Archean evolution of the Pilbara craton and Fortescue basin / Архейская эволюция кратона Пилбара и бассейна Фортескью

Previous investigations of the northern Pilbara Craton are briefly summarized, followed by an outline of the region’s lithostratigraphy and major tectonic units. Previous interpretations of its tectonic evolution have not taken account evidence that the presently preserved 500,000 km2 Pilbara Craton is composed of fragments of much larger Paleoarchean and Mesoarchean continents. This consideration provides important new insights on the original scales of the processes and tectonic units that existed before two major events of continental breakup.The Pilbara Craton is a 500,000 km2 segment of Eo–Mesoarchean granite–greenstone crust underlying the Pilbara region of northwestern Australia (Figs. 1.1 and 1.2). Although large sections of the craton are concealed by Neoarchean– Paleoproterozoic successions of the Fortescue, Hamersley, and Turee Creek Basins, there are areas of erosion that provide large windows onto the granite–greenstones. The largest exposure is a 60,000 km2 inlier that extends 500 km east from the northwest Pilbara coast (Fig. 1.3). Once described as the ‘Pilbara Block’ (Ryan 1965; Blockley 1975; Hickman 1983), the eastern part of this inlier contains the 40,000 km2 East Pilbara Terrane (EPT, Fig. 1.3). This is arguably the world’s best preserved Paleoarchean terrane, providing unique insights on Paleoarchean crustal evolution and the earliest life on Earth. Equally informative is the western area of the inlier where Mesoarchean terranes and basins record the beginning of plate tectonic processes in the Pilbara. <...>