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| Baronas, J. Jotautas; Torres, Mark A.; West, A. Joshua; Rouxel, Olivier; Georg, Bastian; Bouchez, Julien; Gaillardet, Jerome; Hammond, Douglas E.. |
| Solutes derived from the dissolution of silicate minerals play a key role in Earth’s climate via the carbon and other biogeochemical cycles. Silicon (Si) is a unique constituent of silicate minerals and a biologically important nutrient, so tracing its behavior in near-surface environments may provide important insights into weathering processes. However, Si released by weathering is variably incorporated into secondary mineral phases and biota, obscuring signals derived from primary weathering processes. Due to chemical similarities, Germanium (Ge) may help better understand the Si cycle and its relationship to chemical weathering. With this aim, we report new measurements of the concentration and isotopic composition of Ge for both the dissolved and... |
| Tipo: Text |
Palavras-chave: Germanium; Silicon; Isotopes; Rivers; Weathering; Fractionation. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00460/57196/59370.pdf |
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| Baronas, J. Jotautas; Hammond, Douglas E.; Bennett, Mia M.; Rouxel, Olivier; Pitcher, Lincoln H.; Smith, Laurence C.. |
| Glacial environments offer the opportunity to study the incipient stages of chemical weathering due to the high availability of finely ground sediments, low water temperatures, and typically short rock-water interaction times. In this study we focused on the geochemical behavior of germanium (Ge) in west Greenland, both during subglacial weathering by investigating glacier-fed streams, as well as during a batch reactor experiment by allowing water-sediment interaction for up to 2 years in the laboratory. Sampled in late August 2014, glacial stream Ge and Si concentrations were low, ranging between 12–55 pmol/L and 7–33 µmol/L, respectively (Ge/Si = 0.9–2.2 µmol/mol, similar to parent rock). As reported previously, the dissolved stable Ge isotope ratio... |
| Tipo: Text |
Palavras-chave: Glacial weathering; Germanium; Isotope fractionation; Amorphous silica; Experimental dissolution. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00684/79577/82249.pdf |
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| Qi, Hua-wen; Rouxel, Olivier; Hu, Rui-zhong; Bi, Xian-wu; Wen, Han-jie. |
| Organic matter plays an important role in the transport and precipitation of germanium (Ge) in coal-hosted Ge deposits. In this paper. Ge isotopes of coal samples and their combustion products were analyzed in order to investigate the potential use of Ge isotopes as tracers of Ge sources and enrichment mechanisms in coal. Germanium isotopic composition of various samples (mainly Ge-rich lignite) from the Lincang Ge deposit, Yunnan, Southwest China was analyzed using a continuous flow hydride generation system coupled to a Multi Collector Inductively Coupled Plasma Mass Spectrometer (MC-ICP-MS) and the standard-sample bracketing approach. Variations of (74)Ge/(70)Ge ratios are expressed as delta(74)Ge values relative to NIST SRM 3120a Ge standard solution.... |
| Tipo: Text |
Palavras-chave: Germanium; Coal; Stable isotope fractionation; Water-rock interaction; Geochemical tracer. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00041/15249/12676.pdf |
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| Guillermic, Maxence; Lalonde, Stefan; Hendry, Katharine R.; Rouxel, Olivier. |
| Although dissolved concentrations of germanium (Ge) and silicon (Si) in modern seawater are tightly correlated, uncertainties still exist in the modern marine Ge cycle. Germanium stable isotope systematics in marine systems should provide additional constraints on marine Ge sources and sinks, however the low concentration of Ge in seawater presents an analytical challenge for isotopic measurement. Here, we present a new method of pre-concentration of inorganic Ge from seawater which was applied to measure three Ge isotope profiles in the Southern Ocean and deep seawater from the Atlantic and Pacific Oceans. Germanium isotopic measurements were performed on Ge amounts as low as 2.6 ng using a double-spike approach and a hydride generation system coupled to... |
| Tipo: Text |
Palavras-chave: Stable isotopes; Germanium; Silicon; Sponges; Southern Ocean; Chemical oceanography. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00388/49956/50529.pdf |
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