| Summary: | We present a revised set of Euler poles describing therelative motion between Australia and Antarctica fromthe onset of continental rifting at ~160-140 Ma to thereorganisation of the spreading system at ~50 Ma. Ourrevised reconstruction addresses two key issues thatremain unresolved in current plate reconstructions. Firstly, we present new estimates of the pre-rift plateboundary locations for the conjugate Australian-Antarcticmargins. These reconstructions are truly palinspastic,incorporating estimates of crustal thickness along thesemargins, derived from gravity inversions. Integrating thecrustal thickness along tectonic flowlines results in thepre-rift location of the continental plate boundary. Thisintegration relies on defining the present-day extent ofstretched continental crust within the margin, which is thesubject of the companion paper, Williams et al. [2010].Once restored, we are then able to use the pre-rift plateboundary positions to compute full-fit poles of rotationfor Australia relative to Antarctica. This approach allowsus to model a deforming passive margin, withimplications for understanding and modelling theformation of basins and deposition of sediments alongpassive margins. Secondly, reconstructions for plate motions since ~83 Mahave been revised to obtain a better fit along the entireAustralian-Antarctic conjugate margins, which extendfrom at least the Kerguelen Plateau and Broken Ridge inthe west to Tasmania, Australia and Cape Adare,Antarctica in the east. Previously publishedreconstruction models for the period 83-50 Ma hadresulted in a poor fit between the two plates at theextreme ends of the conjugate margins.
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