von Bo Leberecht ; Siu Ying Wong ; Baladev Satish ; Sara Döge ; Jakob Hindman ; Lalitha Venkatraman ; Shambhavi Rajendra Apte ; Katrin Haase ; Isabelle Musielak ; Glen Dautaj ; Ilia A. Solovʹyov ; Michael Winklhofer ; Henrik Mouritsen ; P. J. Hore
National Academy of Sciences (Washington, DC) Proceedings of the National Academy of Sciences of the United States of America Washington, DC : National Acad. of Sciences, 1915 120(2023), 28, Artikel-ID e2301153120, Seite 1-7 Online-Ressource
von Zhimian Cao ; Xinting Rao ; Yating Li ; Qingquan Hong ; Lin Wei ; Yang Yu ; Claudia Ehlert ; Bo Liu ; Christopher Siebert ; Ed C. Hathorne ; Zhouling Zhang ; Florian Scholz ; Sabine Kasten ; Martin Frank
First published: 31 May 2023 ; Gesehen am 12.02.2024
The development of stable barium (Ba) isotope measurements provides a novel tool to investigate the geochemical cycling of Ba in the ocean and its sediments. In sediment pore waters, gradients of dissolved Ba concentrations result from various diagenetic processes. The distribution and fractionation of Ba isotopes in the pore waters are expected to further improve our understanding of these early diagenetic control mechanisms. Here, we present pore water profiles of dissolved stable Ba isotopic signatures (δ138Bapw) from shallow water sediments covering the entire Pearl River Estuary (PRE) in Southern China. We find pronounced depth-dependent Ba isotope variations generally showing a shift from heavy to light δ138Bapw signatures from the sediment surface down to 15 cm depth. These gradients are well reproduced by a diffusion-reaction model, which generates an apparent fractionation factor (138ε) of −0.60 ± 0.10‰ pointing to preferential removal of low-mass Ba isotopes from the pore water during solution-solid phase interactions. Consequently, the combined diagenetic processes induce the highest δ138Bapw values of +0.5 to +0.7‰ in the pore waters of the topmost sediment layer. Although the detrital fraction dominates the Ba content in the PRE surface sediments, the determined gradients of pore water Ba isotopes, together with concentration variations of Ba and other redox-sensitive elements such as manganese (Mn), show that non-detrital excess Ba carriers including Mn oxides and authigenic barite clearly affect the post-depositional Ba dynamics. Stable Ba isotopes are thus a potentially powerful tracer of Ba geochemistry during early sediment diagenesis in estuarine depositional environments.
von Bo Han ; Sven Stephan ; Joshua Thompson ; Martin Esmann ; Carlos Antón-Solanas ; Hangyong Shan ; Nils Kunte ; Samuel Brem ; Sefaattin Tongay ; Christoph Lienau ; Kenji Watanabe ; Takashi Taniguchi ; Martin Silies ; Ermin Malić ; Christian Schneider
von Hangyong Shan ; Ivan Iorsh ; Bo Han ; Christoph Rupprecht ; Heiko Knopf ; Falk Eilenberger ; Martin Esmann ; Kentaro Yumigeta ; Kenji Watanabe ; Takashi Taniguchi ; Sebastian Klembt ; Sven Höfling ; Sefaattin Tongay ; Carlos Antón-Solanas ; Ivan A. Shelykh ; Christian Schneider
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