Otis M. Clarke

• Bauxite and kaolin in the Eufaula bauxite district, Alabama
• Clay and shale of northeastern Alabama
• Clay and shale of northwestern Alabama
• Clays of southeastern Alabama
• Clays of southwestern Alabama
• Mineral resources of Marengo County, Alabama
• Mineral resources of Wilcox County, Alabama
• Porters Creek lightweight aggregate
• Residual clays of the Piedmont province in Alabama