SALT MINING STUDY: Field tests on the feasibility of Lake Torrens salt production to supply raw material for the planned Redcliff Petrochemical Project were continued, with project planning technical data demonstrations given to visiting officials of the Dow Chemical Co., Union Carbide Corp., B.F. Goodrich and Co., and State and Commonwealth Governments, on the progress so far achieved. Following the setting-up of a pilot plant maintenance camp and meteorological station, a series of lake brine concentrator and crystallizer ponds were constructed on Lake Torrens in April-May 1979 to trial the feasibility of producing high-quality salt there. Subsequent salt crystallization batch testing under normal field conditions has indicated that a salt product of purity in the range 99.5-99.9% NaCl may be feasible, provided that contamination from clay and gypsum can be minimised. Data recorded from two identical "Class A" evaporating pans, one filled with Lake Torrens brine taken from sampling trench #11, and one filled with freshwater obtained from the Yadlamalka stock watering pipeline, indicate that dense brine will evaporate onsite at a rate of 67% of that of fresh water. Pump tests of a brine pipeline test facility were also begun in November 1979, using both bare and cement-lined black steel pipes, through which brine will then be pumped for a month, after which the pipes will be cut open and examined for abrasion and for gypsum buildup. BASE METAL EXPLORATION: Late in 1977 a search of the licence area began, under a joint venture with Aquitaine Australia Minerals, for possible Olympic Dam - type mineralisation which might have formed in buried Middle Proterozoic bedrock lying adjacent to the Torrens Hinge Zone. Work included a detailed interpretation of existing aeromagnetic data using the Compudepth method, and also a regional gravity data interpretation; then there took place the deepening to 600.0 m, by diamond drilling, of the earlier Delhi percussion hole BDH4, plus additional deep stratigraphic rotary / diamond drilling (4 more holes totalling 2520 m), and lastly, the acquisition and interpretation of a detailed ground gravity survey near Wilga Point, and of an experimental high resolution reflection seismic survey near Beda Hill. Only one of the latest drillholes, DDH SLT103, penetrated the pre-Adelaidean basement (non-magnetic Gawler Range Volcanics) at 614 m depth. A locally thick and complete Adelaidean stratigraphic section, thickening to the east, is indicated by the geophysical and drilling results. Apart from minor chalcopyrite found in the Backy Point Beds, and traces of ?bornite within the Woocalla Dolomite, no significant metallic mineralisation has yet been encountered during this search.