An area of 7 square miles surrounding the historic shallowly worked Parabarana copper deposit in the far north-eastern Flinders Ranges, which outcrops at Copper Hill as vein-type disseminated secondary ore over a width of around 1200 feet, was retained by North Flinders Mines to allow reconnaissance drill testing of the full extent of the orebody to assess its primary ore potential. An initial campaign of 32 angled or vertical rotary percussion drillholes totalling 10,360 feet of penetration performed during February-May 1970 was designed to test certain recently identified soil geochemical and IP anomalies overlying an east-west aligned zone of intense granitic bedrock chloritisation and sericitisation that is related to overthrust faulting, which was inferred to extend laterally far beyond visible surface limits. This old structural break in part forms the boundary between the Carpentarian Terrapinna Granite in the north and the similar age Mount Neill Granite Porphyry in the south. The drilling found a roughly 40 feet thick mineralised body of brecciated microadamellite which dips northwards at 45-65 degrees, containing mainly disseminated secondary copper minerals which average in grade between 0.6 to < 1.0% Cu. The host unit extends irregularly in the subsurface over a length of about 6000 feet, being truncated and displaced at intervals by cross-shears. A follow-up programme of vertical and inclined diamond drilling was conducted over the period September 1970 to January 1971 to try to intersect possible higher grade downdip projections of the mineralised zone, targeting vertical depths of 1000 feet below the ground surface. Four incomplete NQ/BQ cored holes totalling 3880 feet were attempted, in three instances using 1235 feet of additional percussion drilled precollars (holes NFP 33, 34 and 35) : however, this diamond drilling was aborted without properly testing the target, due to repeated problems of hole blockage caused by numerous thin swelling clay interbeds which were reactive to the water-based drilling fluids, jamming the rods and core barrel in the uncased hole section. A consultant drilling engineer was engaged to study the situation and to propose a solution: this he did, but the recommended alternative drilling practice would be far costlier to implement if the existing diamond drillholes were re-entered.