Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (31) Citing Articles via Google Scholar Google Scholar Articles by Rye, R. Articles by Holland, H. D. Search for Related Content GeoRef GeoRef Citation

Life associated with a 2.76 Ga ephemeral pond?: Evidence from Mount Roe #2 paleosol

¹ California Institute of Technology, Division of Geological and Planetary Sciences, MC 170-25, Pasadena, California 91125, USA
² Harvard University, Department of Earth and Planetary Sciences, 20 Oxford Street, Cambridge, Massachusetts 02138, USA

Dark sericitic material at and near the top of the 2.765 ± 0.01 Ga Mount Roe #2 paleosol in Western Australia contains 0.05–0.10 wt% organic carbon with ¹³C values between –33 and –51 PDB (Peedee belemnite). Such negative isotopic values strongly indicate that methanotrophs once inhabited this material. The textures and the chemical composition of the dark sericitic material indicate that the methanotrophs lived in or at the edges of ephemeral ponds, that these ponds became desiccated, and that heavy rains transported the material to its present sites. The discovery of methanotrophs associated with the Mount Roe #2 paleosol may extend their geologic record on land by at least 1.5 b.y. Methanotrophy in this setting is consistent with the notion that atmospheric methane levels were 20 µatm during the Late Archean. The radiative forcing due to such high atmospheric methane levels could have compensated for the faint younger sun and helped to prevent massive glaciation during the Late Archean.

Key Words: Late Archean • terrestrial life • methanotrophs • paleosol • atmospheric evolution

This article has been cited by other articles:

				C. R. Staples, S. Lahiri, J. Raymond, L. Von Herbulis, B. Mukhophadhyay, and R. E. Blankenship Expression and Association of Group IV Nitrogenase NifD and NifH Homologs in the Non-Nitrogen-Fixing Archaeon Methanocaldococcus jannaschii J. Bacteriol., October 15, 2007; 189(20): 7392 - 7398. [Abstract] [Full Text] [PDF]

				A. Neaman, J. Chorover, and S. L. Brantley Implications of the evolution of organic acid moieties for basalt weathering over geological time Am J Sci, February 1, 2005; 305(2): 147 - 185. [Abstract] [Full Text] [PDF]

				W. Yang and H. D. Holland The Hekpoort paleosol profile in Strata 1 at Gaborone, Botswana: Soil formation during the Great Oxidation Event Am J Sci, March 1, 2003; 303(3): 187 - 220. [Abstract] [Full Text] [PDF]

				Bacterial Residues in Coprolite of Herbivorous Dinosaurs: Role of Bacteria in Mineralization of Feces Palaios, December 1, 2001; 16(6): 547 - 565.

				D. C. Catling, K. J. Zahnle, and C. McKay Biogenic Methane, Hydrogen Escape, and the Irreversible Oxidation of Early Earth Science, August 3, 2001; 293(5531): 839 - 843. [Abstract] [Full Text] [PDF]