Arsenic in ground water of the United States: occurrence and geochemistry
Alan H. Welch, D.B. Westjohn, Dennis R. Helsel, Richard B. Wanty
2000, Ground Water (38) 589-604
Concentrations of naturally occurring arsenic in ground water vary regionally due to a combination of climate and geology. Although slightly less than half of 30,000 arsenic analyses of ground water in the United States were 1 μg/L, about 10% exceeded 10 μg/L....
Dating of major normal fault systems using thermochronology: An example from the Raft River detachment, Basin and Range, western United States
M.L. Wells, L.W. Snee, A.E. Blythe
2000, Journal of Geophysical Research B: Solid Earth (105) 16303-16327
Application of thermochronological techniques to major normal fault systems can resolve the timing of initiation and duration of extension, rates of motion on detachment faults, timing of ductile mylonite formation and passage of rocks through the crystal-plastic to brittle transition, and multiple events of extensional unroofing. Here we determine the...
Problems associated with estimating ground water discharge and recharge from stream-discharge records
K. J. Halford, G.C. Mayer
2000, Ground Water (38) 331-342
Ground water discharge and recharge frequently have been estimated with hydrograph-separation techniques, but the critical assumptions of the techniques have not been investigated. The critical assumptions are that the hydraulic characteristics of the contributing aquifer (recession index) can be estimated from stream-discharge records; that periods of exclusively ground water discharge...
Development of a grid-cell topographic surface for Okefenokee Swamp, Georgia
Cynthia S. Loftin, Wiley Rasberry, Wiley M. Kitchens
2000, Wetlands (20) 487-499
The Okefenokee Swamp is a 160,000 ha freshwater wetland in Southeast Georgia, USA that developed in a landscape basin. Hydrologic variability across the swamp suggests that water-surface elevations are not uniform across the swamp. The topographic surface map discussed herein was developed to describe the swamp topography at local to...
Bed material transport in the Virgin River, Utah
E.D. Andrews
2000, Water Resources Research (36) 585-596
Detailed information concerning the rate and particle size distribution of bed material transport by streamflows can be very difficult and expensive to obtain, especially where peak streamflows are brief and bed material is poorly sorted, including some very large boulders. Such streams, however, are common in steep, arid watersheds. Any...
Contaminant distribution and accumulation in the surface sediments of Long Island Sound
E.L. Mecray, Marilyn R. Buchholtz ten Brink
2000, Journal of Coastal Research (16) 575-590
The distribution of contaminants in surface sediments has been measured and mapped as part of a U.S. Geological Survey study of the sediment quality and dynamics of Long Island Sound. Surface samples from 219 stations were analyzed for trace (Ag, Ba, Cd, Cr, Cu, Hg, Ni, Pb, V, Zn and...
Climatic variability in the eastern United States over the past millennium from Chesapeake Bay sediments
Thomas M. Cronin, Debra A. Willard, A. Karlsen, S. Ishman, S. Verardo, John McGeehin, R. Kerhin, C. Holmes, S. Colman, A. Zimmerman
2000, Geology (28) 3-6
Salinity oscillations caused by multidecadal climatic variability had major impacts on the Chesapeake Bay estuarine ecosystem during the past 1000 yr. Microfossils from sediments dated by radiometry (14C, 137Cs, 210Pb) and pollen stratigraphy indicate that salinity in mesohaline regions oscillated 10-15 ppt during periods of extreme drought (low fresh-water discharge)...
Sedimentary record of the 1872 earthquake and "Tsunami" at Owens Lake, southeast California
J. P. Smoot, R. J. Litwin, J. L. Bischoff, S. J. Lund
2000, Sedimentary Geology (135) 241-254
In 1872, a magnitude 7.5-7.7 earthquake vertically offset the Owens Valley fault by more than a meter. An eyewitness reported a large wave on the surface of Owens Lake, presumably initiated by the earthquake. Physical evidence of this event is found in cores and trenches from Owens Lake, including soft-sediment...
Morphology and processes in Lake Tahoe (California-Nevada)
J.V. Gardner, L. A. Mayer, Clarke J.E. Hughs
2000, Geological Society of America Bulletin (112) 736-746
Lake Tahoe was surveyed using a state-of-the-art, high-resolution, multibeam mapping system to provide an accurate base map for the myriad of ongoing environmental studies in and around the lake. The newly defined basin morphology shows steep basin margins on the northern, eastern, and western sides and a gentle margin on...
A volcano in North Carolina? A closer look at a tall tale
Susan E. Hough
2000, Seismological Research Letters (71) 704-705
The legacy of the 1811-1812 New Madrid, Central United States, earthquakes is one of tremendous enigma. We are left with just enough contemporary information to provide a measure of constraint on the isoseismal contours and therefore magnitudes of the three principal events (Nuttli, 1973; <a class="link...
On the modified Mercalli intensities and magnitudes of the 1811-1812 New Madrid earthquakes
S. E. Hough, J.G. Armbruster, L. Seeber, J.F. Hough
2000, Journal of Geophysical Research B: Solid Earth (105) 23839-23864
We reexamine original felt reports from the 1811–1812 New Madrid earthquakes and determine revised isoseismal maps for the three principal mainshocks. In many cases we interpret lower values than those assigned by earlier studies. In some cases the revisions result from an interpretation of original felt reports with an appreciation...
Debris-flow hazards in the Blue Ridge of central Virginia
G. F. Wieczorek, B. A. Morgan, R. H. Campbell
2000, Environmental & Engineering Geoscience (6) 3-23
The June 27, 1995, storm in Madison County, Virginia produced debris flows and floods that devastated a small (130 km 2 ) area of the Blue Ridge in the eastern United States. Although similar debris-flow inducing storm events may return only approximately once every two thousand years to the same given locale,...
Reproductive ecology of the Maui Parrotbill
John C. Simon, Thane K. Pratt, Kim E. Berlin, James R. Kowalsky
2000, The Wilson Bulletin (112) 482-490
The endangered Maui Parrotbill (Pseudonestor xanthophrys) is an excavating, insectivorous Hawaiian honeycreeper endemic to the high elevation rain forests of east Maui, Hawaii. From March 1994 to June 1997, we studied various aspects of their breeding ecology. We color-banded 18 individuals, located and monitored 9 active nests, and...
Early Agriculture in the eastern Grand Canyon of Arizona, USA
S.W. Davis, M. E. Davis, I. Lucchitta, R. Finkel, M. Caffee
2000, Geoarchaeology - An International Journal (15) 783-798
Abandoned fields in Colorado River alluvium in the eastern Grand Canyon show signs of primitive agriculture. Presence of maize pollen in association with buried soils near Comanche Creek suggests that farming began prior to 3130 yr B.P. Cotton pollen, identified in buried soils near Nankoweap Creek, dates to 1310 yr...
Kansas coal distribution, resources, and potential for coalbed methane
L. L. Brady
2000, The Compass: Earth Science Journal of Sigma Gamma Epsilon (75) 122-133
100 ft (>30 m)] determined from 32 different coal beds. Strippable coal resources at a depth <...
Variability of site response in Seattle, Washington
S. Hartzell, D. Carver, E. Cranswick, A. Frankel
2000, Bulletin of the Seismological Society of America (90) 1237-1250
Ground motion from local earthquakes and the SHIPS (Seismic Hazards Investigation in Puget Sound) experiment is used to estimate site amplification factors in Seattle. Earthquake and SHIPS records are analyzed by two methods: (1) spectral ratios relative to a nearby site on Tertiary sandstone, and (2) a source/site spectral inversion...
Aquifer response to stream-stage and recharge variations. II. Convolution method and applications
P. M. Barlow, L.A. DeSimone, A.F. Moench
2000, Journal of Hydrology (230) 211-229
In this second of two papers, analytical step-response functions, developed in the companion paper for several cases of transient hydraulic interaction between a fully penetrating stream and a confined, leaky, or water-table aquifer, are used in the convolution integral to calculate aquifer heads, streambank seepage rates, and bank storage that...
Correlation of 1- to 10-Hz earthquake resonances with surface measurements of S-wave reflections and refractions in the upper 50 m
R. A. Williams, W. J. Stephenson, A.D. Frankel, E. Cranswick, M. E. Meremonte, J. K. Odum
2000, Bulletin of the Seismological Society of America (90) 1323-1331
Resonances observed in earthquake seismograms recorded in Seattle, Washington, the central United States and Sherman Oaks, California, are correlated with each site's respective near-surface seismic velocity profile and reflectivity determined from shallow seismic-reflection/refraction surveys. In all of these cases the resonance accounts for the highest amplitude shaking at the site...
Mesoproterozoic graphite deposits, New Jersey Highlands: Geologic and stable isotopic evidence for possible algal origins
R.A. Volkert, Craig A. Johnson, Albert V. Tamashausky
2000, Canadian Journal of Earth Sciences (37) 1665-1675
Graphite deposits of Mesoproterozoic age are locally abundant in the eastern New Jersey Highlands, where they are hosted by sulphidic biotite–quartz–feldspar gneiss, metaquartzite, and anatectic pegmatite. Gneiss and metaquartzite represent a shallow marine shelf sequence of locally organic-rich sand and mud. Graphite from massive deposits within metaquartzite yielded δ13C values...
Photographic evaluation of the impacts of bottom fishing on benthic epifauna
J.S. Collie, G.A. Escanero, P. C. Valentine
2000, ICES Journal of Marine Science (57) 987-1001
The gravel sediment habitat on the northern edge of Georges Bank (East coast of North America) is an important nursery area for juvenile fish, and the site of a productive scallop fishery. During two cruises to this area in 1994 we made photographic transects at sites of varying depths that...
Unusual July 10, 1996, rock fall at Happy Isles, Yosemite National Park, California
G. F. Wieczorek, J.B. Snyder, R. B. Waitt, M.M. Morrissey, R. A. Uhrhammer, E. L. Harp, R.D. Norris, M.I. Bursik, L.G. Finewood
2000, Geological Society of America Bulletin (112) 75-85
Effects of the July 10, 1996, rock fall at Happy Isles in Yosemite National Park, California, were unusual compared to most rock falls. Two main rock masses fell about 14 s apart from a 665-m-high cliff southeast of Glacier Point onto a talus slope above Happy Isles in the eastern...
Characterizing Manatee habitat use and seagrass grazing in Florida and Puerto Rico: Implications for conservation and management
L.W. Lefebvre, J.P. Reid, W.J. Kenworthy, J. A. Powell
2000, Pacific Conservation Biology (5) 289-298
The Indian River Lagoon on the Atlantic coast of Florida, USA, and the east coast of Puerto Rico provide contrasting environments in which the endangered West Indian Manatee Trichechus manatus experiences different thermal regimes and seagrass communities. We compare Manatee feeding behaviour in these two regions, examine the ecological effects...
Katmai volcanic cluster and the great eruption of 1912
W. Hildreth, J. Fierstein
2000, Geological Society of America Bulletin (112) 1594-1620
In June 1912, the world's largest twentieth century eruption broke out through flat-lying sedimentary rocks of Jurassic age near the base of Trident volcano on the Alaska Peninsula. The 60 h ash-flow and Plinian eruptive sequence excavated and subsequently backfilled with ejecta a flaring funnel-shaped vent since called Novarupta. The...
Paleogene strata of the Eastern Los Angeles basin, California: Paleogeography and constraints on neogene structural evolution
T. H. McCulloh, L. A. Beyer, R.J. Enrico
2000, Geological Society of America Bulletin (112) 1155-1178
Post-Paleogene dextral slip of 8–9 km is demonstrated for the southeastern part of the Whittier fault zone in the eastern Los Angeles basin area of southern California. A linear axis of greatest thickness for the combined upper Paleocene and lower to lower-middle Eocene clastic formations intersects the fault zone and...
Potential seismic hazards and tectonics of the upper Cook Inlet basin, Alaska, based on analysis of Pliocene and younger deformation
Peter J. Haeussler, Ronald L. Bruhn, Thomas L. Pratt
2000, Geological Society of America Bulletin (112) 1414-1429
The Cook Inlet basin is a northeast-trending forearc basin above the Aleutian subduction zone in southern Alaska. Folds in Cook Inlet are complex, discontinuous structures with variable shape and vergence that probably developed by right-transpressional deformation on oblique-slip faults extending downward into Mesozoic basement beneath the Tertiary basin. The most...
