Structural continuity of the Ross and Delamerian orogens of Antarctica and Australia along the margin of the paleo-Pacific

Abstract

The Delamerian orogen (southeast Australia) and the Wilson terrane (northern Victoria Land, Antarctica) constitute a formerly continuous lower Paleozoic fold-and-thrust belt developed along the paleo-Pacific margin of eastern Gondwana. Major folds and thrust faults in these regions, rooted in mid-crustal detachment zones, transported Cambrian-Ordovician granites and high-temperature- low-pressure metamorphic rocks divergently toward their respective western craton margins and eastern orogen margins and associated cover sequences. The structural imprints are related to the accretion of lower Paleozoic terranes at the eastern margin of the Delamerian orogen and the Wilson terrane. The continuity of the contemporaneous structure patterns in Australia and Antarctica is evidence for continuous convergent tectonism along the lower Paleozoic-Pacific margin of Gondwana.