SGER: Smectite Incubation of Organic Molecules in Seafloor Hydrothermal Systems

Arizona State University, Scottsdale AZ

Investigators

Abstract

The PIs propose an experimental study to examine how the catalysis of organic molecules may be influenced by the conversion of smectite to illite via the I/S (illite/smectite) transitional structural states. Basically, simple organic molecules may be held in interlayer smectite sites while the smectite converts to illite. This mineralogic change could catalyze the formation of more complex organic products in present day hydrothermal systems and the early earth, with implications for the origin of life. The idea is that the polymerized organics would be protected by being in interlayer positions. Experiments will be conducted at 300 degrees C, 250 degrees C, and 200 degrees C, and 250 bars, an appropriate pressure for seafloor hydrothermal systems. Experiments will explore the effects of different starting concentrations, Eh, pH, and salinity conditions on catalysis of polymerized organic molecules. Some experiments will be in sealed capsules, whereas others will be in large vessels that can be sampled from time to time as the smectite changes to illite, with interlayer organics presumably also changing in interesting ways. The experimental materials will be analyzed with XRF, GCMS, HPLC, IC, and FTIR plus MALDI-TOF, a new technique for analyzing small amounts of organics on solids in situ.