Geology topics
Research about Sweetwater County, Wyoming
Source-linked reports with geographic coverage including Sweetwater County, Wyoming.
Soil-gas helium concentrations in the vicinity of a uranium deposit, Red Desert, Wyoming
A survey of the helium concentration in soil-gas was conducted in the Red Desert Area, Sweetwater County, Wyoming. The area studied is directly over a low-grade uranium deposit that may be suitable for recovery by in-situ leaching techniques. The area was sampled twice, once in December, 1977, and again in July, 1978. Wind was a significant factor affecting the helium concentrations. Wind gusts exceeded 110 km/hr (70 mph) during the December, 1977, sampling; wind gusts did not exceed 30 km/hr (20 mph) during the July, 1978, sampling. The average helium concentration for all the July, 1978, soil-gas samples was about twice the average of the December, 1977, samples. In addition, a contour plot of the July, 1978, soil-gas samples showed an area of higher helium values that corresponds to the location of anomalies detected by other exploration techniques, and may be associated with the uranium deposit.
Geology and energy resources of the Sand Butte Rim NW quadrangle, Sweetwater County, Wyoming
The Sand Butte Rim NW 71-minute quadrangle occupies 56 square miles of an arid, windy, sparsely vegetated area of ridges and valleys on the east flank of the Rock Springs uplift in southwest Wyoming. The area is underlain by a succession of sedimentary rocks, about 20,000 feet thick, that includes 28 formations ranging in age from Cambrian to Tertiary. Upper Cretaceous and lower Tertiary formations crop out and dip 3?-6? southeast. They are unfaulted and generally homoclinal, but a minor anticlinal nose is present. Older rocks in the subsurface are faulted and folded. Coal resources are estimated to be nearly I billion short tons of subbituminous coal, in beds more than 2.5 feet thick, under less than 3,000 feet of overburden, in the Fort Union Formation of Paleocene age and the Lance and Almond Formations of Cretaceous age.
Structure contours on top of the Ericson Sandstone, Rock Springs uplift, Sweetwater County, Wyoming
No abstract available.
Geology and energy resources of the Sand Butte Rim NW quadrangle, Sweetwater County, Wyoming
Geologic investigations in the Rock Springs coal field in southwest Wyoming are part of a project undertaken by the U.S. Geological Survey to locate and evaluate mineral deposits on federally owned lands. The Rock Springs project encompasses an area of 2,849 square kilometres (1,100 square miles) and includes twenty 7 1/2-minute quadrangles. This paper presents the results of a study of the geology and energy resources in one of these quadrangles, the Sand Butte Rim NW quadrangle.
Geologic map of the Sand Butte Rim SE quadrangle, Sweetwater County, Wyoming
No abstract available.
Uranium-bearing coal in the central part of the Great Divide basin, Sweetwater County, Wyoming
Field work leading to this report was done by the U.S. Geological Survey for the Division of Raw Materials of the U.S. Atomic Energy Commission. Nearly 24 townships were mapped in the central part of the Great Divide Basin, Sweetwater County, Wyoming. Fourteen of these townships contain outcrops of uranium-bearing coal. Thirty coal beds were mapped, but only seven of them have uranium-bearing coal reserves as defined in this report. Coal beds 2.5 or more feet thick are considered in calculating coal reserves, and of these, only beds containing 0.003 or more percent uranium are considered in calculating reserves of uranium in coal. Reserves of uranium in coal ash include those beds 2.5 or more feet thick that contain 0.015 or more percent uranium in coal ash. Measured and indicated coal reserves total about 700,000,000 short tons which contain about 2,600 short tons of uranium in the coal, or about 2,400 short tons of uranium in the coal ash. Strippable reserves, defined as reserves in beds beneath 60 or less feet of overburden, are about 250,000,000 short tons of coal containing about 1,100 short tons of uranium in coal, or about 600 tons of uranium in coal ash. The thickest coal beds underlie a relatively narrow belt that trends northwest and coincides approximately with the axis of the Red Desert syncline. The coal beds contain the most uranium on the east flank of the syncline near the southwesternmost edge of the Battle Spring formation (new). This formation is of early and middle Eocene age and consists predominantly of very coarse-grained arkosic sandstone which is highly permeable. It intertongues southwestward with the Tess permeable Green River and Wasatch formations. The Green River formation consists from youngest to oldest of the Morrow Creek and Laney shale members and the Tipton and Luman (new) tongues. The Wasatch formation interfingers with the Green River formation and consists from youngest to oldest of the Cathedral Bluffs, Niland, and Red Desert tongues. The latter two are here recognized for the first time and contain all the coal beds in the Wasatch formation. The Morrow Creek member of the Green River formation is of middle Eocene age. The Laney member and Cathedral Bluffs tongue of the Green River and Wasatch formation, respectively intertongue and are in part equivalent, and are of early or middle Eocene age. The other units are of early Eocene age. A broad gentle arch which is either the eastern extension of the Wamsutter arch, or a separate arch en echelon to it, separates the Washakie Basin the southeastern part of the map area from the Red Desert syncline in the northeastern part. The Red Desert syncline plunges gently northwest into the nearly circular structural Niland basin. The south flank of the Wamsutter(?) arch dips southeastward at an average rate of about 230 feet per mile. The northern flank of the arch dips northeastward at an average rate of about 140 feet per mile. North of the Niland basin, the structure is more complex and is dominated by a northwestwardtrending graben which parallels and includes the Cyclone Rim in the northern part of die map area. Schroeckingerite deposits in the northeastern part of the map area lie within this graben in a sequence of arkosic sandstone and clay shale stratigraphically equivalent to the lower part of the Cathedral Bluffs tongue of the Wasatch formation and to the uppermost part of the Tipton tongue of the Green River formation. Weakly radioactive tuffaceous sandstone beds of the Browns Park formation that probably once blanketed the entire Great Divide Basin are preserved a short distance north and northwest of the schroeckingerite deposits. The geologic settings of the schroeckingerite and uranium-bearing coal are similar and their source of uranium is probably the same. The uranium probably was leached from tuffaceous beds in the Browns Park formation and carried to its present site of deposition by groundwater whose circulation was guided by structure and changes in facies.
Airborne radioactivity survey of parts of Sand Creek SW and Sand Creek SE quadrangles, Sweetwater county, Wyoming
The accompanying map shows the results of an airborne radioactivity survey in 125 square miles of Sand Creek SW and Sand Creek SE quadrangles, Wyoming. This area is part of a larger survey made in southern Carbon and Sweetwater counties by the U.S. Geological Survey, November 9-24, 1953. The work was undertaken as part of a cooperative program with the U.S. Atomic Energy Commission. The survey was made with scintillation detection equipment mounted in a C-47 aircraft and consisted of parallel east-west flight lines spaced at quarter mile intervals, flown approximately 500 feet above the ground. Aerial photographs were used for pilot guidance, and the flight path of the aircraft was recorded by a gyrostabilized, continuous-strip-film camera. The distance of the aircraft from the ground was measured with a continuously recording radio altimeter. The width of the zone on the ground form which the anomalous radiation is measured at the nominal 500 foot flight altitude varied with the areal extent and the intensity of radioactivity of the source. For strong sources of radioactivity the width of the zone may be as much as 1,400 feet. Thus, quarter mile spacing of the flight lines would be adequate to detect anomalies from strong sources of radioactivity; however, small areas of considerable radioactivity midway between flight lines may not be noted. The approximate locations of nine radioactivity anomalies are shown on the accompanying map. The plotted position of the anomalies may be in error by as much as a quarter mile owing to the errors in available base maps or to the existence of areas on the base maps up to several square miles in which it is impossible to find and plot recognizable landmarks. The present technique of airborne radioactivity measurement does not permit distinguishing between activity due to thorium and that due to uranium. An anomaly, therefore, may represent radioactivity due entirely to one or to a combination of these elements. The radioactivity anomalies shown on the accompanying map cannot be interpreted in terms of either radioactive content or the extent of the source materials. Any particular anomaly may represent slightly greater-than-average radioactivity over an area of a few thousand square feet or high radioactivity over an area of a few hundred square feet. Thus radioactivity anomalies indicate localities of more-than-average radioactivity and, therefore, suggest areas in which uranium or thorium deposits are more likely to occur.
Mineralogy and geochemistry of a uraniferous coal from the Red Desert Area, Sweetwater County, Wyoming
A sample of subbituminous uraniferous coal from the Red Desert, Sweetwater County, Wyo., was studied mineralogically. The coal contains gypsum (6 percent), kaolinite (1 percent), quartz (0.3 percent), calcite (trace), and limonite (trace). This suite of minerals and the absence of pyrite show that the coal has been subjected to weathering and oxidation. No uranium minerals have been found; mechanical fractionation has indicated that the uranium is associated with the organic constituents of the coal. The minerals that have been isolated contain 0.0006 percent uranium, a content which is to be expected for nonuraniferous sedimentary rocks. The organic components of the coal contain approximately 0.002 percent uranium. On the basis of material balance calculations, the organic components carry 98 percent of the uranium in the coal. Fischer assays of this weathered coal from the Red Desert indicate a yield of 16.7 gallons of tar per ton on low-temperature retorting. In view of the large reserve of subbituminous coal in the Red Desert, its probable ease of mining, and its tar yield, it may be desirable to carry out further evaluation of the coal as a fuel or raw material for the manufacture of tar or chemicals. If economic factors permit utilization of the coal, the uranium, although present in small percentages, could be recovered as a byproduct.
Uranium-bearing coal in the Red Desert, Great Divide Basin, Sweetwater county, Wyoming
Uranium-bearing coal in the Wasatch formation occurs in a zone extending 30 miles north of U.S. Highway 30 and the Union Pacific Railroad at Wamsutter, Sweetwater County, Wyoming. The Wasatch formation intertongues with the Green River formation and the beds are nearly flat lying. Preliminary estimation of total reserves in the area indicates the presence of 610,000,000 tons of subbituminous coal containing 14,800 tons of uranium in beds more than 30 inches thich and overlain by less than 75 feet of overburden. The uranium content of the coal ash ranges from 0.010 percent to 0.020 percent throughout most the area included in the reserves. Locally, the uranium content ranges from 0.001 percent to 0.047 in the coal and 0.005 percent to 0.14 percent in the ash.
Airborne radioactivity survey of the Aspen Mountain area, Sweetwater county, Wyoming
The accompanying map shows the results of an airborne radioactivity survey covering 700 square miles in the Aspen Mountain area, Sweetwater county, Wyoming. The survey was made by the U.S. Geological Survey, October 22, 1952, as part of a cooperative program with the U.S. Atomic Energy Commission. The survey was made with scintillation-detection equipment mounted in a Douglas DC-3 aircraft. Parallel traverse lines, spaced at quarter-mile intervals, were flown approximately 500 feet above the ground. Aerial photographs were used for pilot guidance, and the flight path of the aircraft was recorded by a gyro-stabilized, continuous-strip-film camera. The distance of the aircraft from the ground was measured with a continuously recording radio altimeter. At 500 feet above the ground, the width of the zone from which anomalous radioactivity is measured varies with the intensity of radiation of the source and, for strong sources, the width would be as much as 1,400 feet. Quarter-mile spacing of the flight paths of the aircraft should be adequate to detect anomalies from strong sources of radioactivity. However, small areas of considerable radioactivity midway between flight paths may not be noted. The approximate location of each radioactivity anomaly is shown on the accompanying map. The plotted position of an anomaly may be in error by as much as a quarter of a mile owing to errors in the available base maps up to several square miles in which it is impossible to find and plot recognizable landmarks. The radioactivity anomaly that is recorded by airborne measurements at 500 feet above the ground can be caused by: 1. A moderately large area in which the rocks and soils are slightly more radioactive than the rocks and soils of the surrounding area. 2. A smaller area in which the rocks and soils are considerably more radioactive than rocks and soils in the surrounding area. 3. A very small area in which to rocks and soils are much more radioactive than the rocks and soils of the surrounding area. Any particular anomaly, therefore, may represent either slightly greater-than-average radioactivity over an area of a few thousand square feet, or high radioactivity over an area of a few hundred square feet. The radioactivity anomalies shown on the accompanying map indicate localities of more-than-average radioactivity, and therefore, suggest areas in which uranium or thorium deposits are more likely to occur.
Results of exploration at Lost Creek schroeckingerite deposit, Sweetwater County, Wyoming
The U. S. Geological Survey, on behalf of the Atomic Energy Commission, from July 1951 to February 1952, explored the Lost Creek schroeckingerite deposit, Sweetwater County, Wyoming, by means of auger- drilling, trenching, and bucket-drilling. This report presents an estimate of the inferred ore reserves obtained during this exploration. The inferred reserves are presented under three schedules. Schedule A is the reserves calculated for the main schroeckingerite-bearing area; Schedule B is the reserves for the smaller schroeckingerite-bearing area to the north of the main area. The grade and tonnage estimates for both Schedule A and Schedule B are divided into two groups--data for selective mining, and data for bulk-mining. Schedule C presents reserve estimates for a semi- selective mining method and was calculated for four selected blocks in the western half of the main schroeckingerite-bearing area. The inferred reserves of schroeckingerite available for bulk-mining in the area of Schedule A are about 3,000,000 tons that contain 0.005 percent uranium, or about 140 tons of metallic uranium. By bulk-mining, 900,000 tons containing 0.005 percent uranium, or U£ tons of metallic uranium, are available in the area of Schedule B. The inferred reserves available for selective mining in the area of Schedule A are 100,000 tons of schroeckingerite deposits that contain 0.030 percent uranium, or 30 tons of metallic uranium. By selective mining, 35,000 tons of schroeckingerite deposits that contain the 0.030 percent uranium, or 10 tons of metallic uranium, are available in the area of Schedule Bo Semi- selective mining in the four areas of Schedule C will yield about 650,000 tons of rock containing O.008 percent uranium, or 50 tons of metallic uranium.