UPPER PALEOZOIC OF WESTERN AUSTRALIA: CORRELATION AND PALEOGEOGRAPHY

ABSTRACT The paper reviews the upper Paleozoic rocks in the three most important districts of Western Australia: Irwin River, North-West Division, and West Kimberley Division. The strata and their fossils are described in broad outline and a correlation between the three sequences is suggested. Glacial deposits are found at the base of the sections followed by a variety of marine and lacustrine, or estuarine, sediments of considerable thickness. The Western Australian strata are compared with those of eastern Australia, particularly of New South Wales, and it is indicated that the general succession, lower Marine—lower Coal Measures—upper Marine, which is characteristic of the Hunter River area in New South Wales, can also be recognized in Western Australia. It is concluded that glaciation in Western Australia began about at the beginning of Sakmarian time and that sedimentation continued until the early Kungurian. Correlations with Russia, India, and Timor are made. The Permian glaciation of Australia was a single major event with the strongest refrigeration during the Sakmarian and much less severe conditions, with one major interglacial period, during the Artinskian. Rich marine faunas arrived in Australia after the climax of the glaciation had been passed. The upper Paleozoic strata of Western Australia were deposited in a geosynclinal trough which was marginal to the pre-Cambrian shield and continuous with the Timor geosyncline of the East Indies. The relative geographical position of Australia and the East Indies in late Paleozoic time must have been very much the same as at present.