Biogenicity of silicified microbes from a hydrothermal system; relevance to the search for evidence of life on Earth and other planets

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doi: 10.1016/S0012-821X(01)00421-6
Author(s): Al-Hanbali, Hakam S.; Sowerby, Stephen J.; Holm, Nils G.
Author Affiliation(s): Primary:
Stockholm University, Department of Geology and Geochemistry, Stockholm, Sweden
Volume Title: Earth and Planetary Science Letters
Source: Earth and Planetary Science Letters, 191(3-4), p.213-218. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012-821X CODEN: EPSLA2
Note: In English. 23 refs.; illus., incl. 1 table, sketch map
Summary: Scanning electron microscopy and microprobe analysis have been used to examine microstructures recovered from a hydrothermal mound at the Trans-Atlantic Geotraverse. Our analyses of hydrothermally precipitated Fe-rich cherts shows strong evidence for silicified microorganisms at depths of less than 1 m. The criteria for biogenicity are morphological similarities to living bacteria and an elevated carbon and nitrogen content with an N/C ratio consistent with marine microbes. The absence of calcium means they can not be confused with abiological carbonate or sulfate artifacts. As a modern analog of Archean hydrothermal sites, our results are informative about the mode of microbial preservation, and because of the shallow extraction and proximity to distinctive topographical features, investigation of hydrothermal sites should optimize future explorations for detecting past or present life on the surface of Earth and other planets. Abstract Copyright (2001) Elsevier, B.V.
Year of Publication: 2001
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 12 Stratigraphy, Historical Geology and Paleoecology; Archean; Atlantic Ocean; Bacteria; Biogenic processes; Cenozoic; Deep-sea environment; Electron probe data; Geochemistry; Holocene; Hydrothermal vents; Interplanetary comparison; Leg 158; Life origin; Marine environment; Mars; Microorganisms; Microstructure; Mid-Atlantic Ridge; Modern; Modern analogs; Morphology; Natural analogs; North Atlantic; Ocean Drilling Program; Planets; Precambrian; Precipitation; Quaternary; SEM data; Silicification; TAG hydrothermal field; Terrestrial planets; Thermophilic taxa
Coordinates: N260800 N260800 W0444900 W0444900
Record ID: 2001075261
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands