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Research about Fremont County, Wyoming

Source-linked reports with geographic coverage including Fremont County, Wyoming.

16 recordsLinked to original sources
USGS1995

Water resources of Fremont County, Wyoming

Average annual runoff (inches per year) ranged from 0.90 to 22 in the Mountainous Region of Fremont County and from 0.06 to 0.72 in the Plains Region. The Wind River Formation of Tertiary age has the most well development. Quaternary alluvium and colluvium is the second-most developed. Some wells and springs discharge more than 300 gallons per minute from older selected geologic units. Geologic units are recharged by infiltration of precipi- tation, surface water, or irrigation water, or by leakage from another unit. The general direction of ground-water movement in the two major basins in the county is toward the Sweetwater and Wind Rivers. Ground water is discharged by wells, springs and seeps, evapotranspiration, and discharge to streams, lakes, drains, and other geologic units. Ground- water levels near Riverton's municipal supply were typically deepest in August when ground water was the sole supply. After 1981, ground water only supplemented the supply and water levels appeared to recover. Surface water supplies about 99 percent of total offstream use in Fremont County; irrigation is the largest use. The largest use of ground water is public supply. Twenty-five samples were collected from the Sweetwater River and tributaries in September 1991. Dissolved-solids concentrations ranged from 39 to 271 milligrams per liter, increasing downstream. All six water samples collected from the Cody Shale (Cretaceous age) exceeded 500 milligrams per liter dissolved solids-all samples from Miocene rocks and the White River Formation (Oligocene age) had dissolved solids less than 500 milligrams per liter.

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USGS1974

Mineral resources of Du Noir Addition, Washakie Wilderness area, Fremont County, Wyoming

The Du Noir Addition to the Washakie Wilderness area consists of 34,200 acres (13,840 hectares) of scenic mountainous terrain that adjoins the Teton Wilderness and Washakie Wilderness areas. The area was studied in 1973 by the U.S. Geological Survey and U.S. Bureau of Mines to evaluate its mineral, fuel, and geothermal energy potential. This evaluation is based on a search of the geologic literature, claim and production records, and fieldwork including mapping, inspection of claims and prospects, interpretation of aeromagnetic maps, and analyses of bedrock and stream-sediment samples. Flat-lying Eocene volcaniclastic rocks of the Absaroka volcanic field are exposed in about two-thirds of the Du Noir Addition. These volcanics unconformably overlie the deeply eroded, northwest-trending Du Noir anticline in which Paleozoic marine strata of Devonian through Permian age are exposed. Of lesser importance are small deposits of Eocene non-volcanic conglomerate, and basaltic intrusive and extrusive rocks of late Pliocene and possibly younger age. The results of this study indicate that the mineral, fuel, and geothermal potential of the Du Noir Addition are minimal. Low-grade copper-molybdenum mineralization occurs outside the addition, associated with intrusive rocks, but no indications of alteration or mineralization were found within the study area. Anomalous, but not economically important, concentrations of molybdenum and uranium were found in Permian and Eocene carbonaceous shales. Phosphate rock in the Phosphoria Formation occurs in beds too thin to constitute a resource. Large amounts of very pure limestone are present in the Madison Limestone, but equally pure limestone, much closer to transportation facilities, is found throughout this part of Wyoming. That part of the Du Noir anticline in the addition is too deeply eroded to be a likely reservoir of oil and gas. Present data indicates a low potential for geothermal energy in or near the addition.

Wyoming↗
USGS1973

Geologic map of the Phosphate Reserve in the Lander area, Fremont County, Wyoming

The area was mapped as part of the U.S. Geological Survey program of classifying and evaluating lands in the public domain. Resources of economic interest in the map area include oil, gas, water, phosphate rock, gypsum, and analcime. The area mapped includes the rocks between the Tensleep Sandstone and the Morrison Formation and Tertiary and Quaternary deposits.

Wyoming↗
USGS1968

Late Eocene nonmarine diatoms from the Beaver Divide area, Fremont County, Wyoming

The Beaver Divide is a high escarpment of Tertiary nonmarine strata in central Wyoming separating the Sweetwater Plateau from the relatively low-lying Wind River Basin. The Wagon Bed Formation of middle and late Eocene age and the Beaver Divide Conglomerate Member of the White River Formation-this member being of early Oligocene (Chadronian) age--are exposed near the top of the Beaver Divide in Fremont County, Wyo., about 23 miles southeast of Riverton. The upper part of the Wagon Bed Formation, dated as late Eocene (Uintan) age by Van Houten on the basis of vertebrate fossils, contains a highly silicified fresh-water limestone stratigraphically high in the section with a poorly preserved diatom assemblage. The Beaver Divide Conglomerate Member contains large blocks of similar white limestone, some of which have an assemblage of diatoms the same as that of the Wagon Bed Formation but showing excellent preservation. Both the Wagon Bed limestone and the limestone blocks from the Beaver Divide Conglomerate Member have virtually the same assemblages of nonmarine gastropods. A study of the local geology indicates that a marked erosional topography formed on the Wagon Bed strata before deposition of the Beaver Divide sediments. The Beaver Divide limestone blocks were derived from nearby exposures of the Wagon Bed Formation. The diatom assemblage under consideration was originally deposited in the Wagon Bed limestone and is, therefore, late Eocene rather than early Oligocene in age. This represents the earliest known assemblage of nonmarine diatoms from North America. The diatom assemblage of the Wagon Bed Formation consists of 27 new species, two species known previously from the upper Miocene of France, and five species still found in living assemblages. One new genus containing two species also occurs in the deposit. The Wagon Bed diatom assemblage is strikingly distinct from later Tertiary fresh-water assemblages in that many diatom genera common to the younger deposits are totally lacking in this Eocene formation. These genera may be absent because of a highly specialized paleoecology during deposition of the Wagon Bed limestone, but the meager evidence provided by the few still-living species suggests nothing more specific than deposition in a temperate circumneutral lake.

Wyoming↗
USGS1955

Geology of the Du Noir area, Fremont County, Wyoming

The Du Noir area includes about 250 square miles in the northwestern part of the Wind River Basin, Fremont County, Wyoming. It is bounded on the south by the Wind River and Warm Spring Creek, which flow along the northeast flank of the Wind River Mountains, and on the north by the steep scarps of the southern margin of the Absaroka Mountains. Rugged mountainous terrain dominates both the southwest and northern portions of the mapped area while badland topography and deeply dissected upland surfaces characterize the central part. One of the most significant physiographic and structural features of the region is a belt of folded and faulted Paleozoic and Mesozoic rocks, referred to as the Washakie Range, which lies along the southern margin of the Absaroka Mountains. These highlands, attaining elevations of es much as 10,000 feet, were buried by Tertiary volcanic debris and subsequently partly exhumed as the Wind River Basin was reexcavated by Wind River and its tributaries. The sedimentary rocks exposed in the Du Noir area are more than 12,500 feet thick and range in age from Cambrian to Recent. All systems, with the exception of the Silurian, are represented. Precambrian granite and granite gneiss are present in both the Wind River and Washakie Ranges.

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