Exploration for possible commercial accumulations of sedimentary shallow marine phosphorite ore in the Ediacara 'Sub-basin', 26 km west of Beltana, has consisted of a search within the Early Cambrian strata for any sites or layers of phosphate enrichment which might point to the existence of such accumulations. After reviewing past exploration work in the area, which has mainly targeted stratabound base metals, a number of stored previous exploratory drillhole cores were examined and sedimentologically logged, besides which 315 core samples were taken for phosphate analysis. Only trace to very low phosphate concentrations were detected, most of them occurring within siliceous dolomite breccias of the Ajax Limestone and in weathered shales and siltstones of the Parachilna Formation, the latter occurrences being clearly a product of supergene processes. The best grade found (2.33% P2O5 in Carpentaria DDH E7) is still far short of the minimum 15% P2O5 required for any mining to be feasible. As follow-up to this sampling, another 212 core samples were taken for phosphate analysis from other stored drillholes put down elsewhere in the Arrowie Basin, to test unweathered parts of the Andamooka Limestone, a more basinal equivalent of the Ajax Limestone. All these samples yielded still poorer results, below 0.90% P2O5, so all further work was terminated.