Geological evolution of the Kimberley region of Western Australia

Abstract

The history of the Kimberley region in the far north of Western Australia began in the Paleoproterozoic with rifting along the North Australian Craton margin at 1910-1880 Ma, followed by plate collision as part of a series of 1870-1790 Ma events that formed the Diamantina Craton within the supercontinent Nuna. Collision involved the accretion of an intra-oceanic arc to a continent that included the Kimberley Craton before final collision and suturing with the North Australian Craton. The c. 1835 Ma Speewah Basin formed as a retro-arc foreland basin to the W. The post-orogenic, c. 1800 Ma shallow-marine to fluvial Kimberley Basin and its equivalents had a provenance to the N and extended across both the Lamboo and Hooper provinces. Subsequent late Paleoproterozoic and Mesoproterozoic basins formed broadly similar depositional settings during break-up and reassembly into the supercontinent Rodinia. The intracratonic Yampi Orogeny generated large-scale folding and thrusting and sinistral strike-slip faulting between 1400-1000 Ma. The Neoproterozoic Centralian Superbasin formed as a broad intracratonic sag basin throughout central Australia between c. 830 Ma and the earliest Cambrian, including a series of basins across the Kimberley. Glacigene rocks are present with the most widespread being equivalent to the c. 610 Ma Elatina ("Marinoan") glaciation. Folding, thrusting and strike-slip faulting during the c. 560 Ma King Leopold Orogeny caused a widespread unconformity at the base of the Ord and Bonaparte basins marked by the c. 508 Ma Kalkarindji Continental Flood Basalt Province. In the Early Ordovician, thermal subsidence initiated the Canning Basin. Paleozoic sedimentary rocks, including Devonian reef complexes, were deposited on the Lennard Shelf and in the Fitzroy Trough. In the Halls Creek Orogen, Devonian sedimentary rocks were deposited in subbasins of the Ord Basin during the c. 450-300 Ma Alice Springs Orogeny. A widespread glacigene succession followed in the Canning Basin, but by the early Triassic deposition was restricted and the remainder of the Mesozoic succession forms a veneer over much of the basin.