The generation and assembly of an Archaean supercontinent: evidence from the Yilgarn craton, Western Australia

Abstract

Abstract The Yilgarn craton consists of granites, greenstones and granitic gneisses ranging from at least 3730 to 2550 Ma. These rocks can be divided into a number of tectonostratigraphic terranes that comprise distinct rock units with different geological histories. However all the terranes, regardless of their age and composition, show evidence of intense tectonic, volcanic, plutonic, and metamorphic activity between 2780 and 2630 Ma. This is interpreted as a major episode of plate tectonic activity which swept together and amalgamated a number of diverse crustal fragments (including volcanic arcs, back-arc basins and microcontinents) to form a super-continent, of which the Yilgarn craton is a fragment. The main features of the Narryer, Murchison and Kalgoorlie terranes are described as examples of the diversity of crustal components within the craton and the nature of the processes by which these components were combined to form the Yilgarn craton.