Geographic trend in mercury measured in common loon feathers and blood
Joseph D. Kaplan, Michael W. Meyer, Peter S. Reaman, W. Emmett Braselton, A. Major, Neil Burgess, Anton M. Scheuhammer
1998, Environmental Toxicology and Chemistry (17) 173-183
The common loon (Gavia immer) is a high‐trophic‐level, long‐lived, obligate piscivore at risk from elevated levels of Hg through biomagnification and bioaccumulation. From 1991 to 1996 feather (n = 455) and blood (n = 381) samples from adult loons were collected between June and September in five regions of North America: Alaska,...
A reexamination of the turquoise group: The mineral aheylite, planerite (redefined), turquoise and coeruleolactite
E.E. Foord, J.E. Taggart Jr.
1998, Mineralogical Magazine (62) 93-111
The turquoise group has the general formula: A (sub 0-1) B 6 (PO 4 ) (sub 4-x) (PO 3 OH) x (OH) 8 .4H 2 O, where x = 0-2, and consists of six members: planerite, turquoise, faustite, aheylite, chalcosiderite and an unnamed Fe (super 2+) -Fe (super 3+) analogue. The existence of "coeruleolactite" is doubtful. Planerite is revalidated as a...
Glaciation and regional ground-water flow in the Fennoscandian Shield: Site 94
Alden M. Provost, Clifford I. Voss, C. E. Neuzil
1998, SKI Report 96:11
Results from a regional-scale ground-water flow model of the Fennoscandian shield suggest that ground-water flow is strongly affected by surface conditions associated with climatic change and glaciation. The model was used to run a series of numerical simulations of variable-density ground-water flow in a 1500-km-long and approximately 10-km-deep cross-section that...
Modifications to a one-dimensional model of unsteady flow in the Colorado River through the Grand Canyon, Arizona
Stephen Mark Wiele, Eleanor R. Griffin
1998, Water-Resources Investigations Report 97-4046
Remote sensing in the USGS Mineral Resource Surveys Program in the eastern United States
Lawrence C. Rowan
1998, Report
Mineral deposits commonly occur within special geologic units or structures, such as fault zones, which can be detected and mapped from aircraft and satellite images. Modern techniques analyze multispectral images that record the way solar energy is reflected or emitted by the materials exposed at the Earth's surface. In sparsely...
Revising U.S. Geological Survey mineral-resource assessment methods
Lawrence J. Drew
1998, Report
As a result of public controversy over recommendations related to the wilderness preservation system, the U.S. Geological Survey (USGS) conducted a series of reviews of its mineral-resource assessment methods. The first review panel recommended several short- and long-term modifications to improve future mineral-resource assessments (Harris and Rieber, 1993). Implementation of...
Hydrology and snowmelt simulation of Snyderville Basin, Park City, and adjacent areas, Summit County, Utah
Lynette E. Brooks, James L. Mason, David D. Susong
1998, Technical Publication 115
Increasing residential and commercial development is placing increased demands on the ground- and surface-water resources of Snyderville Basin, Park City, and adjacent areas in the southwestern corner of Summit County, Utah. Data collected during 1993-95 were used to assess the quantity and quality of the water resources in the study...
Level II scour analysis for brigde 5 (STOCTH00360005) on Town Highway 36, crossing Stony Brook, Stockridge, Vermont
Lora K. Striker, Matthew A. Weber
1998, Open-File Report 98-XXX
This report provides the results of a detailed Level II analysis of scour potential at structure STOCTH00360005 on Town Highway 36 crossing Stony Brook, Stockbridge, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S....
General philosophy 5: Concerning nonuniqueness
D. A. Chapin
1998, Book chapter, Geologic applications of gravity and magnetics: Case histories
There are models we might like to accept that just dont fit gravity, magnetic, or electrical data. This benefit of modeling is important. It forces the interpreter to prove that an interpretation is possible, and it eliminates impossible models even seismic models. A simple depth estimate may be all the...
General philosophy 3: Concerning modeling
D. A. Chapin
1998, Book chapter, Geologic applications of gravity and magnetics: Case histories
The trend toward modeling is a healthy change from the days when “prospects” were located solely on the basis of closures on residual maps of mysterious and sometimes secret origin. Although residual maps are valuable for helping us notice unusual relationships, the business of exploration has become less tolerant of...
Sources and age of aquatic humus
Diane M. McKnight, George R. Aiken
1998, Book chapter, Aquatic humic substances: Ecology and biogeochemsitry
As aquatic scientists have recognized the diversity of processes controlled by or dependent upon aquatic humus, it has become important to learn more about the genesis, chemical properties, and concentration of humic substances in aquatic ecosystems. There are three classes of aquatic humus (fulvic acids, humic acids, and humin), all...
Characterization of an old-growth bottomland hardwood wetland forest in Northeast Texas: Harrison Bayou
Laurence C. Walker, Thomas Brantley, Virginia Burkett
1998, Book chapter, Wilderness and natural areas in Eastern North America : Research, management and planning
Most wetland losses in the southern region over the past 200 years have occurred in bottomland hardwood forests. By 1980 the original extent of palustrine bottomland in Texas had been reduced by 63%, from roughly 16 to 6 million acres. Additional losses have occurred during more recent years as a result of conversion...
Flooding and forest succession in a modified stretch along the Upper Mississippi River
Yao Yin
1998, Regulated Rivers: Research & Management (14) 217-225
This research examines the effect of a rare flood on floodplain forest regeneration in a 102-km stretch of the Mississippi River beginning 21 km above the mouth of the Ohio River. The river has been restricted by levees and navigation structures and subjected to sediment dredging to maintain a stable...
Predictive double-layer modeling of metal sorption in mine-drainage systems
K. S. Smith, J. F. Ranville, D.L. Macalady
E. A. Jenne, editor(s)
1998, Book chapter, Adsorption of metals by geomedia: Variables, mechanisms, and model applications
Previous comparison of predictive double-layer modeling and empirically derived metal-partitioning data has validated the use of the double-layer model to predict metal sorption reactions in iron-rich mine-drainage systems. The double-layer model subsequently has been used to model data collected from several mine-drainage sites in Colorado with diverse geochemistry and geology....
Environmental modification of gillraker number in coregonine fishes
Thomas N. Todd
1998, Book chapter, Biology and management of Coregonid fishes-1996
Gillraker number, one of the most important taxonomic characters in the Coregoninae, has been considered genetically determined and not environmentally modifiable. However, laboratory-reared progeny of Coregonus alpenae, C. artedi, C. clupeaformis, C. hoyi, C. kiyi, C. zenithicus, and Prosopium cylindraceum generally had fewer gillrakers than the wild parents from which...
Fundamentals of isotope geochemistry
Carol Kendall, Eric A. Caldwell
1998, Book chapter, Isotope tracers in catchment hydrology
The dominant use of isotopes in catchment research in the last few decades has been to trace sources of waters and solutes. Generally, such data were evaluated with simple mixing models to determine how much was derived from either of the two (sometimes three) constant-composition sources. This chapter illustrates the...
Using transport model interpretations of tracer tests to study microbial processes in groundwater
Richard L. Smith, Stephen P. Garabedian
1998, Book chapter, Mathematical modeling in microbial ecology
It has long been known that microorganisms affect the geochemistry of groundwater. But despite this recognition, little detailed information is available regarding the rates and the factors controlling microbial processes in groundwater. Part of the reason stems from the relatively inaccessible nature of most groundwater and the difficulties encountered in...
Use of restored riparian habitat by the endangered least Bell's vireo (Vireo bellii pusillus)
B.E. Kus
1998, Restoration Ecology (6) 75-82
A primary objective of riparian restoration in California is the creation of habitat for endangered species. Four restoration sites in San Diego County were monitored between 1989 and 1993 and evaluated for their suitability as nesting habitat for Vireo bellii pusillus (Least Bell's Vireo), a state and federally endangered obligate riparian breeder....
The Fremont complex: A behavioral perspective
D.B. Madsen, S.R. Simms
1998, Journal of World Prehistory (12) 255-336
The Fremont complex is composed of farmers and foragers who occupied the Colorado Plateau and Great Basin region of western North America from about 2100 to 500 years ago. These people included both immigrants and indigenes who shared some material culture and symbolic attributes, but also varied in ways not...
Estimating species richness: The Michaelis-Menten model revisited
K.A. Keating, J.F. Quinn
1998, Oikos (81) 411-416
The Michaelis-Menten model has been widely used to estimate the richness (S) of species pools, but is largely untested. We tested whether (1) species accumulation curves follow the form predicted by the model, (2) the model gives unbiased estimates (Ŝ and B̂, respectively) of S and of the sample size,...
Development and testing of a compartmentalized reaction network model for redox zones in contaminated aquifers
Robert H. Abrams , Keith Loague, Douglas B. Kent
1998, Water Resources Research (34) 1531-1541
The work reported here is the first part of a larger effort focused on efficient numerical simulation of redox zone development in contaminated aquifers. The sequential use of various electron acceptors, which is governed by the energy yield of each reaction, gives rise to redox zones. The large difference in...
A comparison of triploid induction validation techniques
R.M. Harrell, W. Van Heukelem, J.H. Kerby
1998, Progressive Fish-Culturist (60) 221-226
Triploidy induction is a technique that allows genetic manipulation of chromosome number to control reproduction and potentially create faster‐growing animals; however, most methods for inducing polyploidy are not 100% effective. Using sunshine bass (white bass Morone chrysops ♀ × striped bass M. saxatilis ♂) as a model, we cross‐validated the most common verification techniques:...
Factors controlling As and U in shallow ground water, southern Carson Desert, Nevada
A. H. Welch, M.S. Lico
1998, Applied Geochemistry (13) 521-539
Unusually high As and U concentrations (> 100 ??g/L) are widespread in shallow ground water beneath the southern Carson Desert. The high concentrations, which locally exceed 1000 ??g/L, are of concern from a human health standpoint because the shallow ground water is used for domestic supply. Possible affects on wildlife...
Predicting CH4 adsorption capacity of microporous carbon using N2 isotherm and a new analytical model
Jielun Sun, S. Chen, M. Rostam-Abadi, M.J. Rood
1998, ACS Division of Fuel Chemistry, Preprints (43) 596-599
A new analytical pore size distribution (PSD) model was developed to predict CH4 adsorption (storage) capacity of microporous adsorbent carbon. The model is based on a 3-D adsorption isotherm equation, derived from statistical mechanical principles. Least squares error minimization is used to solve the PSD without any pre-assumed distribution function....
The provenance and chemical variation of sandstones associated with the Mid-continent Rift System, U.S.A.
R.L. Cullers, P. Berendsen
1998, European Journal of Mineralogy (10) 987-1002
Sandstones along the northern portion of the Precambrian Mid-continent Rift System (MRS) have been petrographically and chemically analyzed for major elements and a variety of trace elements, including the REE. After the initial extrusion of the abundant basalts along the MRS, dominantly volcaniclastic sandstones of the Oronto Group were deposited....
