Evolution and structuring of the offshore Otway Basin, Victoria as delineated by aeromagnetic data

Abstract

A large portion of the western offshore Victorian portion of the Otway Basin appears to have originally been underlain by an extensive horizontal basic magnetic sheet emplaced during the initial stages of basin formation. Subsequent basin extension along transfer faults trending at 210 degrees has fractured this sheet, and evidence of the transfer fault fracture system is given by the present day outlines of the magnetic anomalies arising from the fragments of the sheet. The transfer fault system is further indicated by linear magnetic anomalies within the sedimentary section due to magnetic material accumulated in the fault planes. Gravity and seismic data support the transfer fault model which can be used to explain features of the depositional history and structural development of the area.