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Any that formed were on the high country that is such a small part of the Australian landscape.After being recycled many times over much of the history of the Earth, with no new rock added by volcanism, the soils of arid Australia have been weathered and leached more than any others making them the most nutrient-deficient soils in the world.There are 3 major structural components, the stable Western Shield, the gently warped Central Basin, and the ancient orogony of the Eastern Uplands, which have been rejuvenated by differential uplift in Tertiary and later times.The result is the vast plains and plateaux of the Australian landscape.According to Twidale & Campbell (Source 5), the lack of recent earth movement is a main cause of the widespread prevalence of relatively low-lying plains.The Late Palaeozoic was the time when the most recent episode of mountain building occurred in Australia, with the deformation and uplift of the Eastern Highlands.On the east coast the short, steep rivers have not regressed as much as would be expected, some having eroded headward by about 100 km in about 60 My.

Exoreic streams (rivers that flow to the sea) serve less than half the continent, with the River Murray being of notable length but has a low discharge rate as for much of its length it passes through arid areas.According to Twidale & Campbell, the compact shape of the Australian continent has contributed to the tendency for widespread plantation, with few major indentations or embayments along the extensive coastline.This meant that as sea level changes occurred the resulting changes of river behaviour were limited to the margins of the continent, with the coastal rivers being the only rivers affected, the inland rivers being shielded from such impacts.The Gulf of Carpentaria, Bonaparte Gulf and King Sound on the north coast, Exmouth Gulf and Shark Bay on the west and Port Phillip Bay and gulf St. Tasmania and Kangaroo Island in the south Fraser Island on the east, and Groote Ey Iandt, Melville Island and Bathurst Island off the north coast are the only major islands.Endorheic streams that flow to basins of internal drainage serve more than half of the continental area.