This award in the Mars-Rock Special Research Opportunity activity supports research on iron oxide and iron sulfide minerals by Drs. Richard B. Frankel of California Polytechnic State University, Dennis A. Bazylinski of Iowa State University, Peter R. Buseck of Arizona State University, and Bruce M. Moskowitz of the University of Minnesota. This project is funded by the Office of Polar Programs, the Chemistry Division, and the MPS Office of Multidisciplinary Activities. This group of investigators will direct expertise in magnetism, microbiology, microscopy, and mineralogy to determining the structural, morphological, surface, chemical, and magnetic features of iron oxides and iron sulfides that can serve as markers for biogenic origin. Advanced electron microscopy and magnetic technologies will be used to characterize the samples. In addition to martian meteorite ALH84001, biogenic iron oxides and iron sulfides in both magnetotactic bacteria and iron-reducing and sulfate-reducing bacteria will be characterized. Magnetotactic bacteria and magnetite in pure culture as well as a variety of uncultured bacteria available in high concentrations in chemically-stratified, marine or brackish, semi-anaerobic basins will be sampled. Magnetite and iron sulfides of presumed biogenic origin in the carbonate inclusions in martian meteorite ALH84001 are critical components of the evidence cited for the possible existence of past life on Mars. Alternatively, magnetite in ALH84001 has features that have been cited as evidence for high-temperature formation of the carbonate. This research will develop criteria for distinguishing biogenic from non-biogenic iron-containing minerals in order to develop an improved framework for interpreting the evidence observed in martian meteorite ALH84001.
