Using constrained gravity inversions to identify high-heat-producing granites beneath thick sedimentary cover in the Cooper Basin region of central Australia

• Published in: Geothermics 2014-07, Vol.51, p.483-495
• Main Authors: Meixner, A.J., Kirkby, A.L., Horspool, N.
• Format: Article
• Language: English
• Subjects: Buried granites; Cooper Basin; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Exact sciences and technology; Geothermal; Geothermics; Gravity; Inversion
• ISSN: 0375-6505; 1879-3576
• DOI: 10.1016/j.geothermics.2013.10.010

•We investigate the Cooper Basin of central Australia for unconventional geothermal.•We use gravity inversions to delineate low density granites beneath sediments.•Thermal modelling indicates that some of these granites are high-heat-producing.•New regions are identified that have a high potential for geothermal resources. Geothermal systems in Australia are unconventional, consisting of high-heat-producing granites beneath insulating sediments. Three-dimensional constrained gravity inversions and gravity ‘worming’ were used in the Cooper Basin region of central Australia to delineate low density regions within the basement, that we define as interpreted granite bodies (IGBs). Results of 3D thermal modelling, applied to a 3D model of the region, were compared to down-hole temperature measurements implying that a number of the IGBs are high-heat-producing. Two regions with high-heat-producing IGBs, beneath at least 3000m of sediments, were identified and are considered to have high potential for geothermal resources.