Experimental Simulation of Conditions of the Tasmania and Adélie Continental Blocks Formation at the Early Stage of the Break-Up of the Australian-Antarctic Paleocontinent

Abstract

This study focuses on physical modeling of interaction between the Indian and Pacific spreading axes, which resulted in separation of the Tasmania and Adelie blocks during the final stage of the Gondwana breakup, with separation of Australia and Antarctica. The Indian branch of seafloor spreading propagated eastward across the Archean–Mesoproterozoic lithosphere of the western part of Australia–Antarctica, whereas the Pacific branch moved westward through the Paleozoic–Early Mesozoic Fold Belt of eastern Australia–Antarctica. The experiments demonstrated that the interaction between the two spreading axes led to oblique extension (at an angle of 120°–130°) between two continents. At the same time, a rift branch formed between Antarctica and the Adelie Block, but did not developed further. Subsequent opening of the ocean occurred with sinistral strike-slip, which led to transpressional deformations of the Adelie Block and Sorell Basin within the Tasmania Block.