As part of a regional search for possible economic IOCG type mineralisation in an area of covered Hiltaba Suite granitic intrusions north-west of Tarcoola, EL 3994 (formerly EL 3040) was covered by a regional gravity survey in September-October 2005, acquired initially at a station spacing of 1 km x 1 km, with later infill to 500 m x 500 m. Within the now relinquished northern portion of the tenement, a large positive regional gravity feature was so infilled, and subsequently two 10 km long traverses were examined in detail at a station spacing of 100 m. This work delineated a significant, 7 km x 4 km extent and 10 mGal amplitude gravity high near Twin Rocks, west of Carne Outstation. This high has no associated magnetic response, and was untested. Accordingly, 3D and 2D modelling of the gravity data was undertaken by Minotaur Exploration to predict the density and depth of the anomaly source body. In October 2006 the Twin Rocks gravity anomaly was the target for two vertical RC holes drilled to depths of 198 m and 127 m respectively. Both drillholes encountered predominantly ultramafic basement rocks including gabbroic anorthosite, olivine-rich lherzolite, and biotite+hornblende-rich lherzolite (peridotite). Minor dykes of biotite+plagioclase lamprophyre and syenogranite (?Hiltaba Suite) are also present. Pervasive regional hydrothermal alteration, typical of IOCG-style mineralised systems, is absent. A review of the gravity data and later 1VD processing identified an additional two targets in the northern portion of the tenement: (i) a small, 2 mGal gravity anomaly located ~20 km north-west of Twin Rocks, which is associated with a magnetic response and with exposed Archaean gneisses, and (ii) an anomaly located ~15 km south-west of Twin Rocks, that is interpreted to be a south-west extension of the main 10 mGal anomaly near Twin Rocks.