As part of a regional search for possible economic sodium carbonate (trona) evaporite mineralisation formed within buried Miocene lacustrine sediments in an area located east of Lake Torrens, ground magnetic and gravity surveys were run along four east-west traverses laid out across magnetic high anomalies near Mount Michael, and three drillholes totalling 371 m of penetration were completed to obtain stratigraphic information. Only the first hole was technically successful, being rotary mud drilled to TD 313 m and ending still within the Tertiary section, at a location 11 km west of Motpena Homestead. The other two RC drilled holes, which were put down in an area of sand dunes nearer the lake shore, were ended prematurely after both encountered a very hard silcrete/gypcrete duricrust band at about 30 m depth. No results of mineralogical analyses on the drill cuttings samples were reported during the tenure period, nor was the licensee's revision to its original Miocene depositional environment model explained, before the licence was allowed to expire without renewal.