Economic deposits of Mississippi Valley type stratabound lead-zinc mineralisation within in Cambrian limestones were the targets of exploration undertaken on and near the Wirrealpa Diapir. A preliminary field reconnaissance had shown that surface indications of such mineralisation extend almost continuously over a 40 km strike length of the Early Cambrian Wilkawillina Limestone in the area lying south of the east-west trending Narina Fault, with base metal - mineralised strata up to 2 m thick in places where the sulphides have replaced fossil clasts within mottled archaeocyathid limestone adjacent to local unconformities. A programme of regional and detailed geological mapping (at 1:10,000 scale), rock chip and stream sediment sampling (including analysis of 901 channel samples collected along 22 traverses over the karsted Cambrian outcrop surface adjacent to the Wirrealpa Diapir), plus reverse circulation drilling (7 holes totalling 496.5 m) and percussion/diamond drilling (22 holes totalling 5543 m), was successful in disclosing new sub-economic occurrences of lead and zinc sulphides at a number of localities, including the Donkey Bore prospect and the Wirrealpa mine. In addition, an occurrrence assaying 3.4% Pb+Zn was discovered in Neoproterozoic Wonoka Formation calcarenite that outcrops near Ti Tree Gorge.