Environment of ore deposition in the Creede mining district, San Juan Mountains, Colorado: Part VI. Maximum duration for mineralization of the OH vein
W. R. Campbell, P.B. Barton
2005, Economic Geology (100) 1313-1324
The rate at which ore deposits form is one of the least well established parameters in all of economic geology. However, increased detail in sampling, improved technology of dating, and sophistication in modeling are reducing the uncertainties and establishing that ore formation, at least for the porphyry copper-skarn-epithermal base and...
Magmatic effects of the Cobb hot spot on the Juan de Fuca Ridge
John Chadwick, M. Perfit, I. Ridley, I. Jonasson, G. Kamenov, W. Chadwick, R. Embley, Roux P. le, M. Smith
2005, Journal of Geophysical Research B: Solid Earth (110) 1-16
The interaction of the Juan de Fuca Ridge with the Cobb hot spot has had a considerable influence on the magmatism of the Axial Segment of the ridge, the second-order segment that overlies the hot spot. In addition to the construction of the large volcanic edifice of Axial Seamount, the...
Ground water/surface water responses to global climate simulations, Santa Clara-Calleguas Basin, Ventura, California
Randall T. Hanson, Michael D. Dettinger
2005, Journal of the American Water Resources Association (41) 517-536
Climate variations can play an important, if not always crucial, role in successful conjunctive management of ground water and surface water resources. This will require accurate accounting of the links between variations in climate, recharge, and withdrawal from the resource systems, accurate projection or predictions of the climate variations, and...
Controlling for anthropogenically induced atmospheric variation in stable carbon isotope studies
E.S. Long, R.A. Sweitzer, Duane R. Diefenbach, M. Ben-David
2005, Oecologia (146) 148-156
Increased use of stable isotope analysis to examine food-web dynamics, migration, transfer of nutrients, and behavior will likely result in expansion of stable isotope studies investigating human-induced global changes. Recent elevation of atmospheric CO2 concentration, related primarily to fossil fuel combustion, has reduced atmospheric CO2 ??13C (13C/12C), and this change...
Movement patterns of rural and suburban white-tailed deer in Massachusetts
C.R. Gaughan, S. DeStefano
2005, Urban Ecosystems (8) 191-202
We used satellite land cover data and the program FRAGSTATS toquantify land cover types and calculate the amount of forest edge available in suburban and rural regions of northeastern and northwestern Massachusetts. Cover categories included forest cover, open canopy vegetation, and non-deer habitat. We calculated all edge segments where forest...
Structural evolution of fault zones in sandstone by multiple deformation mechanisms: Moab fault, southeast Utah
N.C. Davatzes, P. Eichhubl, A. Aydin
2005, Geological Society of America Bulletin (117) 135-148
Faults in sandstone are frequently composed of two classes of structures: (1) deformation bands and (2) joints and sheared joints. Whereas the former structures are associated with cataclastic deformation, the latter ones represent brittle fracturing, fragmentation, and brecciation. We investigated the distribution of these structures, their formation, and the underlying...
River nutrient loads and catchment size
S. V. Smith, D.P. Swaney, R. W. Buddemeier, M.R. Scarsbrook, M.A. Weatherhead, Christoph Humborg, H. Eriksson, F. Hannerz
2005, Biogeochemistry (75) 83-107
We have used a total of 496 sample sites to calibrate a simple regression model for calculating dissolved inorganic nutrient fluxes via runoff to the ocean. The regression uses the logarithms of runoff and human population as the independent variables and estimates the logarithms of dissolved inorganic nitrogen and phosphorus...
Paleoproterozoic metamorphism in the northern Wyoming province: Implications for the assembly of Laurentia
P.A. Mueller, H.R. Burger, J. L. Wooden, J.B. Brady, J.T. Cheney, T.A. Hamrs, A.L. Heatherington, D.W. Mogk
2005, Journal of Geology (113) 169-179
U-Pb ages measured on zircons from the Tobacco Root Mountains and monazite from the Highland Mountains indicate that the northwestern Wyoming province experienced an episode of high-grade metamorphism at ???1.77 Ga. Leucosome emplaced in Archean gneisses from the Tobacco Root Mountains contains a distinctive population of zircons with an age...
Solute transport and storage mechanisms in wetlands of the Everglades, south Florida
Judson W. Harvey, James E. Saiers, Jessica T. Newlin
2005, Water Resources Research (41)
Solute transport and storage processes in wetlands play an important role in biogeochemical cycling and in wetland water quality functions. In the wetlands of the Everglades, there are few data or guidelines to characterize transport through the heterogeneous flow environment. Our goal was to conduct a tracer study to help...
Secondary sulfate minerals associated with acid drainage in the eastern US: Recycling of metals and acidity in surficial environments
J. M. Hammarstrom, R.R. Seal II, A. L. Meier, J.M. Kornfeld
2005, Chemical Geology (215) 407-431
Weathering of metal-sulfide minerals produces suites of variably soluble efflorescent sulfate salts at a number of localities in the eastern United States. The salts, which are present on mine wastes, tailings piles, and outcrops, include minerals that incorporate heavy metals in solid solution, primarily the highly soluble members of the...
Transient rheology of the upper mantle beneath central Alaska inferred from the crustal velocity field following the 2002 Denali earthquake
F. F. Pollitz
2005, Journal of Geophysical Research B: Solid Earth (110) 1-16
The M7.9 2002 Denali earthquake, Alaska, is one of the largest strike-slip earthquakes ever recorded. The postseismic GPS velocity field around the 300-km-long rupture is characterized by very rapid horizontal velocity up to ???300 mm/yr for the first 0.1 years and slower but still elevated horizontal velocity up to ???100...
Linking the scales of observation, process, and modeling of dust emissions
K.E. Kohfeld, R. L. Reynolds, J.D. Pelletier, B. Nickling
2005, Conference Paper, Eos
[No abstract available]...
Spring migration of northern pintails from California's Central Valley wintering area tracked by satellite telemetry: Routes, timing, and destinations
M. R. Miller, John Y. Takekawa, J. P. Fleskes, D.L. Orthmeyer, Michael L. Casazza, W.M. Perry
2005, Canadian Journal of Zoology (83) 1314-1332
We used satellite transmitters to track the 2000–2003 spring migrations of adult female Northern Pintails (Anas acuta L., 1758) from California's Central Valley, USA. PTT-tagged Pintails departed during late February to mid-March, and 77%–87% stopped first in the region of south-central Oregon, extreme northwestern Nevada, and northeastern California (SONEC). Subsequently, most...
Integrating seismic reflection and geological data and interpretations across an internal basement massif: The southern Appalachian Pine Mountain window, USA
J.H. McBride, R. D. Hatcher Jr., W. J. Stephenson, R.J. Hooper
2005, Geological Society of America Bulletin (117) 669-686
The southern Appalachian Pine Mountain window exposes 1.1 Ga Grenvillian basement and its metasedimentary Paleozoic(?) cover through the allochthonous Inner Piedmont. The issue of whether the crustal block inside the window was either transported above the master Appalachian (late Alleghanian) de??collement or is an autochthonous block that was overridden by...
Effects of pressure on aqueous chemical equilibria at subzero temperatures with applications to Europa
G.M. Marion, J.S. Kargel, D.C. Catling, S.D. Jakubowski
2005, Geochimica et Cosmochimica Acta (69) 259-274
Pressure plays a critical role in controlling aqueous geochemical processes in deep oceans and deep ice. The putative ocean of Europa could have pressures of 1200 bars or higher on the seafloor, a pressure not dissimilar to the deepest ocean basin on Earth (the Mariana Trench at 1100 bars of...
Time-specific variation in passerine nest survival: New insights for old questions
T.A. Grant, T.L. Shaffer, E.M. Madden, P.J. Pietz
2005, The Auk (122) 661-672
Nest survival likely varies with nest age and date, but until recently researchers had only limited tools to efficiently address those sources of variability. Beginning with Mayfield (1961), many researchers have averaged survival rates within time-specific categories (e.g. egg and nestling stages; early and late nesting dates). However, Mayfield's estimator...
Landscape composition, patch size, and distance to edges: Interactions affecting duck reproductive success
David Joseph Horn, Michael L. Phillips, Rolf R. Koford, William R. Clark, Marsha A. Sovada, Raymond J. Greenwood
2005, Ecological Applications (15) 1367-1376
Prairies and other North American grasslands, although highly fragmented, provide breeding habitat for a diverse array of species, including species of tremendous economic and ecological importance. Conservation and management of these species requires some understanding of how reproductive success is affected by edge effects, patch size, and characteristics of the...
234Th, 210Pb, 210Po and stable Pb in the central equatorial Pacific: Tracers for particle cycling
J.W. Murray, B. Paul, J.P. Dunne, T. Chapin
2005, Deep-Sea Research Part I: Oceanographic Research Papers (52) 2109-2139
Samples were collected during the 1992 US JGOFS EqPac Survey I and II cruises from 12??N to 12??S at 140??W in the central equatorial Pacific for water column profiles of dissolved, particulate and total 234Th, 210Pb and 210Po and total acid soluble stable Pb and sediment trap fluxes of 234Th,...
Glacially-influenced late Pleistocene stratigraphy of a passive margin: New Jersey's Record of the North American ice sheet
J.S. Carey, R. E. Sheridan, G.M. Ashley, J. Uptegrove
2005, Marine Geology (218) 155-173
Glacial isostasy and the sediment supply changes associated with the waxing and waning of ice sheets have dramatic effects on the stratigraphy of adjacent continental shelves. In ancient stratigraphic records, the glacial influences on such deposits could be difficult to recognize because of the removal of coeval terrestrial glacial deposits...
Modeling duckweed growth in wastewater treatment systems
L. Landesman, N. C. Parker, C.B. Fedler, M. Konikoff
2005, Livestock Research for Rural Development (17)
Species of the genera Lemnaceae, or duckweeds, are floating aquatic plants that show great promise for both wastewater treatment and livestock feed production. Research conducted in the Southern High Plains of Texas has shown that Lemna obscura grew well in cattle feedlot runoff water and produced leaf tissue with a...
An efficient strategy to estimate intensity and prevalence: Sampling metacercariae in fishes
Jenny C. Shaw, Leopoldina Aguirre-Macedo, Kevin D. Lafferty
2005, Journal of Parasitology (91) 515-521
Accurate estimates of population-level parameters of parasites, such as prevalence and mean intensity, require large sample sizes. The processing of such samples becomes an overwhelming task when parasites are abundant, as with trematode metacercariae in fishes. In the present study, a subsampling method reduced processing time while maintaining an accurate...
Woody debris along an upland chronosequence in boreal Manitoba and its impact on long-term carbon storage
K.L. Manies, J.W. Harden, B. P. Bond-Lamberty, K. P. O’Neill
2005, Canadian Journal of Forest Research (35) 472-482
This study investigated the role of fire-killed woody debris as a source of soil carbon in black spruce (Picea mariana (Mill.) BSP) stands in Manitoba, Canada. We measured the amount of standing dead and downed woody debris along an upland chronosequence, including wood partially and completely covered by moss growth....
Ecohydrological control of deep drainage in arid and semiarid regions
M.S. Seyfried, S. Schwinning, Michelle Ann Walvoord, W. T. Pockman, B.D. Newman, R.B. Jackson, F. M. Phillips
2005, Ecology (86) 277-287
The amount and spatial distribution of deep drainage (downward movement of water across the bottom of the root zone) and groundwater recharge affect the quantity and quality of increasingly limited groundwater in arid and semiarid regions. We synthesize research from the fields of ecology and hydrology to address the issue...
Viscoelasticity, postseismic slip, fault interactions, and the recurrence of large earthquakes
A.J. Michael
2005, Bulletin of the Seismological Society of America (95) 1594-1603
The Brownian Passage Time (BPT) model for earthquake recurrence is modified to include transient deformation due to either viscoelasticity or deep post seismic slip. Both of these processes act to increase the rate of loading on the seismogenic fault for some time after a large event. To approximate these effects,...
Late Quaternary eolian and alluvial response to paleoclimate, Canyonlands, southeastern Utah
M.C. Reheis, R. L. Reynolds, H. Goldstein, H.M. Roberts, J. C. Yount, Y. Axford, L.S. Cummings, N. Shearin
2005, Geological Society of America Bulletin (117) 1051-1069
In upland areas of Canyonlands National Park, Utah, thin deposits and paleosols show late Quaternary episodes of eolian sedimentation, pedogenesis, and climate change. Interpretation of the stratigraphy and optically stimulated luminescence ages of eolian and nearby alluvial deposits, their pollen, and intercalated paleosols yields the following history: (1) Eolian deposition...
