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 Godthabsfjord region of West Greenland contains the most extensive, bes t exposed and most intensely studied early Archean rocks on Earth. A geolog ical record has been described of numerous magmatic events between similar to 3.9 and 3.6 Ga, and evidence of life at > 3.85 Ga and similar to 3.8-3.7 Ga has been proposed from two widely-separated localities. Some of these c laims have recently been questioned, and the nature of the best preserved r emnants of the oldest known terrestrial volcanic and sedimentary rocks in t he Isua greenstone belt are being reinvestigated and substantially reinterp reted. The first part of this article reviews the evolution of geological r esearch and interpretations, outlining the techniques by which the geologic al history has been determined and the ensuing controversies. The second pa rt re-examines crucial field evidence upon which the antiquity of the oldes t terrestrial life is claimed from the island of Akilia. (C) 2000 Elsevier Science B.V. All rights reserved.