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Page 538, results 13426 - 13450

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Not all publications have extents, not all extents are completely accurate
Clay mineral formation and transformation in rocks and soils
D. D. Eberl
1983, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences (311) 241-257
Three mechanisms for clay mineral formation (inheritance, neoformation, and transformation) operating in three geological environments (weathering, sedimentary, and diagenetic-hydrothermal) yield nine possibilities for the origin of clay minerals in nature. Several of these possibilities are discussed in terms of the rock cycle. The mineralogy of clays neoformed in the weathering...
The nature of carbon dioxide waters in Snaefellsnes, western Iceland
S. Arnorsson, I. Barnes
1983, Geothermics (12) 171-176
Over 20 occurrences of thermal and non-thermal waters rich in carbon dioxide are known in the Snaefellsnes Peninsula of western Iceland. On the basis of the thermal, chemical and isotopic characteristics of these waters, and hydrological considerations, it is concluded that they represent meteoric waters which have seeped to variable...
Kinetic analysis of strontium and potassium sorption onto sands and gravels in a natural channel
Kenneth E. Bencala, Alan P. Jackman, Vance C. Kennedy, Ronald J. Avanzino, Gary W. Zellweger
1983, Water Resources Research (19) 725-731
A kinetic, first-order mass transfer model was used to describe the sorption of strontium onto sand- and gravel-sized streambed sediments. Rate parameters, empirically determined for strontium, allowed for the prediction of potassium sorption with moderate success. The model parameters varied significantly with particle size. The sorption data were collected during...
Simulation of solute transport in a mountain pool-and-riffle stream with a kinetic mass transfer model for sorption
Kenneth E. Bencala
1983, Water Resources Research (19) 732-738
In natural channels there are often long periods of low flow during which solutes have repeated opportunity for contact with relatively immobile bed materials. Such conditions can exist in very small pool-and-riffle mountain streams. If a solute can sorb onto bed materials, then both hydrodynamic and chemical processes control solute...
Process and rate of dedolomitization: Mass transfer and C14 dating in a regional carbonate aquifer
W. Back, B.B. Hanshaw, Niel Plummer, P.H. Rahn, C.T. Rightmire, M. Rubin
1983, Geological Society of America Bulletin (94) 1415-1429
Regional dedolomitization is the major process that controls the chemical character of water in the Mississippian Pahasapa Limestone (Madison equivalent) surrounding the Black Hills, South Dakota and Wyoming. The process of dedolomitization consists of dolomite dissolution and concurrent precipitation of calcite; it is...
Gas-film coefficients for streams
R. E. Rathbun, D. Y. Tai
1983, Journal of Environmental Engineering (109) 1111-1127
Equations for predicting the gas-film coefficient for the volatilization of organic solutes from streams are developed. The film coefficient is a function of windspeed and water temperature. The dependence of the coefficient on windspeed is determined from published information on the evaporation of water from a canal. The dependence of...
Snow and ice in a changing hydrological world
M. F. Meier
1983, Hydrological Sciences Journal (28) 3-22
On the occasion of the 60th anniversary of the International Association of Hydrological Sciences, the 100th and 50th anniversaries of the First and Second International Polar Years, and the 25th anniversary of the International Geophysical Year, it seems appropriate to re-examine the world's water balance and the role of snow...
Nonequilibrium models for predicting forms of precipitated manganese oxides
J.D. Hem, Carol J. Lind
1983, Geochimica et Cosmochimica Acta (47) 2037-2046
Manganese oxides precipitated by bubbling air through 0.01 molar solutions of MnCl2, Mn(NO3)2, MnSO4, or Mn(ClO4)2 at a constantly maintained pH of 8.5 to 9.5 at temperatures of 25°C or higher consisted mainly of hausmannite, Mn3O4. At temperatures near 0°C, but with other conditions the same, the product is feitknechtite, βMnOOH,...
Variable tolerance to copper in two species from San Francisco Bay
Samuel N. Luoma, D.J. Cain, K. Ho, A. Hutchinson
1983, Marine Environmental Research (10) 209-222
In static toxicity experiments, tolerance to soluble Cu of the bivalve, Macoma balthica, and the copepod, Acartia clausi, varied substantially among populations sampled within San Francisco Bay. Intraspecific tolerance differed ten-fold or more for both species over relatively small distances, suggesting geographical isolation of populations is not a prerequisite for...
Requirements for modeling trace metal partitioning in oxidized estuarine sediments
Samuel N. Luoma, J.A. Davis
1983, Marine Chemistry (12) 159-181
The fate of particulate-bound metals is of particular importance in estuaries because major biological energy flows involve consumption of detrital particles. The biological impact of particulate-bound metals is strongly influenced by the partitioning of metals among sediment components at the oxidized sediment-water interface. Adequate methods for directly measuring this partitioning...
Ground-water models for water resource planning
J.E. Moore
1983, GeoJournal (7) 453-458
In the past decade hydrogeologists have emphasized the development of computer-based mathematical models to aid in the understanding of flow, the transport of solutes, transport of heat, and deformation in the ground-water system. These models have been used to provide information and predictions for water managers. Too frequently, ground-water was...
Simulation of solute transport in a mountain pool-and-riffle stream: A transient storage model
Kenneth E. Bencala, Roy A. Walters
1983, Water Resources Research (19) 718-724
The physical characteristics of mountain streams differ from the uniform and conceptually well- defined open channels for which the analysis of solute transport has been oriented in the past and is now well understood. These physical conditions significantly influence solute transport behavior, as demonstrated by a transient storage model simulation...
The saltwater-freshwater interface in the Tertiary limestone aquifer, southeast Atlantic outer-continental shelf of the U.S.A.
R.H. Johnston
1983, Journal of Hydrology (61) 239-249
Hydrologic testing in an offshore oil well abandoned by Tenneco, Inc., determined the position of the saltwater-freshwater interface in Tertiary limestones underlying the Florida-Georgia continental shelf of the U.S.A. Previous drilling (JOIDES and U.S.G.S. AMCOR projects) established the existence of freshwater far offshore in this area. At the Tenneco well...
Development of reaction models for ground-water systems
Niel Plummer, D.L. Parkhurst, D.C. Thorstenson
1983, Geochimica et Cosmochimica Acta (47) 665-685
Methods are described for developing geochemical reaction models from the observed chemical compositions of ground water along a hydrologic flow path. The roles of thermodynamic speciation programs, mass balance calculations, and reaction-path simulations in developing and testing reaction models are contrasted. Electron transfer is included in the mass balance equations...
Terpenoid marker compounds derived from biogenic precursors in volcanic ash from Mount St. Helens, Washington
W. E. Pereira, Colleen E. Rostad
1983, Geochimica et Cosmochimica Acta (47) 2287-2291
A volcanic-ash sample obtained after the 1980 eruption of Mount St. Helens, Washington, was analyzed for cyclic terpenoid organic compounds and polycyclic aromatic hydrocarbons using capillary gas chromatography-mass spectrometry-computer techniques. Various tricyclic diterpenoid acids and hydrocarbons were identified including dehydroabietic acid, dehydroabietin, dehydroabietane, simonellite, and retene. Preliminary evidence indicates that...
Hydrologic and geomorphic studies of the Platte River basin
Water Resources Division, U.S. Geological Survey
1983, Professional Paper 1277
The channels of the Platte River and its major tributaries, the South Platte and North Platte Rivers in Colorado, Wyoming, and Nebraska, have undergone major changes in hydrologic regime and morphology since about 1860, when the water resources of the basin began to be developed for agricultural, municipal, and industrial...
Hydrology of the Ferron Sandstone aquifer and effects of proposed surface-coal mining in Castle Valley, Utah, with a section on stratigraphy and a section on leaching of overburden
Gregory C. Lines, Daniel J. Morrissey, Thomas A. Ryer, Richard H. Fuller
1983, Water Supply Paper 2195
Coal in the Ferron Sandstone Member of the Mancos Shale of Cretaceous age has traditionally been mined by underground techniques in the Emery Coal Field in the southern end of Castle Valley in east-central Utah. However, approximately 99 million tons are recoverable by surface mining. Ground water in the Ferron...
Complexation of copper by aquatic humic substances from different environments
Diane M. McKnight, Gerald L. Feder, E. Michael Thurman, Robert L. Wershaw
1983, Science of the Total Environment (28) 65-76
The copper-complexing properties of aquatic humic substances isolated from eighteen different environments were characterized by potentiometric titration, using a cupric ion selective electrode. Potentiometric data were analyzed using FITEQL, a computer program for the determination of chemical equilibrium constants from experimental data. All the aquatic humic substances could be modelled...