How do geologists find mineral deposits, and what happens after the mines close? What is a critical metal, and where are the deepest mines on earth? Find out how we mine and process minerals above and below ground in our mining fact sheet.
The minerals industry appreciates that whereas it mines and processes minerals to maintain and advance our standard of living, it must do so in a manner that protects the Earth and its environs so that the generations to come are not adversely impacted and can enjoy its bounties.
The Southeast Missouri Barite District and the Valles Mines are located in Washington, Jefferson, and St. Francois Counties, Missouri, where barite and lead ore are present together in surficial and near-surface deposits. Lead mining in the area began in the early 1700’s and extended into the early 1900’s. Hand mining of lead in the residuum resulted in widespread pits (also called shafts or diggings), and there was some underground mining of lead in bedrock. By the 1860’s barite was recovered from the residuum by hand mining, also resulting in widespread diggings, but generally not underground mines in bedrock. Mechanized open-pit mining of the residuum for barite began in the 1920’s. Barite production slowed by the 1980’s, and there has not been any barite mining since 1998. Mechanized barite mining resulted in large mined areas and tailings ponds containing waste from barite mills.
The U.S. Environmental Protection Agency (EPA) has determined that lead is present in surface soils in Washington and Jefferson Counties at concentrations exceeding health-based screening levels. Also, elevated concentrations of barium, arsenic, and cadmium have been identified in surface soils, and lead concentrations exceeding the Federal drinking-water standard of 15 micrograms per liter have been identified in private drinking-water wells. Potential sources of these contaminants are wastes associated with barite mining, wastes associated with lead mining, or unmined natural deposits of barium, lead, and other metals. As a first step in helping EPA determine the source of soil and groundwater contamination, the U.S. Geological Survey (USGS), in cooperation with the EPA, investigated the geology and mining history of the Southeast Missouri Barite District and the Valles Mines.
The West Virginia Geological and Economic Survey provides an interactive map of underground and surface coal mining activity in West Virginia. The map shows areas of active and historical coal mining in both underground and surface mines, with separate colors for auger and highwall mining.
The Utah Geological Survey has produced an interactive map showing the locations of more than 450 abandoned coal mines in Utah. For over half of these, detailed maps of the individual mines are available for download and further use.