Journal articles
Atmospheric record in the Hadean Eon from multiple sulfur isotope measurements in Nuvvuagittuq Greenstone Belt (Nunavik, Quebec)
Abstract : The hydrous magnesiumcarbonate minerals dypingite (Mg-5(CO3)(4)(OH)(2)center dot 5H(2)O) and nesquehonite (MgCO3 center dot 3H(2)O) were precipitated in the presence and absence of Gloeocapsa sp. and Synechococcus sp. cyanobacteria in batch reactors. The Delta C-13(mineral-DIC) is similar in both biotic and abiotic systems. Stable carbon isotope analyses of the precipitated minerals and co-existing fluids indicated that the delta C-13 values of the precipitated carbonates co-vary over time with the delta C-13(DIC) of the fluid phase, even after the precipitation of the carbonate is complete. This observation indicates the continuous isotopic exchange between the carbonates and the fluid, a process that efficiently resets the original delta C-13 values of the solids. Therefore although cyanobacterial-induced Mg carbonates are 10 +/- 5% enriched in C-13 compared to inorganic carbonates, the delta C-13 values of natural hydrousMg carbonates may reflect post precipitation processes and may not be reliable for paleo-environmental reconstructions.
https://hal-insu.archives-ouvertes.fr/insu-01453065
Contributor : Eva Fareau <>
Submitted on : Thursday, April 22, 2021 - 9:42:20 AM
Last modification on : Friday, May 21, 2021 - 3:43:32 AM
Contributor : Eva Fareau <>
Submitted on : Thursday, April 22, 2021 - 9:42:20 AM
Last modification on : Friday, May 21, 2021 - 3:43:32 AM
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