Late Mesozoic strike-slip faulting in Tasmania

Abstract

Jurassic dolerite is well exposed in fresh cuttings and quarries throughout Tasmania, and fault striations were found in a high proportion of these exposures in the south and west of the state. These fault striation provide a record of late Mesozoic faulting dominated by dextral west-northwest–east-southeast-striking faults and sinistral north–south-striking faults. This fault association indicates compression from the NNW. Indirect evidence suggests these structures formed during the Cenomanian (ca 95 Ma) inversion in the Otway and Bass basins, and are probably part of the crustal shortening that formed the Transantarctic Mountains.