Episodic acidification of small streams in the northeastern United States: Fish mortality in field bioassays
J. Van Sickle, J.P. Baker, H. A. Simonin, Barry P. Baldigo, W.A. Kretser, W.E. Sharpe
1996, Ecological Applications (6) 408-421
In situ bioassays were performed as part of the Episodic Response Project, to evaluate the effects of episodic stream acidification on mortality of brook trout (Salvelinus fontinalis) and forage fish species. We report the results of 122 bioassays in 13 streams of the three study regions: the Adirondack mountains of...
Episodic acidification of small streams in the northeastern United states: Effects on fish populations
J.P. Baker, J. Van Sickle, C.J. Gagen, David R. DeWalle, W.E. Sharpe, R.F. Carline, Barry P. Baldigo, Peter S. Murdoch, D.W. Bath, W.A. Kretser, H. A. Simonin, P.J. Wigington Jr.
1996, Ecological Applications (6) 422-437
As part of the Episodic Response Project (ERP), we studied the effects of episodic acidification on fish in 13 small streams in the northeastern United States: four streams in the Adirondack region of New York, four streams in the Catskills, New York, and five streams in the northern Appalachian Plateau,...
Metastable mantle phase transformations and deep earthquakes in subducting oceanic lithosphere
S. H. Kirby, S. Stein, E.A. Okal, David C. Rubie
1996, Reviews of Geophysics (34) 261-306
Earth's deepest earthquakes occur as a population in subducting or previously subducted lithosphere at depths ranging from about 325 to 690 km. This depth interval closely brackets the mantle transition zone, characterized by rapid seismic velocity increases resulting from the transformation of upper mantle minerals to higher-pressure phases. Deep earthquakes...
Summary of the Snake River plain Regional Aquifer-System Analysis in Idaho and eastern Oregon
G. F. Lindholm
1996, Professional Paper 1408-A
Regional aquifers underlying the 15,600-square-mile Snake River Plain in southern Idaho and eastern Oregon was studied as part of the U.S. Geological Survey's Regional Aquifer-System Analysis program. The largest and most productive aquifers in the Snake River Plain are composed of Quaternary basalt of the Snake River Group, which underlies...
Identification of hydraulic conductivity structure in sand and gravel aquifers: Cape Cod data set
J.R. Eggleston, S.A. Rojstaczer, J.J. Peirce
1996, Water Resources Research (32) 1209-1222
This study evaluates commonly used geostatistical methods to assess reproduction of hydraulic conductivity (K) structure and sensitivity under limiting amounts of data. Extensive conductivity measurements from the Cape Cod sand and gravel aquifer are used to evaluate two geostatistical estimation methods, conditional mean as an estimate and ordinary kriging, and...
Overview of a simple model describing variation of dissolved organic carbon in an upland catchment
Elizabeth W. Boyer, George M. Hornberger, Kenneth E. Bencala, Diane M. McKnight
1996, Ecological Modelling (86) 183-188
Hydrological mechanisms controlling the variation of dissolved organic carbon (DOC) were investigated in the Deer Creek catchment located near Montezuma, CO. Patterns of DOC in streamflow suggested that increased flows through the upper soil horizon during snowmelt are responsible for flushing this DOC-enriched interstitial water to the streams. We examined...
Trace elements and organic contaminants in stream sediments from the Red River of the North Basin
M. E. Brigham, L. H. Tornes
1996, Conference Paper, North Dakota Water Quality Symposium
To assess the presence and distribution of a variety of hydro-phobic chemicals in streams in the Red River of the North Basin, bottom sediments were analyzed for trace elements, organochlorines, and polycyclic aromatic hydrocarbons (PAHs). Glaciolacustrine clays and carbonate minerals are common in...
Thermal evolution of sedimentary basins in Alaska
Mark J. Johnsson, David G. Howell, editor(s)
1996, Bulletin 2142
The complex tectonic collage of Alaska is reflected in the conjunction of rocks of widely varying thermal maturity. Indicators of the level of thermal maturity of rocks exposed at the surface, such as vitrinite reflectance and conodont color alteration index, can help constrain the tectonic evolution of such complex regions and, when combined with petrographic, modern...
Middle Pliocene vegetation: Reconstructions, paleoclimatic inferences, and boundary conditions for climate modeling
Robert S. Thompson, R.F. Fleming
1996, Marine Micropaleontology (27) 27-49
The general characteristics of global vegetation during the middle Pliocene warm period can be reconstructed from fossil pollen and plant megafossil data. The largest differences between Pliocene vegetation and that of today occurred at high latitudes in both hemispheres, where warming was pronounced relative to today. In the Northern Hemisphere...
A benthic foraminiferal record of middle to late Pliocene (3.15-2.85 Ma) deep water change in the North Atlantic
Scott E. Ishman
1996, Marine Micropaleontology (27) 165-180
Records of benthic foraminifera from North Atlantic DSDP Site 607 and Hole 610A indicate changes in deep water conditions through the middle to late Pliocene (3.15 to 2.85 Ma). Quantitative analyses of modern associations in the North Atlantic indicate that seven species, Fontbotia wuellerstorfi, Cibicidoides kullenbergi, Uvigerina peregrina, Nuttallides umboniferus, Melonis...
Pliocene and early Pleistocene environments and climates of the western Snake River Plain, Idaho
Robert S. Thompson
1996, Marine Micropaleontology (27) 141-156
Sedimentological, palynological, and magnetic susceptibility data provide paleoenvironmental and paleoclimatic information from a 989 ft (301 m) core of sediments from the upper Glenns Ferry and Bruneau Formations from near the town of Bruneau in Owyhee County, Idaho. Chronology is based on stratigraphic position, paleomagnetism, and biostratigraphic data, which collectively...
Crustal and upper mantle velocity structure of the Salton Trough, southeast California
T. Parsons, J. McCarthy
1996, Tectonics (15) 456-471
This paper presents data and modelling results from a crustal and upper mantle wide-angle seismic transect across the Salton Trough region in southeast California. The Salton Trough is a unique part of the Basin and Range province where mid-ocean ridge/transform spreading in the Gulf of California has evolved northward into...
Linking sediment transport and stratigraphy on the continental shelf
P.L. Wiberg, D.A. Cacchione, Richard W. Sternberg, L. Donelson Wright
1996, Oceanography (9) 153-157
The goal of the shelf sediment dynamics component of STRATAFORM is to link sediment transport processes active on the continental shelf to the formation and preservation of event beds in shelf sediment deposits. An approach combining shelf sediment-transport models with high-resolution measurements of water-column and bed properties over periods from...
Ground-water flow and simulated effects of development in Paradise Valley, a basin tributary to the Humboldt River in Humboldt County, Nevada
David E. Prudic, M.E. Herman
1996, Professional Paper 1409-F
A computer model was used to characterize ground-water flow in Paradise Valley, Nevada, and to evaluate probable long-term effects of five hypothetical development scenarios. One finding of the study is that concentrating pumping at the south end of Paradise Valley may increase underflow from the adjacent Humboldt River valley, and...
Earthquake-induced burial of archaeological sites along the southern Washington coast about A.D. 1700
Steve C. Cole, Brian F. Atwater, Patrick T. McCutcheon, Julie K. Stein, Eileen Hemphill-Haley
1996, Geoarchaeology - An International Journal (11) 165-177
Although inhabited by thousands of people when first reached by Europeans, the Pacific coast of southern Washington has little recognized evidence of prehistoric human occupation. This apparent contradiction may be explained partly by geologic evidence for coastal submergence during prehistoric earthquakes on the Cascadia subduction zone. Recently discovered archaeological sites,...
A model for field toxicity tests
Mark S. Kaiser, Susan E. Finger
1996, Environmetrics (7) 215-229
Toxicity tests conducted under field conditions present an interesting challenge for statistical modelling. In contrast to laboratory tests, the concentrations of potential toxicants are not held constant over the test. In addition, the number and identity of toxicants that belong in a model as explanatory factors are not known and...
Modeling of fluidized ejecta emplacement over digital topography on Venus
Jeffrey R. Johnson, Lisa R. Gaddis
1996, Journal of Geophysical Research E: Planets (101)
The FLOW computer model of McEwen and Malin (1989) modified for application to the study of Venus fluidized ejecta blankets (FEBs) demonstrates that relatively low viscosities, yield strengths, and initial velocities are required to duplicate the observed flow paths of the outflow materials. The model calculates the velocities and simulated...
Large-scale right-slip displacement on the East San Francisco Bay region fault system, California: Implications for location of late Miocene to Pliocene Pacific plate boundary
R. J. McLaughlin, W.V. Sliter, D. H. Sorg, P.C. Russell, A.M. Sarna-Wojcicki
1996, Tectonics (15) 1-18
A belt of northwardly younging Neogene and Quaternary volcanic rocks and hydrothermal vein systems, together with a distinctive Cretaceous terrane of the Franciscan Complex (the Permanente terrane), exhibits about 160 to 170 km of cumulative dextral offset across faults of the East San Francisco Bay Region (ESFBR) fault system. The...
Intermediate‐depth intraslab earthquakes and arc volcanism as physical expressions of crustal and uppermost mantle metamorphism in subducting slabs
Stephen H. Kirby, E. Robert Engdahl, Roger P. Denlinger
1996, Book chapter, Subduction: Top to bottom
We elaborate on the well-known spatial association between axc volcanoes and Wadati Benioff zones and explore in detail their genetic relationships as dual physical expressions of slab metamorphism of the oceanic crust and uppermost mantle. At hypocentral depths less than 200 km intra slab Wadati-Benioff earthquakes tend to occur near...
40Ar/39Ar whole-rock data constraints on Acadian diagenesis and Alleghanian cleavage in the Martinsburg formation, eastern Pennsylvania
R. P. Wintsch, Michael J. Kunk, Jack B. Epstein
1996, American Journal of Science (296) 766-788
A comparison of 40Ar/39Ar age spectra of whole-rock mudstone and slate samples from the Ordovician Martinsburg Formation at Lehigh Gap, Pennsylvania and stratigraphic and thermal constraints support Alleghanian age for regional slaty cleavage and a late Acadian age for diagenesis in these rocks. Age spectra from mud-stones have a sigmodal shape,...
Geodynamic Evolution of the Transantarctic Mountains and the West Antarctica Rift System: Proceedings of a workshop
Terry J. Wilson, Carol A. Finn, editor(s)
1996, Report
The workshop "Geodynamic Evolution of the Transantarctic Mountains and West Antarctic Rift System" was convened to provide a forum for discussion of future research on Antarctic rifting processes. The workshop drew on the expertise of thirty-one geologists and geophysicists currently involved in Antarctic research or investigating other rift systems. The...
National Biological Service Research Supports Watershed Planning
Craig D. Snyder
1996, Report, Watershed Events: an EPA bulletin on integrated aquatic ecosystem protection
The National Biological Service's Leetown Science Center is investigating how human impacts on watershed, riparian, and in-stream habitats affect fish communities. The research will provide the basis for a Ridge and Valley model that will allow resource managers to accurately predict and effectively mitigate human impacts on water quality....
Use of a deterministic fire growth model to test fuel treatments
J. W. van Wagtendonk
1996, Book chapter, Sierra Nevada Ecosystem Project: Final report to Congress, Volume II
Fuel treatments are necessary in many vegetated areas of the Sierra Nevada to mitigate the effects of decades of fire suppression and land-management activities on fuel accumulations and understory canopies. Treating fuels will reduce the severity of wildfires and, as a result, the threat to human lives, the destruction of property and valuable resources, and...
An overview of fire in the Sierra Nevada
K.S. McKelvey, C.N. Skinner, C. Chang, D.C. Erman, S.J. Husari, D.J. Parsons, J. W. van Wagtendonk, C.P. Weatherspoon
1996, Book chapter, Sierra Nevada Ecosystem Project: Final report to Congress, Volume II
Fire, ignited by lightning and Native Americans, was common in the Sierra Nevada prior to 20th century suppression efforts. Presettlement fire return intervals were generally less than 20 years throughout a broad zone extending from the foothills through the mixed conifer forests. In the 20th century, the areal extent of fire was greatly reduced. This...
Mediterranean-type ecosystems: the influence of biodiversity on their functioning
George W. Davis, David M. Richardson, Jon E. Keeley, Richard J. Hobbs
H. A. Mooney, J.H. Cushman, E. Medina, O.E. Sala, E. #NAME? Schulze, editor(s)
1996, Book chapter, Functional Roles of Biodiversity: A Global Perspective
Ecosystems in the Mediterranean-climate regions of the world have served as a unit for comparative ecological studies for over two decades. The cohesiveness of research in this set of widely distributed regions rests on the similarity of the climates where they occur, and the identifiable convergence in elements of...
