Basin-forming structures and their relevance to hydrocarbon exploration in Bass Basin, southeastern Australia

Interpretation of high-quality seismic reflection data from Bass Basin, SE Australia, has led to the recognition of major Early Cretaceous extensional normal faults segmented by contemporaneous transfer faults. The normal faults, described here, and associated tilt-block edges have had a major influence on structural evolution in the overlying hydrocarbon-prospective Eastern View Coal Measures (EVCM). A play concept is presented that relates the mid-basin tilt-block/normal fault system and associated transfer faults to structures, facies variations, and source maturity within the EVCM. A geohistory analysis of a specific location containing such a structure associated with possible direct hydrocarbon indicators shows that the lower EVCM has been oil-mature since the Oligocene and it is suggested, therefore, that the prospectivity of the Bass Basin should be upgraded.-Authors