Rock and Mineral Resources of East Texas

This report treats the rock and mineral resources of a 33,000- square-mile-area of eastern and northeastern Texas, including the following 42 counties: Anderson, Angelina. Bowie, Camp, Cass, Cherokee, Delta, Franklin, Freestone, Gregg. Harrison, Henderson, Hopkins, Houston, Jasper, Lamar, Leon, Limestone, Madison, Marion, Montgomery, Morris, Nacogdoches, Newton, Panola, Polk. Rains, Red River, Robertson, Rusk, Sabine, San Augustine. San Jacinto, Shelby, Smith, Titus, Trinity, Tyler. Upshur, Van Zandt, Walker, and Wood. Mineral industries: contribute significantly to the economy of East Texas. Oil and gas are the chief mineral industries, though industries based on processing such materials as ceramic clay, nonceramic clay, iron ore, and salt, are also well developed in relation to markets available. Although much of East Texas is rural and nonindustrial, large industrial centers and a population of about 4 million occur within the general market area of the region. Abundance and variety of mineral raw materials, technological advances in processing and marketing mineral raw materials, and continually increasing and urbanized population within existing market areas provide the economic framework for a more extensive and broad- balled development of East Texas mineral industries and mineral resources. Expansion of certain existing mineral industries and development of new mineral industrial are possible. However, advantages of resources and markets as a base for development can be realized only through accurate appraisal of the mineral resources of the area and through detailed evaluation of existing and potential markets for mineral raw materials and products. Principal rock and mineral resources of the area include mineral fuels (oil, natural gas, lignite, and natural asphalt), metallic minerals: (iron and aluminum ores), and industrial rock and minerals (ceramic and nonceramic clay, sand and gravel, industrial sand, salt, limestone, chalk, sandstone, peat, heavy minerals, volcanic ash, and glauconite. Total value of minerals produced during 1963 in this region of the State amounted to about $490 million, or about 11 percent of the total State mineral production. Value of minerals produced exceeds the value of manufactured products, and though the majority of the population in the area is rural, value of mineral products is 2.5 times the total agricultural income. Iron ore is the principal metallic ore of East Texas, with reserves of mineable ore estimated at 200 million tons. These ores are used as raw materials for steel making, as mineral fillers and additives, and as portland cement additives. The large market for iron and steel products in Texas and the favorable location of deposits near large oil and gas fields assure future interest in East Texas iron ores. Due to the relatively low grade of these ores and the lack of suitable coking coal in the area, future plants will probably utilize direct reduction methods rather than blast-furnace smelting now employed. Additional reserves of metallic ores in East Texas include aluminum in the form of high-alumina clays, heavy minerals (Ilmenite and zircon) occurring as fractions in quartz sands, and trace metals concentrated in lignites. Lignite or low-rank coal deposits occur in 30 East Texas counties with recoverable reserves estimated at approximately 3 billion tons. Lignite mined for use as industrial and domestic fuel supported a widespread mineral industry in East Texas prior to general availability of natural gas. Currently, in local areas or under special circumstances, lignite can compete with natural gas as a large-volume source of fuel, though its potential as a solid fuel is dependent upon the availability and cost of natural gas. Lignite is utilized in East Texas as a raw material for the manufacture of activated carbon and has other potential nonfuel uses, such as filling and stabilizing agents. Extensive deposits of clay in East Texas support well-developed ceramic and nonceramic clay industries. Approximately 50 percent of the State's total production of ceramic clay, used chiefly in the manufacture of structural clay products, and a like percent of the State’s total production of nonceramic clay, used as drilling muds, oil-decolorizing agents, and mineral fillers, are produced and processed in the area. Principal types include light-firing structural clays, ball clays, refractory clays, kaolin, bentonite, fullers earth, and miscellaneous clays. Reserves are sufficiently large for indefinite expansion and development of the clay industries. The existing industry is dominated by a few large producers, with the general trend toward the expansion of these concerns. Future development of the East Texas clay industry will be based on expansion of existing plants, on development of new uses of clay materials, and the commercial development, through technology, of specialty clays requiring special processing or beneficiation. Salt occurs in 13 shallow domes in East Texas with reserves (limited to shallow salt within 2 miles of ground surface) estimated at approximately 75 cubic miles. Production of salt in Texas varies from 4 -to 5 million tons per year and is geared closely to demand by the heavy chemical industry. Salt produced in East Texas is marketed mostly as rock salt and evaporated salt. Deposits of silica sand suitable for a variety of specialty uses are extensive in East Texas. Currently, about 35,000 tons of specialty sand are processed and marketed annually in East Texas as blast sand, foundry sand, filter sand, hydraulic fracturing sand, engine sand, and pulverized sand. These sands must be upgraded for use in the glass and chemical industries. The sizeable market for low-iron, high-silica sands will in cases justify beneficiation costs, though producers must compete with silica sand produced in north-central Texas and southern Oklahoma. Deposits of natural materials suitable for use as constructional crushed or processed stone are limited in East Texas. Production in the area amounts to less than 5 percent of the State's total and provides less than half the local consumption; accordingly, construction materials must be shipped in from other parts of the State. Constructional sand and gravel deposits are mainly confined to higher terraces along major streams in East Texas and are mined and processed significantly in only four counties. Local deposits of limestone, deposits of indurated sandstone above certain salt domes, and local deposits of quartzitic sandstone in southeastern Texas are intermittent sources of crushed stone. Residual ironstone pebbles widespread in East Texas; individual deposits generally are small, and the more readily accessible ones are being depleted rapidly. Clays that can be processed as lightweight or standard weight aggregates are extensive in East Texas; manufactured aggregates are not now produced in the area, though the demand for aggregate and the scarcity of natural materials will probably lead to a manufactured aggregate industry in the near future. Abundant sources of the principal raw materials needed for the manufacture of portland cement occur in northeastern Texas; however, the lack of' a 1arge and populous local market and strong competition from existing cement plants in adjacent areas probably preclude development of a local cement industry. Limestone and chalk of the area generally are not sufficiently pure for burning to a high-quality lime, for use as a chemical raw material, or for use as flux stone. Both can be used as agricultural limestone, though the availability of aglime as a low-cost by-product from existing limestone crushing plants would supplant any local advantage of northeastern Texas deposits. Glauconite, a complex hydrous iron silicate, occurs throughout wide areas of central East Texas. Utilization as a soil-conditioning agent, as a source of potash, and as a water-softening agent is limited by low content of potassium and the availability of other more suitable raw materials and manufactured products for these uses. The most significant potential of glauconite is as a low grade iron ore; average content of iron (expressed as an oxide) is about 25 percent. Special smelting processes would be necessary however, recover iron from the silicate in which it occurs. Deposits of peat occur in bogs and marshes of poorly drained areas of East Texas. Peat has been produced in Texas in recent years but is not produced at the present time. Annual consumption of peat in Texas is approximately 10,000 tons, sufficiently large to support a local industry provided a uniform and acceptable product is processed. Heavy minerals in East Texas sand deposits are potential sources of titanium and zircon minerals. Concentrations are too low to warrant commercial extraction, though heavy minerals possibly could be recovered as a by-product in the processing of other rock materials. Phosphorite (phosphorous oxide 20 to 25 percent) occurs as thin lenses in chalk and day deposits of northeastern Texas. These generally are suitable for direct soil application, a few meet specifications for furnace-grade rock, but none tested are of acid grade. Significant development is limited by low grade and occurrence in a matrix of hard rock, but chiefly by the availability of rock phosphate from extensive deposits worked in Florida and Tennessee. Deposits of volcanic ash, common in south-eastern Texas, are potential sources of large volume low-cost construction materials, including use as a cement additive or pozzolan, as a partial substitute for portland cement, and as an additive or partial substitute for lime used in soil and base stabilization. Processing for such specialty uses as abrasives, ceramic glazes, and mineral fillers possibly could be economical as an adjunct to large-volume production as construction materials. Natural asphalt and related bituminous materials are found locally as surface and near-surface deposits in East Texas. Use as a paving material is limited by general availability of manufactured asphalt from petroleum. East Texas asphaltic sands are a current source of crude petroleum.
William L. Fisher

Fisher, W. L., and others, 1965, Rock and Mineral Resources of East Texas: The University of Texas at Austin, Bureau of Economic Geology, Report of Investigations No. 54, 439 p.

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The University of Texas at Austin, Bureau of Economic Geology
Report of Investigation