. Many traditional methods...

Multi-proxy, localised reconstructions of climate and weathering from cave speleothem samples

Christopher Day , Philip Pogge von Strandmann , Franziska Lechleitner & Heather Stoll
Speleothems (secondary calcium carbonate formations) offer significant potential for recording environmental processes above caves, an area increasingly referred to as the Critical Zone. Speleothems grow for hundreds to millions of years, with absolute chronology from U-Th and U-Pb chronometers. The solution properties of rainwater infiltrating the soil and underlying caves respond to environmental controls. These environmental signals can be preserved within speleothem carbonates. Recent efforts to calibrate, model and interpret this complex geochemistry has progressed...

Hipercorig Hallstatt History (H3): Accessign a deep time window of Lake Hallstatt´s preHistory

Michael Strasser, Flavio Anselmetti, Achim Brauer, Stefano Fabbri, Ulrich Harms & Kerstin Kowarik

Drilling overdeepened (Eastern) Alpine Valleys and Basins

Markus Fiebig , Flavio Anselmetti , Marius Büchi , Gerald Gabriel , Ernst Kroemer , Frank Preusser , Jürgen Reitner , Sebastian Schaller , Bennet Schuster , David Tanner & Ulrike Wielandt-Schuster
The panalpine project "DOVE" (Drilling Overdeepened Alpine Valleys), co-funded by the International Continental Scientific Drilling Program (ICDP), is drilling a series of overdeepened glacial troughs around the Alps that were formed by subglacial erosion during past glaciations. In the northeastern section of the DOVE project, we (re)investigate the inneralpine basin of Bad Aussee (Traun glacier area, Austria), the subalpine basin of the Salzach Foreland glacier (Neusillersdorf, Bavaria), and the tongue basin area of the Pleistocene...

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...

Molybdenum isotope evidence for forearc mantle recycling at the Tongan subduction zone

Qasid Ahmad , Martin Wille , Stephan König , Carolina Rosca , Angela Hensel , Thomas Pettke & Jörg Hermann
Molybdenum isotope ratios (δ98/95Mo) of marine sediments constitute an important tracer for paleoredox reconstructions of the ancient ocean. Due to its redox-sensitivity, significant mass-dependent Mo isotope fractionation is induced in present-day low temperature environments leading to distinct Mo concentrations and isotope compositions in different marine lithologies. Subduction and recycling of such fractionated material can thus be potentially traced in arc magmas. Indeed, Mo isotope variations are observed in mafic arc lavas that are attributed to...

Significance of epidosite alteration for seafloor sulphide deposits and for fluid fluxes through the oceanic crust

Larryn William Diamond , Samuel Weber , Peter Alt-Epping & Alannah Brett
Epidosites are a prominent type of subseafloor hydrothermal alteration of basalts in ophiolites and Archean greenstone belts, showing an end-member mineral assemblage of epidote + quartz + titanite + Fe-oxide. Epidosites are known to form within crustal-scale upflow zones and their fluids have been proposed to be deep equivalents of ore-forming, black-smoker seafloor vent fluids. Proposals for the mass of fluid per mass of rock (W/R ratio) needed to form epidosites are contradictory, varying from...

An archive of many hats: speleothems for coupled climate and ecosystem reconstructions

Franziska Anna Lechleitner
Speleothems are secondary cave carbonate deposits and an established terrestrial paleoclimate archive. Moreover, they have the potential to record conditions in the ecosystem overlying the cave, particularly the vegetation and soil. Coupled records of paleoclimate and -ecological information from a single speleothem would be an invaluable source of information to understand the past and future sensitivity of terrestrial ecosystems to climate change, particularly under the lens of anthropogenic forcing. In order to develop proxies that...

Registration Year

  • 2022
    10

Resource Types

  • Text
    10

Affiliations

  • University of Bern
    10
  • Keele University
    1
  • University of Adelaide
    1
  • University of Plymouth
    1
  • Spanish Institute of Oceanography
    1
  • Columbia University
    1
  • Bayerisches Landesamt für Umwelt
    1
  • Andalusian Earth Sciences Institute
    1
  • Oregon State University
    1
  • University of California, San Diego
    1