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Association of anatase (TiO(2)) and microbes: Unusual fossilization effect or a potential biosignature?

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Original languageEnglish
Title of host publicationICDP-USGS DEEP DRILLING PROJECT IN THE CHESAPEAKE BAY IMPACT STRUCTURE: RESULTS FROM THE EYREVILLE CORE HOLES
EditorsGS Gohn, C Koeberl, KG Miller, WU Reimold
PublisherGeological Society of America
Pages965-975
Number of pages11
DOIs
Publication statusPublished - 2009

Publication series

NameGeological Society of America Special Papers
PublisherGEOLOGICAL SOC AMER INC
Volume458
ISSN (Print)0072-1077

Abstract

We combined microbial paleontology and molecular biology methods to study the Eyreville B drill core from the 35.3-Ma-old Chesapeake Bay impact structure, Virginia, USA. The investigated sample is a pyrite vein collected from the 1353.81-1353.89 m depth interval, located within a section of biotite granite. The granite is a pre-impact rock that was disrupted by the impact event. A search for inorganic (mineral) biosignatures revealed the presence of micron-size rod morphologies of anatase (TiO(2)) embedded in chlorite coatings on pyrite grains.

Neither the Acridine Orange microbial probe nor deoxyribonucleic acid (DNA) extraction followed by polymerase chain reaction (PCR) amplifi cation showed the presence of DNA or ribonucleic acid (RNA) at the location of anatase rods, implying the absence of viable cells in the investigated area. A Nile Red microbial probe revealed the presence of lipids in the rods. Because most of the lipids are resistant over geologic time spans, they are good biomarkers, and they are an indicator of biogenicity for these possibly 35-Ma-old microbial fossils. The mineral assemblage suggests that rod morphologies are associated with low-temperature (<100 degrees C) hydrothermal alteration that involved aqueous fluids. The temporal constraints on the anatase fossils are still uncertain because pre-impact alteration of the granite and postimpact heating may have provided identical conditions for anatase precipitation and microbial preservation.

    Research areas

  • MOUNT BRUCE SUPERGROUP, BAY BOLIDE IMPACT, TITANIUM-DIOXIDE, ANCIENT DNA, MOLECULAR FOSSILS, NILE RED, PHOTOCATALYTIC DISINFECTION, WESTERN-AUSTRALIA, ESCHERICHIA-COLI, WASTE-WATER

ID: 25246729