Australia: The Land Where Time Began

A biography of the Australian continent 

Aka the Adelaide Rift Complex, this is a major central South Australian geological province that stretches from the northern parts of the Flinders Ranges to Kangaroo Island. The Flinders Ranges and the Mt Loft Ranges, the 2 major ranges of South Australia, are included in this province. The sedimentary rocks were deposited in a depression that is believed to have formed as the crust was stretched during the breakup of the supercontinent of Rodinia. It was in the form of an arc about 1000 km long and several hundred km wide. At their deepest the deposits of limestones, shales and sandstones, as well as some volcanics, reach up to 24,000 m thick. The nature of the rocks suggest they were deposited in a mostly marine environment. At the time of their deposition, between the Middle Proterozoic and the end of the Cambrian (about 870 million years ago to about 500 million years ago) the area was on the east coast of the continent. Some have noticed that similar rocks are found on the west cost of North America, leading to the suggestion that before the fragmentation of Rodinia, North America was connected to eastern Gondwana.

In the Late Cambrian, 500 Ma, the Adelaide Rift Complex was inverted to become the Adelaide Fold Belt.

Sources & Further reading

1. Walter & Veevers in Veevers, J. J  (ed.), 2000, Billion-year earth history of Australia and neighbours in Gondwanaland, GEMOC Press Sydney.

Australian Neoproterozoic

Interglacial Carbonates, Umberatana Group, Flinders Ranges, South Australia