An area centred about the Pidinga Lakes, 200 km north-west of Ceduna, was taken under licence to explore for economic Tertiary coal and lignite deposits because of several reported intersections of lignite made in drillholes by previous explorers. In this district too, following their discovery by the SA Department of Mines in 1948, subsurface alunite-bearing clays occurring in the vicinity of Lake Ifould are known to contain significant levels of potash, a vital ingredient for commercial fertiliser production. Southern Coal Holdings was interested in establishing the extent of this potentially economic industrial mineral occurrence, and hoped to outline an in situ alunitic clay resource of the order of 1 Mt. The company was also mindful that alunite is a prominent alteration mineral associated with high sulphidation epithermal gold deposits. To appraise the previously found lignite occurrences, the licensee conducted a thorough literature review, which revealed that 57 of 129 exploratory holes previously drilled on the tenement area had made only slight intercepts of lignite. The company concluded that the potential for finding any significant seams of lignite appeared to be limited. To implement its alunite search, Southern Coal Holdings proposed to conduct low impact vertical dual-tube aircore drilling on exposed dry lake beds, and planned to complete an initial 20 small diameter holes each to ~20 m depth on a 200 m x 200 m prospect grid set out around Lake Ifould basins B and C. However, despite obtaining all of the necessary prior access approvals from environmental management authorities, the company was unable to negotiate a satisfactory access agreement with the affected Native Title Claimant groups, and consequently the planned drilling programme was abandoned, and the exploration licence allowed to expire at the end of the second year of its term. As part of the preparations for drilling, senior company directors carried out a reconnaissance site visit to Pidinga and collected three surface white clay samples that were submitted for potash analysis. No significant potash was recorded.