GEL 257 was one of 6 geothermal licences granted to Proactive Energy Developments Ltd (PED) covering areas of the central and northern Gawler Craton during 2006/2007. In early 2007 PED changed their name to Granite Power Ltd. GEL 257 was granted 22nd March 2007 covering an area of 451km2 over the Weedina area for an initial term of 5 years. This area is located on the western margin of the Boorthanna trough which in turn is located on the north eastern edge of the Gawler Craton. No field activities were conducted but a review of the geothermal prospectivity of all geothermal tenements was completed by Earth Resources Australia (ERA). Target areas for a geothermal resource were nominally a cover sequence of sedimentary rocks of 2-4 kms thickness overlying a high heat source such as radiogenic granites or iron oxide deposits. Based on available drill-hole data and a reasonable regional seismic network it was interpreted that the post Proterozoic cover was unlikely to exceed 2500 meters and more likely to be a maximum of 1500 m. It was further deemed that it was unlikely that heat bearing granites occurred in the licence area. Based on these 2 issues, lack of cover depth and lack of heat producing granites saw the licence surrendered on 10th August 2007 before the end of the first licence year.