Browsing Geochemie, Mineralogie, Petrologie by Issue Date
Now showing items 1-20 of 282
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On the Propagation of Reaction Fronts in a Sandy Aquifer Over 20+ Years: Lessons From a Test Site in Northwestern Germany
; Post, Vincent E. A.; Gröger‐Trampe, Jens; ; (Water Resources Research, 2021-08-09)
Despite reduction measures, nitrate and aluminum concentrations remain high in aquifers in northwestern Europe. To evaluate the effectiveness of groundwater protection policies, the long‐term fate of these contaminants in ... -
Constraining Global Marine Iron Sources and Ligand‐Mediated Scavenging Fluxes With GEOTRACES Dissolved Iron Measurements in an Ocean Biogeochemical Model
; ; Wallmann, Klaus; Scholz, Florian; ; ; Muglia, Juan; ; (Global Biogeochemical Cycles, 2021-08-09)
Iron is a key micronutrient controlling phytoplankton growth in vast regions of the global ocean. Despite its importance, uncertainties remain high regarding external iron source fluxes and internal cycling on a global ... -
Evolution of (Bio‐)Geochemical Processes and Diagenetic Alteration of Sediments Along the Tectonic Migration of Ocean Floor in the Shikoku Basin off Japan
; ; ; Tsang, Man‐Yin; ; ; ; ; ; ; (Geochemistry, Geophysics, Geosystems, 2021-08-03)
Biogeochemical processes in subseafloor sediments are closely coupled to global element cycles. To improve the understanding of changes in biogeochemical conditions on geological timescales, we investigate sediment cores ... -
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 ... -
Czochralski growth of mixed cubic sesquioxide crystals in the ternary system Lu2O3–Sc2O3–Y2O3
(Acta Crystallographica Section B, 2021-07-15)Cubic rare‐earth sesquioxide crystals are strongly demanded host materials for high power lasers, but due to their high melting points investigations on their thermodynamics and the growth of large‐size crystals of high ... -
The Importance of the Representation of DMS Oxidation in Global Chemistry‐Climate Simulations
; ; ; ; (Geophysical Research Letters, 2021-07-08)
The oxidation of dimethyl sulfide (DMS) is key for the natural sulfate aerosol formation and its climate impact. Multiphase chemistry is an important oxidation pathway but neglected in current chemistry‐climate models. ... -
Assessment of C, N, and Si Isotopes as Tracers of Past Ocean Nutrient and Carbon Cycling
; ; ; Fietz, S.; ; ; ; ; Ren, H.; ; ; GEOTRACES PAGES Biological Productivity Working Group Members (Global Biogeochemical Cycles, 2021-07-02)
Biological productivity in the ocean directly influences the partitioning of carbon between the atmosphere and ocean interior. Through this carbon cycle feedback, changing ocean productivity has long been hypothesized as ... -
Migration of Arc Magmatism Above Mantle Wedge Diapirs With Variable Sediment Contribution in the Aegean
; ; ; Melfos, V.; Klemd, R. (Geochemistry, Geophysics, Geosystems, 2021-06-17)
Compiled data show the age progression of magmatic centers along the two approximately linear profiles from NE Greece and NW Turkey to the South Aegean Volcanic Arc. The age progression reveals the southwestward migration ... -
Restricted Oxygen‐Deficient Basins on the Northern European Epicontinental Shelf Across the Toarcian Carbon Isotope Excursion Interval
; ; ; Wille, Martin; (Paleoceanography and Paleoclimatology, 2021-06-09)
The worldwide recognition of the Toarcian carbon isotope excursion (T‐CIE) in organic‐rich sedimentary rocks has been linked to an oceanic anoxic event (OAE) which implies the world's deep oceans were anoxic ∼183 Ma. The ... -
Impact of increasing carbon dioxide on dinitrogen and carbon fixation rates under oligotrophic conditions and simulated upwelling
; ; ; ; ; (Limnology and Oceanography, 2021-06-04)
Dinitrogen (N2) fixation is a major source of bioavailable nitrogen to oligotrophic ocean communities. Yet, we have limited understanding how ongoing climate change could alter N2 fixation. Most of our understanding is ... -
Crystallographic analysis of the lattice metric (CALM) from single electron backscatter diffraction or transmission Kikuchi diffraction patterns
(Journal of Applied Crystallography, 2021-05-28)A new software is presented for the determination of crystal lattice parameters from the positions and widths of Kikuchi bands in a diffraction pattern. Starting with a single wide‐angle Kikuchi pattern of arbitrary ... -
Modelling the structural variation of quartz and germanium dioxide with temperature by means of transformed crystallographic data
(Acta Crystallographica Section B, 2021-05-27)The pseudocubic (PC) parameterization of O4 tetrahedra [Reifenberg & Thomas (2018). Acta Cryst. B74, 165–181] is applied to quartz (SiO2) and its structural analogue germanium dioxide (GeO2). In α‐quartz and GeO2, the ... -
Resolution of a bent‐crystal spectrometer for X‐ray free‐electron laser pulses: diamond versus silicon
(Acta Crystallographica Section A, 2021-05-27)The resolution function of a spectrometer based on a strongly bent single crystal (bending radius of 10 cm or less) is evaluated. It is shown that the resolution is controlled by two parameters: (i) the ratio of the lattice ... -
Sulfide Dissolution and Awaruite Formation in Continental Serpentinization Environments and Its Implications to Supporting Life
; Vrijmoed, J. C.; Engelmann, J. M.; ; Wiechert, U.; Rohne, R.; (Journal of Geophysical Research: Solid Earth, 2021-05-20)
Serpentinization environments are key locations that support microbial communities by the abiogenic formation of reduced species associated with peridotite alteration. Here we studied partially serpentinized peridotites ... -
Ice Age‐Holocene Similarity of Foraminifera‐Bound Nitrogen Isotope Ratios in the Eastern Equatorial Pacific
; ; Ren, Haojia; ; ; Martínez‐García, Alfredo; Haug, Gerald H.; (Paleoceanography and Paleoclimatology, 2021-05-19)
Bulk sediment δ15N records from the eastern tropical Pacific (ETP) extending back to the last ice age most often show low glacial δ15N, then a deglacial δ15N maximum, followed by a gradual decline to a late Holocene δ15N ... -
Zircon and Melt Extraction From a Long‐Lived and Vertically Extensive Magma System Underneath Ilopango Caldera (El Salvador)
; ; ; Schindlbeck‐Belo, J. C.; Hernández, W.; Sims, K. W. W.; ; ; ; Wang, K.‐L.; Lee, H.‐Y.; Trumbull, R. B. (Geochemistry, Geophysics, Geosystems, 2021-05-12)
The Tierra Blanca (TB) eruptive suite comprises the last four major eruptions of Ilopango caldera in El Salvador (≤45 ka), including the youngest Tierra Blanca Joven eruption (TBJ; ∼106 km3): the most voluminous event ... -
Formation of Small Craters in the Lunar Regolith: How Do They Influence the Preservation of Ancient Melt at the Surface?
; ; Haber, Thomas; Wünnemann, Kai (Journal of Geophysical Research: Planets, 2021-05-11)
The impact melt that records the formation time of basins is essential for the understanding of the lunar bombardment history. To better understand melt distribution on the Moon, this study investigates mixing of melt by ... -
Linking the Dissolved and Particulate Domain of Organic Carbon in Inland Waters
(Journal of Geophysical Research: Biogeosciences, 2021-05-11)
Organic carbon (OC) in inland waters is found in either dissolved or particulate states, each contributing differently to carbon cycling through state‐specific forms of transport, processing, and mineralization. Degradation ... -
Sulfur cycling in oceanic oxygen minimum zones
; ; Kuypers, Marcel M. M.; Yilmaz, Pelin; Lavik, Gaute; ; ; (Limnology and Oceanography, 2021-05-10)
The sulfur cycle is an important, although understudied facet of today's modern oxygen minimum zones (OMZs). Sulfur cycling is most active in highly productive coastal OMZs where sulfide‐rich sediments interact with the ... -
Structure determination of organic compounds by a fit to the pair distribution function from scratch without prior indexing
(Journal of Applied Crystallography, 2021-05-09)A method for the ab initio crystal structure determination of organic compounds by a fit to the pair distribution function (PDF), without prior knowledge of lattice parameters and space group, has been developed. The method ...