Arenig volcanic and sedimentary strata, central New Brunswick and eastern Maine
W. H. Poole, Robert B. Neuman
2002, Atlantic Geology (38) 109-134
Arenig strata in the Napadogan area of the Miramichi Highlands of west-central New Brunswick are similar to those of the Lunksoos anti-clinorial area of eastern Maine. Strata from both areas were deposited in a volcanic back-arc setting upon Cambrian-Tremadoc, deep-water, turbiditic quartzose strata on the northwest-facing Gander margin of Gondwana....
An upwelling model for the Phosphoria sea: A Permian, ocean-margin sea in the northwest United States
D.Z. Piper, P. K. Link
2002, American Association of Petroleum Geologists Bulletin (86) 1217-1235
The Permian Phosphoria Formation, a petroleum source rock and world-class phosphate deposit, was deposited in an epicratonic successor basin on the western margin of North America. We calculate the seawater circulation in the basin during deposition of the lower ore zone in the Meade Peak Member from the accumulation rates...
Seismic structure of the crust and uppermost mantle of North America and adjacent oceanic basins: A synthesis
G.S. Chulick, Walter D. Mooney
2002, Bulletin of the Seismological Society of America (92) 2478-2492
We present a new set of contour maps of the seismic structure of North America and the surrounding ocean basins. These maps include the crustal thickness, whole-crustal average P-wave and S-wave velocity, and seismic velocity of the uppermost mantle, that is, Pn and Sn. We found the following: (1) The average thickness...
Assessing mine drainage pH from the color and spectral reflectance of chemical precipitates
D.J. Williams, J.M. Bigham, C.A. Cravotta III, S.J. Traina, J.E. Anderson, J.G. Lyon
2002, Applied Geochemistry (17) 1273-1286
The pH of mine impacted waters was estimated from the spectral reflectance of resident sediments composed mostly of chemical precipitates. Mine drainage sediments were collected from sites in the Anthracite Region of eastern Pennsylvania, representing acid to near neutral pH. Sediments occurring in acidic waters contained primarily schwertmannite and goethite...
Seismological evidence for a sub-volcanic arc mantle wedge beneath the Denali volcanic gap, Alaska
D.E. McNamara, M.E. Pasyanos
2002, Geophysical Research Letters (29) 61-1-61-4
Arc volcanism in Alaska is strongly correlated with the 100 km depth contour of the western Aluetian Wadati-Benioff zone. Above the eastern portion of the Wadati-Benioff zone however, there is a distinct lack of volcanism (the Denali volcanic gap). We observe high Poisson's ratio values (0.29-0.33) over the entire length...
Magnetostratigraphy, paleomagnetic correlation, and deformation of pleistocene deposits in the south central Puget Lowland, Washington
J.T. Hagstrum, D. B. Booth, K. G. Troost, R.J. Blakely
2002, Journal of Geophysical Research B: Solid Earth (107) EPM 6-1-EPM 6-13
Paleomagnetic results from Pleistocene sedimentary deposits in the central Puget Lowland indicate that the region has experienced widespread deformation within the last 780 kyr. Three oriented samples were collected from unaltered fine-grained sediments mostly at sea level to determine the magnetostratigraphy at 83 sites. Of these, 47 have normal, 18...
Tar Creek study, Sargent oil field, Santa Clara County, California
David L. Wagner, Bill Fedasko, J.R. Carnahan, Ross Brunetti, Leslie B. Magoon, Paul G. Lillis, T.D. Lorenson, Richard G. Stanley
2002, Report
Field work in the Tar Creek area of Sargent oil field was performed June 26 to 28, 2000. The Santa Clara County study area is located in Sections, 30, 31, and 32, Township 11 South, Range 4 East, M.D.B&M; and in Sections 25 and 36, Township 11 South, Range 3...
Ancient and modern subduction zone contributions to the mantle sources of lavas from the Lassen region of California inferred from Lu-Hf isotopic systematics
L. E. Borg, Janne Blichert-Toft, Michael A. Clynne
2002, Journal of Petrology (43) 705-723
Hafnium isotopic compositions have been determined on a suite of calc-alkaline and high-alumina-olivine tholeiitic lavas from the Lassen region of California and are used, in conjunction with previously published mineralogical, geochemical, and isotopic data, to constrain their petrogenesis. Positive correlation between εHf values and geochemical indices of the modern subduction component...
Fault structure and mechanics of the Hayward Fault, California from double-difference earthquake locations
Felix Waldhause, William L. Ellsworth
2002, Journal of Geophysical Research B: Solid Earth (107) ESE 3-1-ESE 3-15
The relationship between small-magnitude seismicity and large-scale crustal faulting along the Hayward Fault, California, is investigated using a double-difference (DD) earthquake location algorithm. We used the DD method to determine high-resolution hypocenter locations of the seismicity that occurred between 1967 and 1998. The DD technique incorporates catalog travel time data...
A strategy for estimating the rates of recent United States land-cover changes
Thomas R. Loveland, Terry L. Sohl, S.V. Stehman, Alisa L. Gallant, K. L. Sayler, D.E. Napton
2002, Photogrammetric Engineering and Remote Sensing (68) 1091-1099
Information on the rates of land-use and land-cover change is important in addressing issues ranging from the health of aquatic resources to climate change. Unfortunately, there is a paucity of information on land-use and land-cover change except at very local levels. We describe a strategy for estimating land-cover change across...
Stream piracy in the Black Hills: A geomorphology lab exercise
Brent J. Zaprowski, Edward B. Evenson, Jack B. Epstein
2002, Journal of Geoscience Education (50) 380-388
The Black Hills of South Dakota exhibits many fine examples of stream piracy that are very suitable for teaching geomorphology lab exercises. This lab goes beyond standard topographic map interpretation by using geologic maps, well logs, gravel provenance and other types of data to teach students about stream piracy. Using...
Use of regional climate model output for hydrologic simulations
L.E. Hay, M.P. Clark, R.L. Wilby, W.J. Gutowski, G.H. Leavesley, Z. Pan, R.W. Arritt, E.S. Takle
2002, Journal of Hydrometeorology (3) 571-590
Daily precipitation and maximum and minimum temperature time series from a regional climate model (RegCM2) configured using the continental United States as a domain and run on a 52-km (approximately) spatial resolution were used as input to a distributed hydrologic model for one rainfall-dominated basin (Alapaha River at Statenville, Georgia)...
A step increase in streamflow in the conterminous United States
G.J. McCabe, D.M. Wolock
2002, Geophysical Research Letters (29) 38-1-38-4
Annual minimum, median, and maximum daily streamflow for 400 sites in the conterminous United States (U.S.), measured during 1941-1999, were examined to identify the temporal and spatial character of changes in streamflow statistics. Results indicate a noticeable increase in annual minimum and median daily streamflow around 1970, and a less...
San Andreas fault zone, California: M≥5.5 earthquake history
Tousson R. Toppozada, D.M. Branum, M.S. Reichle, C.L. Hallstrom
2002, Bulletin of the Seismological Society of America (92) 2555-2601
The San Andreas fault zone has been a very significant source of major California earthquakes. From 1812 to 1906 it generated four major earthquakes of M ∼7 or larger in two pairs on two major portions of the fault. A pair of major earthquakes occurred on the central to southern region, where...
Timing of large earthquakes since A.D. 800 on the Mission Creek strand of the San Andreas fault zone at Thousand Palms Oasis, near Palm Springs, California
T. E. Fumal, M. J. Rymer, G. G. Seitz
2002, Bulletin of the Seismological Society of America (92) 2841-2860
Paleoseismic investigations across the Mission Creek strand of the San Andreas fault at Thousand Palms Oasis indicate that four and probably five surface-rupturing earthquakes occurred during the past 1200 years. Calendar age estimates for these earthquakes are based on a chronological model that incorporates radiocarbon dates from 18 in situ burn layers...
Concordant paleolatitudes for Neoproterozoic ophiolitic rocks of the Trinity Complex, Klamath Mountains, California
E. A. Mankinen, N. Lindsley-Griffin, J. R. Griffin
2002, Journal of Geophysical Research B: Solid Earth (107) EPM 11-1-EPM 11-18
New paleomagnetic results from the eastern Klamath Mountains of northern California show that Neoproterozoic rocks of the Trinity ophiolitic complex and overlying Middle Devonian volcanic rocks are latitudinally concordant with cratonal North America. Combining paleomagnetic data with regional geologic and faunal evidence suggests that the Trinity Complex and related terranes...
Distribution and significance of small, artificial water bodies across the United States landscape
S. V. Smith, W. H. Renwick, J.D. Bartley, R. W. Buddemeier
2002, Science of the Total Environment (299) 21-36
At least 2.6 million small, artificial water bodies dot the landscape of the conterminous United States; most are in the eastern half of the country. These features account for approximately 20% of the standing water area across the United States, and their impact on hydrology, sedimentology, geochemistry, and ecology is...
Magnitude estimates of two large aftershocks of the 16 December 1811 New Madrid earthquake
S. E. Hough, S. Martin
2002, Bulletin of the Seismological Society of America (92) 3259-3268
The three principal New Madrid mainshocks of 1811-1812 were followed by extensive aftershock sequences that included numerous felt events. Although no instrumental data are available for either the mainshocks or the aftershocks, available historical accounts do provide information that can be used to estimate magnitudes and locations for the large...
The flora of Oktibbeha County, Mississippi
A. Leidolf, S. McDaniel, T. Nuttle
2002, SIDA, Contributions to Botany (20) 691-765
We surveyed the flora of Oktibbeha County, Mississippi, U.S.A., from February 1994 to 1996. Occupying 118 square kilometers in east-central Mississippi, Oktibbeha County lies among 3 physiographic regions that include, from west to east, Interior Flatwoods, Pontotoc Ridge, and Black Prairie. Accordingly, the county harbors a diverse flora. Based on...
Place vs. time and vegetational persistence: A comparison of four tropical mires from the Illinois Basin during the height of the Pennsylvanian Ice Age
William A. DiMichele, T.L. Phillips, W. John Nelson
2002, International Journal of Coal Geology (50) 43-72
Coal balls were collected from four coal beds in the southeastern part of the Illinois Basin. Collections were made from the Springfield, Herrin, and Baker coals in western Kentucky, and from the Danville Coal in southwestern Indiana. These four coal beds are among the principal mineable coals of the Illinois...
Geochemical evidence for diversity of dust sources in the southwestern United States
M.C. Reheis, J. R. Budahn, P. J. Lamothe
2002, Geochimica et Cosmochimica Acta (66) 1569-1587
Several potential dust sources, including generic sources of sparsely vegetated alluvium, playa deposits, and anthropogenic emissions, as well as the area around Owens Lake, California, affect the composition of modern dust in the southwestern United States. A comparison of geochemical analyses of modern and old (a few thousand years) dust...
Mesozoic thermal history and timing of structural events for the Yukon-Tanana Upland, east-central Alaska: 40Ar/39Ar data from metamorphic and plutonic rocks
Cynthia Dusel-Bacon, Marvin A. Lanphere, W.D. Sharp, P.W. Layer, V. L. Hansen
2002, Canadian Journal of Earth Sciences (39) 1013-1051
We present new 40Ar/39Ar ages for hornblende, muscovite, and biotite from metamorphic and plutonic rocks from the YukonTanana Upland, Alaska. Integration of our data with published 40Ar/39Ar, kinematic, and metamorphic pressure (P) and temperature (T) data confirms and refines the complex interaction of metamorphism...
Influence of topography on density of grassland passerines in pastures
R.B. Renfrew, C. A. Ribic
2002, American Midland Naturalist (147) 315-325
Pastures provide substantial habitat for grassland birds of management concern in the Driftless Area of southwestern Wisconsin. The rolling topography in this region is characterized by lowland valleys surrounded by relatively steep and often wooded slopes which are set apart from more expansive treeless uplands. We hypothesized that there would...
The relationship between the abundance of smallmouth bass and double-crested cormorants in the eastern basin of Lake Ontario
Brian F. Lantry, Thomas H. Eckert, Clifford P. Schneider, Jana R. Chrisman
2002, Journal of Great Lakes Research (28) 193-201
Available population and diet data on double-crested cormorant (Phalacrocorax auritus) and smallmouth bass (Micropterus dolomieui) numbers, demographics, and exploitation rates were synthesized to examine the relationship between cormorant and smallmouth bass abundance in the U.S. waters of the eastern basin of Lake Ontario....
Morphology, volcanism, and mass wasting in Crater Lake, Oregon
C. R. Bacon, J.V. Gardner, L. A. Mayer, M.W. Buktenica, P. Dartnell, D.W. Ramsey, J.E. Robinson
2002, Geological Society of America Bulletin (114) 675-692
Crater Lake was surveyed nearly to its shoreline by high-resolution multibeam echo sounding in order to define its geologic history and provide an accurate base map for research and monitoring surveys. The bathymetry and acoustic backscatter reveal the character of landforms and lead to a chronology for the concurrent filling...
