Position of the end-Permian mass extinction level and Permian Triassic boundary in Australia

Abstract

Late Permian (late Changhsingian), Early Triassic Induan (Dienerian), and early Olenekian (Smithian) condonts have been recovered from the Hovea Member of the Kockatea Shale in the exploration well Corybas-1, northern Perth Basin, Western Australia. Ongoing studies of the Kockatea Shale from other Perth Basin wells are providing additional conodont material that further refine the international calibration and correlation of the Australian Upper Permian - Lower Triassic. Based on the recovered conodonts, coupled with megaspore data and previously reported Cisotope, macrofossil and geochemical data, the Permian Triassic boundary (GSSP level) is placed in the lower part of the Sapropelic Interval of the Hovea Member of the Kockatea Shale, and the mass-extinction level at the Inertinitic-Sapropelic boundary within the Hovea Member. The presence of 'Clarkina jolfensis' Kozur internationally calibrates the Australian endemic 'Protohaploxypinus microcorpus' palynofloral zone and the basal part of the Sapropelic Interval of the Hovea Member as late (but not latest) Changhsingian age.