Understanding the active tectonics in Australia: Implications of geothermal resources

Abstract

Great Artesian Basin (GAB) in east-central Australia has a significant potential for geothermal resource, which is believed to be due to radiogenic heat production in basement granitic rocks. We examine an alternative hypothesis proposing that the mantle degassing may be the heat source (at least partly) in association with active tectonics. This study applies methodologies in geochronology, isotope geochemistry and structural geology to assess the role of neotectonic reactivation of Phanerozoic faults in permeability creation and mantle degassing in generation of geothermal resources. Isotopic dating results and stable isotope geochemistry of hydrothermal minerals in basement rocks are interpreted as indicating that Cretaceous extensional tectonic events controlled the thermal history of central-eastern Australian basins and distribution of fracture zones allowing recent uprise of hot mantle fluids.