Experimental Investigation of Organic Synthesis in Submarine Hydrothermal Systems

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

It is widely thought that abiotic synthesis is a widespread source of organic compounds in submarine hydrothermal systems and the igneous ocean crust. Yet, with the possible exception of methane, organic compounds with a demonstrably abiotic origin have never been identified in samples from these environments, and criteria to distinguish between abiotic compounds and organic compounds derived from biological sources have not been established. Consequently, laboratory studies are required to establish the characteristics of organic synthesis in hydrothermal environments for comparison with natural samples. This research is a series of laboratory experiments that is characterizing the products of abiotic organic synthesis reactions under hydrothermal conditions. In particular, the experiments are: (1) investigating which minerals in the ocean crust are capable of catalyzing organic synthesis and under what conditions, (2) characterizing the composition and relative abundance of organic synthesis products, (3) measuring the isotopic fractionation of organic synthesis from CO2, and (4) evaluating how the product composition and isotopic fractionation vary as a function of environmental variables such as temperature and CO2/H2 ratio. The results will provide criteria that will allow abiotic compounds to be identified in future studies of organic matter from hydrothermal systems and the ocean crust. Since abiotic organic compounds are believed to play a significant role in providing nutrients to microbes in these environments, the results will also help in understanding the distribution and abundance of heterotrophic microbes in surface and subsurface habitats. In addition, since hydrothermal systems were prevalent on the early Earth as well as on other planetary bodies, the results will aid in interpretation of the origin of organic matter in rocks from ancient hydrothermal systems, samples form Mars, and meteorites.