Volcanism and soil mercury on Mars - Consequences for terrestrial microorganisms

An earth-Mars depletion formula proposed by Anders and Owen for volatiles is used to calculate a range of putative Hg levels for Martian volcanic soils based upon analyzed samples from Hawaii. The range is about 50-150 microgram per kg. When applied either in conventional or special media (e.g., basalt powder), these levels of Hg are effective inhibitors of the growth of earth microorganisms. Taken together with other hostile chemical and physical factors, volcanic toxicants would appear to provide a further deterrent to the accidental establishment of terrestrial microbiota on Mars.