Old Lead Belt, Missouri, USAi

Regional Level Types
Old Lead Belt	Mining Sub-district
Missouri	State
USA	Country

Old Lead Belt, Southeast Missouri Lead District, Missouri, USA

Primarily located in St. Francois County, with minor production in Washington and Ste. Genevieve Counties encompassed mines in the vicinity of Desloge, Flat River, Leadwood (collectively now known as Park Hills), Bonne Terre, and Doe Run. The district produced more than 90 percent of the lead and zinc mined in southeastern Missouri before the advent of mining in the Viburnum Trend.

Between 1864 and 1972, the St. Joseph Lead Company (referred to as St. Joe in this text) operated numerous mines and mills in the Old Lead Belt. Lead and zinc were the primary commodities produced. During the first 70 years, as many as 14 other companies operated in the Old Lead Belt, including the American Smelting and Refining Company, St. Louis Smelting and Refining (later National Lead Company), and the Flat River Lead Company. By the mid-1930s, St. Joe had absorbed all of the competing operations; National Lead Company was the last company to be purchased.

Nearly all mining in the Old Lead Belt before 1869 was from scattered and shallow workings above the water table. Exploratory drilling led to the discovery of deeper ores, and underground mining soon commenced, resulting in a complex of underground mines 200 to 300 ft deep that were connected by more than 250 mi of underground railroad. Mining was active in Bonne Terre from 1864 to 1961, Doe Run from 1887 to 1914, Desloge from 1929 to 1958, and Leadwood from 1915 to 1962. The first St. Joe mine at Bonne Terre closed in 1961 after 97 years of continuous mining. The last mine to close was at Flat River and production ceased in 1972. St. Joe opened a lead smelter at Herculaneum in 1891; its smelting operations have been continuously based there since.

Galena was the principal ore mineral, although in the early days of mining, oxidized lead ores comprised of cerussite also were mined. Much of this ore was contained in residual material at the ground surface. Minor zinc (from sphalerite) and copper (from chalcopyrite) were recovered at the Federal Mill in Flat River. Total production figures for the Old Lead Belt are not readily available; however, more than 8.5 million tons of lead were estimated to have been produced.

Mineralization in the Old Lead Belt occurred throughout the Bonneterre Formation and extended 100 ft into the underlying Lamotte Sandstone. Ore generally followed depositional features and post-lithification faulting. Much of the mineralization was in reef and related carbonate facies; some also occurred in bar-reef complexes and where the Bonneterre Formation onlapped or pinched out against Precambrian knobs. Lead mineralization primarily is galena replacing the dolomite; however, ore also was present along bedding-plane contacts, in fracture zones, and occasionally as breccia cement. The orebodies spread laterally for hundreds of feet and vertically up to 200 ft.