TARGET: Potentially commercial gypsum, salt or silica occurrences in Holocene paralic lakes and marginal dunes, in an area immediately north-east of Coffin Bay. EXPLORATION: Bulk sampling of lacustrine evaporitic sediments and related aeolian deposits was undertaken by trenching and auger drilling, to obtain material for calcining and laboratory testing. Determinations were carried out on sample pH value, free moisture, colour, whiteness, purity and salt content, and particle size and crystal structure. The tests of material properties applicable to plasterboard manufacture included investigations on water/plaster ratio, setting time, compressive and flexural strength, paper bonding and efflorescence. RESULTS: A possible resource of gypsum / gypsarenite totalling 1,988,800 tonnes, with an average grade of 96.2% CaSO4.2H2O when using a cut-off of 80% gypsum, was defined by the exploratory drilling and sampling. The largest volume of gypsiferous sediments was shown to occur within eight Recent dunes, measured for size at up to 3 km long but otherwise less than 9 m high and 100 m wide, which border or protrude into the eastern part of Lake Malata and some adjacent smaller lakes. In addition, limited vibrocore drilling down to 4 m depth in very unconsolidated lake muds on Lake Greenly disclosed a layer of coarsely crystalline selenite, but such drilling for a similar target was unable to be carried out on Lake Malata owing to physical access difficulties. The shape of the aeolian gypsum crystals, plus the fact that there is clay bound up inside these crystals, renders the untreated raw material unsuitable for plaster manufacture. However, dune gypsum beneficiation in the form of desalinisation by water washing, followed by dewatering and fine grinding, generally yielded products suitable for plasterboard manufacture. Further exploration of the Lake Malata area is recommended to clarify sampling result uncertainties and to probe the bed of Lake Malata for additional selenite deposits. A mining feasibility / cost study should then be performed.