Open AccessMicrobial Sulfur Isotope Fractionation in the Chicxulub Hydrothermal System
Author(s) -
D. A. Kring,
Martin J. Whitehouse,
M. Schmieder
Publication year - 2021
Publication title -
astrobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.234
H-Index - 90
eISSN - 1531-1074
pISSN - 1557-8070
DOI - 10.1089/ast.2020.2286
Subject(s) - pyrite , hydrothermal circulation , sulfate , sulfur , fractionation , geology , impact crater , isotope fractionation , geochemistry , δ34s , sulfide , mineralogy , sulfide minerals , environmental chemistry , chemistry , astrobiology , paleontology , fluid inclusions , physics , organic chemistry
Target lithologies and post-impact hydrothermal mineral assemblages in a new 1.3 km deep core from the peak ring of the Chicxulub impact crater indicate sulfate reduction was a potential energy source for a microbial ecosystem (Kring et al., 2020). That sulfate was metabolized is confirmed here by microscopic pyrite framboids with δ 34 S values of -5 to -35 ‰ and ΔS sulfate-sulfide values between pyrite and source sulfate of 25 to 54 ‰, which are indicative of biologic fractionation rather than inorganic fractionation processes. These data indicate the Chicxulub impact crater and its hydrothermal system hosted a subsurface microbial community in porous permeable niches within the crater's peak ring.