Gawler Craton

rdf:langString Gawler Craton

rdf:langString The Gawler Craton covers approximately 440,000 square kilometres of central South Australia. Its Precambrian crystalline basement crustal block was cratonised ca. 1550–1450 Ma. Prior to 1550 Ma the craton comprised a number of active Proterozoic orogenic belts extending back in time to at least 2450 Ma. The Craton can be subdivided into a number of tectonic subdomains on the basis of structure and tectonostratigraphic history. The south-central Eyre Peninsula straddles the boundary between the Archaean to early Palaeoproterozoic Coulta Subdomain and the Cleve Subdomain, a Palaeoproterozoic orogenic belt ("mobile zone") probably representing a shelf or basinal depository for the Hutchison Group (ca. 1900–1845 Ma) prior to its deformation during the Kimban orogeny (ca. 1845–1710 Ma). On northeastern Eyre Peninsula, the Cleve Subdomain is bounded by the slightly younger Moonta Subdomain which is characterised by less intensely deformed metamorphosed acid volcanics and sediments ranging from the Myola Volcanics and Moonta Porphyry to the Moonabie Formation and Wandearah Metasiltstone. Subsequent deformation on the craton has been largely epeirogenic forming shallow fault-bounded intracontinental depressions represented by Cainozoic basins, the southern continental margin and Spencer Gulf.