Exploration and evaluation of two large, outcropping willemite zinc orebodies, previously discovered in the Puttapa area by other parties, has been commenced under tenure of Mineral Claim 5092 newly taken up by SML 153 licensee Electrolytic Zinc Co. of Australasia Ltd (E-Z). Initial work has comprised semi-detailed geological mapping of the main orebody at 1:480 scale, and its subsurface delineation by the drilling of 62 vertical diamond holes (total 14,161 feet) on a 100-foot spaced grid pattern, plus complementary percussion drilling (total 5374 feet) for shallow ore detection and bulk sampling. In the course of the early mapping, two other small areas of outcropping willemite were located to the north-east of the main orebody; these were tested by diamond holes PUT 1 and PUT 2 (274 feet) and 8 percussion holes (370 feet), but proved to be surficial, minor tabular bodies only, with no significant downward ore persistence below 10 feet of depth. During the progress of diamond drilling throughout 1968, E-Z made several successive announcements to the press concerning the growing quantum of calculated proven ore reserves: the final figure, quoted on 23/4/1969, stands at 856,100 tons grading 2.1% Pb and 36.3% Zn, plus 246,800 tons grading 11.4% Pb and 12.8% Zn. The reserve is based on orebody extent measured from level plans with a vertical separation of 20 feet, with grades calculated from a series of 50-foot cross-sections. A parcel of 10,000 tons of willemite ore has recently been mined and shipped to Risdon, Tasmania, where mineral processing and concentrate refining experimental work is being carried out at the E-Z treatment plant. A further 5,000 tons of ore has been mined and stockpiled at Beltana. A mineralogical study has been made by the Amdel Laboratories in Adelaide on the mineralised dolomite surrounding the above quantified Beltana orebody. Red dolomite is a constant associate of willemite occurrences in the Lower Cambrian limestone. This rock is a recrystallised carbonate in which the colour is induced by ochre. Any zinc present occurs essentially in solid solution, and probably substitutes for magnesium in the dolomite. Zinc silicate, as willemite, is not recognisable as discrete grains within the dolomite halo surrounding orebodies. Minor zinc arsenate crystals are intergrown with quartz crystals in the dolomite halo. Rare grains of hedyphane are apparent in petrological thin sections of the dolomite. Exploration work has also been advanced outside of the Mineral Claim boundaries, within several parts of SML 153. 26 of 28 percussion holes, totalling 4210 feet, were put down at two new surface rock chip geochemical anomaly prospects referred to as Moolooloo and Emu. Only minor mineralisation was encountered at Emu, but at Moolooloo an interesting zone of lead mineralisation, lately identified as mimetite, was intersected at depth. Rock chip and soil geochemical sampling has been undertaken east of MC 5350 on 100 foot x 500 foot grids to cover the Ajax Limestone outcrop and the Copper King ochre mine. Percussion drilling has been started on the latter site (Mining Lease 1948 held under option for one year by E-Z) to test for buried mineralisation to a depth of 250 feet. Locally detailed mapping is being done across the SML by consultant palaeontologist/stratigrapher Brian Daily, to record faunal variation within the limestones, and to gain new information on structure. From the broader E-Z geological and geochemical mapping done so far, good correlations are becoming evident between places having the red dolomite lithology, and areas of anomalous zinc content, or areas with structural features such as faulting and fold axes, etc. Geophysical prospecting methods have been tried out over the known deposits, without giving a great deal of encouragement. The magnetometer is ineffective. Induced polarisation obtains anomalies in those places where there is a concentration of manganese, but this often does not indicate ore. The gravity meter proved the most successful, and it seems likely that it would give results where there is sufficient thickness of high specific gravity ore.