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2. Fast assimilation of serpentinized mantle by basaltic magma

Author

Borisova, Anastassia Y., Zagrtdenov, Nail R., Toplis, Michael J., Ceuleneer, Georges, Safonov, Oleg G., Pokrovski, Gleb S., Jochum, Klaus Peter, Stoll, Brigitte, Weis, Ulrike, Shcheka, Svyatoslav, and Bychkov, Andrew Y.

Subjects
Condensed Matter - Materials Science, Astrophysics - Earth and Planetary Astrophysics, Physics - Geophysics
Abstract

The most abundant terrestrial lavas, mid-ocean ridge and ocean island basalt (MORB and OIB), are commonly considered to be derived from a depleted MORB-mantle component and more specific, variably enriched mantle plume sources. However, findings of oceanic lavas and mafic cumulates issued from melts, enriched in chlorine and having a radiogenic Sr ratio, can be attributed to an interaction between the asthenosphere-derived melts and lithospheric peridotite variably hydrated due to penetration of hydrothermal water down to and below Moho level. To constrain mechanisms and rates responsible for the interaction, we report results of experiments of reaction between serpentinite and tholeiitic basaltic melt. Results show that the reaction proceeds via a multi-stage mechanism: (i) transformation of serpentinite into Cr-rich spinel-bearing harzburgite containing pore fluid, (ii) partial melting and dissolution of the harzburgite assemblage with formation of interstitial hydrous melts, and (iii) final assimilation of the Cr-rich spinel-bearing harzburgite/dunite and formation of hybrid basaltic melts with high MgO and elevated Cr and Ni contents. Assimilation of serpentinite by basaltic melt may occur under elevated melt/rock ratios and may lead to chromitite formation. Our experiments provide evidence that MORB and high-Mg-Cr orthopyroxene-rich cumulates depleted in incompatible elements can be produced from common mid-ocean ridge basaltic melts modified by reaction with hydrated lithospheric peridotite. We established that the rate of assimilation of serpentinized peridotite is controlled by silica diffusion in the reacting hydrous basaltic melt., Comment: 6 figures, 6 tables, Frontiers in Earth Science, accepted

Published
2020
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3. Planetary Felsic Crust Formation at Shallow Depth

Author

Borisova, Anastassia Y., Zagrtdenov, Nail R., Toplis, Michael J., Bohrson, Wendy A., Nedelec, Anne, Safonov, Oleg G., Pokrovski, Gleb S., Ceuleneer, Georges, Bindeman, Ilya N., Melnik, Oleg E., Jochum, Klaus Peter, Stoll, Brigitte, Weis, Ulrike, Bychkov, Andrew Y., Gurenko, Andrey A., Shcheka, Svyatoslav, Terehin, Artem, Polukeev, Vladimir M., Varlamov, Dmitry A., Chariteiro, Kouassi E. A., Gouy, Sophie, and De Parseval, Philippe

Subjects
Astrophysics - Earth and Planetary Astrophysics, Condensed Matter - Materials Science, Physics - Geophysics
Abstract

Current theories suggest that on Earth and, possibly, on other terrestrial planets early in their history, the first continental crust may has been produced by direct melting of hydrated peridotite. However, the conditions, mechanisms and necessary ingredients of such production remain elusive. To fill this gap, we have conducted experiments of serpentinite melting in the presence of variable proportions of basaltic melt, at typical conditions of the shallow lithosphere and asthenosphere. These experiments revealed formation of silica-rich liquids, which are similar to tonalite-trondhjemite-granodiorite magmas (TTG) identified in modern terrestrial oceanic mantle settings. Our results suggest a new mechanism of aqueous fluid-assisted partial melting of peridotite that may have operated on the early Earth and Mars just after the solidification of an ultramafic-mafic magma ocean, leading to the formation of the first embryos of continental crust. The proposed mechanism of the continental crust formation may have been predominant before the onset of plate tectonics., Comment: 62 pages, 9 figures, submitted to Frontiers in Earth Science

Published
2020

4. Zinc isotopes in Late Pleistocene fossil teeth from a Southeast Asian cave setting preserve paleodietary information

Author

Bourgon, Nicolas, Jaouen, Klervia, Bacon, Anne-Marie, Jochum, KlausPeter, Dufour, Elise, Duringer, Philippe, Ponche, Jean-Luc, Joannes-Boyau, Renaud, Boesch, Quentin, Antoine, Pierre-Olivier, Hullot, Manon, Weis, Ulrike, Schulz-Kornas, Ellen, Trost, Manuel, Fiorillo, Denis, Demeter, Fabrice, Patole-Edoumba, Elise, Shackelford, Laura L., Dunn, Tyler E., Zachwieja, Alexandra, Duangthongchit, Somoh, Sayavonkhamdy, Thongsa, Sichanthongtip, Phonephanh, Sihanam, Daovee, Souksavatdy, Viengkeo, Hublin, Jean-Jacques, and Tütken, Thomas

Published
2020

5. Preface: Special Issue on Probing the Open Ocean With the Research Sailing Yacht Eugen Seibold for Climate Geochemistry

Author

Schiebel, Ralf, Aardema, Hedy M., Calleja, Maria Ll., Dragoneas, Antonis, Heins, Lena, Hrabe de Angelis, Isabella, Pöhlker, Christopher, Slagter, Hans, Vonhof, Hubert, Walter, David, Arns, Anthea I., Adolphs, Nils, Auderset, Alexandra, Basic, Sanja, Bieler, Aaron, Brüwer, Jan D., Chaabane, Sonia, Cheng, Yafang, Chiliński, Michal T., Cybulski, Jonathan D., Disper, Thomas, Duprey, Nicolas, Eichele, Gregor, Fiedler, Björn, Fischer, Alexa, Foreman, Alan D., Fuchs, Bernhard M., Galer, Steve, Härri, Jana, Jochum, Klaus Peter, Jost, Adrian, Jung, Jonathan, Kleta, Henry, Lammel, Gerhard, Larink, Otto, Leibold, Patrick, Martínez‐García, Alfredo, Moretti, Simone, Müller, Jann‐Gerrit, Nillius, Björn, Pan, Xihao, Raj, Subha S., Repschläger, Janne, Rodrigues, Elizandro, Ruff, S. Emil, Schmitt, Mareike, Schmitter, Janine L., Lara, Andrew Sellers, Silva, Péricles, Smart, Sandi M., Sörgel, Matthias, Stoll, Brigitte, Su, Hang, Vogt, Meike, Wald, Tanja, Weber, Bettina, Weber, Jens, Weis, Ulrike, Amann, Rudolf, Arístegui, Javier, Dittmar, Thorsten, González, Melchor, O’Dea, Aaron, Pöschl, Ulrich, Haug, Gerald H., Schiebel, Ralf, Aardema, Hedy M., Calleja, Maria Ll., Dragoneas, Antonis, Heins, Lena, Hrabe de Angelis, Isabella, Pöhlker, Christopher, Slagter, Hans, Vonhof, Hubert, Walter, David, Arns, Anthea I., Adolphs, Nils, Auderset, Alexandra, Basic, Sanja, Bieler, Aaron, Brüwer, Jan D., Chaabane, Sonia, Cheng, Yafang, Chiliński, Michal T., Cybulski, Jonathan D., Disper, Thomas, Duprey, Nicolas, Eichele, Gregor, Fiedler, Björn, Fischer, Alexa, Foreman, Alan D., Fuchs, Bernhard M., Galer, Steve, Härri, Jana, Jochum, Klaus Peter, Jost, Adrian, Jung, Jonathan, Kleta, Henry, Lammel, Gerhard, Larink, Otto, Leibold, Patrick, Martínez‐García, Alfredo, Moretti, Simone, Müller, Jann‐Gerrit, Nillius, Björn, Pan, Xihao, Raj, Subha S., Repschläger, Janne, Rodrigues, Elizandro, Ruff, S. Emil, Schmitt, Mareike, Schmitter, Janine L., Lara, Andrew Sellers, Silva, Péricles, Smart, Sandi M., Sörgel, Matthias, Stoll, Brigitte, Su, Hang, Vogt, Meike, Wald, Tanja, Weber, Bettina, Weber, Jens, Weis, Ulrike, Amann, Rudolf, Arístegui, Javier, Dittmar, Thorsten, González, Melchor, O’Dea, Aaron, Pöschl, Ulrich, and Haug, Gerald H.

Abstract

The 72‐foot sailing yacht Eugen Seibold is a new research platform for contamination‐free sampling of the water column and atmosphere for biological, chemical, and physical properties, and the exchange processes between the two realms. Ultimate goal of the project is a better understanding of the modern and past ocean and climate. Operations started in 2019 in the Northeast Atlantic, and will focus on the Tropical Eastern Pacific from 2023 until 2025. Laboratories for air and seawater analyses are equipped with down‐sized and automated state‐of‐the‐art technology for a comprehensive description of the marine carbon system including CO 2 concentration in the air and sea surface, pH, macro‐, and micro‐nutrient concentration (e.g., Fe, Cd), trace metals, and calcareous plankton. Air samples are obtained from ca. 13 m above sea surface and analyzed for particles (incl. black carbon and aerosols) and greenhouse gases. Plankton nets and seawater probes are deployed over the custom‐made A‐frame at the stern of the boat. Near Real‐Time Transfer of underway data via satellite connection allows dynamic expedition planning to maximize gain of information. Data and samples are analyzed in collaboration with the international expert research community. Quality controlled data are published for open access. The entire suite of data facilitates refined proxy calibration of paleoceanographic and paleoclimate archives at high temporal and spatial resolution in relation to seawater and atmospheric parameters. Plain Language Summary The new research sailing yacht Eugen Seibold ( ES ) enables clean, contamination‐free sampling of air and seawater to better understand the interactions between ocean and climate. For example, the oceans remove increasingly less carbon dioxide (CO 2 ) from the atmosphere the more saturated they are with CO 2 (ocean acidification). However, a detailed systematic understanding of air‐sea exchange processes remains to be developed. We analyze air and seawater

Published
2024
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6. On the Variability of Phytoplankton Photophysiology Along a Latitudinal Transect in the North Atlantic Surface Ocean.

Author

Aardema, Hedy M., Slagter, Hans A., Hrabe de Angelis, Isabella, Calleja, Maria Ll., Dragoneas, Antonis, Moretti, Simone, Schuback, Nina, Heins, Lena, Walter, David, Weis, Ulrike, Haug, Gerald H., and Schiebel, Ralf

Subjects
ABSORPTION cross sections, OCEAN temperature, MARINE biology, PHOTOSYSTEMS, BIOLOGICAL productivity
Abstract

Phytoplankton photosynthesis is the first step of energy capture in the open ocean and is therefore fundamental for global biogeochemical processes and ecosystem functioning. High‐resolution methods are required to fully capture the variability of marine photosynthesis and its environmental drivers. Here, we combine two high‐resolution underway methods to study phytoplankton photophysiology, Fast Repetition Rate fluorometry and Flow Cytometry, along a transect in the North‐East Atlantic Ocean from the polar circle to the equator. Significant spatial distinctions in photophysiological strategies were found between biogeographical provinces. The most pronounced distinction was present between the subarctic North Atlantic and the oligotrophic subtropical gyre, where the latter was typified by high photosystem II (PSII) turnover rates, low pigment‐to‐cell volume ratios, low PSII quantum efficiency and low absorption cross sections for photochemistry in PSII. Small‐scale variability along the transect results from varying diel cycles in photophysiology, possibly governed by light availability and cell metabolism. In general, we found that variability in PSII photochemistry was associated with variability in sea surface temperature, whereas the median mixed layer irradiance could explain more of the variation in the light harvesting capacity of the phytoplankton community. This implies that the expected climate change driven shoaling of the mixed layer may impact phytoplankton light harvesting strategies. Plain Language Summary: Marine photosynthesis is the basis of life in the ocean and therefore plays a fundamental role in the worlds' largest ecosystem. Phytoplankton adjust their photosynthesis to different environmental conditions, such as nutrients and light. Here, we combine data from two high‐resolution methods to study phytoplankton in the eastern North Atlantic Ocean from the polar circle to the equator. We show that the photosynthesis of phytoplankton differs between oceanographic regions and that daily cycles as well as environmental drivers play a role in the observed variability in marine photosynthesis. These insights are important to improve our predictions and understanding of the effects of climate change on marine ecosystems and biological productivity. Key Points: Combining underway methods on a small sailing sampling platform allows for high‐resolution characterization of phytoplankton photophysiologyDistinct photophysiological adaptation per marine biogeographical province reflects prevailing geochemical conditions across spatio‐temporal scalesNon‐linear relationships between photophysiology and environmental variables were present with superimposed diel trends [ABSTRACT FROM AUTHOR]

Published
2024
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14. Erratum to “Geochemical insights into the relationship of rock varnish and adjacent mineral dust fractions” [Chemical Geology 551 (2020) 119775]

Author

Otter, Laura M., primary, Macholdt, Dorothea S., additional, Jochum, Klaus Peter, additional, Stoll, Brigitte, additional, Weis, Ulrike, additional, Weber, Bettina, additional, Scholz, Denis, additional, Haug, Gerald H., additional, Al-Amri, Abdullah M., additional, and Andreae, Meinrat O., additional

Published
2022
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16. Geostandards and Geoanalytical Research Bibliographic Review 2020

Author

Weis, Ulrike, Stoll, Brigitte, Förster, Michael W., Hell, Katharina, Kaiser, Viktoria, Otter, Laura M., Jochum, Klaus Peter, 1Climate Geochemistry Department Max Planck Institute for Chemistry P.O. Box 3060 Mainz 55020 Germany, 27788Department of Earth and Environmental Sciences Macquarie University Sydney NSW 2109 Australia, and 32219Research School of Earth Sciences Australian National University Canberra 0200 Australia

Subjects
Geochemistry and Petrology, ddc:551.9, Geology
Abstract

Key Points: Literature review of 7200 geoanalytical publications for the year 2020. 628 selected articles with summaries of target analytes, relevant reference materials and producers. Selected publications include data obtained by new analytical developments and improved analytical protocols for established RMs, and identifies recently developed RMs for specific scientific topics. image, This bibliographic review gives an overview of scientific publications in 2020 that contribute important data for geoanalytical reference materials (RMs).

Published
2022

17. Temperature calibration for high Mg-calcite planktic Foraminifera shells from the Gulf of Aqaba

Author

Levy, Noy, Torfstein, Adi, Schiebel, Ralf, Chernihovsky, Natalie, Jochum, Klaus Peter, Weis, Ulrike, Stoll, Brigitte, and Haug, Gerald H.

Abstract

Hypersaline, oligotrophic seas have been shown to accommodate planktic Foraminifera (PF) with enriched Mg/Ca in their calcareous shells, compared to other marine environments. Although Mg/Ca is a widely used proxy applied as a paleothermometer, its systematics in extreme hypersaline systems is not well understood. We measured element ratios using LASER ablation ICP-MS on the tests of the two abundant PF species, Globigerinoides ruber albus and Turborotalita clarkei, obtained from monthly resolved time series sediment traps at various water column depths in the northern part of the GOA. Globigerinoides ruber albus shows a positive relationship between Mg/Ca and surface water temperatures of the surface mixed layer down to 60 m water depth. Although T. clarkei does not show the same positive relationship, it exhibits high Mg/Ca during water column mixing (March–April) possibly reflecting the movement of two water masses in the water column. Using common calibration equations (Anand et al., 2003; Kisakürek et al., 2008; Gray et al., 2018), the high-Mg (5-25 mmol/mol) provided higher than measured in-situ (IS) ambient seawater temperatures (TMg/Ca and TIS, respectively). The high salinity at the GOA (>40) is assumed to be the main reason of the high shell-bound Mg. Comparing surface dwelling G. ruber albus versus subsurface dwelling T. clarkei may facilitate reconstruction of the absolute and relative seasonal development temperature and surface water stratification. We suggest that species specific Mg/Ca-T calibrations for the GOA provide more accurate regional palaeoceanography and paleoclimate reconstruction of hypersaline environments.

Published
2022
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18. Hadean zircon formed due to hydrated ultramafic protocrust melting

Author

Borisova, Anastassia Y., primary, Nédélec, Anne, additional, Zagrtdenov, Nail R., additional, Toplis, Michael J., additional, Bohrson, Wendy A., additional, Safonov, Oleg G., additional, Bindeman, Ilya N., additional, Melnik, Oleg E., additional, Pokrovski, Gleb S., additional, Ceuleneer, Georges, additional, Jochum, Klaus Peter, additional, Stoll, Brigitte, additional, Weis, Ulrike, additional, Bychkov, Andrew Y., additional, and Gurenko, Andrey A., additional

Published
2021
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19. Hydrated Peridotite – Basaltic Melt Interaction Part I: Planetary Felsic Crust Formation at Shallow Depth

Author

Borisova, Anastassia Y., primary, Zagrtdenov, Nail R., additional, Toplis, Michael J., additional, Bohrson, Wendy A., additional, Nédélec, Anne, additional, Safonov, Oleg G., additional, Pokrovski, Gleb S., additional, Ceuleneer, Georges, additional, Bindeman, Ilya N., additional, Melnik, Oleg E., additional, Jochum, Klaus Peter, additional, Stoll, Brigitte, additional, Weis, Ulrike, additional, Bychkov, Andrew Y., additional, Gurenko, Andrey A., additional, Shcheka, Svyatoslav, additional, Terehin, Artem, additional, Polukeev, Vladimir M., additional, Varlamov, Dmitry A., additional, Chariteiro, Kouassi, additional, Gouy, Sophie, additional, and de Parseval, Philippe, additional

Published
2021
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29. Hydrated Peridotite–Basaltic Melt Interaction Part II: Fast Assimilation of Serpentinized Mantle by Basaltic Magma

Author

Borisova, Anastassia Y., primary, Zagrtdenov, Nail R., additional, Toplis, Michael J., additional, Ceuleneer, Georges, additional, Safonov, Oleg G., additional, Pokrovski, Gleb S., additional, Jochum, Klaus Peter, additional, Stoll, Brigitte, additional, Weis, Ulrike, additional, Shcheka, Svyatoslav, additional, and Bychkov, Andrey Y., additional

Published
2020
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30. Nano-Powdered Calcium Carbonate Reference Materials: Significant Progress for Microanalysis?

Author

Jochum, Klaus Peter, Garbe-Schönberg, Dieter, Veter, Marina, Stoll, Brigitte, Weis, Ulrike, Weber, Michael, Lugli, Federico, Jentzen, Anna, Schiebel, Ralf, Wassenburg, Jasper A., Jacob, Dorrit E., and Haug, Gerald H.

Abstract

Homogeneity, mass fractions of about forty trace elements and Sr isotope composition of Ca carbonate reference materials (RMs) between original and nano-powdered pellets are compared. Our results using nanosecond and femtosecond LA-(MC)-ICP-MS show that the nano-pellets of the RMs MACS-3NP, JCp-1NP and JCt-1NP are about a factor of 2–3 more homogeneous than the original samples MACS-3, JCp-1 and JCt-1, and are therefore much more suitable for microanalytical purposes. With the exception of Si, the mass fractions of the synthetic RM MACS-3 agree with its fine-grained analogue MACS-3NP. Very small, but significant, differences between original and nano-pellets are observed in the RMs JCp-1 and JCt-1 for some trace elements with very low contents, indicating the need for re-certification. Strontium mass fractions in the analysed RMs are high (1500–7000 mg kg−1), and their isotope compositions determined by LA-MC-ICP-MS in the original and the nano-pellets agree within uncertainty limits.

Published
2019
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31. Preface: Special Issue on Probing the Open Ocean With the Research Sailing Yacht Eugen Seiboldfor Climate Geochemistry

Author

Schiebel, Ralf, Aardema, Hedy M., Calleja, Maria Ll., Dragoneas, Antonis, Heins, Lena, Hrabe de Angelis, Isabella, Pöhlker, Christopher, Slagter, Hans, Vonhof, Hubert, Walter, David, Arns, Anthea I., Adolphs, Nils, Auderset, Alexandra, Basic, Sanja, Bieler, Aaron, Brüwer, Jan D., Chaabane, Sonia, Cheng, Yafang, Chiliński, Michal T., Cybulski, Jonathan D., Disper, Thomas, Duprey, Nicolas, Eichele, Gregor, Fiedler, Björn, Fischer, Alexa, Foreman, Alan D., Fuchs, Bernhard M., Galer, Steve, Härri, Jana, Jochum, Klaus Peter, Jost, Adrian, Jung, Jonathan, Kleta, Henry, Lammel, Gerhard, Larink, Otto, Leibold, Patrick, Martínez‐García, Alfredo, Moretti, Simone, Müller, Jann‐Gerrit, Nillius, Björn, Pan, Xihao, Raj, Subha S., Repschläger, Janne, Rodrigues, Elizandro, Ruff, S. Emil, Schmitt, Mareike, Schmitter, Janine L., Lara, Andrew Sellers, Silva, Péricles, Smart, Sandi M., Sörgel, Matthias, Stoll, Brigitte, Su, Hang, Vogt, Meike, Wald, Tanja, Weber, Bettina, Weber, Jens, Weis, Ulrike, Amann, Rudolf, Arístegui, Javier, Dittmar, Thorsten, González, Melchor, O’Dea, Aaron, Pöschl, Ulrich, and Haug, Gerald H.

Abstract

The 72‐foot sailing yacht Eugen Seiboldis a new research platform for contamination‐free sampling of the water column and atmosphere for biological, chemical, and physical properties, and the exchange processes between the two realms. Ultimate goal of the project is a better understanding of the modern and past ocean and climate. Operations started in 2019 in the Northeast Atlantic, and will focus on the Tropical Eastern Pacific from 2023 until 2025. Laboratories for air and seawater analyses are equipped with down‐sized and automated state‐of‐the‐art technology for a comprehensive description of the marine carbon system including CO2concentration in the air and sea surface, pH, macro‐, and micro‐nutrient concentration (e.g., Fe, Cd), trace metals, and calcareous plankton. Air samples are obtained from ca. 13 m above sea surface and analyzed for particles (incl. black carbon and aerosols) and greenhouse gases. Plankton nets and seawater probes are deployed over the custom‐made A‐frame at the stern of the boat. Near Real‐Time Transfer of underway data via satellite connection allows dynamic expedition planning to maximize gain of information. Data and samples are analyzed in collaboration with the international expert research community. Quality controlled data are published for open access. The entire suite of data facilitates refined proxy calibration of paleoceanographic and paleoclimate archives at high temporal and spatial resolution in relation to seawater and atmospheric parameters. The new research sailing yacht Eugen Seibold(ES) enables clean, contamination‐free sampling of air and seawater to better understand the interactions between ocean and climate. For example, the oceans remove increasingly less carbon dioxide (CO2) from the atmosphere the more saturated they are with CO2(ocean acidification). However, a detailed systematic understanding of air‐sea exchange processes remains to be developed. We analyze air and seawater as well as the exchange of greenhouse gases and other substances such as aerosols and soot (black carbon) between air and seawater at high resolution using modern materials and technologies. Scaled‐down, energy‐efficient, and automated probes developed over the past decade are being used to measure around 50 different characteristics of the marine environment. The work deck at the stern of the boat allows the use of custom‐made water samplers and plankton nets to study the ocean to below 1,000 m depth. In addition, the new data enables a better understanding of past ocean archives, such as the marine plankton accumulated in seafloor sediments, to reconstruct past climate changes. From 2019 to 2022, the S/Y ESsailed in the eastern North Atlantic and will operate in the tropical eastern Pacific until 2025. New research platform for contamination‐free sampling of the water column and atmosphere of biological, chemical, and physical propertiesComprehensive marine geochemical analyzes including carbon (e.g., CO2) in air and sea surfaceProxy calibration of paleoclimate archives at high temporal and spatial resolution in relation to seawater and atmospheric parameters New research platform for contamination‐free sampling of the water column and atmosphere of biological, chemical, and physical properties Comprehensive marine geochemical analyzes including carbon (e.g., CO2) in air and sea surface Proxy calibration of paleoclimate archives at high temporal and spatial resolution in relation to seawater and atmospheric parameters

Published
2024
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33. Nano‐Powdered Calcium Carbonate Reference Materials: Significant Progress for Microanalysis?

Author

Jochum, Klaus Peter, primary, Garbe‐Schönberg, Dieter, additional, Veter, Marina, additional, Stoll, Brigitte, additional, Weis, Ulrike, additional, Weber, Michael, additional, Lugli, Federico, additional, Jentzen, Anna, additional, Schiebel, Ralf, additional, Wassenburg, Jasper A., additional, Jacob, Dorrit E., additional, and Haug, Gerald H., additional

Published
2019
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34. Geostandards and Geoanalytical Research Bibliographic Review 2019.

Author

Weis, Ulrike, Stoll, Brigitte, Arns, Jodok, Förster, Michael W., Kaiser, Viktoria, Otter, Laura M., Reichstein, Lea, and Jochum, Klaus Peter

Subjects
*REFERENCE sources, *STABLE isotopes, *GEOCHEMISTRY, *MASS spectrometry
Abstract

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. [ABSTRACT FROM AUTHOR]

Published
2021
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36. Femtosecond Laser Ablation-ICP-Mass Spectrometry and CHNS Elemental Analyzer Reveal Trace Element Characteristics of Danburite from Mexico, Tanzania, and Vietnam

Author

Huong, Le, primary, Otter, Laura, additional, Förster, Michael, additional, Hauzenberger, Christoph, additional, Krenn, Kurt, additional, Alard, Olivier, additional, Macholdt, Dorothea, additional, Weis, Ulrike, additional, Stoll, Brigitte, additional, and Jochum, Klaus, additional

Published
2018
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38. GGR Biennial Critical Review: Analytical Developments Since 2014

Author

Linge, Kathryn L., primary, Bédard, L. Paul, additional, Bugoi, Roxana, additional, Enzweiler, Jacinta, additional, Jochum, Klaus Peter, additional, Kilian, Rüdiger, additional, Liu, Jingao, additional, Marin-Carbonne, Johanna, additional, Merchel, Silke, additional, Munnik, Frans, additional, Morales, Luiz F.G., additional, Rollion-Bard, Claire, additional, Souders, A. Kate, additional, Sylvester, Paul J., additional, and Weis, Ulrike, additional

Published
2017
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46. Chemical composition of modern and fossil Hippopotamid teeth and implications for paleoenvironmental reconstructions and enamel formation - Part 2: Alkaline earth elements as tracers of watershed hydrochemistry and provenance [Discussion paper]

Author

Brügmann, Gerhard, Krause, Joachim, Brachert, Thomas C., Stoll, Brigitte, Weis, Ulrike, Kullmer, Ottmar, Ssemmanda, Immaculate, and Mertz, Dieter F.

Subjects
ddc:560
Abstract

For reconstructing environmental change in terrestrial realms the geochemistry of fossil bioapatite in bones and teeth is among the most promising applications. This study demonstrates that alkaline earth elements in enamel of Hippopotamids, in particular Ba and Sr are tracers for water provenance and hydrochemistry. The studied specimens are molar teeth from Hippopotamids found in modern and fossil lacustrine settings of the Western Branch of the East African Rift system (Lake Kikorongo, Lake Albert, and Lake Malawi) and from modern fluvial environments of the Nile River. Concentrations in enamel vary by ca. two orders of magnitude for Ba (120–9336 μg g−1) as well as for Sr (9–2150 μg g−1). Concentration variations in enamel are partly induced during post-mortem alteration and during amelogenesis, but the major contribution originates from the variable water chemistry in the habitats of the Hippopotamids which is dominated by the lithologies and weathering processes in the watershed areas. Amelogenesis causes a distinct distribution of Ba and Sr in modern and fossil enamel, in that element concentrations increase along profiles from the outer rim towards the enamel-dentin junction by a factor of 1.3–1.5. These elements are well correlated with MgO and Na2O in single specimens, thus suggesting that their distribution is determined by a common, single process. Presuming that the shape of the tooth is established at the end of the secretion process and apatite composition is in equilibrium with the enamel fluid, the maturation process can be modeled by closed system Rayleigh crystallization. Enamel from many Hippopotamid specimens has Sr/Ca and Ba/Ca which are typical for herbivores, but the compositions extend well into the levels of plants and carnivores. Within enamel from single specimens these element ratios covary and provide a specific fingerprint of the Hippopotamid habitat. All specimens together, however, define subparallel trends with different Ba/Sr ranging from 0.1 to 3. This ratio varies on spatial and temporal scales and traces provenance signals as well as the fractionation of the elements in the hydrological cycle. Thus, Sr concentrations and Ba/Sr in enamel differentiate between habitats having basaltic or Archean crustal rocks as the ultimate sources of Sr and Ba. The provenance signal is modulated by climate change. In Miocene to Pleistocene enamel from the Lake Albert region, Ba/Sr decreases systematically with time from about 2 to 0.5. This trend can be correlated with changes in climate from humid to arid in vegetation from C3 to C4 biomass as well as with increasing evaporation of the lake water. The most plausible explanation is that with time, Ba mobility decreased relative to that of Sr. This can arise if preferential adsorption of Ba to clay and Fe-oxide-hydroxide is related to increasing aridification. Additionally, weathering solutions and lake water can become increasingly alkaline and barite becomes stable. In this case, Ba will be preferentially deposited on the watershed of Lake Albert and rivers with low Ba/Sr will feed the habitats of the Hippopotamids.

Published
2012

48. Influence of Compensating Defect Formation on the Doping Efficiency and Thermoelectric Properties of Cu2-ySe1–xBrx

Author

Day, Tristan W., primary, Weldert, Kai S., additional, Zeier, Wolfgang G., additional, Chen, Bor-Rong, additional, Moffitt, Stephanie L., additional, Weis, Ulrike, additional, Jochum, Klaus P., additional, Panthöfer, Martin, additional, Bedzyk, Michael J., additional, Snyder, G. Jeffrey, additional, and Tremel, Wolfgang, additional

Published
2015
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