| Abstract: | The structure and tectonic style of Australia, to the north of the Musgrave Block and the southern Canning Basin and to the west of the Tasman Orogenic Province, are summarized.Northern Australia is largely occupied or underlain by the early Proterozoic North Australian Orogenic Province, which is bounded by younger mid-Proterozoic mobile belts of the Central Australian Orogenic Province along the eastern and southern margins. In the north, a basement of the Archaean West Australian Orogenic Province underlies the North Australian Orogenic Province. The strata of the North Australian Platform Cover were mildly to moderately deformed at the time when the mid-Proterozoic mobile belts were active. The late Proterozoic and Palaeozoic Central Australian Platform Cover developed over both the North and Central Australian Orogenic Provinces. Finally, the Mesozoic—Cainozoic Trans-Australian Platform Cover transgressed most of the region.The tectonic evolution of northern Australia can be clearly related to the times of cratonisation of its basement. A comparatively uniform pattern of major fractures, trending roughly northerly and northwest, was established throughout the region very early in its history. The subsequent evolution resulted from repeated reactivation of these fractures.Much of the structure may possibly be explained by a simple model in which a central block, roughly between the Kimberleys and Mount Isa, was displaced northwards relative to the blocks on either side and locally, the horizontal displacements were absorbed along east—west-trending zones of thrusting and folding, where the cover was crumpled against rigid blocks. |
