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biogeochemistry of the Lost City hydrothermal field |
The Lost City field, discovered in December 2000 by Deb Kelly, Jeff Karson and Gretchen Fruh-Green is unlike any previously known hydrothermal system (here is an article about its discovery).
Lipid extracts from carbonate rocks of the Lost City Hydrothermal Field yield a predominance of biomarkers diagnostic for methanogenic archaea including the ether lipids archaeol, sn-2 and sn-3 hydroxyarchaeol, dihydroxyarchaeol and the hydrocarbon 2,6,10,15,19-pentamethylicosane (PMI). Sterols and hopanoids, diagnostic for eukaryotes and bacteria respectively, are subordinate. At ten sites surveyed thus far, biomarker types were not correlated with vent temperature or activity. Hydroxyarchaeols were detected in three active and two inactive vents. Glycerol monoethers with saturated and unsaturated C15-C20 n-alkyl chains, diagnostic for sulfate-reducing bacteria, were detected in five active and three inactive vents. Carbohydrates were detected in four active vents, but not in the inactive vents. High concentrations of sn-2 and sn-3 hydroxyarchaeol and a dihydroxyarchaeol in numerous Lost City samples suggests that methane cycling is the dominant metabolic processes. |
schematic of the Lost City hydrothermal field, figure from Kelley et. al. (2005) Science
307: 1428-34.
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Funding sources: MIT
Publications:
Deborah S. Kelley, Jeffrey A. Karson, Gretchen L. Früh-G reen, Dana R. Yoerger, Timothy M. Shank, David A. Butterfield, John M. Hayes, Matthew O. Sch re nk, Eric J. Olson, Giora Proskurowski, Mike Jakuba, Al Bradley, Ben Larson, Kristin Ludwig, Deborah Glickson, Kate Buckman, Alexander S. Bradley, William J. Brazelton, Kevin Roe, Mitch J. Elend, Adélie Delacour, Stefano M. Bernasconi, Marvin D. Lilley, John A. Baross, Roger E. Summons , and Sean P. Sylva (2005). A Serpentinite-Hosted Ecosystem: The Lost City Hydrothermal Field. Science 307: 1428-1434 .
Bradley A.S., Hayes J.M. and Summons R.E. (2003). Geolipids produced by methanogens and sulfate-reducing bacteria at the Lost City Hydrothermal Field Eos Trans. AGU, 84(46), Fall Meet. Suppl. Abstract B12A-0773.
Further resources:
the webpage for the Lost City Project
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