HR: 0800h
AN: B31B-0988    [Abstracts]
TI: Volcanic Source for Abiotic Organics and Inorganics on Early Earth and Mars
AU: * NNA MVONDO, D
EM: nnamvondod@inta.es
AF: Centro de AstrobiologĦa (CSIC/INTA), INTA Ctra. De Ajalvir, km 4., Torrej˘n de Ardoz, 28850 Spain
AU: MARTINEZ-FRIAS, J
EM: martinezfrias@mncn.csic.es
AF: Centro de AstrobiologĦa (CSIC/INTA), INTA Ctra. De Ajalvir, km 4., Torrej˘n de Ardoz, 28850 Spain
AB: Volcanic activity has been theoretically proposed as a potential source of organic compounds on Early Earth. Volcanoes could also potentially constituted an important source of fixed nitrogen in the early Earth, producing as much as ~1011 mol yr-1 during major episodes of volcanism (Mather et al., 2004). Volcanic source can produce water-soluble polyphosphates through partial hydrolysis of P4O10, which seems to be the only viable mechanism identified so far for the production of these species on the primitive Earth (Yamagata et al., 1991). Moreover, the predominance of high-temperature mafic (e.g. picrites) and ultra-mafic (like komatiites) lava on early Earth would have favor effusive eruptions with high H2 and CO contents in volcanic gases owing to CO-CO2 and H2O-H2 equilibria in magmatic gases. In addition, the amount of CO and H2 (and NH3) increases if magmas were more reduced (fO2 down to C0 -, Fe0 -bearing buffers) than on the present Earth. These buffers provide significant thermodynamic drive to form hydrocarbons below ~400°C. The best conditions for organic synthesis on early Earth is achieved in submarine Hawaiian-type eruptions of high temperature and/or reduced magmas. The hydrocarbons might be formed by Fisher-Tropsh type synthesis catalyzed by magnetite and/or Fe0 present in solid volcanic products (Anderson, 1984). Fisher-Tropsch-type reactions may have produced hydrophobic compounds. Such hydrophobic material would have formed a hydrophobic layer on the surface of the sea, which would have provided an environment thermodynamically more suitable than water for the concentration and polymerization of organic molecules fundamental to life, particularly amino acids and pyridine bases. In the purpose of studying the significance of volcanic activity for producing compounds important for life and its evolution, we have decided to develop laboratory simulations of the volcanic source performing high-temperature experiments under early Earth and Mars conditions, with the presence of komatiite. We are introducing and explaining such experimental study.
DE: 1060 Planetary geochemistry (5405, 5410, 5704, 5709, 6005, 6008)
DE: 5200 PLANETARY SCIENCES: ASTROBIOLOGY
DE: 5215 Origin of life
DE: 5225 Early environment of Earth
DE: 5480 Volcanism (6063, 8148, 8450)
SC: Planetary Sciences [P]
MN: Fall Meeting 2005