Deep crustal seismic surveys for identifying prospective areas under cover ? example from North Queensland

Abstract

Geoscience Australia has been acquiring deep crustal reflection seismic transects throughout Australia since the 1960s. The results of these surveys have motivated major interpretations of important geological regions, contributed to the development of continental-scale geodynamic models and improved understanding about large-scale controls on mineral systems. Under the Onshore Energy Security Program, Geoscience Australia has acquired, processed and interpreted over 5000 km of new seismic reflection data [over what period?]. These transects are targeted over geological terrains in all mainland states which have potential for hydrocarbons, uranium and/ or geothermal energy systems, but also have implications for other mineral systems. The first project was undertaken in the Mt Isa and Georgetown regions of North Queensland. Interpretations of these results have identified several features of interest to mineral and energy explorers: a previously unknown basin with possible hydrocarbon and geothermal potential; a favourable setting for iron oxide uraniumcopper- gold deposits; and a favourable structural setting for orogenic gold deposits under basin cover. Magnetic, gravity, and MT data were used to map some of these features under cover in 3D, areas away form the seismic line. Seismic imaging of the full thickness of the crust provides fundamental data to economic geologists, to explain why major deposits occur where they do, and reduces risk for companies considering expensive exploration programs under cover.