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Project Progress

Geobiology of Neogene Hematitic Sedimentary Rocks (dm)

This is a new subproject to study the geobiology of Neogene hematitic sedimentary rocks. Iron-rich rocks are widely distributed in sedimentary basins older than ca. 1850 million years. A number of these preserve microfossils and chemical signatures of ancient life, yet interpretation of these records has been difficult. At the same time, the Mars exploration community is likely to choose as a primary landing site for the 2003 Mars MER mission an area characterized by aqueously deposited hematite. Studies of Precambrian iron formations and martian hematite share a need for modern terrestrial analog ecosystems where biological and physical processes can be tied directly to paleobiological and geochemical patterns in deposited iron-rich sediments. The Rio Tinto drainage area of southern Spain offers just such an opportunity.

In collaboration with members of the Spanish Center for Astrobiology, we studying Neogene iron deposits associated with the Rio Tinto system. To date, we have begun petrological, paleontological and geochemical studies of sedimentary rock samples (including XRD and Moessbauer spectroscopy). Fieldwork will begin in September 2001. We have also obtained a promise from Steve Squyres, PI of the 2003 Mars MER rover, to analyze Rio Tinto samples using the instrument package that will fly to Mars. This will provide an illuminating study of what the rover can actually expect to “see” when it lands on Mars.