Geology topics

Kathy Muller Ogle

Publications and source records attributed to Kathy Muller Ogle.

4 recordsLinked to original sources

USGS2002

Potentiometric surfaces, altitudes of the tops, and hydrogeology of the Minnelusa and Madison aquifers, Black Hills area, Wyoming

The topographically defined Black Hills and adjacent areas (Black Hills area) of Wyoming (fig. 1) are underlain by two regionally important aquifers - the Minnelusa and the Madison. The Minnelusa aquifer is used extensively in the Black Hills area as a source of domestic and livestock water. The Madison aquifer is an important source of municipal, industrial, agricultural, and domestic water in both the Black Hills area and other parts of Wyoming. Increased demand for water from the Minnelusa and Madison aquifers in the Black Hills area of Wyoming and South Dakota have created a need for better understanding of the hydrology of these two important aquifers. This report presents information on the potentiometric surfaces and altitudes of the tops of the Minnelusa and Madison aquifers in the Black Hills area of northeastern Wyoming using new data collected since completion of earlier studies. In addition, ground-water levels in selected wells are examined, and the relative age of a limited number of ground-water samples are discussed. The information will be of use to government officials, land planners and other individuals who must manage the limited water resources of this growing and developing area. The scope of the project was limited to wells and springs in the Black Hills area of Wyoming. Water levels were measured during 1998 and 1999 in wells completed in the Minnelusa and Madison aquifers to construct potentiometric-surface maps. The potentiometric surfaces and altitudes of the tops of the Minnelusa and Madison aquifers were contoured at the same scale (1:100,000) as studies of the aquifers recently conducted by the U.S. Geological Survey (USGS) in the Black Hills area within South Dakota (Carter and Redden, 1999a, 1999b; Strobel and others, 2000a, 2000b). The contours in these studies of the Minnelusa and Madison aquifers in South Dakota were "edge matched" as closely as possible along the Wyoming-South Dakota State line using the same contour interval. Use of the same contour interval and edge matching will allow for the use of the maps across State boundaries and improve understanding of the aquifers in a larger area within the Black Hills uplift. In places, some contours could not be matched across the Wyoming-South Dakota State line because this investigation was completed after the South Dakota investigations, and additional control points used in this investigation were located in Wyoming near the State line. The reader should note that Minnelusa and Madison outcrop areas and some structural features may not match in some areas along the Wyoming-South Dakota State line when maps in this study area are aligned or "edge matched" with maps produced for the South Dakota studies because different sources of geological mapping were used for the studies. Ground-water samples were collected from a subset of measured wells and analyzed for tritium to qualitatively estimate the time of ground-water recharge. This project was conducted by the USGS in cooperation with the Wyoming State Engineer's Office (WSEO). The study area was almost entirely within Crook and Weston Counties in Wyoming and was bordered on the east by the Wyoming-South Dakota State line.

Hydrologic Atlas↗

USGS2002

Water quality and environmental isotopic analyses of ground-water samples collected from the Wasatch and Fort Union Formations in areas of coalbed methane development — Implications to recharge and ground-water flow, eastern Powder River Basin, Wyoming

Chemical analyses of ground-water samples were evaluated as part of an investigation of lower Tertiary aquifers in the eastern Powder River Basin where coalbed methane is being developed. Ground-water samples were collected from two springs discharging from clinker, eight monitoring wells completed in the Wasatch aquifer, and 13 monitoring or coalbed methane production wells completed in coalbed aquifers. The ground-water samples were analyzed for major ions and environmental isotopes (tritium and stable isotopes of hydrogen and oxygen) to characterize the composition of waters in these aquifers, to relate these characteristics to geochemical processes, and to evaluate recharge and ground-water flow within and between these aquifers. This investigation was conducted in cooperation with the Wyoming State Engineer's Office and the Bureau of Land Management. Water quality in the different aquifers was characterized by major-ion composition. Samples collected from the two springs were classified as calcium-sulfate-type and calcium-bicarbonate-type waters. All ground-water samples from the coalbed aquifers were sodium-bicarbonate-type waters as were five of eight samples collected from the overlying Wasatch aquifer. Potential areal patterns in ionic composition were examined. Ground-water samples collected during this and another investigation suggest that dissolved-solids concentrations in the coalbed aquifers may be lower south of the Belle Fourche River (generally less than 600 milligrams per liter). As ground water in coalbed aquifers flows to the north and northwest away from an inferred source of recharge (clinker in the study area), dissolved-solids concentrations appear to increase. Variation in ionic composition in the vertical dimension was examined qualitatively and statistically within and between aquifers. A relationship between ionic composition and well depth was noted and corroborates similar observations by earlier investigators in the Powder River Basin in both Wyoming and Montana. This relationship results in two different water-quality zones with different characteristics - a shallow zone, comprising the upper part of the Wasatch aquifer, characterized by mixed cation composition and either sulfate or bicarbonate as the dominant anion; and a deeper zone, comprising the lower (deeper) part of the Wasatch aquifer and the underlying coalbed aquifers, characterized by sodium-bicarbonate-type waters. The zonation appears to be related to geochemical processes described by earlier investigators such as dissolution and precipitation of minerals, ion exchange, sulfate reduction, and mixing of waters. Qualitative and statistically significant differences were observed in sulfate concentrations between the coalbed aquifers and the overlying Wasatch aquifer. Ionic composition suggests that bacterially mediated redox processes such as sulfate reduction were probably the dominant geochemical processes in the anaerobic coalbed aquifers. Tritium was used to qualitatively estimate the time of ground-water recharge. Tritium concentrations in both springs suggests that both were recharged after 1952 and contain modern water. Tritium was not detected at concentrations suggestive of modern water in any ground-water samples collected from the coalbed aquifers or in six of eight ground-water samples collected from the overlying Wasatch aquifer. Tritium concentrations in the remaining two wells from the Wasatch aquifer suggest a mixture between submodern (recharged before 1952) and modern water, although the low concentrations suggest that ground water in these two wells have very little modern water. The relative absence of modern water in all aquifers in the study area suggests that recharge processes to these aquifers are probably very slow. Paired d 2 H (deuterium/hydrogen isotopic ratio) and d 18 O (oxygen-18/oxygen-16 isotopic ratio) values for samples collected from the springs and all aquifers are close to the Global Meteoric Water Line, a meteoric water line for North American continental precipitation, and an estimated local meteoric water line, suggesting the water in the aquifers is of meteoric origin. The d 2 H and d 18 O values suggest that the waters were recharged in a colder climate or temperature, mid-latitudes, and mid-continent. In general, the samples do not form separate groups based on aquifer origin; this suggests either intermixing of the waters in the aquifers or that the different aquifers are subject to similar recharge and/or evolutional paths for the water. However, examination of the differences in the values of d 2 H and d 18 O, in combination with major-ion chemistry at three monitoring-well clusters, suggest that changes in the values with depth may represent different timing or sources of recharge to the different aquifers. The areal distribution of d 2 H was examined and an apparent break in the d 2 H along a northwest to southeast trend was observed. In the coalbed aquifers, all but one ground-water sample (collected from the Big George coal bed), show a pattern where the d 2 H values become more negative towards the center of the Powder River Basin and values greater (less negative) than an arbitrary reference value of -140 ‰ (per mil or parts per thousand) were observed near the outcrop area of the Wyodak-Anderson coal zone. In the overlying Wasatch aquifer, the d 2 H values became less negative towards the center of the basin. The values more negative than -140 ‰ are near the outcrop area and the values that are less negative than -140 ‰ are closer to the basin center. It is unclear if this pattern is a result of sample size, different recharge mechanisms, geochemical processes, or if the processes producing these differences are independent or unrecognized. Results of water-quality sampling were compared with selected regulatory and non-regulatory standards as well as commonly-used guidelines for proposed water uses. Dissolved solids was the measure that most frequently exceeded U.S. Environmental Protection Agency public water-supply standards and State of Wyoming domestic-use standards in ground-water samples collected from the Wasatch aquifer and coalbed aquifers. The State of Wyoming agricultural standards (irrigation) for sulfate and dissolved solids were exceeded in some samples collected from the Wasatch aquifer and coalbed aquifers. The State of Wyoming livestock standard for pH was exceeded in some samples collected from the Wasatch aquifer. Water from the Wasatch aquifer ranged from soft to very hard, and water from the coalbed aquifers ranged from moderately hard to very hard. Samples collected from wells completed in both the Wasatch aquifer and coalbed aquifers plotted in a wide range of both sodium- and salinity-hazard classes, but most samples clustered in or near the combined medium-sodium-hazard—high-salinity-hazard classes.

Wyoming↗

USGS1999

Water quality of Rob Roy Reservoir and Lake Owen, Albany County, and Granite Springs and Crystal Lake Reservoirs, Laramie County, Wyoming, 1997-98

The water quality of four reservoirs was assessed during 1997 and 1998 as a cooperative project between the Cheyenne Board of Public Utilities and the U. S. Geological Survey. The four reservoirs, Rob Roy, Lake Owen, Granite Springs, and Crystal Lake, provide approximately 75 percent of the public water supply for Cheyenne, Wyoming. Samples of water and bottom sediment were collected and analyzed for selected physical, chemical, and biological characteristics to provide data about the reservoirs. Water flows between the reservoirs through a series of pipelines and stream channels. The reservoirs differ in physical characteristics such as elevation, volume, and depth. Profiles of temperature, dissolved oxygen, specific conductance, and pH were examined. Three of the four reservoirs exhibited stratification during the summer. The profiles indicate that stratification develops in all reservoirs except Lake Owen. Stratification developed in Rob Roy, Granite Springs, and Crystal Lake Reservoirs by mid-July in 1998 and continued until September, with the thickness of the epilimnion increasing during that time. Secchi disk readings indicated Rob Roy Reservoir had the clearest water of the four reservoirs studied. The composition of the phytoplankton community was different in the upper two reservoirs from that in the lower two reservoirs. Many of the species found in Rob Roy Reservoir and Lake Owen are associated with oligotrophic, nutrient-poor conditions. In contrast, many of the species found in Granite Springs and Crystal Lake Reservoirs are associated with mesotrophic or eutrophic conditions. The total number of taxa identified also increased downstream. The chemical water type in the reservoirs was similar, but dissolved-solids concentrations were greater in the downstream reservoirs. Water in all four reservoirs was a calcium-bicarbonate type. In the fall of 1997, Rob Roy Reservoir had the lowest dissolved-solids concentration (19 milligrams per liter), whereas Crystal Lake Reservoir had the highest concentration (63 milligrams per liter). Relatively little differences in the concentrations of major-ion species were noted between samples collected near the surface and near the bottom of the same reservoir. In contrast, iron and manganese concentrations generally were higher in samples collected near the bottom of a reservoir than in near-surface samples collected from the same reservoir. Composite bottom-sediment samples from all four reservoirs contained similar concentrations of bulk constituents such as aluminum, iron, phosphorus and titanium, but varied in concentrations of trace elements. Trace-element concentrations in Rob Roy Reservoir and Lake Owen were similar to the crustal average, whereas in Granite Springs and Crystal Lake Reservoirs the concentrations were similar to granitic rocks.

Wyoming↗

USGS1994

Water resources of Hot Springs County, Wyoming

The wells and springs inventoried in Hot Springs County most commonly had been completed in or issued from the Quaternary alluvium, Quaternary terrace deposits, Fort Union and Mesaverde Formations, Cody Shale, and the Frontier and Chugwater Formations. The largest discharges measured were from the Quaternary terrace deposits (400 gallons per minute) and the Phosphoria Formation (1,000 gallons per minute). Discharges from all other geologic units varied, but most wells and springs yielded 50 gallons per minute or less. Water-quality samples collected from springs that issued from the Absaroka Volcanic Supergroup, the Bighorn Dolomite, and the Flathead Sandstone had the lowest dissolved-solids concentrations, which ranged from 58 to 265 milligrams per liter, and the least variable water types. Water from the volcanic rocks was a sodium bicarbonate type; whereas, water from the Flathead Sandstone was a calcium bicarbonate type. Water types for all the other aquifers varied from sampling site to sampling site; however, water samples from the Fort Union Formation and the Cody Shale were consistently of the sodium sulfate type. The effect of oil- and gas-development at Hamilton Dome on thermal spring discharges at Hot Springs State Park near Thermopolis was studied. The estimated drawdown from 1918, when the Hamilton Dome oil field was discovered, to 1988 was made using drill-stem data from previous studies. Drawdown at Big Spring in the Park was estimated to be less than 3 feet on the basis of recent oil- and water-production data, previous modeling studies, and the estimated water-level drawdown of 330 feet in wells at the Hamilton Dome oil field. Streams originating in the Plains region of the county, such as Middle Fork Owl Creek, are ephemeral or intermittent; whereas, streams originating in the mountains, such as Gooseberry Creek, are perennial. Average annual runoff across the county ranges from 0.26 inches at a representative streamflow-gaging station near Worland in the plains region to 5.4 inches in the Owl Creek Mountains and southeastern Absaroka Range.

Wyoming↗