Limestone and Dolomite Resources, Lower Cretaceous Rocks, Texas

Limestone is one of the most important nonfuel mineral resources in Texas. Annual production exceeds $30 million; value added in the manufacture of such products as cement and lime amounts to about $100 million annually. Lower Cretaceous limestone is the source of more than 40 percent of the State's total production of limestone and is utilized chiefly as crushed stone (aggregate and constructional stone), sources of raw materials for lime and portland cement, chemical and industrial process stone, agricultural limestone, fluxstone, and dimension stone. Lower Cretaceous dolomite is deadbumed to refractory dolomite. Study of Lower Cretaceous limestone and dolomites (including Edwards, Comanche Peak, Goodland, Glen Rose, Devils River, and Salmon Peak Formations) from approximately 250 localities in 49 Texas counties in North Texas, Central Texas,Callahan Divide, Edwards Plateau, southeastern Balcones Escarpment, southern High Plains, and Trans-Pecos Texas, and of chemical analyses of approximately 1,000 samples delineates the occurrence, distribution, quality, reserves , and availability of these rocks as industrial raw materials. Best stone in terms of physical and chemical quality occurs in the Edwards, Devils River, and Salmon Peak Formations; the only significant deposits ofLower Cretaceous dolomite are in the Edwards Formation. Other Lower Cretaceous limestones generally are too soft for use as a quality aggregate and insufficiently pure for use as chemical grade stone. Argillaceous limestone of the Goodland and Comanche Peak Formations is suitable raw material for portland cement. Total tonnage of Lower Cretaceous limestone (Edwards and associated formations) in outcrop in Texas amounts to approximately 8 trillion tons, about 40 percent of which contains 97 percent or more calcium carbonate (high-calcium limestone). Total tonnage of Lower Cretaceous dolomite (Edwards and associated formations) in outcrop amounts to about 450 billion tons, of which about 30 percent contains at least 16 percent magnesium oxide (high-magnesium dolomite). Of the total tonnage of 8.4 trillion tons of limestone and dolomite, approximately 6 percent, or 500 billion tons, is within competitive hauling distance of existing markets. Current annual consumption of limestone in Texas amounts to about 30 million tons