West Mojave Plan FEIR/S - Desert Managers Group

potential areas are actually borrow deposits, suitable for fill, road repair work or subbase. Bynecessity, these must be located near roads and highways. Local sources of aggregate are criticalto lowering construction costs. The average cost of a ton of aggregate will double if it is hauled35 miles (Beeby et al., 1999).Common clays occur in the playas and Tertiary-age sedimentary rocks. Whether thesedeposits have potential for development depends on the proximity to markets and conflicts withother resources.The El Paso Mountains are particularly favorable for the occurrence of pumice andpumicite.3.4.3.2 Strategic and Critical MineralsStrategic and critical materials are materials that (1) would be needed to supply themilitary, industrial, and essential civilian needs of the United States during a national defenseemergency, and (2) are not found or produced in the United States in sufficient quantities to meetsuch needs (U.S. Bureau of Mines, 1983, p. 1). A strategic and Critical Materials Report to theCongress is submitted annually by the Department of Defense. The report details the operationsof the National Defense Stockpile (NDS) and includes tables of the subject metals, minerals andmaterials. Among the 33 items on Table 5 (Stockpile Goals and Inventory Status) aremanganese ore, tungsten ore, lead, silver and zinc, which occur in the planning area.Three zones in the Cady Mountains have high potential for the occurrence of manganeseresources, and several hundred tons of ore were produced during the first and second world wars(Wright et al., 1953, p. 114-117). Manganese is used for hardening steel and the United Stateshas an import reliance of 100 percent, with most coming from Gabon, Brazil, and Australia.Tungsten resources occur at Atolia and Searles Lake. As previously mentioned, up until1938, Atolia was the principal source of tungsten ore in the state. Tungsten is used in hightemperaturestructural materials and electrical elements, and the United States import reliance is68 percent, with most coming from China.Chapter 3 3-224