Geilert, S. and Grasse, P. and Wallman, K. and Liebetrau, V. and Menzies, C.D. (2020) 'Serpentine alteration as source of high dissolved silicon and elevated δ 30 5 Si 6 values to the marine Si cycle.', Nature communications., 11 . 5123 .
Abstract
Serpentine alteration is recognized as an important process for element cycling, however, related silicon fluxes are unknown. Pore fluids from serpentinite seamounts sampled in the Mariana forearc region during IODP Expedition 366 were investigated for their Si, B, and Sr isotope signatures (δ30Si, δ11B, and 87Sr/86Sr, respectively) to study serpentinization in the mantle wedge and shallow serpentine alteration to authigenic clays by seawater. While serpentinization in the mantle wedge caused no significant Si isotope fractionation, implying closed system conditions, serpentine alteration by seawater led to the formation of authigenic phyllosilicates, causing the highest natural fluid δ30Si values measured to date (up to +5.2 ± 0.2‰). Here we show that seafloor alteration of serpentinites is a source of Si to the ocean with extremely high fluid δ30Si values, which can explain anomalies in the marine Si budget like in the Cascadia Basin and which has to be considered in future investigations of the global marine Si cycle.
| Item Type: | Article |
|---|---|
| Full text: | Publisher-imposed embargo (AM) Accepted Manuscript File format - PDF (18475Kb) |
| Full text: | (VoR) Version of Record Available under License - Creative Commons Attribution. Download PDF (1216Kb) |
| Status: | Peer-reviewed |
| Publisher Web site: | https://doi.org/10.1038/s41467-020-18804-y |
| Publisher statement: | This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. |
| Date accepted: | 15 September 2020 |
| Date deposited: | 05 October 2020 |
| Date of first online publication: | 12 October 2020 |
| Date first made open access: | 22 October 2020 |
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