From Ohio History Central
Sand and gravel deposits are abundant in Ohio and are primarily a result of deposition by running water during the Pleistocene Ice Age. The terms sand and gravel refer to size of the grains of the materials rather than their composition. The generally rounded grains are rock fragments of sedimentary, metamorphic, and igneous rocks. The latter two categories represent rocks transported by glaciers from Canada and deposited in Ohio as the ice melted. Large volumes of meltwater from the glaciers filled river valleys with sand and gravel in deposits known collectively as outwash. Some sand and gravel deposits formed in subglacial tunnels (eskers) or in holes in the ice or along the ice edge as conical hills (kames). These loose, unconsolidated materials are easily mined in open-pit surface mines.
Ohio ranks sixth nationally in sand and gravel production and produces 52 million tons annually, valued at $247 million. These deposits are mined in 64 Ohio counties, including deposits dredged from the bed of Lake Erie. Ohio is fortunate to have such widespread abundance of these commodities as transportation costs are greatly reduced if the deposits are close to their point of use. Most sand and gravel is used for construction in road-base material, as an aggregate in concrete and asphalt, glass making, and molding sand for casting iron and aluminum. Sand and gravel deposits are important aquifers for ground water.