Browsing Geochemie, Mineralogie, Petrologie by Issue Date
Now showing items 1-20 of 129
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The polymict carbonaceous breccia Aguas Zarcas: A potential analog to samples being returned by the OSIRIS‐REx and Hayabusa2 missions
; ; ; ; ; ; ; ; ; ; ; (Meteoritics & Planetary Science, 2021-02-02)
Abstract On April 23, 2019, a meteorite fall occurred in Aguas Zarcas, Costa Rica. According to the Meteoritical Bulletin, Aguas Zarcas is a brecciated CM2 chondrite dominated by two lithologies. Our X‐ray computed tomography ... -
Effective Diahaline Diffusivities in Estuaries
; ; ; ; ; (Journal of Advances in Modeling Earth Systems, 2021-02-01)
Abstract The present study aims to estimate effective diahaline turbulent salinity fluxes and diffusivities in numerical model simulations of estuarine scenarios. The underlying method is based on a quantification of ... -
Elastic stiffness coefficients of thiourea from thermal diffuse scattering
(Journal of Applied Crystallography, 2021-01-29)The complete elastic stiffness tensor of thiourea has been determined from thermal diffuse scattering (TDS) using high‐energy photons (100 keV). Comparison with earlier data confirms a very good agreement of the tensor ... -
Facilitated crystal handling using a simple device for evaporation reduction in microtiter plates
(Journal of Applied Crystallography, 2021-01-29)In the past two decades, most of the steps in a macromolecular crystallography experiment have undergone tremendous development with respect to speed, feasibility and increase of throughput. The part of the experimental ... -
The spatial distribution of sedimentary compounds and their environmental implications in surface sediments of Lake Khar Nuur (Mongolian Altai)
(Earth Surface Processes and Landforms, 2021-01-26)Abstract Lake sediments are valuable natural archives to reconstruct paleoclimate and paleoenvironmental changes which consist of inorganic and organic sediment compounds of allochthonous origin from the catchment and of ... -
Disordered sodium alkoxides from powder data: crystal structures of sodium ethoxide, propoxide, butoxide and pentoxide, and some of their solvates
(Acta Crystallographica Section B, 2021-01-25)The crystal structures of sodium ethoxide (sodium ethanolate, NaOEt), sodium n‐propoxide (sodium n‐propanolate, NaOnPr), sodium n‐butoxide (sodium n‐butanolate, NaOnBu) and sodium n‐pentoxide (sodium n‐amylate, NaOnAm) ... -
Stable isotopes of water reveal differences in plant – soil water relationships across northern environments
; ; ; ; ; ; ; ; (Hydrological Processes, 2021-01-24)
Abstract We compared stable isotopes of water in plant stem (xylem) water and soil collected over a complete growing season from five well‐known long‐term study sites in northern/cold regions. These spanned a decreasing ... -
Determining paracrystallinity in mixed‐tacticity polyhydroxybutyrates
(Journal of Applied Crystallography, 2021-01-22)Recently, the authors reported on the development of crystallinity in mixed‐tacticity polyhydroxybutyrates. Comparable values reported in the literature vary depending on the manner of determination, the discrepancies being ... -
Influence of Species‐Specific Feeding Ecology on Mercury Concentrations in Seabirds Breeding on the Chatham Islands, New Zealand
(Environmental Toxicology and Chemistry, 2021-01-20)Abstract Mercury (Hg) is a toxic metal that accumulates in organisms and biomagnifies along food webs; hence, long‐lived predators such as seabirds are at risk as a result of high Hg bioaccumulation. Seabirds have been ... -
Sampling, separation, and quantification of N‐acyl homoserine lactones from marine intertidal sediments
; ; ; ; ; ; ; (Limnology and Oceanography: Methods, 2021-01-20)
Abstract N‐acyl homoserine lactones (AHLs) are molecules produced by many Gram‐negative bacteria as mediators of cell‐cell signaling in a mechanism known as quorum sensing (QS). QS is widespread in marine bacteria regulating ... -
Effect‐Based Trigger Values for Mixtures of Chemicals in Surface Water Detected with In Vitro Bioassays
(Environmental Toxicology and Chemistry, 2021-01-13)Abstract Effect‐based trigger (EBT) values for in vitro bioassays are important for surface water quality monitoring because they define the threshold between acceptable and poor water quality. They have been derived for ... -
Disentangling the Impact of Catchment Heterogeneity on Nitrate Export Dynamics From Event to Long‐Term Time Scales
; ; ; ; ; (Water Resources Research, 2021-01-12)
Abstract Defining effective measures to reduce nitrate pollution in heterogeneous mesoscale catchments remains challenging when based on concentration measurements at the outlet only. One reason for this is our limited ... -
A history of violence: magma incubation, timing and tephra distribution of the Los Chocoyos supereruption (Atitlán Caldera, Guatemala)
(Journal of Quaternary Science, 2021-01-11)ABSTRACT The climactic Los Chocoyos (LCY) eruption from Atitlán caldera (Guatemala) is a key chronostratigraphic marker for the Quaternary period given the extensive distribution of its deposits that reached both the Pacific ... -
Water Content of the Dehydration Melting Layer in the Topmost Lower Mantle
(Geophysical Research Letters, 2021-01-09)Abstract The water‐rich mantle transition zone and dry lower mantle suggest that a dehydration melting layer can form at the 660‐km depth boundary. However, the water content of the melting layer (CH2Omelt), which dominates ... -
Measured and Simulated Carbon Dynamics in Midwestern U.S. Corn‐Soybean Rotations
; ; ; ; (Global Biogeochemical Cycles, 2020-12-29)
Abstract Corn (Zea mays L.) and soybean (Glycine max [L.] Merr.) production dominate Midwestern U.S. agriculture and impact the regional carbon and nitrogen cycles. Sustaining soil carbon is important for corn‐soybean ... -
Long‐term intercomparison of two pCO2 instruments based on ship‐of‐opportunity measurements in a dynamic shelf sea environment
; ; ; ; (Limnology and Oceanography: Methods, 2020-12-28)
Abstract The partial pressure of carbon dioxide (pCO2) in surface seawater is an important biogeochemical variable because, together with the pCO2 in the atmosphere, it determines the direction of air–sea carbon dioxide ... -
Geostandards and Geoanalytical Research Bibliographic Review 2019
(Geostandards and Geoanalytical Research, 2020-12-28)This bibliographic review gives an outline of publications in 2019 focusing on reference materials (RMs) used in geochemistry and related fields, such as palaeoclimate and environmental research. -
Inter‐laboratory Characterisation of Apatite Reference Materials for Chlorine Isotope Analysis
(Geostandards and Geoanalytical Research, 2020-12-25)Here we report on a set of six apatite reference materials (chlorapatites MGMH#133648, TUBAF#38 and fluorapatites MGMH#128441A, TUBAF#37, 40, 50) which we have characterised for their chlorine isotope ratios; these RMs ... -
Why productive lakes are larger mercury sedimentary sinks than oligotrophic brown water lakes
; ; ; (Limnology and Oceanography, 2020-12-25)
Abstract Mercury accumulation in lake sediments is a widespread environmental problem due to the biomagnification of Hg in the aquatic food chain. Soil Hg concentrations, catchment vegetation, erosion, and lake productivity ... -
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 ...