The Bureau of Mineral Resources completed a major marine multi-channel seismic reflection survey (MCS) off southeast Queensland in December 1989. The research cruise, using RV 'Rig Seismic: was designed to investigate the structure, stratigraphy and petroleum resource potential of offshore basins along this sector of the Australian continental margin. About half of the 2900 km of seismic data acquired were recorded over the Capricorn Basin and margins of the northern Tasman Basin. The survey included seismic ties to the only deep offshore wells in the region, Aquarius-1 and Capricorn-lA, located in the northern Capricorn Basin. It was the first MCS survey shot in the region since 1974. Sonobuoy refraction, gravity, magnetic and bathymetric data were also collected. The Capricorn Basin evolved in the Late Cretaceous as a failed rift arm at the northern end of the Tasman rift system. From the seismic data, basin development in the Capricorn Basin is seen as typically comprising 0.5 ? 1.0 s twt of syn-rift continental/Irestricted marine deposits (Late Cretaceous-early Palaeogene) overlain by about 1.5 s twt of Eocene-Recent, mainly marine, post-rift sediments.