A three-dimensional, finite element model for coastal and estuarine circulation
R. A. Walters
1992, Continental Shelf Research (12) 83-102
This paper describes the development and application of a three-dimensional model for coastal and estuarine circulation. The model uses a harmonic expansion in time and a finite element discretization in space. All nonlinear terms are retained, including quadratic bottom stress, advection and wave transport (continuity nonlinearity). The equations are solved...
A reconnaissance study of herbicides and their metabolites in surface water of the midwestern united states using immunoassay and gas chromatography/mass spectrometry
E. Michael Thurman, D. A. Goolsby, M. T. Meyer, M. S. Mills, M.L. Pomes, Dana W. Kolpin
1992, Environmental Science & Technology (26) 2440-2447
Preemergent herbicides and their metabolites, particularly atrazine, deethylatrazine, and metolachlor, persisted from 1989 to 1990 in the majority of rivers and streams in the midwestern United States. In spring, after the application of herbicides, the concentrations of atrazine, alachlor, and simazine were frequently 3-10 times greater than the U.S. Environmental...
Leaks in pipe networks
Ranko S. Pudar, James A. Liggett
1992, Journal of Hydraulic Engineering (118) 1031-1046
Leak detection in water‐distribution systems can be accomplished by solving an inverse problem using measurements of pressure and/or flow. The problem is formulated with equivalent orifice areas of possible leaks as the unknowns. Minimization of the difference between measured and calculated heads produces a solution for the areas. The quality...
Effect of water saturation in soil organic matter on the partition of organic compounds
D.W. Rutherford, G.T. Chlou
1992, Environmental Science & Technology (26) 965-970
No abstract available. ...
The oldest known Rocky Mountain bristlecone pines (Pinus aristata Engelm.)
F.C. Brunstein, D.K. Yamaguchi
1992, Arctic and Alpine Research (24) 253-256
We have found 12 living Rocky Mountain bristlecone pines (Pinus aristata) more than 1600 yr old, including four that are more than 2100 yr old, on Black Mountain, near South Park, and on Almagre Mountain, in the southern Front Range, Colorado. A core from the oldest of these trees has...
Humic substances and trace metals associated with Fe and Al oxides deposited in an acidic mountain stream
Diane M. McKnight, R.L. Wershaw, K.E. Bencala, G. W. Zellweger, G. L. Feder
1992, Science of Total Environment (117-118) 485-498
Hydrous iron and aluminum oxides are deposited on the streambed in the confluence of the Snake River and Deer Creek, two streams in the Colorado Rocky Mountains. The Snake River is acidic and has high concentrations of dissolved Fe and Al. These metals precipitate at the confluence with the pristine,...
Deep Sea Drilling Project Site 612 bolide event: New evidence of a late Eocene impact-wave deposit and a possible impact site, US east coast
W. Wei, C. Wylie Poag, Lawrence J. Poppe, David W. Folger, David S. Powars, Robert B. Mixon, Lucy E. Edwards, Scott Bruce
1992, Geology (20) 771-774
A remarkable >60-m-thick, upward-fining, polymictic, marine boulder bed is distributed over >15 000 km2 beneath Chesapeake Bay and the surrounding Middle Atlantic Coastal Plain and inner continental shelf. The wide varieties of clast lithologies and microfossil assemblages were derived from at least seven known Cretaceous, Paleocene, and Eocene stratigraphic units....
U-Pb dating of uranium deposits in collapse breccia pipes of the Grand Canyon region
K.R. Ludwig, K. R. Simmons
1992, Economic Geology (87) 1747-1765
Two major periods of uranium mineralization are indicated by U-Pb isotope dating of uranium ores from collapse breeeia pipes in the Grand Canyon region, northern Arizona. The Hack 2 and 3, Kanab North, and EZ 1 and 2 orebodies apparently formed in the interval of 200 + or - 20...
Groundwater flow, velocity, and age in a thick, fine-grained till unit in southeastern Wisconsin
W.W. Simpkins, K. R. Bradbury
1992, Journal of Hydrology (132) 283-319
Piezometer nests were installed at study sites in each of five north-south-trending end moraines of the late Pleistocene Oak Creek Formation in southeastern Wisconsin. The formation is composed primarily of a fine-grained glacial diamicton (till) and laterally continuous and discontinuous, coarse-grained lake and meltwater stream sediment. It overlies the Silurian...
Enzymatic uranium precipitation
Y.A. Gorby, Derek R. Lovley
1992, Environmental Science & Technology (26) 205-207
No abstract available....
Paleomagnetic data bearing on the origin of arcuate structures in the French Peak-Massachusetts Mountain area of southern Nevada
M.R. Hudson
1992, Geological Society of America Bulletin (104) 581-594
The eastern margin of the Yucca Flat basin, in southern Nevada, is bounded by north-northwest-striking tilted fault blocks of the Halfpint Range whose strikes curve as much as 90° clockwise into east-northeast strikes in the French Peak-Massachusetts Mountain (FPMM) area. This pattern of...
Patterns and rates of ground-water flow on Long Island, New York
Herbert T. Buxton, Edward Modica
1992, Groundwater (30) 857-866
Increased ground-water contamination from human activities on Long Island has prompted studies to define the pattern and rate of ground-water movement. A two-dimensional, fine-mesh, finite-element model consisting of 11,969 nodes and 22,880 elements was constructed to represent ground-water flow along a north-south section through central Long Island. The model represents...
The study of the undiscovered mineral resources of the Tongass National Forest and adjacent lands, Southeastern Alaska
D. A. Brew, L.J. Drew, S. D. Ludington
1992, Nonrenewable Resources (1) 303-322
The quantitative probabilistic assessment of the undiscovered mineral resources of the 17.1-million-acre Tongass National Forest (the largest in the United States) and its adjacent lands is a nonaggregated, mineral-resource-tract-oriented assessment designed for land-planning purposes. As such, it includes the renewed use of gross-in-place values (GIPV's) in dollars of the estimated...
Compost: Brown gold or toxic trouble?
D.A. Kovacic, R.A. Cahill, T.J. Bicki
1992, Environmental Science & Technology (26) 38-41
Limited data are available regarding the occurrence of potentially hazardous constituents in raw, uncomposted yard wastes, partially composted yard wastes, and finished compost (15, 16). Environmental monitoring at composting operations or facilities is lacking, and currently published research on the environmental fate of composted yard waste constituents is extremely limited....
Subglacial water flow inferred from stream measurements at South Cascade Glacier, Washington, USA
A. G. Fountain
1992, Journal of Glaciology (38) 51-64
The subglacial drainage system of South Cascade Glacier is inferred by examining how discharges of water, solutes and artificial tracers in streams draining the glacier respond to meltwater and precipitation on the glacier surface. Results indicate that the glacier is divided into three (two large and one...
Depressions and other lake-floor morphologic features in deep water, southern Lake Michigan
Steven M. Colman, D.S. Foster, D.W. Harrison
1992, Journal of Great Lakes Research (18) 267-279
The most common features are subcircular depressions, commonly compound, that are irregularly distributed across the lake floor. The depressions are most common in the southern basin of the lake where lacustrine sediments are more than a few meters thick, corresponding to water depths greater than about 90 m. We have...
Lithology, stratigraphy, and paleoenvironments of the Mobil 312-1 well, Georges Bank Basin, US North Atlantic outer continental shelf
L.J. Poppe, C. W. Poag, R.W. Stanton
1992, Northeastern Geology (14) 156-170
The Mobil 312-1 hydrocarbon exploratory well, southeastern Georges Bank Basin penetrated a section entirely composed of sedimentary rocks that range from Middle to Pliocene age. Carbonates are the dominant lithologies in the intervals at 6096-3444 m, 2560-2096 m and 1067-887 m; siliciclastics make up most of the remaining section. Although...
Species dominance and equitability: patterns in Cenozoic foraminifera of eastern North America
T. G. Gibson, E.E. Hill
1992, Journal of Foraminiferal Research (22) 34-51
Species dominance in benthonic foraminifera, represented by percent of the assemblage composed of the single most abundant species, shows little change in observed range of values from shallow into deep-marine waters in 1005 samples from the Gulf of Mexico, Atlantic, and Arctic margins of North America. This finding contrasts with...
Bluff recession rates along the Lake Michigan shoreline in Illinois
R.W. Jibson, J.-M. Staude
1992, Bulletin of the Association of Engineering Geologists (29) 103-117
For two time periods, 1872-1937 and 1937-1987, rates of retreat vary from 10 to 75 cm/yr between discrete segments of bluffs (defined by lithology) and between time periods for a given bluff segment. The average retreat rates for the entire area, however, do not vary significantly between the two time...
Using soil gas radon and geology to estimate regional radon potential
G.M. Reimer
1992, Conference Paper, Radiation Protection Dosimetry
Two important parameters have been identified in order to estimate the radon potential of a region. They are the soil gas radon concentration and the geological rock type from which soils are derived. A simple soil gas collection and analytical technique has been developed to provide information on soil gas...
Modeling transport in transient ground-water flow: An unacknowledged approximation
Daniel J. Goode
1992, Ground Water (30) 257-261
During unsteady or transient ground-water flow, the fluid mass per unit volume of aquifer changes as the potentiometric head changes, and solute transport is affected by this change in fluid storage. Three widely applied numerical models of two-dimensional transport partially account for the effects of transient flow by removing terms...
Crystalline solution series and order-disorder within the natrolite mineral group
M. Ross, M.J.K. Flohr, D.R. Ross
1992, American Mineralogist (77) 685-703
Electron microprobe and X-ray analyses were made of natrolite, tetranatrolite, gonnardite, and thomsonite from the Magnet Cove alkaline igneous complex, Arkansas, and of selected specimens from the U.S. National Museum. This information and data from the literature indicate that natrolite, mesolite, scolecite, edingtonite, and tetraedingtonite show only small deviations from...
Ground-water models cannot be validated
Leonard F. Konikow, J.D. Bredehoeft
1992, Advances in Water Resources (15) 75-83
Ground-water models are embodiments of scientific hypotheses. As such, the models cannot be proven or validated, but only tested and invalidated. However, model testing and the evaluation of predictive errors lead to improved models and a better understanding of the problem at hand....
Decomposition techniques
T. T. Chao, R. F. Sanzolone
1992, Journal of Geochemical Exploration (44) 65-106
Sample decomposition is a fundamental and integral step in the procedure of geochemical analysis. It is often the limiting factor to sample throughput, especially with the recent application of the fast and modern multi-element measurement instrumentation. The complexity of geological materials...
Remagnetization of the Coast Range ophiolite at Stanley Mountain, California, during accretion near 10°N paleolatitude
Jonathan T. Hagstrum
1992, Geology (20) 503-506
Paleomagnetic data are presented for a 50-m-thick sequence of Oxfordian to Tithonian sedimentary rocks conformably overlying Upper Jurassic pillow basalt within the Coast Range ophiolite at Stanley Mountain, California. These new data are similar in direction and polarity to previously published paleomagnetic data for the pillow basalt. The Jurassic sedimentary...
