Roxby Downs - type base metal deposits, potentially associated with linear and discrete magnetic anomalies of unknown origin in the basement, were the prime targets of exploration in an area extending between Koonalda and Hughes, adjacent to the SA/WA State border. Ground magnetic and gravity surveys, for basement anomaly source depth estimation, were undertaken prior to percussion pre-collaring and later diamond drilling of selected geophysical or stratigraphic unit targets (7 holes, total 1303 m, including 407 m of coring). Drilling of coincident magnetic and gravity anomalies by hole CD1 penetrated a sequence of interbedded basaltic lava flows at 300 m depth, but these had insignificant base metal contents on spectrochemical analysis, although traces of native copper and chalcopyrite mineralisation were seen in amygdaloidal cavities during detailed petrographic and mineragraphic inspections of basalt core sample thin sections. Six of the holes were drilled to test for possible oil shales within the Lower Cretaceous Madura Formation, but the oil yields upon core sample analysis were too low to be of interest.