1 item with the tag “sulfate minerals

  • Microbial Pyrite Oxidation in Nature and the Lab: Sulfate Mineral Biosignature Investigation
    NAI 2009 University of Wisconsin Annual Report

    Deposits of minerals containing the chemical species sulfate, a constituent of ocean water, have been identified on the surface of Mars. Although there might be other methods for its formation, the process we are investigating is one that occurs on Earth and is the result of the metabolic activity of microbes, which oxidize the iron sulfide mineral pyrite (Fool’s Gold) to form sulfate. We have made the oxygen in water in a bacterial culture medium traceable by addition of a non-radioactive isotopic tracer and can thus differentiate oxygen from the atmosphere, used by biological processes, from oxygen in water, used by the non-biological processes. Our new data and approaches defy conventional wisdom, and offer a novel way for investigating the origin of sulfates on Mars by in situ instruments.