The Precambrian orogenic belt of North-western Queensland

Abstract

An area of 25,000 square miles in the extreme north-west of Queensland contains outcrops of Precambrian rocks ranging in age from probable Archaean to Upper Proterozoic. In the course of the thesis it is shown that the Lower Proterozoic rocks formed part of an orogenic belt which was involved in two major orogenies. The belt, in the course of its evolution, went through a eugeosynclinal and a miogeosynclinal phase of development; throughout much of its history it possessed two main depositional basins, separated by a tectonic welt from which the lavas were extruded during the eugeosyncltnal phase. In addition to interpreting the history of evolution and the paleogeography of the belt some generalizations are drawn. An attempt is also made to determine the stress environ­ment of the region.