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Project Progress

A paper describing the experiments generating abiogenic hydrocarbons under hydrothermal conditions (400C, 500 bars) was published this year (Fu, Q., Sherwood Lollar, B., Horita, J., Lacrampe-Couloume, G., Seyfried, W.E. Abiotic formation of hydrocarbons under hydrothermal conditions: Constraints from chemical and isotope data (2007) Geochimica et Cosmochimica Acta, Vol.71:1982-1998). This is the first integration of isotopic analysis for both compound specific carbon and hydrogen signatures with experimental synthesis of hydrocarbon generation. Based on the above results, a second set of experiments was undertaken to evaluate carbon and hydrogen isotope fractionation effects during Fischer-Tropsch synthesis using powdered metal catalysts.

Working with Dr. Tom McCollom (University of Colorado) we are investigating the hypothesis that the isotopic signature of abiogenic hydrocarbons may be somewhat different for higher hydrocarbons produced directly from CO₂ and/or CO in Fischer-Tropsch synthesis, versus those produced by polymerization from a methane precursor generated itself by Fischer-Tropsch synthesis. The results will have implications for the interpretation schemes presently used to determine the abiogenic or biogenic origin of methane both on Earth and for investigations on Mars and other planets.