Deep carbon cycle constrained by carbonate solubility

Autor: Mohamed Mezouar, Stefan Farsang, Remo N. Widmer, Simon A. T. Redfern, Angelika Dorothea Rosa, Xiaolei Feng, Chaoshuai Zhao, Jin Liu, Marion Louvel
Přispěvatelé: Farsang, Stefan [0000-0002-4918-5566], Mezouar, Mohamed [0000-0001-5336-544X], Rosa, Angelika D [0000-0002-2304-1943], Widmer, Remo N [0000-0001-7664-4791], Feng, Xiaolei [0000-0003-4410-4576], Liu, Jin [0000-0002-1670-8199], Redfern, Simon AT [0000-0001-9513-0147], Apollo - University of Cambridge Repository, Redfern, Simon A T [0000-0001-9513-0147], Department of Earth Sciences, University of Cambridge, University of Cambridge [UK] (CAM), Institut für Mineralogie-Münster, Westfälische Wilhelms-Universität Münster (WWU), Center for High Pressure Science & Technology Advanced Research (HPSTAR), European Synchrotron Radiation Facility (ESRF), Swiss Federal Laboratories for Materials Science and Technology (EMPA), Asian School of the Environment (ASE), Nanyang Technological University [Singapour], Rosa, Angelika D. [0000-0002-2304-1943], Widmer, Remo N. [0000-0001-7664-4791], Redfern, Simon A. T. [0000-0001-9513-0147]
Rok vydání: 2021
Předmět:
Zdroj: Nature Communications
Nature Communications, Nature Publishing Group, 2021, 12 (1), ⟨10.1038/s41467-021-24533-7⟩
Nature Communications, Vol 12, Iss 1, Pp 1-9 (2021)
'Nature Communications ', vol: 12, pages: 4311-1-4311-9 (2021)
ISSN: 2041-1723
Popis: Earth’s deep carbon cycle affects atmospheric CO2, climate, and habitability. Owing to the extreme solubility of CaCO3, aqueous fluids released from the subducting slab could extract all carbon from the slab. However, recycling efficiency is estimated at only around 40%. Data from carbonate inclusions, petrology, and Mg isotope systematics indicate Ca2+ in carbonates is replaced by Mg2+ and other cations during subduction. Here we determined the solubility of dolomite [CaMg(CO3)2] and rhodochrosite (MnCO3), and put an upper limit on that of magnesite (MgCO3) under subduction zone conditions. Solubility decreases at least two orders of magnitude as carbonates become Mg-rich. This decreased solubility, coupled with heterogeneity of carbon and water subduction, may explain discrepancies in carbon recycling estimates. Over a range of slab settings, we find aqueous dissolution responsible for mobilizing 10 to 92% of slab carbon. Globally, aqueous fluids mobilise \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${35}_{-17}^{+20}$$\end{document}35−17+20% (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${27}_{-13}^{+16}$$\end{document}27−13+16 Mt/yr) of subducted carbon from subducting slabs.
Carbonate mineral aqueous solubility decreases as carbonates become more Mg-rich during subduction. Coupled with regional variations in amounts of carbon and water subducted, this explains discrepancies in estimates of carbon recycling, suggesting that only around a third returns to the surface.
Databáze: OpenAIRE
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