Abstract

The distribution of striated pavements, tillite, outwash deposits, faceted and striated stones, boulders preserved in laminated sequences and interpreted as dropped by ice floes, and other records, show that a large part of Australia was glaciated during the late Paleozoic. Alpine glaciers grew in the Carboniferous upon mountain ranges bordering the Tasman geosyncline in Queensland and northern New South Wales, beginning in the latest Namurian and culminating during the Westphalian and early Stephanian. Later, following deep erosion, continental ice sheets expanded at the end of the Carboniferous (latest Stephanian), and reached their maximum extent in the Early Permian (Sakmarian), when they spread across Tasmania, Victoria, South Australia, and much of New South Wales. They reached the Northern Territory in central Australia, and covered a large part of Western Australia, with centers in regions bordering the Perth, Carnarvon, Canning, Officer, and Bonaparte Gulf basins. A broad arcuate depression, at times occupied by the sea, crossed the continent from Western Australia, through central South Australia, and northeastward into Queensland. The ice sheets rapidly dwindled in the Artinskian; although in eastern Australia and Tasmania, large blocks were dropped into marine sediments from distant glaciers, continuing into the Late Permian (early Kazanian).

The piecemeal stratigraphic record indicates that continental ice spread northeastward into Tasmania from highlands bordering the region on the southwest, and northward through glacial valleys along the coast of South Australia. The apparent source region is now under the deep ocean, but in the late Paleozoic was probably occupied by then-adjacent Antarctica. The spread northward of continental ice sheets at the end of the Carboniferous corresponds with a rapid shift of paleolatitude as determined from published paleomagnetic studies. Continental glaciers apparently grew when Gondwanaland moved near the South Pole and an unfrozen paleo-Pacific was close by to provide abundant moisture.

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