Reconnaissance sampling and exploratory drrilling have been undertaken to locate suitable brickmaking clay for the proposed city of Monarto. Samples from exposures and boreholes in Quaternary and Tertiary sediments and in weathered bedrock have been test-fired. Altered phyllite near Callington was found to be the most suitable of the brickmaking material examined. Finniss Clay from Ponde, Blanchetown Clay from Mypolonga and clay from the Ettrick Formation at Hartley are potentially suitable as plastic components in brick clay blends. Large reserves of dark organic plastic clay are available in the Coonambidgal Formation at Reedy Creek, but can be used only sparingly in blends. Weathered material from the Kanmantoo Group reduces shrinkages in clay mixtures. Blending with locally available materials was ineffective in overcoming the friability which was characteristic of the majority of fired specimens of Pooraka Formation and Blanchetown Clay.