Vestiges of life in the oldest Greenland rocks? A review of early Archean geology in the Godthabsfjord region, and reappraisal of field evidence for > 3850 Ma life on Akilia.
The Godthåbsfjord region of West Greenland contains the most extensive, best exposed and most intensely studied early Archean rocks on Earth. A geological record has been described of numerous magmatic events between ~3.9 and 3.6 Ga, and evidence of life at >3.85 Ga and ~3.8-3.7 Ga has been proposed from two widely-separated localities. Some of these claims have recently been questioned, and the nature of the best preserved remnants of the oldest known terrestrial volcanic and sedimentary rocks in the Isua greenstone belt are being reinvestigated and substantially reinterpreted. The first part of this article reviews the evolution of geological research and interpretations, outlining the techniques by which the geological history has been determined and the ensuing controversies. The second part re-examines crucial field evidence upon which the antiquity of the oldest terrestrial life is claimed from the island of Akilia.
Myers
J S
JS
Department of Earth Sciences, Memorial University of Newfoundland, ST John's, Newfoundland, Canada A1B 3X5. jmyers@sparky2.esd.mun.ca
Crowley
J L
JL
D005075:Biological Evolution; D002247:Carbon Isotopes; D055593:Geological Phenomena; D005844:Geology; D006116:Greenland; D007554:Isotopes; D007854:Lead; D010163:Paleontology; D014501:Uranium; D018707:Volcanic Eruptions
D002247:Carbon Isotopes; D007554:Isotopes; D007854:Lead; D014501:Uranium