As part of the evaluation of a known occurrence of possibly pegmatite-related, kaolinised Cambrian talcose sandstone in the Mount Crawford area, located about 35 miles north-east of Adelaide, 74 scout auger drillholes were sunk, 25 separated clay samples were analysed, and cursory field geological mapping was done as preliminaries to determining the worth of the kaolin component for supplying the local and overseas paper-coating and ceramic industries. In subsequent data collection made to support a technical feasibility study, bulk sampling via backhoe (13 trenches) and bulldozer (4 trenches) costeaning was performed, plus deeper drilling on a 250 m spaced grid pattern over about 1 square mile (42 percussion drillholes totalling 2671 feet of continuous core drilling) that identified a white clay matrix of sufficient purity for materials testing as being present in 8 of the holes, although the clay quality variability is clearly very high both laterally and vertically within the deposit. A possible hydrothermal origin for the kaolin was discounted in favour of it being the result of prolonged Tertiary weathering processes acting on talcose and albite feldspar-rich metamorphosed arkosic rocks, leading to the formation firstly of montmorillonite and later, by variably intense near-surface oxidation and soil acidic conversion, the kaolinite clay. After an overseas clay mining and processing specialist firm conducted laboratory tests on 40 of the cored clay samples, only those obtained from one hole, AGP2, showed paper-coating properties considered to be adequate for clay extraction to be feasible, but exploiting this isolated, probable 189,350 ton occurrence alone was deemed as insufficient for commercial development of the deposit, where it is estimated that at least 10 million tons of high grade kaolin material would be required to support a viable production operation.