2003 Annual Science Report
Arizona State University Reporting | JUL 2002 – JUN 2003
Organic Synthesis at High Temperature
We have advanced a corollary to our previously published hypothesis that degassing of seafloor basaltic magmas provides hydrogen and carbon dioxide for abiotic organic syntheses (Holloway & O’Day, 2000) by demonstrating that the same processes can operate with more silicic magmas (Holloway, submitted).
We have demonstrated that smectite clay minerals, commonly found in seafloor hydrothermal systems, provide reactive sites for synthesis of complex organic compounds such as hexamethylbenzene and long-chain methyl esters from aqueous methanol solutions (Williams, et al., 2002; Canfield, et al., 2003). This research is ongoing. We are continuing to explore synthesis of organic compounds from hydrogen and carbon dioxide in the presence of mineral catalysts at seafloor hydrothermal conditions.
We are continuing to develop novel tools for studying hydrothermal microhabitats. We are using synchrotron computed microtomography to study the physical structure of young hydrothermal chimneys from 9°N East Pacific Rise. This analysis shows a loosely connected network of euhedral mineral grains (predominantly sulfide by bulk X-ray diffraction measurements) and no channelized flow, such that the physical structure is dominated by porosity (i.e., fluid) rather than minerals. This physical structure may serve as an effective molecular sieve for the adsorption of organic compounds and bacteria from vent fluid and seawater, and provides a model for how organic compounds may accumulate on surfaces under pre-biotic conditions.
PROJECT INVESTIGATORS:John Holloway
Project InvestigatorPeggy O'Day
PROJECT MEMBERS:S. Cary
RELATED OBJECTIVES:Objective 3.1
Sources of prebiotic materials and catalysts
Origins and evolution of functional biomolecules
Environmental changes and the cycling of elements by the biota, communities, and ecosystems