North Carolina's major industrial mineral districts

North Carolina’s major industrial mineral Jeffrey C. Reid North Carolina Geological Survey, 1612 Mail Service Center, Raleigh, NC 27699-1612 Author contact: jeff.reid@ncmail.net; 919.733.2423 -www.geology.enr.state.nc.us ABSTRACT Principal industrial mineral districts in North Carolina are shown along with illustrations of many operations. North Carolina produced $846 million in 2005 (not including ultrapure quartz and synthetic gemstones), the latest year for which reporting statistics are available. This is -5% of the state’s appropriated budget. The annual direct and indirect economic impact of mineral resource extraction is estimated at $11.3 billion. All mining is from 785 permitted active mines that cover 112,857 permitted acres, or only about 0.37 % of the state’s -48,000 square miles of land area. This is about $7,400 per permitted acre. Despite the state’s relative high population density recent mineral discoveries have been made by industry (heavy minerals and decorative flagstone) and collaborative work by the NC Geological Survey and NCSU’s mineral research laboratory (garnet, glass sand, lota-grade high purity quartz, quartz and feldspar). Spodumene is not currently mined nor are some dimension stone and glass sand deposits. Identified new resources are heavy minerals resources (rutile, ilmenite, zircon, leucoxene), glass sand, frac sand and abrasives (garnet). Speculative industrial resources include diamonds, uranium, and combined mixtures of sodium- and potassium-feldspar plus silica to make glass, and absorbent clay, and rare-earth elements contained in monazite. Unexploited mineral fuels include coal-bed methane in Triassic basins, and offshore oil and gas, and gas hydrates in federal waters. Current elevated gold prices may stimulate reevaluation of historic gold districts. North Carolina offers good ports for international commerce, inland ports, rail and road systems, international airport cargo hubs, and economic development zones. The ocean ports of Morehead and Wilmington may become hubs for ocean delivered aggregates from elsewhere on the US East Coast or even Canada. Several industries provide value added to industrial and metallic minerals including specialty steel production, fiberglass insulation, fiber optic production. Flagstone - rapid growth industry serving large urban areas in Georgia, Tennessee and western North Carolina and beyond. Crushed stone, is -2/3 of the state’s industrial mineral production, by monetary value ($548.2 million) and tonnage. Atypical Piedmont quarry shown here is in metavolcanic rocks. Piedmont and mountain quarries are in granitic and metamorphic rocks. Coastal crushed stone quarries are in limestone as shown below. Dimension stone (building stone) Left -Amoco Building (now Aon Center) in Chicago, IL, is faced with 670,000 square feet of Mt. Airy granite. The building is over 1 ,100 feet high). Right - Many monuments and public buildings are made of this white granite. Left and below - Sand operations are important in eastern NC. J7: ЛЕ! 4- щ. ШШ f _ #78M product North Carolina Granite Corp. has a major integrated mining, cutting and finishing and polishing operation. Many public building and public work projects use this white granite (technically a leucogranodiorite). Feldspar, quartz, mica ore from Spruce Pine (right); mining operations (left). Important Industrial-Mineral Mining Districts in North Carolina Cherryville granite - used for mica and kaolin (white brick) ¥ Feldspar, Mica, Kaolin, Silica, Olivine, Gem Stones MOUNTAINS Dimension Stone Heavy Clay Minerals Phosphate 1TVs . .v. "> v* t ■ •-"■"Г mS c %- m Г i. 4 High purity quartz, feldspar and mica from Spruce Pine, NC. Ore, high purity quartz products and flotation (immediate left). lota grade quartz - recently recognized in the central NC Piedmont by NCGS and NCMRL staff. COASTAL PLAIN Roofing granules - rock such as this intermediate volcanic rock from the Piedmont are used and sought for roofing granule materials and crushed stone. Granitic dimension stone color at other quarries in North Carolina range from white to pink (shown below). Large uncut blocks are shipped overseas for cutting, polishing and to clad buildings. i i ill CENTIMETRES Dimension Stone Gem Feldspar, Mica, Kaolin Lithium Coal Pyrophyllite 0 12.5 25 50 75 100 Miles Peat - compressed core from the Coastal Plain Refractory minerals (left) - pyrophyllite and andalusite are mined from volcanic hydrothermal centers in the Piedmont. High temperature refractory bricks are fired nearby from these materials. •* - Spodumene (lithium) ore BEAR creek' >OLDSTO AN SON VIC CENTIMETRES Dimension stone - argillite mined in the Piedmont is frequently used for flooring, window sills, countertops, etc. Argillite and brick are used for the NC Veteran’s memorial (right). Heavy minerals - (above) - Heavy mineral concentrates (ilmenite, rutile, zircon, leucoxene) may be mined from Piedmont Fall Zone deposits in the future. Diamond - 19/64th carat stone, Burke Co., NC Bricks - North Carolina leads the nation in brick production. Fired bricks are shipped to rapidly growing cities from Georgia to Virginia. A wide variety of sizes and colors of bricks are made. Automated (robot-driven) plants are increasingly the choice to meet product demand and production efficiency. i Emerald - (above and right) - 18.8 carat ‘Carolina Queen’ emerald. *1 • ГГ J LA-’'. Г- rvfrL'f |V-^' '• T: :h ask* a fa« 15 North American emerald mine pit and aerial view. Ports (above and right) - North Carolina’s ports (Wilmington and Morehead City) are major points of export and import of domestic and international trade and commerce. The state’s port authority has inland sites as well that facilitate international commerce. Good railroad and roads help transport raw materials and manufactured goods. : ЖрВЯЦЕаза * ** : е , Sijjp; -Г1**:’ Above - RDU International Airport in Raleigh / Durham and the Douglas International Airport in Charlotte are international cargo and passenger hubs. ШЯШШВВяВт^ "PJmi&'-i --у S- -s-=- ГЗ := JT 1 -LilY? :\it :r . kie£&£$ Garnet (abrasive) - (Below - large potential garnet reserves may be mined for abrasives in the future. These deposits are in western NC. Glass sand (frac sand) (above) - The Pinehurst Formation (yellow) has extensive reserves of glass sand that may also prove to be a frac sand. Moissanite (left) stones in broach. Gemstone production (natural and synthetic are increasingly important in North Carolina. Natural emerald is mined (upper Left and mine photographs. Thirteen natural diamonds (upper right) are known from the Piedmont but their source (lamproites?) has not been found. Moissanite (star setting above), a synthetic stone with characteristics that rival diamonds is produced and marketed in near Raleigh, NC. Phosphate - PCS Phosphate is a large integrated phosphate mining and chemical product plant. (Right) - shark tooth. For additional information: Jeffrey C. Reid, North Carolina Geological Survey 1612 Mail Service Center Raleigh, North Carolina 27699-1612 919.733.2423 - http://www.geology.enr.state.nc.us Email: jeff.reid@ncmail.net ГЧ.С. > '