Australia: The Land Where Time Began

A biography of the Australian continent 

Mesoproterozoic Australia

The Mesoproterozoic Era has been subdivided into the:

• Calymmian 1,600-1,400 Ma
• Ectasian     1,400-1,200 Ma
• Stenian       1,200-1,000 Ma

It has been Proposed that during the Palaeoproterozoic to Mesoproterozoic a supercontinent, Columbia (aka Nuna, Hudsonland), existed that predated the supercontinent Rodinia, which in turn predated Pangaea, as suggested by lithostratigraphic, tectonothermal, geochronological and palaeomagnetic data, from collisional orogens dating to 2.1-1.8 Ga, related to cratonic blocks around the world.

The red dome-shaped hills, bornhardts, the eroded remnants of the silicic volcanic rocks of the Gawler Ranges Volcanics are of Mesoproterozoic age.

It was during the Early Mesoproterozoic that it has been proposed that the arc-like rocks of the Musgrave Block, 1.59-1.55 Ga, indicate the presence of an active margin between the North Australian Craton and the South Australian Craton, the Australian continent being subsequently sutured along their margins. Also during the Mesoproterozoic, the presence of arc-like magmatism in the Musgrave Block suggests there was a period of major crustal growth in Australia in the Proterozoic with important implications for current Palaeoproterozoic reconstructions of Australia, as well as the fit into the Rodinia supercontinent.

At the end of the Mesoproterozoic Rodinia is believed to have been surrounded  by a single, pan-Rodinia Mirovoi Ocean.

Sources & Further reading

1. Terra Australis Orogen: Rodinia breakup and development of the Pacific and Iapetus margins of Gondwana during the Neoproterozoic and Paleozoic
2. Mesoproterozoic