Search USGS⌕ Search

SEARCH · Search USGS

Results for “Journal of Chemical Physics”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
USGS2002

Interpretation with a Donnan-based concept of the influence of simple salt concentration on the apparent binding of divalent ions to the polyelectrolytes polystyrenesulfonate and dextran sulfate

It has been shown that the apparent enhancement of divalent metal ion binding to polyions such as polystyrenesulfonate (PSS) and dextran sulfate (DS) by decreasing the ionic strength of these mixed counterion systems (M2+, M+, X-, polyion) can be anticipated with the Donnan-based model developed by one of us (J.A.M.). Ion-exchange distribution methods have been employed to measure the removal by the polyion of trace divalent metal ion from simple salt (NaClO4)-polyion (NaPSS) mixtures. These data and polyion interaction data published earlier by Mattai and Kwak for the mixed counterion systems MgCl2-LiCl-DS and MgCl2-CsCl-DS have been shown to be amenable to rather precise analysis by this model. ?? 1985 American Chemical Society.

Journal of Physical Chemistry↗
USGS2006

Thermodynamic calculations in the system CH4-H2O and methane hydrate phase equilibria

Using the Gibbs function of reaction, equilibrium pressure, temperature conditions for the formation of methane clathrate hydrate have been calculated from the thermodynamic properties of phases in the system CH4-H 2O. The thermodynamic model accurately reproduces the published phase-equilibria data to within ??2 K of the observed equilibrium boundaries in the range 0.08-117 MPa and 190-307 K. The model also provides an estimate of the third-law entropy of methane hydrate at 273.15 K, 0.1 MPa of 56.2 J mol-1 K-1 for 1/n CH4??H 2O, where n is the hydrate number. Agreement between the calculated and published phase-equilibria data is optimized when the hydrate composition is fixed and independent of the pressure and temperature for the conditions modeled. ?? 2006 American Chemical Society.

Journal of Physical Chemistry B↗
USGS1976

Prehnite in plutonic and metamorphic rocks of the northern Santa Lucia Range, Salinian block, California

Prehnite is abundant as monomineralic veins, as lenses in biotite, and as discrete patches and apparent primary crystals in both plutonic and metamorphic rocks along the west edge of the Salinian block in the northern Santa Lucia Range. The prehnite appears to be concentrated near the Sur fault zone but is very rare in Franciscan rocks west of the fault zone. The prehnite does not appear to have been derived by local alteration of minerals in the country rocks (either plutonic or metamorphic). I suggest that solutions, derived from a "substratum" (possibly Franciscan graywacke) beneath the tectonically thinned west margin of the Salinian block, migrated through the fractured rocks of the Salinian block near the Sur fault zone and that the chemical and physical nature of these rocks favored selective prehnite deposition.

California↗
USGS1978

Models for calculating density and vapor pressure of geothermal brines

In a model for estimating density of a brine, the density of a natural brine at a known temperature, pressure, and composition can be calculated from the densities of the component salt solutions in the complex brine. A model for estimating vapor pressure requires two direct or indirect estimates of the vapor pressure and uses a published "reference-substance principle" to extrapolate,; these data 200° to 300° above the temperature of the highest observation. The methods can be used to estimate the partial molal volume and partial molal enthalpy of H 2 O in the natural brine and the partial molal volume change and partial molal heat change for the H2O component in the vaporization process. The equations for density and vapor pressure and the derived thermochemical properties will help in designing turbines for operation with geothermal and geopressured brines, in optimizing production conditions, and in physical and chemical modeling of a geothermal reservoir.

Journal of Research of the U.S. Geological Survey↗
USGS2011

Hydrogeology, Chemical and Microbial Activity Measurement Through Deep Permafrost

Little is known about hydrogeochemical conditions beneath thick permafrost, particularly in fractured crystalline rock, due to difficulty in accessing this environment. The purpose of this investigation was to develop methods to obtain physical, chemical, and microbial information about the subpermafrost environment from a surface-drilled borehole. Using a U-tube, gas and water samples were collected, along with temperature, pressure, and hydraulic conductivity measurements, 420 m below ground surface, within a 535 m long, angled borehole at High Lake, Nunavut, Canada, in an area with 460-m-thick permafrost. Piezometric head was well above the base of the permafrost, near land surface. Initial water samples were contaminated with drill fluid, with later samples <40% drill fluid. The salinity of the non-drill fluid component was <20,000 mg/L, had a Ca/Na ratio above 1, with ??18O values ???5??? lower than the local surface water. The fluid isotopic composition was affected by the permafrost-formation process. Nonbacteriogenic CH4 was present and the sample location was within methane hydrate stability field. Sampling lines froze before uncontaminated samples from the subpermafrost environment could be obtained, yet the available time to obtain water samples was extended compared to previous studies. Temperature measurements collected from a distributed temperature sensor indicated that this issue can be overcome easily in the future. The lack of methanogenic CH4 is consistent with the high sulfate concentrations observed in cores. The combined surface-drilled borehole/U-tube approach can provide a large amount of physical, chemical, and microbial data from the subpermafrost environment with few, controllable, sources of contamination. ?? 2010 The Author(s). Journal compilation ?? 2010 National Ground Water Association.

Ground Water↗
USGS1987

Mineralogy and petrology of the Cretaceous- Tertiary boundary clay bed and adjacent clay-rich rocks, Raton Basin, New Mexico and Colorado.

The Cretaceous-Tertiary (K-T) boundary is preserved in a sequence of coal-bearing, fluvial rocks in the lower part of the Raton Formation (Late Cretaceous and Paleocene) at several sites in the east-central part of the Raton Basin. The K-T boundary occurs at the top of a kaolinitic claystone layer, commonly referred to as the "boundary clay layer," in an interval of coal and carbonaceous shale. The boundary is defined by the disappearance of certain fossil-pollen taxa. The boundary clay layer also contains shocked quartz grains and abundance anomalies of iridium, chromium, and other elements. Each of these characteristics support the hypothesis of an asteroid impact at the end of the Cretaceous. Small goyazite spheres were also found in the boundary clay bed; however, their origin is uncertain. X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and thin-section petrography have shown that the boundary clay bed exhibits unique mineralogic and petrologic characteristics not possessed by other clay-rich beds in coal-bearing rocks of the Raton Basin. The boundary clay bed is composed primarily of well-crystallized kaolinite but also contains subordinate, randomly interstratified, mixed-layer illite/smectite, both of which appear to have been formed by the alteration of vitreous material in a coal-swamp environment. The bulk mineralogy of the boundary clay bed is similar to that of other kaolinite-rich clay beds (tonsteins) that altered in coal swamps from airfall volcanic ash. The alteration process and diagenetic products of the host material in the boundary clay bed, however, differed from those of the tonsteins, resulting in a unique petrographic fabric. The boundary clay bed is characterized by an overall imbricate fabric that may reflect an original vitreous material that included shards, bubbles, and spheres. The original fallout material of the boundary clay bed first altered to "cabbage-like" microspherules, indicating a halloysite or allophane precursor, and then to well-crystallized kaolinite; the well-crystallized kaolinite is the diagenetic stable phase for these rocks at their maximum burial conditions. In comparison, the vitreous components of the tonsteins were altered directly to coarse vermicular and platey kaolinite. Alteration of the original fallout material in the boundary bed was probably rapid, leading to hydrated, disordered, fine-grained clay minerals that formed into curled spherical or tubular shapes. The factors that produced these unique fabrics in the boundary clay bed existed at all K-T sites in the Raton Basin and were much different from those that formed the coarse platey and vermicular fabrics of ordinary tonsteins. The distinctive character of the boundary clay may be due to the unique nature and chemistry of the fallout material and (or) physical or chemical conditions existing shortly after its deposition.

Journal of Sedimentary Petrology↗
USGS2005

Geochemistry and the understanding of ground-water systems

Geochemistry has contributed significantly to the understanding of ground-water systems over the last 50 years. Historic advances include development of the hydrochemical facies concept, application of equilibrium theory, investigation of redox processes, and radiocarbon dating. Other hydrochemical concepts, tools, and techniques have helped elucidate mechanisms of flow and transport in ground-water systems, and have helped unlock an archive of paleoenvironmental information. Hydrochemical and isotopic information can be used to interpret the origin and mode of ground-water recharge, refine estimates of time scales of recharge and ground-water flow, decipher reactive processes, provide paleohydrological information, and calibrate ground-water flow models. Progress needs to be made in obtaining representative samples. Improvements are needed in the interpretation of the information obtained, and in the construction and interpretation of numerical models utilizing hydrochemical data. The best approach will ensure an optimized iterative process between field data collection and analysis, interpretation, and the application of forward, inverse, and statistical modeling tools. Advances are anticipated from microbiological investigations, the characterization of natural organics, isotopic fingerprinting, applications of dissolved gas measurements, and the fields of reaction kinetics and coupled processes. A thermodynamic perspective is offered that could facilitate the comparison and understanding of the multiple physical, chemical, and biological processes affecting ground-water systems.

Hydrogeology Journal↗
USGS2002

Vapor-liquid phase equilibria of potassium chloride-water mixtures: Equation-of-state representation for KCl-H2O and NaCl-H2O

Measurements of isothermal vapor-liquid compositions for KCl-H2O as a function of pressure are reported. An equation of state, which was originally proposed by Pitzer and was improved and used by Tanger and Pitzer to fit the vapor-liquid coexistence surface for NaCl-H2O, has been used for representation of the KCl-H2O system from 300 to 410??C. Improved parameters are also reported for NaCl-H2O from 300 to 500??C. ?? 1990 American Chemical Society.

Journal of Physical Chemistry↗
USGS2018

Effects of sea lamprey substrate modification and carcass nutrients on macroinvertebrate assemblages in a small Atlantic coastal stream

Aquatic macroinvertebrates respond to patch dynamics arising from interactions of physical and chemical disturbances across space and time. Anadromous fish, such as sea lamprey, Petromyzon marinus , migrate from the ocean and alter physical and chemical properties of recipient spawning streams. Sea lamprey disturb stream benthos physically through nest construction and spawning, and enrich food webs through nutrient deposition from decomposing carcasses. Sea lamprey spawning nests support greater macroinvertebrate abundance than adjacent reference areas, but concurrent effects of stream bed modification and nutrient supplementation have not been examined sequentially. We added carcasses and cleared substrate experimentally to mimic the physical disturbance and nutrient enrichment associated with lamprey spawning, and characterized effects on macroinvertebrate assemblage structure. We found that areas receiving cleared substrate and carcass nutrients were colonized largely by Simuliidae compared to upstream and downstream control areas that were colonized largely by Hydropsychidae, Philopotamidae, and Chironomidae. Environmental factors such as stream flow likely shape assemblages by physically constraining macroinvertebrate establishment and feeding. Our results indicate potential changes in macroinvertebrate assemblages from the physical and chemical changes to streams brought by spawning populations of sea lamprey.

Maine↗
USGS1970

Control methods for snail-borne zoonoses

All trematodes which cause infections and diseases in humans (zoonoses) require snails for their first intermediate host. Some have additional intermediate hosts such as crustaceans, fishes and frogs. In this paper I have discussed the use of various procedures for controlling snail populations thereby reducing the population of trematodes whose cercariae penetrate the skin of man, or which are acquired by eating raw aquatic vegetation such as watercress, or which cause pathology in fish. Biological, chemical, and physical snail control techniques are discussed. The most promising molluscucides are copper compounds, Bayluscide, biocidal rubber and molluscicidal bait.

Journal of Wildlife Diseases↗
USGS2006

Quantity-activity relationship of denitrifying bacteria and environmental scaling in streams of a forested watershed

The spatial variability of subreach denitrification rates in streams was evaluated with respect to controlling environmental conditions, molecular examination of denitrifying bacteria, and dimensional analysis. Denitrification activities ranged from 0 and 800 ng-N gsed-1 d-1 with large variations observed within short distances (<50 m) along stream reaches. A log-normal probability distribution described the range in denitrification activities and was used to define low (16% of the probability distributibn), medium (68%), and high (16%) denitrification potential groups. Denitrifying bacteria were quantified using a competitive polymerase chain reaction (cPCR) technique that amplified the nirK gene that encodes for nitrite reductase. Results showed a range of nirK quantities from 103 to 107 gene-copy-number gsed.-1 A nonparametric statistical test showed no significant difference in nirK quantifies among stream reaches, but revealed that samples with a high denitrification potential had significantly higher nirK quantities. Denitrification activity was positively correlated with nirK quantities with scatter in the data that can be attributed to varying environmental conditions along stream reaches. Dimensional analysis was used to evaluate denitrification activities according to environmental variables that describe fluid-flow properties, nitrate and organic material quantities, and dissolved oxygen flux. Buckingham's pi theorem was used to generate dimensionless groupings and field data were used to determine scaling parameters. The resulting expressions between dimensionless NO3- flux and dimensionless groupings of environmental variables showed consistent scaling, which indicates that the subreach variability in denitrification rates can be predicted by the controlling physical, chemical, and microbiological conditions. Copyright 2006 by the American Geophysical Union.

Journal of Geophysical Research G: Biogeosciences↗
USGS2017

Field-scale observations of a transient geobattery resulting from natural attenuation of a crude oil spill

We present evidence of a geobattery associated with microbial degradation of a mature crude oil spill. Self-potential measurements were collected using a vertical array of nonpolarizing electrodes, starting at the land surface and passing through the smear zone where seasonal water table fluctuations have resulted in the coating of hydrocarbons on the aquifer solids. These passive electrical potential measurements exhibit a dipolar pattern associated with a current source. The anodic and cathodic reactions of this natural battery occur below and above the smear zone, respectively. The smear zone is characterized by high magnetic susceptibility values associated with the precipitation of semiconductive magnetic iron phase minerals as a by-product of biodegradation, facilitating electron transfer between the anode and the cathode. This geobattery response appears to have a transient nature, changing on a monthly scale, probably resulting from chemical and physical changes in subsurface conditions such as water table fluctuations.

Journal of Geophysical Research G: Biogeosciences↗
USGS1996

Modeling impact of small Kansas landfills on underlying aquifers

Small landfills are exempt from compliance with Resource Conservation and Recovery Act Subtitle D standards for liner and leachate collection. We investigate the ramifications of this exemption under western Kansas semiarid environments and explore the conditions under which naturally occurring geologic settings provide sufficient protection against ground-water contamination. The methodology we employed was to run water budget simulations using the Hydrologic Evaluation of Landfill Performance (HELP) model, and fate and transport simulations using the Multimedia Exposure Assessment Model (MULTIMED) for several western Kansas small landfill scenarios in combination with extensive sensitivity analyses. We demonstrate that requiring landfill cover, leachate collection system (LCS), and compacted soil liner will reduce leachate production by 56%, whereas requiring only a cover without LCS and liner will reduce leachate by half as much. The most vulnerable small landfills are shown to be the ones with no vegetative cover underlain by both a relatively thin vadose zone and aquifer and which overlie an aquifer characterized by cool temperatures and low hydraulic gradients. The aquifer-related physical and chemical parameters proved to be more important than vadose zone and biodegradation parameters in controlling leachate concentrations at the point of compliance.

Journal of Environmental Engineering↗
USGS1978

Chabazite in siliceous tuffs of a Pliocene lacustrine deposit near Durkee, Baker County, Oregon

A relatively pure chabazite deposit of at least 75 X 10 6 metric tons occurs near the Durkee type locality of erionite. This erionite is in a welded tuff interbedded with lacustrine rocks- of a closed Pliocene basin. The zeolites, chabazite, erionite, clinoptilolite, and other authigenic silicate minerals are confined to a 27-square-kilometer area of altered rocks enclosed in relatively freshwater lacustrine beds. About 135 meters of the lower part of the 350-m stratigraphic section at the southeastern part of the lake basin contain zeolitic tuff. The chabazite is an early product of the reaction between glass of rhyolitic or dacitic composition and alkaline (pH>9) saline lake waters. Erionite, clinoptilolite, analcime, and potassium feldspar follow chabazite in the paragenetic sequence. At the erionite type locality, chabazite and clinoptilolite form megascopic crystal clusters within fractures and cavities in unaltered welded tuff. Elsewhere in the basin, most zeolite crystals in the altered airfall or reworked tuffs are less than 80 micrometers long. Chemical analyses, unit-cell determinations, and mean indices of refraction show that fine-grained chabazite varies in composition and physical parameters.

Oregon↗
USGS1976

Feeding ecology of breeding gadwalls on saline wetlands

The feeding ecology of breeding gadwalls ( Anas strepera ) from saline wetlands in North Dakota was examined in relation to sex, pair mates, reproductive status, food availability, and wetland type during the spring and summer of 1971 and 1972. Esophagi of males and females contained 40.4 and 48.2 percent animal food, respectively, between 17 April and 25 August. Animal foods consumed by paired females varied with reproductive condition and were independent of their mates. Invertebrates increased from 47.7 i?? 17.4 percent in the diet during prelaying to 72.0 i?? 18.4 percent during laying and declined to 46.3 i?? 30.0 percent during postlaying. Aquatic insects dominated the diet during egg-laying and were selected disproportionately relative to their availability. Esophageal contents indicated that diversity of plant and animal foods in the diet varied inversely with specific conductance. Major factors influencing food selection of the breeding birds are discussed as interactions among their physiological status, their anatomical and behavioral characteristics, and the abundance and behavior of food organisms as influenced by chemical and physical features of the environment. The data suggested that these interrelated ecological factors act simultaneously to control the phenology of events and determine the foods utilized.

North Dakota↗
USGS1996

Development of a 10-year limnological study of Crater Lake, Crater Lake National Park, Oregon, USA

This paper summarizes the development of a limnological study of Crater Lake conducted between 1983 and 1992. The program was mandated by Congress in the fall of 1982 after a panel of limnologists found the lake data base (1896–1981) to be inadequate to determine if the phytoplankton community had changed and if the lake was decreasing in clarity as suggested from independent studies between 1978 and 1981. Congress authorized and directed the Secretary of the Interior to promptly instigate studies and investigations as to the status and trends of changes of water quality and to immediately implement such actions as necessary to assure the retention of the lake's natural pristine water quality. Program goals were to develop a detailed data base and an understanding of physical, chemical, and biological characteristics and processes of the lake. Ecological relationships among trophic levels and environmental conditions were stressed to evaluate the hypothesis that the lake had changed in water quality and clarity.

Journal of Lake and Reservoir Management↗