Microbial Sulfur Isotope Fractionation in the Chicxulub Hydrothermal System

David A Kring; Martin J Whitehouse; Martin Schmieder

doi:10.1089/ast.2020.2286

Microbial Sulfur Isotope Fractionation in the Chicxulub Hydrothermal System

Astrobiology. 2021 Jan;21(1):103-114. doi: 10.1089/ast.2020.2286. Epub 2020 Oct 30.

Authors

David A Kring¹, Martin J Whitehouse², Martin Schmieder^{1

3}

Affiliations

¹ Lunar and Planetary Institute, Universities Space Research Association, Houston, Texas, USA.
² Department of Geosciences, Swedish Museum of Natural History, Stockholm, Sweden.
³ HNU-Neu-Ulm University of Applied Sciences, Neu-Ulm, Germany.

Abstract

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 δ³⁴S 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.

Keywords: Chicxulub.; Hydrothermal; Impact crater; Origin of life.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Chemical Fractionation
Microbiota*
Sulfates*
Sulfur Isotopes / analysis

Substances

Sulfates
Sulfur Isotopes