Subducted organic matter buffered by marine carbonate rules the carbon isotopic signature of arc emissions

S. Tumiati (), S. Recchia, L. Remusat, C. Tiraboschi, D. A. Sverjensky, C. E. Manning, A. Vitale Brovarone, A. Boutier, D. Spanu and S. Poli
Additional contact information
S. Tumiati: Università degli Studi di Milano
S. Recchia: Università degli Studi dell’Insubria
L. Remusat: Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie (IMPMC), Sorbonne Universités – UPMC
C. Tiraboschi: Università degli Studi di Milano
D. A. Sverjensky: Johns Hopkins University
C. E. Manning: University of California
A. Vitale Brovarone: Alma Mater Studiorum Università di Bologna
A. Boutier: Università degli Studi di Torino
D. Spanu: Università degli Studi dell’Insubria
S. Poli: Università degli Studi di Milano

Nature Communications, 2022, vol. 13, issue 1, 1-10

Abstract: Abstract Ocean sediments consist mainly of calcium carbonate and organic matter (phytoplankton debris). Once subducted, some carbon is removed from the slab and returns to the atmosphere as CO2 in arc magmas. Its isotopic signature is thought to reflect the bulk fraction of inorganic (carbonate) and organic (graphitic) carbon in the sedimentary source. Here we challenge this assumption by experimentally investigating model sediments composed of 13C-CaCO3 + 12C-graphite interacting with water at pressure, temperature and redox conditions of an average slab–mantle interface beneath arcs. We show that oxidative dissolution of graphite is the main process controlling the production of CO2, and its isotopic composition reflects the CO2/CaCO3 rather than the bulk graphite/CaCO3 (i.e., organic/inorganic carbon) fraction. We provide a mathematical model to relate the arc CO2 isotopic signature with the fluid–rock ratios and the redox state in force in its subarc source.

Date: 2022
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
https://www.nature.com/articles/s41467-022-30421-5 Abstract (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:natcom:v:13:y:2022:i:1:d:10.1038_s41467-022-30421-5

Ordering information: This journal article can be ordered from
https://www.nature.com/ncomms/

DOI: 10.1038/s41467-022-30421-5

Access Statistics for this article

Nature Communications is currently edited by Nathalie Le Bot, Enda Bergin and Fiona Gillespie

More articles in Nature Communications from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().