Auflistung Geochemie, Mineralogie, Petrologie nach Titel
Anzeige der Dokumente 338-357 von 567
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Optimized reconstruction of the crystallographic orientation density function based on a reduced set of orientations
(Journal of Applied Crystallography, 2020)Crystallographic textures, as they develop for example during cold forming, can have a significant influence on the mechanical properties of metals, such as plastic anisotropy. Textures are typically characterized by a ... -
Origin and fate of dissolved organic matter in four shallow Baltic Sea estuaries
(Biogeochemistry, 2020-10-15)Coastal waters have strong gradients in dissolved organic matter (DOM) quantity and characteristics, originating from terrestrial inputs and autochthonous production. Enclosed seas with high freshwater input therefore ... -
Origin of 182W Anomalies in Ocean Island Basalts
(Geochemistry, Geophysics, Geosystems, 2023-02-18)Ocean island basalts (OIB) show variable 182W deficits that have been attributed to either early differentiation of the mantle or core‐mantle interaction. However, 182W variations may also reflect ... -
Origin of High Mg and SO4 Fluids in Sediments of the Terceira Rift, Azores-Indications for Caminite Dissolution in a Waning Hydrothermal System
(Geochemistry, Geophysics, Geosystems, 2019)During R/V Meteor cruise 141/1, pore fluids of near surface sediments were investigated to find indications for hydrothermal activity in the Terceira Rift (TR), a hyperslow spreading center in the Central North Atlantic ... -
Origin of isolated seamounts in the Canary Basin (East Atlantic): The role of plume material in the origin of seamounts not associated with hotspot tracks
(Terra Nova, 2020)In contrast to seamount chains, small solitary seamounts/seamount groups have rarely been sampled despite their large number and therefore their origins remain enigmatic. Here we present new 40Ar/39Ar, trace element and ... -
Oxygen Consumption of Resuspended Sediments of the Upper Elbe Estuary: Process Identification and Prognosis
(Aquatic Geochemistry, 2021-11-30)The resuspension of sediment leads to an increased release of nutrients and organic substances into the overlying water column, which can have a negative effect on the oxygen budget. Especially in the warmer months with a ... -
Oxygen Dependent Temperature Regulation of Benthic Fluxes in Reservoirs
(Global Biogeochemical Cycles, 2023-04-02)Temperature and dissolved oxygen concentration are critical factors affecting the exchange of solutes between sediment and water; both factors will be affected by warming of lakes and thereby influence water quality. ... -
Oxygen Vacancy Ordering in Aluminous Bridgmanite in the Earth's Lower Mantle
(Geophysical Research Letters, 2019)Oxygen vacancies (OVs), that charge-balance the replacement of octahedrally coordinated Si4+ by Al3+ in the mineral bridgmanite, will influence transport properties in the lower mantle but little is known about their ... -
Oxygen Vacancy Substitution Linked to Ferric Iron in Bridgmanite at 27 GPa
(Geophysical Research Letters, 2020)Ferric iron can be incorporated into the crystal structure of bridgmanite by either oxygen vacancy substitution (MgFeO2.5 component) or charge-coupled substitution (FeFeO3 component) mechanisms. We investigated the ... -
Papanin Ridge and Ojin Rise Seamounts (Northwest Pacific): Dual Hotspot Tracks Formed by the Shatsky Plume
(Geochemistry, Geophysics, Geosystems, 2021-09-15)Although previous findings support an origin of the Shatsky Rise igneous plateau (Northwest Pacific) through interaction of a mantle plume with a mid‐ocean ridge triple junction, the evidence for the involvement of a mantle ... -
Parameterizing Air-Water Gas Exchange in the Shallow, Microtidal New River Estuary
(Journal of Geophysical Research: Biogeosciences, 2019)Estuarine CO2 emissions are important components of regional and global carbon budgets, but assessments of this flux are plagued by uncertainties associated with gas transfer velocity (k) parameterization. We combined ... -
Partial melting and reaction along deformation features in plagioclase
(Journal of Metamorphic Geology, 2022-12-07)Geological processes involving deformation and/or reactions are highly influenced by the rock grain size, especially if diffusion‐controlled processes take place such as metamorphic reactions and diffusion creep. Although ... -
Partially open grain and phase boundaries as fluid pathways in metamorphic and magmatic rocks
(Journal of Metamorphic Geology, 2021-07-28)Transmission electron microscopy and 3D focused ion beam/scanning electron microscope nanotomography are applied to grain and phase boundaries between quartz, plagioclase, K‐feldspar, clinopyroxene, amphibole, and calcite. ... -
Particle‐Phase Uptake and Chemistry of Highly Oxygenated Organic Molecules (HOMs) From α‐Pinene OH Oxidation
(Journal of Geophysical Research: Atmospheres, 2022-08-16)Secondary organic aerosol (SOA) forms a major part of the tropospheric submicron particle mass. Still, the exact formation mechanisms of SOA have remained elusive. It is now admitted that highly oxygenated organic molecules ... -
Past and Future Climate Variability Uncertainties in the Global Carbon Budget Using the MPI Grand Ensemble
(Global Biogeochemical Cycles, 2021-08-21)Quantifying the anthropogenic fluxes of CO2 is important to understand the evolution of carbon sink capacities, on which the required strength of our mitigation efforts directly depends. For the historical period, the ... -
Past penguin colony responses to explosive volcanism on the Antarctic Peninsula
(2017)Changes in penguin populations on the Antarctic Peninsula have been linked to several environmental factors, but the potentially devastating impact of volcanic activity has not been considered. Here we use detailed ... -
Pedogenic carbonates as a proxy for palaeo-CO2 in the Palaeozoic atmosphere
(Elsevier2006)According to a model by Cerling (1991, 1999), the carbon isotope composition of calcretes should depend on the soil type and the CO2-concentration in the atmosphere. We have tested Cerling’s model by investigating 14 ... -
Permafrost Organic Carbon Turnover and Export Into a High‐Arctic Fjord: A Case Study From Svalbard Using Compound‐specific 14C Analysis
(Journal of Geophysical Research: Biogeosciences, 2021-03-14)In a warming climate, thawing permafrost soils in the circumpolar Arctic region are subject to enhanced microbial turnover as well as mass mobilization and other erosion processes. High‐Arctic settings such as Svalbard are ... -
Permafrost soil complexity evaluated by laboratory imaging Vis-NIR spectroscopy
(European Journal of Soil Science, 2020)The biogeochemical functioning of soils (e.g., soil carbon stabilization and nutrient cycling) is determined at the interfaces of specific soil structures (e.g., aggregates, particulate organic matter (POM) and organo-mineral ... -
Permeability Variations in Illite-Bearing Sandstone: Effects of Temperature and NaCl Fluid Salinity
(Journal of Geophysical Research: Solid Earth, 2020)Temperature changes and variations in pore fluid salinity may negatively affect the permeability of clay-bearing sandstones with implications for natural fluid flow and geotechnical applications alike. In this study these ...