51 holes were drilled to assess weathered shale and plastic clay reserves. Tertiary plastic clay and clayey sand overlie red firing weathered Adelaidean shale, and extends eastwards under Hancock Road into Clay and Mineral Sales pit (formerly Dreckows), the major source of white plastic clay. Both materials are suitable for brickmaking, but the presence of soluble salts requires the blending of other clays to reduce scumming. Reserves are 1 200 000 of plastic clay and 59 000 tonnes of shale + 100 000 and 330 000 tonnes if mining is allowed beneath Hancock Road.