A king-sized theropod coprolite
K. Chin, T.T. Tokaryk, G.M. Erickson, L. C. Calk
1998, Nature (393) 680-682
Fossil faeces (coprolites) provide unique trophic perspectives on ancient ecosystems. Yet, although thousands of coprolites have been discovered, specimens that can be unequivocally attributed to carnivorous dinosaurs are almost unknown. A few fossil faeces have been ascribed to herbivorous dinosaurs, but it is more difficult to identify coprolites produced by...
Regional and local hydrogeology of calcareous fens in the Minnesota river basin, USA
J.E. Almendinger, J.H. Leete
1998, Wetlands (18) 184-202
Six calcareous fens in the Minnesota River Basin, USA are in regional hydrogeologic settings with large discharges of calcareous ground water. These settings juxtapose topographically high areas of ground-water recharge with fens in lower areas of discharge, thus creating steep upward hydraulic gradients at the fens. Coarse glacial deposits with...
Foods of Buller's shearwaters (Puffinus bulleri) associated with driftnet fisheries in the central North Pacific Ocean
P. Gould, P. Ostrom, W. Walker
1998, Notornis (45) 81-93
We examined digestive tract contents and stable nitrogen isotope ratios (??15N) in breast muscles of Buller's shearwaters (Puffinus bulleri) salvaged from squid and largemesh driftnets in the central North Pacific Ocean. The epipelagic Pacific saury (Cololabis saira) was the predominant prey, making up 71% of prey mass in digestive tracts....
Peat characteristics and groundwater geochemistry of calcareous fens in the Minnesota River Basin, U.S.A
J.E. Almendinger, J.H. Leete
1998, Biogeochemistry (43) 17-41
Calcareous fens in Minnesota are spring-seepage peatlands with adistinctive flora of rare calciphilic species. Peat characteristics andgroundwater geochemistry were determined for six calcareous fens in theMinnesota River Basin to better understand the physical structure andchemical processes associated with stands of rare vegetation. Onset of peataccumulation in three of the fens...
Depositional facies and sequence stratigraphy of a Lower Carboniferous bryozoan-crinoidal carbonate ramp in the Illinois Basin, mid-continent USA
Z. Lasemi, R. D. Norby, J.D. Treworgy
1998, Geological Society Special Publication (149) 369-395
The Lower Carboniferous Fort Payne and Ullin Formations in the Illinois Basin form the transgressive and highstand systems tracts that were deposited in a carbonate ramp setting. During deposition of the Ullin Limestone, biotic communities dominated by fenestrate bryozoans and echinoderms (primarily crinoids) proliferated, possibly in response...
Geochemical and isotopic (Nd-Pb-Sr-O) variations bearing on the genesis of volcanic rocks from Vesuvius, Italy
R. A. Ayuso, B. de Vivo, G. Rolandi, R.R. Seal II, A. Paone
1998, Journal of Volcanology and Geothermal Research (82) 53-78
Alkaline volcanism produced by Monte Somma-Vesuvius volcano includes explosive plinian and subplinian activity in addition to effusive lava flows. Pumice, scoria, and lava (150 samples) exhibit major- and trace-element gradients as a function of SiO2 (58.9-47.2 wt%) and MgO (0-7.8 wt%); Mg value are ???50. Internally gradational chemical groups or...
Amphibians of the Fort Lewis Military Reservation, Washington: Sampling techniques and community patterns
M. J. Adams, R. Bruce Bury, Scott A. Swarts
1998, Northwestern Naturalist (79) 12-18
The 27,000 ha Fort Lewis Military Reservation is situated in the Puget lowlands and contains a wide variety of aquatic habitats offering potential refuge for native amphibians. We surveyed amphibians on Fort Lewis from 1992 through 1995 to examine occupancy patterns relative to wetland characteristics. We documented 9 native amphibians...
Maturation of male age-0 Atlantic salmon following a massive, localized flood
B. H. Letcher, T.D. Terrick
1998, Journal of Fish Biology (53) 1243-1252
Maturation of male age-0 Atlantic salmon Salmo salar parr in New England, U.S.A. streams is rare (˜5%), but age-0 parr maturation was high (74%) by autumn in the Sawmill River following a massive, localized flood. Maturation was low in two other study streams (3, 7%) in the same year as the flood,...
Habitat change in a perched dune system along Lake Superior
Walter L. Loope, A. Kathryn McEachern
Michael J. Mac, Paul A. Opler, Catherine E. Puckett Haecker, Peter D. Doran, editor(s)
1998, Book chapter, Status and trends of the nation's biological resources, vol. 1
Episodes of habitat change, driven by changes in levels of the Great Lakes, must be considered when assessing human effects upon coastal vegetation and rare species. Paleoecological studies, baseline inventories, and long-term monitoring programs within the Grand Sable Dunes, a perched-dune system along Lake Superior, provide a window on...
Amphibians of the northern Great Plains
Diane L. Larson, Ned H. Euliss Jr., Michael J. Lannoo, David M. Mushet
M. J. Mac, P.A. Opler, C. E. Puckett Haecker, P.D. Doran, editor(s)
1998, Book chapter, Status and trends of the nation's biological resources
No cry of alarm has been sounded over the fate of amphibian populations in the northern grasslands of North America, yet huge percentages of prairie wetland habitat have been lost, and the destruction continues. Scarcely 30% of the original mixedgrass prairie remains in Nebraska, South Dakota, and North Dakota (See...
Herbivore effects on plant species density at varying productivity levels
L. Gough, J.B. Grace
1998, Ecology (79) 1586-1594
Artificially increasing primary productivity decreases plant species richness in many habitats; herbivory may affect this outcome, but it has rarely been directly addressed in fertilization studies. This experiment was conducted in two Louisiana coastal marshes to examine the effects of nutrient enrichment and sediment addition on herbaceous plant communities with...
The role of sediment ingestion in exposing wood ducks to lead
W. N. Beyer, L. J. Blus, Charles J. Henny, D. Audet
1997, Ecotoxicology (6) 181-186
Waterfowl on lateral lakes of the Coeur d'Alene River and on Lake Coeur d'Alene have been poisoned for many years by lead (Pb) from mining and smelting. In 1992 we undertook a study in the area to determine the importance of sediment ingestion in exposing wood ducks (Aix sponsa)...
Stochastic seasonality and nonlinear density-dependent factors regulate population size in an African rodent
H. Leirs, N. C. Stenseth, J.D. Nichols, J.E. Hines, R. Verhagen, W. Verheyen
1997, Nature (389) 176-180
Ecology has long been troubled by the controversy over how populations are regulated. Some ecologists focus on the role of environmental effects, whereas others argue that density-dependent feedback mechanisms are central. The relative importance of both processes is still hotly debated, but clear examples of both processes acting in...
Is incest common in gray wolf packs?
Deborah E. Smith, Thomas J. Meier, Eli Geffen, L. David Mech, John W. Burch, Layne G. Adams, Robert K. Wayne
1997, Behavioral Ecology (8) 384-391
Wolf packs generally consist of a breeding pair and their maturing offspring that help provision and protect pack young. Because the reproductive tenure in wolves is often short, reproductively mature offspring might replace their parents, resulting in sibling or parent-offspring matings. To determine the extent of incestuous pairings, we measured...
Estimation of population trajectories from count data
W.A. Link, J.R. Sauer
1997, Biometrics (53) 488-497
Monitoring of changes in animal population size is rarely possible through complete censuses; frequently, the only feasible means of monitoring changes in population size is to use counts of animals obtained by skilled observers as indices to abundance. Analysis of changes in population size can be severely biased if...
Nitrate and selected pesticides in ground water of the Mid-Atlantic region
Scott W. Ator, Matthew J. Ferrari
1997, Water-Resources Investigations Report 97-4139
Data from more than 850 sites were compiled and analyzed to document the occurrence of nitrate and pesticides in ground water of the Mid-Atlantic region as part of the Mid-Atlantic Integrated Assessment program of the U.S. Environmental Protection Agency. Only those data collected by the U.S. Geological Survey as part...
The Areal Extent of Continuous Type Gas Accumulations in Lower Silurian Clinton Sands and Medina Group Sandstones of the Appalachian Basin and the Environments Affected by Their Development
C. J. Wandrey, Robert T. Ryder, Vito F. Nuccio, Kerry L. Aggen
1997, Open-File Report 97-272
In order to best preserve and manage our energy and natural resources we must understand the relationships between these resources and the impacts of their development. To further this understanding the U.S. Geological Survey is studying unconventional continuous-type and, to a lesser extent, conventional oil and gas accumulations and the...
Revised preliminary geologic map of the Rifle Quadrangle, Garfield County, Colorado
R. R. Shroba, R. B. Scott
1997, Open-File Report 97-852
The Rifle quadrangle extends from the Grand Hogback monocline into the southeastern part of the Piceance basin. In the northeastern part of the map area, the Wasatch Formation is nearly vertical, and over a distance of about 1 km, the dip decreases sharply from about 70-85o to about 15-30o toward...
Water-quality assessment of part of the upper Mississippi River Basin, Minnesota and Wisconsin — Pesticides in streams, streambed sediment, and ground water, 1974-94
J. D. Fallon, A. L. Fong, W. J. Andrews
1997, Water-Resources Investigations Report 97-4141
Available data on pesticides in streams, streambed sediment, and ground water from Federal, state, and local agencies are reviewed for part of the Upper Mississippi River Basin study unit of the National Water-Quality Assessment Program. The analysis focuses on a smaller study area encompassing 19,500 square miles that includes the...
Eutrophication potential of Payette Lake, Idaho
Paul F. Woods
1997, Water-Resources Investigations Report 97-4145
Payette Lake was studied during water years 1995-96 to determine the 20.5-square-kilometer lake's assimilative capacity for nutrients and, thus, its eutrophication potential. The study included quantification of hydrologic and nutrient budgets, characterization of water quality in the limnetic and littoral zones, development of an empirical nutrient load/lake response model, and...
Urbanization and recharge in the vicinity of East Meadow Brook, Nassau County, New York: Part 4 — Water quality in the headwaters area, 1988-93
C. J. Brown, M. P. Scorca, G. G. Stockar, Frederick Stumm, H. F. Ku
1997, Water-Resources Investigations Report 96-4289
Surface-water and ground-water quality in the East Meadow Brook headwaters area was monitored during 1988-93 to determine the effects of urban stormwater on water quality before, and for 1 year after, the construction of a stormwater-detention basin in 1992. Stormwater samples were collected from the stream during storms. Between storms,...
Digital simulation of ground-water flow in the Warwick Aquifer, Fort Totten Indian Reservation, North Dakota
Thomas B. Reed
1997, Water-Resources Investigations Report 97-4114
The demand for water from the Warwick aquifer, which underlies the Fort Totten Indian Reservation in northeastern North Dakota, has been increasing during recent years. Therefore, the Spirit Lake Sioux Nation is interested in resolving questions about the quantity and quality of water in the aquifer and in developing a...
Occurrence of nitrate, pesticides, and volatile organic compounds in the Kirkwood-Cohansey aquifer system, southern New Jersey
Paul E. Stackelberg, Jessica A. Hopple, Leon J. Kauffman
1997, Water-Resources Investigations Report 97-4241
Water samples were collected from a network of 72 shallow monitoring wells to assess the chemical quality of recently recharged ground water in the surficial Kirkwood- Cohansey aquifer system of southern New Jersey. The wells are randomly distributed among agricultural, urban, and undeveloped areas to provide data representative of chemical...
Surface-water-quality assessment of the upper Illinois River Basin in Illinois, Indiana, and Wisconsin– Results of investigations through April 1992
Arthur R. Schmidt, Stephen F. Blanchard
1997, Water-Resources Investigations Report 96-4223
A water-quality assessment of the upper Illinois River Basin (10,949 square miles) was conducted during water years 1987-91. This assessment involved interpretation of available data; 4 years of intensive data collection, including monthly sample collection at eight fixed-monitoring stations in the basin; and synoptic studies of selected water-quality constituents at...
Initiation of debris flows in tributaries of the Colorado River in Grand Canyon, Arizona
Peter G. Griffiths, Robert Webb, Theodore S. Melis
1997, Conference Paper, Proceedings of the 1997 1st international conference on debris-flow hazards mitigation: Mechanics, prediction, and assessment
Debris flows are initiated in tributaries of the Colorado River in Grand Canyon when intense rainfall causes failures in colluvium and (or) bedrock. Most debris flows occur in the summer during localized convective thunderstorms with rainfall intensities as high as 40 mm/hr. Rarer and larger debris flows occur during unusually...
