Geology topics
Research about Arkansas
Source-linked reports with geographic coverage including Arkansas.
Minor elements in Arkansas bauxite
A study of the minor elements in Arkansas bauxite has revealed some striking relationships between their concentration in the parent nepheline syenite rocks as compared with their concentration in the bauxite . The ratios of concentration, in general, follow a pattern predicted by Gold-schmidt (3),2 based upon the ionic radius and ionic charge of each element present. In the Arkansas deposits, Mg, Ca, Ba, La, and Sr were depleted during the change from nepheline syenite to bauxite . The average concentration of Pb remained the same in the samples tested. Y, Mn, Be, V, Sc, Ti, and Zr were concentrated, but not as much as Al; while Mo, Nb (Cb), Ga, Cu, and Cr were concentrated more than Al.' Niobium (columbium) apparently is found in sufficient quantities to warrant search for methods to extract it commercially as a by-product of alumina plants.
Preliminary total-intensity aeromagnetic maps of three Arkansas quadrangles-Bald Knob, Pleasant Plains, and Cave City
No abstract available.
Ground water for industrial use in the vicinity of Little Rock, Arkansas
Several inquiries about the availability of ground water and its quality for industrial use in the vicinity of Little Rock, Ark. have led to the assembling of the following information from the files of the United States Geological Survey in Little Rock and Fayetteville. There are large undeveloped reserves of ground water in the vicinity of Little Rock that can be made available through large-capacity wells. However, the water probably would require treatment for most industrial uses. Ground water is used in Little Rock and vicinity at an estimated rate of about 10 million gallons per day. The most productive water-bearing material consists of alluvial deposits along the Arkansas River and in a large area extending northeast, east, and southeast of the city. Records of 41 selected wells and chemical analyses of water from 28 wells tapping these deposits are given below. The areas in which the productive deposits occur and the location of the wells are shown on the map.
Chemical composition of Arkansas surface waters, 1949
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Total intensity aeromagnetic map of the Magnet Cove area, Hot Spring County, Arkansas
No abstract available.
Relations of bauxite and Kaolin in the Arkansas bauxite deposits
Investigation of the Arkansas bauxite deposits by the U. S. Geological Survey during the years 1942 to 1945 has brought out the fact that secondary kaolinization or silication of the bauxite is much more common than has been generally recognized. On the other hand no direct evidence was found of the development of bauxite from kaolin. These facts have led us to reconsider the genetic relations of bauxite and kaolin. We do not mean to deny that there has been direct kaolinization of the nepheline syenite; but in view of the above observations and of the character of the kaolin derived from bauxite, we believe that the relations of bauxite and kaolin in the Arkansas deposits are more readily explained on the assumption that the bauxite is derived directly from the nepheline syenite, rather than from kaolinized nepheline syenite. The silica causing its subsequent kaolinization may be derived from overlying sediments or from remnants of unbauxitized nepheline syenite within or adjacent to it .Our conclusions about the relations of the kaolinized and bauxitized nepheline syenite are based entirely on rock weathered in place.
The quartz crystal deposits of western Arkansas
Extensive geological investigations of domestic deposits of quartz crystals were undertaken by the Geological Survey of the United States Department of the Interior in the fall of 1942 in response to the urgent demand for crystals for war purposes. The work was continued throughout 1943 and took survey geologists into some 20 states in which over 1,400 deposits or reports of deposits were examined. Of the numerous highly varied occurrences of quartz examined, only the deposits in western Arkansas, in the Piedmont and Blue Ridge provinces of Virginia, North Carolina and Georgia and the placer quartz of Mokelumne Hill, California, were of sufficient promise to warrant detailed work. Production in 1943 from these areas totaled slightly less than 4 tons of oscillator quartz, over 85 per cent of which came from Arkansas.The Arkansas deposits occur throughout the thick, deformed Paleozoic shales, sandstones, and cherts exposed along the central belt of the Ouachita Mountains. Steeply dipping fractures closely related to the major folds control the deposition of most quartz.Clear quartz is confined largely to the terminal parts of primary crystals, which have developed without disturbance or interference, are commonly elongate parallel to their C axes and are bounded by relatively simple forms. Deposition of silica during and subsequent to the fracturing of crystals resulted in the formation of complex crystals which are characterized by extensive optical twinning and lineage structures, and commonly are bounded by aggregates of the simpler crystal forms. The principal defects in all types of crystals are twinning, smokiness, cavities, solid inclusions and fractures.The Arkansas quartz deposits include veins, sheeted zones and stock-works. They are largely cavity fillings, apparently deposited by rising, attenuated, hydrothermal solutions, at relatively low temperatures and pressures. Minerals associated with the quartz, which constitutes 90 per cent or more of the cavity fillings, include dickite and carbonaceous material, calcite, adularia, and chlorite. The constituents of the cavity fillings could have been derived principally from magmatic sources or more probably from underlying rocks, with small additions from the rocks enclosing the cavities. The complex vein fabrics apparently resulting from intermittent regional deformation during the deposition of the quartz, and certain structural relations of the deposits, indicate that they were formed in the final stages of the Ouachita orogeny, probably in mid-Pennsylvanian time.
Geologic map and structure sections of the Batesville district, Independence County, Arkansas
No abstract available.
Geology and mineral resources of the western part of the Arkansas coal field
No abstract available.
Occurrence of enargite and wulfenite in ore deposits of northern Arkansas
One of the several contrasting features between zinc and lead deposits of the Mississippi Valley type and those of the Cordilleran type is the mineralogic simplicity of the Mississippi Valley ores. Because the usual ore and gangue minerals are few in kind and are those that can conceivably be carried in solution by circulating ground waters, special theories of origin that have prevailed for the Mississippi Valley deposits have carried more weight than might be the case if the ores were chemically and mineralogically more complex. In summarizing the characters of the Mississippi Valley type, Lindgren 2 points out that the elements gold, antimony, arsenic and molybdenum are almost wholly absent. In view of this long recognized dearth of certain elements, it is believed that the discovery of two of them in typical Mississippi Valley lead and zinc ores of northern Arkansas may be of some interest.
Zinc and lead deposits of northern Arkansas
Zinc and lead ores occur in the northern counties of Arkansas, from the Arkansas-Oklahoma line on the west to the Coastal Plain, in Lawrence County, on the east, but are concentrated chiefly in Marion, Boone, Newton, Searcy, Sharp, and Lawrence Counties. Lead ore was reported in the region as early as 1818, and small reduction plants were built in the vicinity of Lead Hill in 1851 or 1852. The Confederate forces obtained lead from northern Arkansas during the Civil War. Zinc mining began at a somewhat later date and reached its peak between 1914 and 1917, but since that time mining has been at a low ebb. The later history of lead mining in the region has closely paralleled that of zinc. The production from the region since 1907, according to statistics compiled by the United States Geological Survey, has been, in round numbers, 1,900 tons of lead sulphide concentrates, 11,5000 tons of zinc sulphide concentrates, and 51,3000 tons of zinc carbonate and silicate concentrates.
Stratigraphy of the El Dorado oil field, Arkansas, as determined by drill cuttings
No abstract available.