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R. E. Davis

Publications and source records attributed to R. E. Davis.

14 recordsLinked to original sources
USGS1989

Chemical characteristics, including stable-isotope ratios, of surface water and ground water from selected sources in and near East Fork Armells Creek basin, southeastern Montana, 1985

Water samples were collected from 29 sites to provide synoptic chemical data, including stable-isotope ratios, for an area of active surface coal mining and to explore the effectiveness of using the data to chemically distinguish water from different aquifers. Surface-water samples were collected from one spring, four sites on East Armells Creek, one site on Stocker Creek, and two fly-ash ponds. Streamflows in East Fork Armells Creek ranged from no flow in several upstream reaches to 2.11 cu ft/sec downstream from Colstrip, Montana. Only one tributary, Stocker Creek, was observed to contribute surface flow in the study area. Groundwater samples were collected from wells completed in Quaternary alluvium or mine spoils, Rosebud overburden, Rosebud coal bed, McKay coal bed, and sub-McKay deposits of the Tongue River Member, Paleocene Fort Union Formation. Dissolved-solids concentrations, in mg/L, were 840 at the spring, 3,100 to 5,000 in the streams, 13,000 to 22,000 in the ash ponds, and 690 to 4 ,100 in the aquifers. With few exceptions, water from the sampled spring, streams, and wells had similar concentrations of major constituents and trace elements and similar stable-isotope ratios. Water from the fly-ash ponds had larger concentrations of dissolved solids, boron, and manganese and were isotopically more enriched in deuterium and oxygen-18 than water from other sources. Water from individual aquifers could not be distinguished by either ion-composition diagrams or statistical cluster analyses. (USGS)

Water-Resources Investigations Report↗
USGS1986

Ground-water movement and effects of coal strip mining on water quality of high-wall lakes and aquifers in the Macon-Huntsville area, north-central Missouri

Glacial drift and Pennsylvanian bedrock were mixed together forming spoil during pre-reclamation strip mining for coal in north-central Missouri. This restructuring of the land increases the porosity of the material, and increases aqueous concentrations of many dissolved constituents. Median sodium and bicarbonate concentrations were slightly greater, calcium 5 times greater, magnesium 6 times greater, manganese 15 times greater, iron 19 times greater, and sulfate 24 times greater in water from spoil than in water from glacial drift. Median potassium concentrations were slightly greater, and chloride concentrations were two times greater in water from glacial drift than in water from spoil. Water types in glacial drift and bedrock were mostly sodium bicarbonate and calcium bicarbonate; in spoil and lakes in the spoil, the water types were mostly calcium sulfate. Median pH values in water from spoil were 6.6, as compared to 7.4 in water from glacial drift and 9.0 in water from bedrock. Neutralization of acid by carbonate rocks causes the moderate pH values in water from spoil; a carbonate system closed to the atmosphere may result in alkaline pH values in bedrock. Transmissivities generally are greatest for spoil, and decrease in the following order: alluvium, glacial drift, and bedrock. Recharge to spoil is from precipitation, lateral flow from glacial drift, and lateral and vertical flow from bedrock. The rate of recharge to the aquifers is unknown, but probably is small. Groundwater discharge from the glacial drift, bedrock, and spoil is to alluvium. The direction of flow generally was from high-wall lakes in the spoil toward East Fork Little Chariton River or South Fork Claybank Creek. Significant differences (95% confidence level) in values and concentrations of aqueous constituents between spoil areas mined at different times (1940, 1952, and 1968) were obtained for pH, calcium, magnesium, manganese, sulfate, chloride, and dissolved solids, but not for iron. These differences are attributed to local variations in the geohydrologic system rather than spoil age. (Lantz-PTT)

Missouri↗
USGS1986

Results of experiments related to contact of mine-spoils water with coal, West Decker and Big Sky Mines, southeastern Montana

Batch-mixing experiments using spoils water and coal from the West Decker and Big Sky Mines were conducted to determine possible chemical changes in water moving from coal-mine spoils through a coal aquifer. The spoils water was combined with air-dried and oven-dried chunks of coal and air-dried and oven-dried crushed coal at a 1:1 weight ratio, mixed for 2 hr, and separated after a total contact time of 24 hr. The dissolved-solids concentration in water used in the experiments decreased an average 210 mg/liter (5-10%). Other chemical changes included general decreases in the concentrations of magnesium, potassium, and bicarbonate, and general increases in the concentrations of barium and boron. The magnitude of the changes increased as the surface area of the coal increased. The quantity of extractable cations and exchangeable cations on the post-mixing coal was larger than on the pre-mixing coal. Equilibrium and mass-transfer relations indicate that adsorption reactions or ion-exchange and precipitation reactions, or both, probably are the major reactions responsible for the chemical changes observed in the experiments. (Authors ' abstract)

Water-Resources Investigations Report↗
USGS1984

Geochemistry and geohydrology of the West Decker and Big Sky coal-mining areas, southeastern Montana

In the West Decker Mine area, water levels west of the mine at post-mining equilibrium may be almost 12 feet higher than pre-mining levels. Dissolved-solids concentration in water from coal aquifers is about 1,400 milligrams per liter and from mine spoils is about 2,500 milligrams per liter. About 13 years will be required for ground water moving at an average velocity of 2 feet per day to flow from the spoils to the Tongue River Reservoir. The increase in dissolved-solids load to the reservoir due to mining will be less than 1 percent. In the Big Sky Mine area, water levels at post-mining equilibrium will closely resemble pre-mining levels. Dissolved-solids concentration in water from coal aquifers is about 2,700 milligrams per liter and from spoils is about 3,700 milligrams per liter. About 36 to 60 years will be required for ground water moving at an average velocity of 1.2 feet per day to flow from the spoils to Rosebud Creek. The average annual increase in dissolved-solids load to the creek due to mining will be about 2 percent, although a greater increase probably will occur during summer months when flow in the creek is low.

Montana↗
USGS1984

Assessment of selected ground-water-quality data in Montana

Ground-water-quality data for Montana in the U.S. Geological Survey 's computer data file WATSTORE were evaluated for nine geohydrologic units in part of the State east of the Rocky Mountains and for two geohydrologic units in the western mountainous part of the stated region. The availability of data for inorganic, trace, and organic constituents for each grouping of units was assessed. Median dissolved-solids concentrations for the groupings of units range from about 100 to 5,000 milligrams per liter. However, the number and distribution of data sites for some groupings of units wee inadequate to be representative of the aquifer as a whole. Concentrations of most trace constituents do not exceed Federal primary drinking-water standards, although exceptions occur. Few data were available for organic constituents. (USGS)

Water-Resources Investigations Report↗
USGS1984

Example calculations of possible ground-water inflow to mine pits at the West Decker, East Decker, and proposed North Decker mines, southeastern Montana

Proposed plans to raise the spillway of the Tongue River Dam, Montana, 14 feet would result in an increase in the reservoir stage, which will affect the amount of ground-water inflow from the reservoir to existing and proposed surface coal mine pits near Tongue River Reservoir. Example calculations are based on flow from the reservoir to the mine pits through areas approximately perpendicular to the long axis of the reservoir. The planned increase in the stage of the reservoir will result in an increase of inflow to the mine pits in most areas. The increases will be greatest where the mine pits are near the reservoir and separated from the reservoir solely by aquifer zones of relatively large hydraulic conductivity. However, the inflow determined from the calculations is subject to a large degree of error, owing to the simplified method of calculation and the assumptions used. (USGS)

Water-Resources Investigations Report↗
USGS1961

Geology and mineral deposits of the Carlile quadrangle, Crook County, Wyoming

The Carlile quadrangle-is along the northwestern flank of the Black Hills uplift in Crook County, Wyo. The area-is primarily one of canyons and divides that are a result of downcutting by the Belle Fourche River and its tributaries through an alternating succession of sandstone, siltstone, and mudstone or shale beds. The present topography is also influenced by the regional structure, as reflected by the beds that dip gently westward and by the local structural features such as anticlines, domes, synclines, basins, and terraces, which are superimposed upon the regional setting. Rocks exposed include shale and thin limestone and sandstone beds belonging to the Redwater shale member of the Sundance formation and to the Morrison formation, both of Late Jurassic age; sandstone, siltstone, and mudstone of the Lakota and Fall River formations of Early Cretaceous age; and shale and sandstone of the Skull Creek shale, Newcastle sandstone, and Mowry shale, also of Early Cretaceous age. In the southwestern part of the quadrangle rocks of the Upper Cretaceous series are exposed. These include the Belle Fourche shale, Greenhorn formation, and Carlile shale. Gravel terraces, landslide debris, and stream alluvium comprise the surficial deposits. The Lakota and Fall River formations, which make up the Iriyan Kara group, contain uranium deposits locally in the northern Black Hills. These formations were informally subdivided in order to show clearly the vertical and lateral distribution of the sandstone, siltstone, and mudstone facies within them. The Lakota was subdivided into a sandstone unit and an overlying mudstone unit; the Fall River was subdivided, in ascending order, into a siltstone unit, a mudstone unit, a sandstone unit, and an upper unit. The lithologic character of the Lakota changes abruptly locally, and the units are quite inconsistent with respect to composition, thickness, and extent. This is in contrast to a notable consistency in the lithologic character and thickness among all the Fall River units, with the exception of the upper unit. Petrographic studies on selected samples of units from both formations show differences in composition between Lakota and Fall River rocks. The Carlile quadrangle lies immediately east of the monocline that marks the outer limit of the Black Hills uplift, and the rocks in this area have a regional dip of less than 2° outward from the center of the uplift. Superimposed upon the regional uplift are many subordinate structural features anticlines, synclines, domes, basins, and terraces which locally modify the regional features. The most pronounced of these subordinate structural features are the doubly-plunging Pine Ridge, Oil Butte, and Dakota Divide anticlines, and the Eggie Creek syncline. Stress throughout the area was relieved almost entirely through folding; only a few small nearly vertical normal faults were found within the quadrangle. Uranium has been mined from the Carlile deposit, owned by the Homestake Mining Co. The ore minerals, carnotite and tyuyamnuite occur in a sandstone lens that is enclosed within relatively impermeable clayey beds in the mudstone unit of the Lakota formation. The ore also includes unidentified black vanadium minerals and possibly coffinite. Uranium minerals are more abundant in and adjacent to thicker carbonaceous and silty seams in the sandstone lens. A mixture of fine-grained calcium carbonate and calcium sulfate fills the interstices between detrital quartz grains in mineralized sandstone. Selenium and arsenic are more abundant in samples that are high in uranium. Drilling on Thorn Divide about 1 mile west of the Carlile mine has roughly outlined concentrations of a sooty black uranium mineral associated with pyrite In two stratigraphic intervals of the Lakota formation. One is in the same sandstone lens that contains the ore at the Carlile mine; the other is in conglomeratic sandstone near the base of the Lakota. These deposits are relatively deep, and no mining has been attempted. The mineralogy of the Carlile deposits and the lithologic features of the sandstone host rock suggest that uranium and vanadium were transported in the high-valent state by carbonate or sulfate solutions, were extracted from solution by organic material, and were reduced to low-valent states to form an original assemblage of oxides and silicates. These primary minerals were oxidized in place, and the present carnotite-tyuyamunite assemblage was formed. In general, radioactivity analyses correspond fairly closely with chemical analyses of uranium, thus it is believed that only minor solution and migration of uranium has occurred since the present suite of oxidized minerals was formed. The factors responsible for ore localization are not clear, but probably a combination of three lithologic and structural elements contributed to provide a favorable environment for precipitating uranium from aqueous solutions: abundant carbonaceous material or pyrite in a thin, permeable sandstone enclosed within relatively thick impermeable clays; local structural basins; and a regional structural setting involving a broad syncline between two anticlines. The structural features controlled the regional flow of ground water and the lithologic features controlled the local rate of flow and provided the proper chemical environment for uranium deposition. Bentonite has been mined from an opencut in the Mowry shale in the southwest part of the quadrangle. A bentonite bed in the Newcastle sandstone also seems to be of minable thickness and quality. Exploration for petroleum has been unsuccessful within the quadrangle; however, some wells that yielded oil were recently drilled on small anticlines to the west and southeast. It is possible that similar structural features in the Carlile area, that were previously overlooked, may be equally productive.

Wyoming↗