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Radiolytically reworked Archean organic matter in a habitable deep ancient high-temperature brine.
- Source :
- Nature Communications; 10/3/2023, Vol. 14 Issue 1, p1-15, 15p
- Publication Year :
- 2023
-
Abstract
- Investigations of abiotic and biotic contributions to dissolved organic carbon (DOC) are required to constrain microbial habitability in continental subsurface fluids. Here we investigate a large (101–283 mg C/L) DOC pool in an ancient (>1Ga), high temperature (45–55 °C), low biomass (10<superscript>2</superscript>−10<superscript>4</superscript> cells/mL), and deep (3.2 km) brine from an uranium-enriched South African gold mine. Excitation-emission matrices (EEMs), negative electrospray ionization (–ESI) 21 tesla Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS), and amino acid analyses suggest the brine DOC is primarily radiolytically oxidized kerogen-rich shales or reefs, methane and ethane, with trace amounts of C<subscript>3</subscript>–C<subscript>6</subscript> hydrocarbons and organic sulfides. δ<superscript>2</superscript>H and δ<superscript>13</superscript>C of C<subscript>1</subscript>–C<subscript>3</subscript> hydrocarbons are consistent with abiotic origins. These findings suggest water-rock processes control redox and C cycling, helping support a meagre, slow biosphere over geologic time. A radiolytic-driven, habitable brine may signal similar settings are good targets in the search for life beyond Earth. A deep, ancient, and uranium-rich brine in South Africa reveals evidence of radiolytically oxidized kerogen and C<subscript>1</subscript>–C<subscript>3</subscript> hydrocarbons with abiotic isotopic signatures that support a low biomass microbial community over time. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 20411723
- Volume :
- 14
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- Nature Communications
- Publication Type :
- Academic Journal
- Accession number :
- 172755181
- Full Text :
- https://doi.org/10.1038/s41467-023-41900-8