In order to further test a large Delamerian granite pluton for its potential to host an economic porphyry molybdenum deposit of the Climax, Colorado type (following initial exploratory drilling and IP surveys that had been carried out by the SA Department of Mines during the period 1971-1977), a 796.0 m deep, near vertical NQ/BQ diamond cored drillhole was put down in the Anabama Hill area by EL 753 licensee CSR Ltd during May-June 1981. The Government-managed previous diamond drilling of IP anomalies had located shallow, low grade molybdenite mineralisation, and the new company drillhole was designed to probe a zone of greisen and K-feldspar alteration, showing a combined Mo and Cu surface anomaly, to look for a possible high grade base metal source at depth. Below a 22 m thick saprolite zone, and a further 63.1 m thick interval of saprock, hole DDH AN7 passed through a sequence of hydrothermally altered acid and intermediate igneous intrusive rocks (granodiorite and porphyritic microdiorite). Sparse veining with traces of chalcopyrite and molybdenite was intersected in classical porphyry copper - style alteration zones, but the target high grade orebody was not located. Best geochemical results obtained from assaying of samples of split drill core were 24 m @ 0.06% Mo below 281 m depth, 27 m @ 0.19% Cu from below 548 m depth, and 29 m @ 3 g/t Ag below 764 m depth. Gold concentrations were uniformly below the analytical detection limit of 0.05 ppm. The hole was terminated within Ordovician adamellite, after having drilled through 625.15 m of granodiorite cut by numerous dykes of porphyritic microdiorite. Rock unit contact relationships observed in the drill core suggested to CSR that the underlying adamellite is the youngest intrusive phase.