Mineral Resources of Indiana: Road Materials

Rock used for road construction in Indiana is obtained from glacial deposits of sand and gravel, from deposits of residual gravels, and from quarries in the bedrock formations. The glacial deposits include several different rock types, chiefly quartzites and granites, with gneiss, limestone, schist, and basic igneous rocks present in smaller quantities. They occur in irregular and discontinuous deposits along streams, and in moraines, oskers, and outwash plains, in the glaciated portions of the state