Sand and Gravel Resources
Kentucky has a finite amount of sand and gravel resources. The primary deposits are located along the Ohio River Valley, and major tributaries of the Ohio such as the Kentucky, Green, Licking, Tennessee, and Cumberland Rivers. Many streambeds in Kentucky have been exploited for gravel and sand deposits. Once the larger deposits are exhausted along the Ohio River Valley, resources for this commodity will become more difficult to obtain. Another constraint on these deposits is "sterilization": because urban development along river towns builds upon these natural resources, it prevents them from being used for construction purposes.
Kentucky produced 8 million tons (U.S. Geological Survey, 2013 ) of sand and gravel, and because sand and gravel are relatively low-value, high-bulk commodities, they must be located near the consuming market in order to keep transportation and construction costs economical. Sand and gravel make up about 15 percent of aggregate produced in Kentucky, and represent finite, nonrenewable resources essential for the construction and maintenance of structures, dams, and highways.
Northern Kentucky Region
Sediment-laden, glacial meltwaters flowing down the Ohio River Valley during late Pleistocene time deposited Kentucky's major source of high-quality sand and gravel. Terrace remnants along the valley containing these sediments are of agricultural, urban, and industrial interest because these sand and gravel deposits form an important regional aquifer and provide a convenient, economical source of construction material. Expansion of urban centers and construction of residential tracts, industrial parks, and power plants on the high terraces, however, have been removing potential high-quality aggregate from Kentucky's resource base. Competition for this limited land area, therefore, compels responsible agencies to formulate long-range plans for sequential, multiple land use that will permit the recovery of this valuable resource.
River dredges operate along the Ohio River and produce sand and gravel for construction and industrial use. These dredges also help maintain a navigable waterway along this important transportation route. These dredges produce a large percentage of sand and gravel for the state.
Jackson Purchase Region
Abundant sand and gravel deposits occur in the Purchase area and have been exploited for many years. The deposits are blanket Cretaceous outwash and are abundant. All of these deposits contain sand and gravel and have been mined in many areas.
The McNairy sand has been mined for common sand in Calloway County. The McNairy is a fluvial deltaic micaceous sandstone that locally contains a high percentage of a pure silica sand. The high percentage of muscovite in the McNairy could also mean an additional byproduct for mining operations. In some areas the McNairy is limonitic (hydrous ferric oxide) or hematitic (ferric oxide) sandstone containing small amounts of titanium minerals such as rutile and ilmenite.
Many of the sand and gravel deposits in Mississippian and Pennsylvanian rocks are weathered and of poor quality and have limited commercial use.
Many sandstone deposits have been mined and used for aggregate, road base, and anti-skid material, and some sandstones have been used in silica sands. Several quarries are in the eastern and western parts of the state. Many of these quarries operate intermittently, and many abandoned quarries may still have reserves left for future mining.
Silica sand deposits are sand or sandstone deposits that contain high-purity silica. Generally, these deposits have low amounts of iron or other deleterious materials and are suitable for plate glass, auto glass, dinnerware, and other glass-making industries. The McNairy sand in western Kentucky and sandstones in the Corbin and Lee Formations in eastern Kentucky have potential for silica sand. Silica sand deposits have been prospected in Marshall, McCracken, Carlisle, and Calloway Counties in western Kentucky and Johnson, Bell, and Pike Counties in eastern Kentucky.
Oil and Natural Gas Fracture (Frac) Sand
Although Kentucky has abundant sand, frac sand (used in the "fracking" process) requires special proppant characteristics such as roundness, sphericity, crush resistance, acid solubility, and mineability. Any potential sands that Kentucky might have would occur in the Pennsylvanian, Mississippian, and Cretaceous sands. Preliminary review of about 10 representative frac sand samples from Kentucky show that they are angular and not well rounded, contain impurities, and are indurated, so would not meet the American Petroleum Institute standards for proppants. Read more