High base metal values, particularly for zinc, that resulted from the sampling of pits and costeans at Eukaby Hill, led North to a close examination of the unremarkable calcareous siltstone host rock to find the cause of suspected syngenetic mineralisation at the Baratta Mining Field. Extensive petrological studies were commissioned which revealed that the Pb-Zn ore occurs as a subtle replacement of previous carbonates, i.e. the mined deposit represents an enriched, oxidised capping to a possible buried primary sedimentary orebody. Deep drilling of the area was commenced, but failed to reveal any significant base metal values or signs of fine-grained stratiform sulphides. Pervasive quartz-calcite-siderite veining of the host sediments was encountered, which appears to be following the orientation of minor fold cleavage / bedding plane lineations pitching westwards down the axis of a regional syncline. Further drilling confirmed the existence of a linear pipe some 50 to 100 feet thick of disseminated vein and fracture-filling mineralisation internally averaging about 11% Pb, 10% Zn and 3.4 oz/ton Ag, which exhibits an unusual degree of continuity along strike, and conformity with the local fold limbs. However, consideration of the results of the percussion drilling (4 holes, total 649 feet) and diamond drilling (6 holes, total 4229 feet) indicates that the lode system does not have the potential of becoming an economic mining proposition. Other, concomitant work by North addressing the prospectivity of the mining field consisted of detailed geological mapping, rock chip geochemistry and face sampling of old workings, test biogeochemical and gravity surveys, structural analysis of observed outcrop deformation patterns, and the construction of a theory of ore occurrence which draws parallels to that envisaged on a larger scale for the Broken Hill orebody.