Thomson Orogen - development of an integrated geological/geophysical interpretation

Abstract

The Thomson Orogen, which underlies the Channel Country in far northwest New South Wales, is a major, largely unknown region overlain by the Mesozoic Eromanga Basin and Cainozoic sediments. The region has potential for arc- and ocean-crust-related gold and base metal deposits while the northern part of the Lachlan Orogen immediately to the south of the orogen, may have potential for Mississippi Valley style zinc and lead deposits. The prospective targets are obscured by variable thicknesses of Mesozoic and Cainozoic sedimentary units. To develop a better understanding of the tectonic setting and mineral potential of the Thomson Orogen an integrated geoscience program has included high resolution aeromagnetic and radioelement data; deep seismic data; new gravity stations; regolith mapping through classification of satellite data; review of past and present company data; baseline geochemistry; stratigraphic drilling; and studies of lithofacies, age data, geochemistry and petrology from selected drill core acquired by exploration companies. The data are the basis for the new Thomson Orogen GIS. The first stage of this integrated study has been completed and indicates that the Thomson Orogen in NSW has many similarities to the mineral-rich Lachlan Orogen. In conjunction with CRCLEME, an Explorers? Guide has been developed to assist mineral exploration in this regolith dominated terrane.