Copper minerals are widespread within the Oraparinna and Enorama diapiric structures and along faults which radiate therefrom; some thirty copper prospects are known and barytes lodes, including the deposits being mined by S.A. Barytes Ltd., are common. A genetic association of copper and barytes is evident as there are generally traces of copper minerals in barytes veins within and marginal to the diapirs. The only useful copper producer has been the Appeallina Mine, operated during the periods 1859-1860 and 1896-1914 when rich ore was recovered from the zone of secondary enrichment above the 190ft level, where the lode comprised copper carbonates, chalcocite, native copper and chalcopyrite in association with iron oxides and calcite. Below this zone the ore occurs in narrow veins of chalcopyrite of unpayable grade. Production amounted to 1000 tons of 30% copper ore (Wade and Cochrane, 1954). Other named “mines” in the region which were operated at the turn of the Century include Appeallina Homeward Bound, Love’s, Mt. Emily and Green Hill while numerous shallow prospecting pits were sunk on showings of copper minerals that included malachite, chalcocite, bornite and chalcopyrite (Brown, 1908; Jones, 1908, 1909a, 1909b). The mode of occurrence of copper minerals is very varied as under – • Associated with veins rich in quartz, calcite, siderite or haematite (e.g. Appeallina, Mt. Emily Mines). • As disseminated primary sulphides, primary and secondary copper minerals infilling amygdules in melaphyre or as secondary sulphides and carbonates in fractures within melaphyre and diabase (e.g. Green Hill Mine). • As disseminations, veins along bedding or crosscutting veins within rafts of dolomite and dolomitic siltstone (analogous to the mine type dolomite of Blinman). • As carbonates in diapiric breccia. The possible association of copper mineralisation with basic intrusive rocks was suggested by Ulrich in 1872 (in Brown, 1908, p.88) who recognised dykes of diorite greenstone in the vicinity of the Mt. Emily Mine, by Howchin (1922) with regard to the Blinman mining field and more recently, by Wade and Cochrane (op.cit.) who observed that “north and west of Mount Caernarvon the axial plane has been much distributed by faulting and a major crush zone has been formed. Associated with this there has been magmatic intrusion and the widespread development of basic dykes. Similar conditions are found in the Blinman area and in both cases copper mineralisation is associated with basic intrusives”. The suggestion that the core of the Blinman and other similar domal structures in the region are of diapiric origin was made by Webb (1960). Subsequently, Coats (1964) demonstrated a close spatial relationship of copper, silver and lead minerals and gold with diapiric structures throughout the Northern Flinders Ranges. Special Mining Lease No. 86 was aquired by South Allligator Uranium N.L. on 1st August, 1965 to explore for copper over an area of 561 square miles that included the Blinman, Oraparinna, Enorama and Worumba diapirs. The area was reduced to 345 square miles on 4th August, 1966 when the Worumba area was surrendered and the lease was wholly relinquished on 1st March, 1967. Geological mapping was undertaken and a reconnaissance induced polarisation survey was conducted on widely spread lines across the structures but only “small and poorly mineralised copper occurrences” were located (McGain and Bettles, 1966, 1967; McGain, 1966). Arsarco (Australia) Pty. Ltd. Was granted Special Mining Lease No. 166 over an area of 650 square miles which included the Oraparinna and Enorama diapirs on 1st December, 1967. A stream sediment geochemical survey indicated widespread copper mineralisation and, in particular, located significant copper anomalies in the southern part of the Oraparinna diapir where surface geological mapping revealed a large area over which disseminated copper sulphides and carbonates occur within melaphyres. Detailed mapping and sampling were completed over four selected prospect areas in the southwestern extremity of that structure, shallow trenches were excavated and a programme of diamond and percussion drilling was undertaken before the lease was surrendered on 9th April, 1969 (Hosking, 1968; Allchurch, 1968, 1969). This report has been prepared to summarise the recent exploration activity which has been directed towards the search for useful concentrations of copper minerals in the basic igneous rocks of the Oraparinna and Enorama diapiric structures.