During July 2012, at a location approximately 90 km south-east of Oodnadatta, EL 3680 licensee Energia Minerals completed the drilling at the BC4 gravity anomaly target of a single vertical rotary mud/diamond tailed hole to a total depth of 144.3 m (99 m precollared; 45.3 m HQ cored). The drill programme was in part funded by the State Government's PACE 2020 Discovery Drilling subsidy programme, as approved collaborative drilling project DPY7-26. 3D inversion modelling and forward modelling of the BC4 gravity anomaly, undertaken for Energia by Southern Geoscience Consultants, identified a discrete ~20 mGal positive feature striking 5 km N-S and 800 m wide, that lies oblique to the dominant trend of the basement geology. The gravity anomaly coincides with a distinct non-magnetic zone visible in the regional magnetic data. The source of the BC4 target was interpreted to be either a non-magnetic, dense igneous intrusion, or an alteration zone in the basement such as an extensive zone of haematite. The modelling indicated a depth to the top of the source of ~225–335 m. It was proposed to initially drill just one hole to test the BC4 anomaly, at a point where the gravity modelling indicated the shallowest depth to reach this target. The drillhole was designed to use a combination of rotary mud drilling through the cover sequence to a depth of ~250 m, followed by drilling a diamond cored tail (NQ2) to ~380 m depth. The actual top of the basement in hole BC4DD001 was reached at a much shallower depth than expected (92 m, versus ~250 m prognosed), and the subsequently drill cored Proterozoic mafic igneous rock (sheared gabbro/amphibolite with an average SG of 3.0-3.1) penetrated below the Cretaceous Cadna-owie Formation was thought to be responsible for the geophysical anomaly. The rotary mud precollar was taken to 99 m depth. The entire hole was lithologically, structurally and geotechnically logged. Two rock bulk density measurements were made on drill core recovered from 98.5 m and 144.2 m depth. Petrographic examinations performed on on two samples of drill core from around these depths identified the country rocks as a slightly altered ortho-amphibolite, and a biotite ortho-amphibolite. Energia also conducted magnetic susceptibility measurements on the drill core, and hand-held scintillometer readings were recorded from all samples that were submitted to the assay laboratory. No significant anomalous geochemistry was returned from drill sample analyses carried out via both hand-held XRF spectroscopic instrumental scans and laboratory wet assay methods. The maximum copper value returned was 765 ppm Cu from the depth interval 136-137 m; the maximum uranium assay result was 4.3 ppm U. Minor visual copper mineralisation (malachite/azurite) was noted from sandstone drill cuttings recovered from throughout the Cadna-owie Formation, but XRF scans of the cuttings revealed only trace to elevated copper and some other base metals content apparently associated with finely disseminated magnetite. No further drilling was recommended.