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New Perspectives Workshop, September 2014
Presented by AIG Victoria and AusIMM Central Victoria Branch, Romsey Victoria

Early tectonic and metallogenic evolution of the Tasmanides: the Delamarian and Benambran tectonic cycles

David C Champion and David L Huston

Geoscience Australia, Canberra ACT, Australia

Abstract

Through much of the Phanerozoic the Tasman Element of eastern Australia was a convergent margin. Glen (2005, Geological Society of London Special Publication 246, p. 23?96) and Collins and Richards (2008, Geology 36, p. 559? 562) have demonstrated that the growth of this element can be subdivided into a series of tectonic cycles that were (re)initiated by subducting slab roll?back and the formation of a volcanic arc and back?arc basin, and were terminated by orogenesis associated with arc or exotic terrane accretion or a shallowing of subduction. The earliest cycles, the 600?490 Ma Delamarian and the 490?430 Ma Benambran not only laid the foundations upon which the Tasman Element was built, but are two of the more richly mineralised periods in Australian geological history. In this presentation we compare the evolution of the Delamarian and Benambran cycles in the northern and southern Tasman Element, in particular the styles of tectonic evolution and the assemblages of associated mineral deposits, and then explore the implications of the Lachlan Orocline model for eastern Australian tectonic evolution and metallogenesis.

About the Speakers

David Champion joined Geoscience Australia in 1993 and currently works in the Resources Division as part of the Mineral Systems Group. Since joining GA, David has worked on Archean to Phanerozoic granites of Australia, their genesis and mineral potential, and implications for continental growth and geodynamic environments. This includes several AMIRA projects and the Predictive Mineral Discovery CRC, as well as mapping projects in the Yilgarn and Pilbara. David has a BSc in Geology from James Cook University Townsville and a PhD in Geochemistry from the Australian National University in Canberra.

David Huston joined Geoscience Australia in 1995 and currently works in the Resources Division as part of the Mineral Systems Group. Since joining GA, David has worked on metallogenesis of Australian mineral provinces ranging from the Paleoarchean to the Phanerozoic and relating it to tectonic evolution. He has a BSc in Geological Engineering from Colorado School of Mines, an MSc in Geosciences from the University of Arizona and a PhD in Geology from the University of Tasmania.

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