Micrometer-scale porosity as a biosignature in carbonate crusts
Abstract
We formed calcite crusts in the presence and absence of the heterotrophic bacterium Desulfovibrio desulfuricans strain G20 to investigate microbial morphological signatures in fast-accreting carbonate precipitates. Submicrometer- to micrometer-sized pores (micropores) were present and ubiquitous in the G20 crusts but absent in abiotically precipitated crusts. Bacterial micropores resemble inclusions under transmitted light, but have distinct size, biological shapes and patterns (swirling or dendritic) and are distributed differently from common fluid inclusions. We observed similar porosity in both modern and ancient carbonate crusts of putative biotic origin. Our experiments support the microbial origin of micropores and help define specific criteria whereby to recognize these features as biosignatures in the rock record.
Additional Information
© 2004 Geological Society of America. Manuscript received 18 March 2004. Revised manuscript received 17 May 2004. Manuscript accepted 18 May 2004. We thank Ma Chi, George Rossman, Kenneth H. Nealson, Randall Mielke, Alicia Thompson, François Morel, Ben Weiss, and the members of the Newman lab for their help, comments, and support. The Agouron Institute (Bosak), Luce and Packard Foundations (Newman), and Spanish Ministerio de Ciencia y Tecnología (Souza-Egipsy) are acknowledged for financial support.Additional details
- Eprint ID
- 37488
- Resolver ID
- CaltechAUTHORS:20130313-094545347
- Agouron Institute
- Luce and Packard Foundations
- Spanish Ministerio de Ciencia y Tecnología
- Created
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2013-03-13Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences