In order to appraise a potentially economic discovery of very pure, high reflectivity kaolin clay located near Kapinnie on southern Eyre Peninsula, a drilling programme is planned by Endeavour Oil which aims to outline around 33 million tons of kaolin that may be present in the pallid zone of a Tertiary lateritic deep weathering profile developed over Precambrian granitic to gneissic basement. As part of a separate joint venture exploration effort continuing to target sedimentary uranium mineralisation, licence farminee Le Nickel sought to define the position of prospective buried palaeochannels using seismic methods. After conducting a field trial of shallow penetration, hammer - sourced seismic reflection and refraction methods, a total of 77.9 line km of reflection profiles were acquired during August-September 1972 along five east-west seismic traverses spaced about 6.5 to 8 km apart. This work was successful in mapping the buried top of basement, and revealed the structure and geometry of at least four channel features. Concurrently, dynamite-shot seismic refraction spreads totalling 14.25 line km were recorded at about 2 km intervals on average along the seismic traverses, to obtain data for estimating the velocity of the Cainozoic sediments : these data were later supplemented by log readings obtained from downhole well velocity surveys conducted in twelve purpose-drilled upholes. During 1971 Endeavour Oil had found gamma log radioactivity anomalies of >10x background in 11 of the uranium exploration holes that it had drilled on SML 483, with the highest log readings being recorded in holes Kapi 8, 10 and 11. Coring of the radiometrically anomalous zone in five of these drillholes had yielded assay values peaking at 110 ppm U3O8 in hole 8, from sidewall core samples of a kaolinitic quartz-mica sand. The causative uranium mineral, occurring in close association with pyrite, was tentatively identified as autunite or meta-autunite. To follow up this discovery and further appraise the local palaeochannel system as delineated by its seismic work, Le Nickel drilled 24 open rotary holes during September 1972 along five east-west traverses sited in between the seismic profile lines, for a total penetration of 1520 m, plus 6.1 m of sidewall core sampling in hole Kapi 26a (conventional triple tube coring was attempted here first, but satisfactory core recovery proved impossible from the water-saturated, coarse grained sediments). Within the target Tertiary sedimentary sequence 8 of the company's drillholes intersected at least one horizon exhibiting radioactivity >10x local background, with gamma log readings commonly above 400 counts per second : the highest drill core assay result corresponding to a peak gamma log reading of 990/40 cps was 153 ppm U3O8 found in the upper part of a palaeochannel fill penetrated by drillhole 26a, which is believed to subcrop over a restricted area in the south of the licence near Lake Baird, between Le Nickel's Drilling Traverse 1 and Seismic Profile A. The sand section of this palaeochannel fill appears to be divided into three units, each representing a different period of deposition, although there is some interfingering of Units I and II. An environment favourable to the trapping and concentration of mobile uranium is thought to have developed within unit III and the top of Unit II. The majority of gamma log highs seen elsewhere in the sediment sequence are thought to be due to thorium or potassium, the latter reflecting the presence of highly kaolinitic sands up to 10 m thick which produce radioactivity averaging 300 to 350 cps. Le Nickel made a detailed study of the various kinds of downhole radiometric anomalies recorded, with regard to the local host sedimentology, structuring and possible sources of uranium, and concluded that of the three main mapped palaeochannels which probably converge south of Cummins, none are preserved in a basin large enough to meet the company's exploration requirement, viz. one large enough to hold a minimum of 15,000 short tons of U3O8 in one or several lenses of sandstone-hosted, Colorado Plateau and/or Wyoming type uranium mineralisation.