Pathways for the Abiotic Formation of Organic Compounds in Geologic Environments

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

McCollom EAR- 0229837 This work is an experimental investigation of reactions that synthesize abiotic organic compounds in geologic environments. Although the common occurrence of abiotic hydrocarbons in geologic samples indicates that their formation has been widespread throughout the history of the Earth, the circumstances under which these compounds form remain poorly understood. The study will employ several experimental approaches to examine reaction pathways for the formation of organic compounds from reduction of CO2, and define the geologic conditions that allow these reactions to proceed. In particular, the experiments will address: (i) the role of aqueous phase versus vapor phase reactions in abiotic organic synthesis, (ii) the generation of abiotic hydrocarbons during hydrothermal alteration of olivine-rich rocks (serpentinization), and (iii) formation of graphite and organic matter during thermal decomposition of iron-bearing carbonates. The results will enhance our understanding of the origin of abiotic organic compounds in geologic samples such as igneous rocks, hydrothermal fluids, serpentinites, and meteorites. This information will be useful in constraining the magnitude of the flux of abiotic hydrocarbons and their potential role in global carbon cycles. The results will also be useful in understanding the contribution of abiotic sources to the reduced carbon found in rock samples from the early Earth, and in defining sources of prebiotic organic compounds for the origin and early evolution of life.