title: Early life recorded in archean pillow lavas.
abstract: Pillow lava rims from the Mesoarchean Barberton Greenstone Belt in South Africa contain micrometer-scale mineralized tubes that provide evidence of submarine microbial activity during the early history of Earth. The tubes formed during microbial etching of glass along fractures, as seen in pillow lavas from recent oceanic crust. The margins of the tubes contain organic carbon, and many of the pillow rims exhibit isotopically light bulk-rock carbonate delta13C values, supporting their biogenic origin. Overlapping metamorphic and magmatic dates from the pillow lavas suggest that microbial life colonized these subaqueous volcanic rocks soon after their eruption almost 3.5 billion years ago.
authors.affiliation: Department of Earth Science, University of Bergen, Allegaten 41, 5007 Bergen, Norway. Harald.Furnes@geo.uib.no
authors.forename: Harald
authors.initials: H
authors.lastname: Furnes
authors.forename: Neil R
authors.initials: NR
authors.lastname: Banerjee
authors.forename: Karlis
authors.initials: K
authors.lastname: Muehlenbachs
authors.forename: Hubert
authors.initials: H
authors.lastname: Staudigel
authors.forename: Maarten
authors.initials: M
authors.lastname: de Wit
mesh_terms: D001419:Bacteria / Q000254:growth & development; D015415:Biomarkers; D002247:Carbon Isotopes / Q000032:analysis; D002254:Carbonates / Q000032:analysis; D019015:Geologic Sediments; D005898:Glass; D019369:Life; D010163:Paleontology; D013019:South Africa; D013995:Time; D018707:Volcanic Eruptions
chemical_list: D015415:Biomarkers; D002247:Carbon Isotopes; D002254:Carbonates