HR: 15:25h
AN: V43C-08 INVITED     [Abstracts]
TI: Serpentinization and Life on Mars
AU: * Schulte, M
EM: schultemd@missouri.edu
AF: NASA Ames Research Center, Mail Stop 239-4, Moffett Field, CA 94035 United States
AU: * Schulte, M
EM: schultemd@missouri.edu
AF: University of Missouri, Dept. of Geological Sciences 101 Geology Building, Columbia, MO 65211 United States
AB: The low-grade hydrothermal process of serpentinization has been demonstrated to generate significant concentrations of H2 and methane in terrestrial settings, and is thought to be at least partially responsible for the generation of heat that can help drive hydrothermal convection [1,2]. Furthermore, serpentinization in hydrothermal systems on Earth has been shown to support diverse microbial communities in both deep-sea and continental hydrothermal systems. These systems can serve as analogs to evaluate similar processes that could have supported or may currently support a putative martian biosphere [3]. Because the bulk compositions of Mars and Earth are similar, it is possible that serpentinization was an important process on early Mars when liquid water was present in near-surface environments. Additionally, it is possible that serpentinization is currently operating in the martian subsurface. This hypothesis could explain recent observations of olivine outcrops [4] that correlate with elevated atmospheric methane concentrations. During serpentinization, olivine reacts with water to produce H2, which can in turn react with oxidized carbon to produce methane. Geochemical models are used to assess the hypothesis that current subsurface serpentinization could be the source for methane in the modern martian atmosphere. Furthermore, generation of both H2 and methane during serpentinization could support both methanogenesis and methanotrophy in a putative martian biosphere. References: [1] Kelley D. S. et al. (2001) Nature 412, 145-149. [2] Kelley D. et al. (2005) Science 307, 1428-1434. [3] Schulte, M. et al. (2005) Astrobiology, in revision. [4] Hoefen et al. (2001) Science.
DE: 1034 Hydrothermal systems (0450, 3017, 3616, 4832, 8135, 8424)
DE: 3672 Planetary mineralogy and petrology (5410)
DE: 5220 Hydrothermal systems and weathering on other planets
DE: 6225 Mars
DE: 8416 Mid-oceanic ridge processes (1032, 3614)
SC: Volcanology, Geochemistry, Petrology [V]
MN: Fall Meeting 2005