Most organic geochemical studies of the Permian–Triassic mass extinction (PTME)
have utilised marine sections, and the boundary is readily identified by a negative
carbon isotope excursion. It is now well understood from various locations around the
world that the marine ecosystem collapse is accompanied by biomarker evidence for
photic zone euxinia, including isorenieratane, crocetane and 2,3,6-aryl isoprenoids (e.g.
Grice et al., 2005). Far fewer studies have been carried out on non-marine PTME
sections, and in particular no biomarker studies have been carried out on Australian
sections, despite there being extensive Permian and Triassic sequences in eastern
Australia, notably in the Bowen and Sydney basins.