The Eromanga-Brisbane geoscience transect : a guide to basin development across Phanerozoic Australia in southern Queensland

Crustal dynamics throughout geological history have played an important role in the development of sedimentary basins. A basic knowledge of major crustal structures is, therefore, crucial to any interpretations aimed at modelling particular basin systems. This Bulletin contains papers by authors from a number of geoscience institutions and companies on various aspects of crustal and basin development along an 1100 km east-west transect in southern Queensland, the Eromanga-Brisbane Geoscience Transect In particular, deep seismic profiling along this transect has enabled, for the first time, a 3-dimensional interpretation of deep structures and processes which have controlled the development of major basin systems in eastern Australia. Complete answers to all questions on basin development are still evolving, but the papers presented in this Bulletin, together with the 1:1 000 000 scale map folio, provide a much improved basis for further, detailed investigations. The Eromanga-Brisbane Geoscience Transect crosses three major basement provinces in eastern Australia: 1) the Thomson Fold Belt under the central Eromanga Basin and its infra-basins, 2) the northernmost Lachlan Fold Belt under the Taroom Trough of the Bowen Basin and Surat Basin, and 3) the New England Fold Belt under the Clarence-Moreton Basin. Basement geology in this region has, until now, been only poorly understood because it is largely obscured by the Mesozoic cover rocks of the Eromanga, Surat and Clarence-Moreton Basins. However, the application of geophysical techniques (seismic methods in particular) in recent years has enabled a much better understanding of the crustal architecture and processes likely to have been involved in the development of the major basins. Such an understanding provides the framework for more detailed investigations directed primarily at economic resources of oil, gas, coal, groundwater and many minerals.The precis paper at the end of this Bulletin should be consulted for a summary of geoscience results. It is evident from these results that the transect interpretation has now firmly established concepts of crustal-scale ramp structures, multiple intra-crustal detachment surfaces, strike-slip fault architecture, lower crustal magmatism/underplating, Moho remobilisation, and intra-crustal terranes into the geological reconstructions of southern Queensland. In so doing, it has played a major role in developing a better understanding of the sedimentary basins of eastern Australia.