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Geology topics

W.C. Steinkampf

Publications and source records attributed to W.C. Steinkampf.

11 recordsLinked to original sources
USGS2000

Hydrologic and geologic characteristics of the Yucca Mountain site relevant to the performance of a potential repository

Yucca Mountain, located ~100 mi northwest of Las Vegas, Nevada, has been designated by Congress as a site to be characterized for a potential mined geologic repository for high-level radioactive waste. This field trip will examine the regional geologic and hydrologic setting for Yucca Mountain, as well as specific results of the site characterization program. The first day focuses on the regional setting with emphasis on current and paleo hydrology, which are both of critical concern for predicting future performance of a potential repository. Morning stops will be southern Nevada and afternoon stops will be in Death Valley. The second day will be spent at Yucca Mountain. The field trip will visit the underground testing sites in the "Exploratory Studies Facility" and the "Busted Butte Unsaturated Zone Transport Field Test" plus several surface-based testing sites. Much of the work at the site has concentrated on studies of the unsaturated zone, an element of the hydrologic system that historically has received little attention. Discussions during the second day will compromise selected topics of Yucca Mountain geology, hydrology and geochemistry and will include the probabilistic volcanic hazard analysis and the seismicity and seismic hazard in the Yucca Mountain area. Evening discussions will address modeling of regional groundwater flow, the results of recent hydrologic studies by the Nye County Nuclear Waste Program Office, and the relationship of the geology and hydrology of Yucca Mountain to the performance of a potential repository. Day 3 will examine the geologic framework and hydrology of the Pahute Mesa-Oasis Valley Groundwater Basin and then will continue to Reno via Hawthorne, Nevada and the Walker Lake area.

Nevada↗
USGS1991

Isotopic discontinuities in ground water beneath Yucca Mountain, Nevada

Analytical data for stable isotopes in ground water from beneath Yucca Mountain, when examined in map view, show areal patterns of heterogeneity that can be interpreted in terms of mixing of at least three end members. One end member must be isotopically heavy in terms of hydrogen and oxygen and have a young apparent 14C age such as water found at the north end of Yucca Mountain beneath Fortymile Wash. A second end member must contain isotopically heavy carbon and have an old apparent 14C age such as water from the Paleozoic aquifer. The third end member cannot be tightly defined. It must be isotopically lighter than the first with respect of hydrogen and oxygen and be intermediate to the first and second end members with respect to both apparent 14C age and ?? 13C. The variable isotopic compositions of hydrogen and oxygen indicate that two of the end members are waters, but the variable carbon isotopic composition could represent either a third water end member or reaction of water with a carbon-bearing solids such as calcite.

Conference Paper↗
USGS1989

Oxygen-isotope composition of ground water and secondary minerals in Columbia Plateau basalts: Implications for the paleohydrology of the Pasco Basin

Concentrations of 18 O and deuterium in ground waters beneath the Hanford Reservation, Washington State, suggest that the meteoric waters recharging the basalt aquifers have been progressively depleted in these isotopes since at least Pleistocene time. This conclusion is supported by oxygen-isotope analyses of low-temperature secondary minerals filling vugs and fractures in the basalts, which are used to approximate the 18 O content of ground water at the time the mineral assemblage formed. A fossil profile of δ 18 O values projected for ground water in a 1500 m vertical section beneath the reservation suggests that the vertical mixing of shallow and deep ground water indicated by present-day hydrochemical data was also occurring during Neogene time. These data also suggest that a unidirectional depletion of 18 O and deuterium recorded in Pleistocene ground waters may have extended considerably further back in time. This shift is tentatively attributed to the orographic depletion of 18 O associated with the progressive uplift of the Cascade Range since the middle Miocene.

Geology↗
USGS1989

Water-quality characteristics of the Columbia Plateau regional aquifer system in parts of Washington, Oregon, and Idaho

Water quality data for the period 1982 through 1983 from about 350 wells in three Miocene basalt units in the Columbia Plateau regional aquifer system, Washington, show that the quality of groundwater generally is suitable for most uses. The dominant water type is calcium magnesium bicarbonate at shallow depths, and evolves toward sodium bicarbonate at depth. Calcium magnesium sulfate chloride type waters occur less commonly and are associated with shallow wells, the absence of a thick overburden, and agricultural land use. Dissolved-solids concentrations generally are less than 500 mg/L. Water in the Saddle Mountains unit has a mean dissolved-solids concentration of 488 mg/L. Nitrogen species and sulfate concentrations relate to overburden thickness and land use. Water in the Wanapum unit, below the Saddle Mountains unit, has a mean dissolved- solids concentration of 270 mg/L. High nitrogen concentrations (10 mg/L or greater) occur mostly in wells with depths less than 300 ft in areas with little or no overburden in the central part of the plateau. The Grande Ronde unit, below the Wanapum, has the lowest mean dissolved- solids concentrations, 230 mg/L, and nitrogen concentrations ar less than 2 mg/L. (USGS)

Water-Resources Investigations Report↗
USGS1985

Geochemical controls on dissolved sodium in basalt aquifers of the Columbia Plateau, Washington

Miocene basaltic aquifers of the Columbia Plateau are the principal source of water for agricultural, domestic, and municipal use in Washington State. Irrigation with groundwaters with relatively high sodium concentrations has been cause for concern in recent years, because of the tendency of such waters to reduce soil permeability. Chemical reactions involving groundwater and the basalts are the primary mechanisms responsible for the input of sodium to groundwater in the plateau. This conclusion is supported by the sequence of secondary alteration products found and by progressive changes in groundwater chemistry with depth and position along regional flow paths. Upgradient and shallow groundwaters have low sodium concentrations and sodium-adsorption ratios (SAR's), and are predominantly calcium sodium bicarbonate waters. Groundwaters from deeper and downgradient locations have higher sodium concentrations and SAR 's and are predominantly sodium bicarbonate water. Volcanic glass and cryptocrystalline matrix are the major sources of groundwater sodium, and are dissolved by a combination of silicate hydrolysis and dissolution by carbonic acid. Magnesium, iron, and calcium are removed from solution by the formation of an iron magnesium smectite, calcite , and amorphous iron oxyhydroxide. The addition of sodium, silicon, and potassium by dissolution of basalt exceeds their removal by the precipitation of secondary minerals, and their concentrations increase in the initial stages of this process. In later stages, these continued increases produce a water saturated with clinoptilolite and silica phases, and these begin to precipitate. While the timing of these processes is unclear, the mineralogy of secondary alteration and estimated cooling rates of the basalt flows suggest that observed alteration products formed primarily at low temperature, under conditions similar to those existing at the present time. (USGS)

Water-Resources Investigations Report↗
USGS1985

Controls on ground-water chemistry in the Horse Heaven Hills, south-central Washington

Miocene basaltic aquifers are the source of domestic and municipal water, and about 20,000 acre-feet of irrigation water annually, in the Horse Heaven Hills in south-central Washington State. Groundwater chemical variations derive from the hydraulic characteristics is of the geohydrologic system, from groundwater basalt reactions, and from irrigation. Some dissolved species concentrations increase with residence time; others decrease. Recharge area groundwaters are calcium magnesium sodium bicarbonate waters with sodium-adsorption ratios (SAR's) less than 1.0. They evolve to sodium potassium bicarbonate waters with SAR 's as high as 17. Glassy and cryptocrystalline phases of the basalt are the main sources of dissolved sodium. They dissolve by silicate hydrolysis in carbon dioxide charged waters that recharge the aquifer system. Dissolved silicon, iron, and aluminum concentrations are controlled by the solubilities of amorphous secondary alteration products, which order to silica phases, oxyhydroxides, and smectite. Carbonate mineral precipitation is induced by increasing pH from the hydrolysis reaction. Sodium and potassium concentrations increase until clinoptilolite saturation is reached and precipitation begins. Deviations from the general variation patterns are due to localized geologic structures which distort the groundwater flow system, and to the irrigation use of Columbia River water. (USGS)

Water-Resources Investigations Report↗
USGS1982

Origins and distribution of saline ground waters in the Floridan Aquifer in coastal southwest Florida

Twenty-three ground-water samples from the Floridan aquifer in coastal southwest Florida show that water quality deteriorates to the south and west. The waters grade from a fresh calcium magnesium bicarbonate sulfate type to a very saline sodium magnesium chloride type downgradient. Bromide-chloride and specific conductance ratios indicate that dilution of marine-like ground water is a signigicant mechanism in the evolution of the different water types found. Calcium, magnesium , and bicarbonate concentrations occur within a relatively narrow range and are primarily a function of mineral equilibria. Magnesium and strontium concentration distributions suggest several mineral-water interactions, including aragonite inversion, incongruent solution of magnesium calcite to a lower magnesian form, and dedolomitization. Sulfate concentrations increase downgradient and evince gypsum-anhydrite solution, particularly in the fresher waters. The extent to which each factor affects dissolved specie concentrations is a function of the location of the water in the flow system. (USGS)

Water-Resources Investigations Report↗
USGS1978

Water resources of east-central Iowa

Water is vital in the lives of the people and the economy of any area. To utilize this natural resource in the most efficient and beneficial manner, a basic knowledge and understanding of its sources and the occurrence and potential of each source must be gained. To provide this knowledge, the Water Resources Division of the U.S. Geological Survey in cooperation with the Iowa Geological Survey compiled this atlas describing the water resources available for development in an 12-county area in east-central Iowa. The report contains information on the availability, quality, and utilization of water from all known sources and the future demands upon the water resources in east-central Iowa. The information is presented to aid water users and other persons searching for and evaluating sources of water in a particular place, and planners and water managers who must consider water resources on a regional basis.

Iowa↗