The Australian central Eromanga Basin project: An introduction

Abstract

The Australian Bureau of Mineral Resources is carrying out a major multidisciplinary program of geological and geophysical studies in southwestern Queensland in cooperation with the Geological Survey of Queensland. The project is aimed at providing information on the regional structure and depositional history of the central Eromanga Basin and the underlying Adavale, Cooper and Galilee basins. The information being obtained is particularly relevant to a better understanding of the petroleum prospectivity of the area. The program includes geophysical surveys involving 1400 km of new six-fold CDP seismic reflection coverage on regional traverses up to 400 km long crossing the main structural elements of the area; gravity measurements along all new seismic reflection traverses; refraction surveys along two major east-west and north-south traverses and magnetotelluric soundings along the same major east-west traverse. LANDSAT imagery studies are providing new perspective on many regional structures when used in conjunction with seismic and gravity information. Wireline logs and synthetic seismograms are being used with the new seismic data to re-examine stratigraphic correlations. Palynologic and lithologic studies are underway to assist in determining depositional environments. Source rock, maturation, hydrological and geochemical studies are providing information on the generation and migration of hydrocarbons. A significant feature of the program is the extension of the recording time of all new reflection data to 20 s to obtain good quality deep crustal reflection information comparable to that obtained on COCORP programs in the United States. The reflection data is being interpreted with the refraction, gravity and magnetotelluric data to investigate the relationship of deep crustal and upper mantle features to the sedimentary basins in the central Eromanga Basin area.