Under a joint venture agreement made between North Flinders Mines and Dampier Mining Co. (a BHP Exploration subsidiary), operative over the 7 square mile SML 705 between 14/9/1973 and 14/3/1974, at least 3500 feet of additional appraisal diamond drilling funded by Dampier was required on previously identified copper orebodies. By April of 1974 that company had drilled 5 percussion/diamond holes for a total of 5042 feet, had then sampled and assayed the drill core, had re-interpreted the subsurface geology from all the Parabarana deposit drill cores, and had prepared a 1:6000 scale, structurally oriented, detailed surface geological map of the area between Gunsight and Parabarana. The drilling results were disappointing, with the best intersection being from 1753-1775 feet in PDD14, which averaged 0.8% Cu, within a wider interval of mineralisation down to 1795 feet which averaged 0.49% Cu. Dampier have concluded that, consistent with their model of the probable genesis of copper mineralisation and their drilling results at the Parabarana prospect, they consider it unlikely that readily defineable drilling targets exist which could be expected to indicate a large tonnage of high grade copper ore. They also feel that sufficient drilling has been carried out in the immediate vicinity of the Copper Hill mineralized zone to suggest that there is little likelihood of increasing the ore reserves, considering the amount of drilling between 800E and 2000W and the patchy distribution of mineralization along the main Paralana Fault shear zone.