Major source of construction materials for metropolitan Adelaide, currently supplies 25% of natural construction sand, 60% of white plastic clay and 45% of brick shale. 2 brick works produce 63 million bricks annually. Total reserves of 85 million tonnes of construction sand, 11 million tonnes of white plastic clay, and 25 million tonnes of brick shale are indicated, based on drilling by SADM in 1976 and 1977. Existing land use, zoning, and operating limitations reduce available reserves to 22 million tonnes of sand and 5 million tonnes of white plastic clay. Most of the brick shale is available for extraction. Extensive rezoning is necessary to maximize yield and ensure efficient resource management and effective rehabilitation.