Auflistung Geochemie, Mineralogie, Petrologie nach Titel
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Seasonal Carbon Dynamics in the Near‐Global Ocean
(Global Biogeochemical Cycles, 2020-12-23)The seasonal cycle represents one of the largest signals of dissolved inorganic carbon (DIC) in the ocean, yet these seasonal variations are not well established at a global scale. Here, we present the Mapped Observation‐Based ... -
Seasonality of Organic Matter Degradation Regulates Nutrient and Metal Net Fluxes in a High Energy Sandy Beach
(Journal of Geophysical Research: Biogeosciences, 2020)During seawater circulation in permeable intertidal sands, organic matter degradation alters the composition of percolating fluids and remineralization products discharge into surficial waters. Concurrently, coastal seawater ... -
Secondary Minerals Drive Extreme Lithium Isotope Fractionation During Tropical Weathering
(Journal of Geophysical Research: Earth Surface, 2022-02-15)Lithium isotopes are used to trace weathering intensity, but little is known about the processes that fractionate them in highly weathered settings, where secondary minerals play a dominant role in weathering reactions. ... -
Sectioning effects of porphyritic chondrules: Implications for the PP/POP/PO classification and correcting modal abundances of mineralogically zoned chondrules
(Meteoritics & Planetary Science, 2020)Mineralogically zoned chondrules are a common chondrule type in chondrites. They consist of olivine cores, surrounded by low-Ca pyroxene rims. By serial sectioning porphyritic chondrules from carbonaceous, ordinary, and ... -
Sediment Properties Drive Spatial Variability of Potential Methane Production and Oxidation in Small Streams
(Journal of Geophysical Research: Biogeosciences, 2020)Emissions of the potent greenhouse gas methane (CH4) from streams and rivers are a significant component of global freshwater methane emissions. The distribution of CH4 production and oxidation within stream sections and ... -
Sediment Release in the Benguela Upwelling System Dominates Trace Metal Input to the Shelf and Eastern South Atlantic Ocean
(Global Biogeochemical Cycles, 2022-09-25)Upwelling of subsurface waters injects macronutrients (fixed N, P, and Si) and micronutrient trace metals (TMs) into surface waters supporting elevated primary production in Eastern Boundary Upwelling Regions. The eastern ... -
Sedimentological and carbonate isotope signatures to identify fluvial processes and catchment changes in a supposed impact ejecta‐dammed lake (Miocene, Germany)
(Sedimentology, 2021-06-20)The identification and distinction of fluvial from lacustrine deposits and the recognition of catchment changes are crucial for the reconstruction of climate changes in terrestrial environments. The investigated drill core ... -
Separation of the inelastic and elastic scattering in time‐of‐flight mode on the pinhole small‐angle neutron scattering diffractometer KWS‐2
(Journal of Applied Crystallography, 2021-07-30)To study and control the incoherent inelastic background in small‐angle neutron scattering, which makes a significant contribution to the detected scattering from hydrocarbon systems, the KWS‐2 small‐angle neutron scattering ... -
Serpentinization-driven H2 production from continental break-up to mid-ocean ridge spreading: unexpected high rates at the West Iberia margin
(2021)Molecular hydrogen (H2) released during serpentinization of mantle rocks is one of the main fuels for chemosynthetic life. Processes of H2 production at slow-spreading mid-ocean ridges (MORs) have received much attention ... -
Shallow‐marine carbonate cementation in Holocene segments of the calcifying green alga Halimeda
(Sedimentology, 2021-09-15)Early‐diagenetic cementation of tropical carbonates results from the combination of numerous physico‐chemical and biological processes. In the marine phreatic environment it represents an essential mechanism for the ... -
Shock-induced formation of wüstite and fayalite in a magnetite-quartz target rock
(Meteoritics & Planetary Science, 2019)Projectile–target interactions as a result of a large bolide impact are important issues, as abundant extraterrestrial material has been delivered to the Earth throughout its history. Here, we report results of shock-recovery ... -
Silicon and iron isotopes in components of enstatite chondrites: Implications for metal–silicate–sulfide fractionation in the solar nebula
(Meteoritics & Planetary Science, 2023-06-28)Silicon and iron isotope compositions of different physically separated components of enstatite chondrites (EC) were determined in this study to understand the role of nebular and planetary scale events in fractionating ... -
Silicon Isotopes in an EMIC's Ocean: Sensitivity to Runoff, Iron Supply, and Climate
(Paleoceanography and Paleoclimatology, 2020)The isotopic composition of Si in biogenic silica (BSi), such as opal buried in the oceans' sediments, has changed over time. Paleorecords suggest that the isotopic composition, described in terms of δ30Si, was generally ... -
Simulated Future Trends in Marine Nitrogen Fixation Are Sensitive to Model Iron Implementation
(Global Biogeochemical Cycles, 2022-02-24)Biological nitrogen fixation is an important oceanic nitrogen source, potentially stabilizing marine fertility in an increasingly stratified and nutrient‐depleted ocean. Iron limitation of low latitude primary producers ... -
Single‐Crystal Elasticity of Antigorite at High Pressures and Seismic Detection of Serpentinized Slabs
(Geophysical Research Letters, 2022-08-26)The subduction of serpentinized slabs is the dominant process to transport “water” into Earth's mantle, and plays a pivotal role for subduction dynamics. Antigorite, the most abundant serpentine mineral in subduction ... -
Site dependence of the magnetocaloric effect in Mn5−xFexSi3
(Journal of Applied Crystallography, 2022-09-06)The nuclear and magnetic structures of Mn3Fe2Si3 are investigated in the temperature range from 20 to 300 K. The magnetic properties of Mn3Fe2Si3 were measured on a single crystal. The compound undergoes a paramagnetic to ... -
Small shards and long distances — three cryptotephra layers from the Nahe palaeolake including the first discovery of Laacher See Tephra in Schleswig‐Holstein (Germany)
(Journal of Quaternary Science, 2020-12-13)Investigations of Lateglacial to Early Holocene lake sediments from the Nahe palaeolake (northern Germany) provided a high‐resolution palynological record. To increase the temporal resolution of the record a targeted search ... -
Small-scale diagenetic facies heterogeneity controls porosity and permeability pattern in reservoir sandstones
(Environmental Earth Sciences, 2020-09-15)The fluvial-aeolian Upper Rotliegend sandstones from the Bebertal outcrop (Flechtingen High, Germany) are the famous reservoir analog for the deeply buried Upper Rotliegend gas reservoirs of the Southern Permian Basin. ... -
Small‐angle neutron scattering of long‐wavelength magnetic modulations in reduced sample dimensions
(Journal of Applied Crystallography, 2022-12-15)Magnetic small‐angle neutron scattering (SANS) is ideally suited to providing direct reciprocal‐space information on long‐wavelength magnetic modulations, such as helicoids, solitons, merons or skyrmions. SANS of such ... -
Small‐angle X‐ray scattering from GaN nanowires on Si(111): facet truncation rods, facet roughness and Porod's law
(Acta Crystallographica Section A, 2020-12-24)Small‐angle X‐ray scattering from GaN nanowires grown on Si(111) is measured in the grazing‐incidence geometry and modelled by means of a Monte Carlo simulation that takes into account the orientational distribution of the ...