Lower Proterozoic crystalline rocks of the Willyama Complex include phyllite, carbonaceous slate, mica-sillimanite schist and gneiss, feldspathic meta quartzite, quartzo feldspathic gneiss, calc-silicate rocks and iron formations. The oldest rocks in the succession are high grade metamorphic sillimanite-garnet gneisses in the Radium Hill - Mutooroo area, east of Olary. These rocks host the Broken Hill silver-lead-zinc deposits in NSW, and the Mutooroo area in SA is most prospective for this type of deposit. Copper mineralization and lead-zinc anomalism is common throughout the stratigraphically conformable Ethiudna Calc-silicate, which extends from Old Boolcoomata, through Ameroo Hill, Weekeroo, Mount Howden, Kalabity, and the Dome Rock mine. The Ettlewood Calc-silicate Member of the Allendale Metasediments (Broken Hill Group), is possibly the equivalent of the Ethiudna Calc-silicate in the Broken Hill area. Both units contain stratiform lead-zinc sulphides, and although no economic deposits have yet been discovered in the Olary Province, the Kalabity area has potential for Broken Hill style lead-zinc mineralization. Stratiform base metal mineralization, similar to Mount Isa and McArthur River sediment-hosted exhalative lead- zinc deposits, has been discovered in Early to Middle Proterozoic shallow water calc-pelites which unconformably overlie the Willyama Supergroup of the Benagerie Ridge. Further exploration, particularly adjacent to basement lineaments and faults, is warranted in this area.