GEOC 137 |
| Alexis S. Templeton1, Thomas P. Trainor2, Peter J. Eng3, Brad E. Bailey4, Hubert Staudigel4, and Brad Tebo1. (1) Marine Biology Research Division, Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0202, (2) Department of Chemistry and Biochemistry, University of Alaska, Fairbanks, Fairbanks, AK 99775-6160, (3) Consortium for Advanced Radiation Sources, University of Chicago, Chicago, IL 60637, (4) Institute for Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0225 |
| Recent work suggests that the rates of chemical exchange between basaltic glasses and seawater may be significantly influenced by microbial activity. In particular, we are investigating the role of chemolithoautotrophs, which may use reduced Fe(II) & Mn(II) in the glasses as an energy source, as catalysts of glass dissolution in the deep ocean. We have coupled a series of synchrotron-based surface-sensitive spectroscopic techniques (Reflectivity, TR-XRF, GI-XANES) to probe how the activity of psychrophillic Fe & Mn-oxidizing organisms affects the rates and mechanisms of glass dissolution, metal redistribution and oxidation. These measurements demonstrate significantly increased rates of Fe & Mn remobilization from the glasses, the propagation of a Fe oxidation front several thousand angstroms into the glasses and the accumulation of oxidized Mn in overlying biofilms that is not observed from abiotic interaction with seawater alone. |
|
Microbially Mediated Manganese and Iron Oxidation in the Biosphere
8:00 AM-12:15 PM, Wednesday, March 31, 2004 Marriott -- Marquis NE, Oral
Division of Geochemistry |