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2001

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Articles 241 - 270 of 285

Full-Text Articles in Earth Sciences

Ichnology Of Holocene Carbonate Eolianites Of The Bahamas, H. Allen Curran, Brian White Jan 2001

Ichnology Of Holocene Carbonate Eolianites Of The Bahamas, H. Allen Curran, Brian White

Geosciences: Faculty Publications

No abstract provided.


Behavioral Plasticity Of Modern And Cenozoic Burrowing Thalassinidean Shrimp, M. F. Miller, H. Allen Curran Jan 2001

Behavioral Plasticity Of Modern And Cenozoic Burrowing Thalassinidean Shrimp, M. F. Miller, H. Allen Curran

Geosciences: Faculty Publications

No abstract provided.


Resilience And Recovery Of Coral Reefs From Large-Scale Disturbances: Contrasting Patterns For San Salvador Island, Bahamas, And Belize, Paulette M. Peckol, H. Allen Curran, Martha Robbart, Benjamin J. Greenstein Jan 2001

Resilience And Recovery Of Coral Reefs From Large-Scale Disturbances: Contrasting Patterns For San Salvador Island, Bahamas, And Belize, Paulette M. Peckol, H. Allen Curran, Martha Robbart, Benjamin J. Greenstein

Geosciences: Faculty Publications

Benjamin J. Greenstein and Cindy K. Carney (eds)

San Salvador, Gerace Research Center


Coastal Effects Of Hurricane Floyd On San Salvador Island, Bahamas, H. Allen Curran, Priscilla Delano, Brian White, Meredith Barrett Jan 2001

Coastal Effects Of Hurricane Floyd On San Salvador Island, Bahamas, H. Allen Curran, Priscilla Delano, Brian White, Meredith Barrett

Geosciences: Faculty Publications

Hurricane Floyd, a Category 4 storm with winds up to I 55 mph, made a close encounter with San Salvador Island on September 13-14, 1999. In addition to inflicting severe damage to homes, tourist facilities, businesses, and infrastructure on the island, the storm also caused considerable beach erosion and coastal modification, mostly on the western and northern coasts. This paper reports and documents with photos the findings of a survey of coastal erosion effects on four areas of the San Salvador coastline: Coast Guard Beach, Rocky Point south to Cockburn Town and Fernandez Bay, South of Sugarloaf toward Grotto Bay, …


Lithospheric Flexure Of The Devils Lake Basin, North Dakota, Erica M. Peterson Jan 2001

Lithospheric Flexure Of The Devils Lake Basin, North Dakota, Erica M. Peterson

Theses and Dissertations

Devils Lake is the largest lake in a chain of approximately 20 interconnected lakes in east central North Dakota. The Devils Lake drainage basin of approximately 8,600 km2, lies in a bowl sculpted by glaciation; thus it is closed and receives and loses water only through precipitation and evapotranspiration. Since 1940, the lake level has risen 14.4 m due to increased precipitation. Geological data show that in the past 10,000 years the lake has alternately dried up and filled due to climate fluctuations (Murphy et al., 1997). During this time it has reached its spill elevation of 444. 7 m …


Flow Through Well Screens As A Function Of Pump Intake Location, Kristjan F. Bekker Jan 2001

Flow Through Well Screens As A Function Of Pump Intake Location, Kristjan F. Bekker

Theses and Dissertations

Greater well efficiency and lower production costs may result from a knowledge of water flow through well screens. Current practice generally locates the intake of a pump in the cased section of the well above the screen. This work shows that placing the pump within the screen will increase well efficiency and therefore lower energy cost. This work also shows a correlation of increased well efficiency with respect to larger sand size, larger screen slot size, and lower flow rates.

A semicircular model based on the radial symmetry of a well and screen was used to simulate water flow from …


Major Herbicides In Ground Water: Results From The National Water-Quality Assessment, Jack . E. Barbash, Gail P. Thelin, Dana W. Kolpin, Robert J. Gilliom Jan 2001

Major Herbicides In Ground Water: Results From The National Water-Quality Assessment, Jack . E. Barbash, Gail P. Thelin, Dana W. Kolpin, Robert J. Gilliom

United States Geological Survey: Staff Publications

To improve understanding of the factors affecting pesticide occurrence in ground water, patterns of detection were examined for selected herbicides, based primarily on results from the National Water-Quality Assessment (NAWQA) program. The NAWQA data were derived from 2227 sites (wells and springs) sampled in 20 major hydro- logic basins across the USA from 1993 to 1995. Results are presented for six high-use herbicides—atrazine (2-chloro-4-ethylamino-6-iso-propylamino- s-triazine), cyanazine (2-[4-chloro-6-ethylamino-1,3,5-triazin-2-yl]amino]-2-methylpropionitrile), simazine (2-chloro-4,6-bis- [ethylamino]-s-triazine), alachlor (2-chloro-N-[2,6-diethylphenyl]-N- [methoxymethyl]acetamide), acetochlor (2-chloro-N-[ethoxymethyl]- N-[ 2-ethyl-6-methylphenyl]acetamide), and metolachlor (2-chloro-N- [2-ethyl-6-methylphenyl]-N-[2-methoxy-1-methylethyl]acetamide)— as well as for prometon (2,4-bis[isopropylamino]-6-methoxy-s-triazine), a nonagricultural herbicide detected frequently during the study. Concentrations were <1 μg L-1 at 98% …


Impact Of Climate And Parent Material On Chemical Weathering In Loess-Derived Soils Of The Mississippi River Valley, Daniel R. Muhs, E. A. Bettis Iii, J. Been, J. P. Mcgeehin Jan 2001

Impact Of Climate And Parent Material On Chemical Weathering In Loess-Derived Soils Of The Mississippi River Valley, Daniel R. Muhs, E. A. Bettis Iii, J. Been, J. P. Mcgeehin

United States Geological Survey: Staff Publications

Peoria Loess-derived soils on uplands east of the Mississippi River the midcontinent of North America (Ruhe, 1969; Hall valley were studied from Louisiana to Iowa, along a south-to-north and Anderson, 2000), Alaska (Muhs et al., 2001), and gradient of decreasing precipitation and temperature. Major element China (Maher et al., 1994). Critical to paleoclimatic interanalyses of deep loess in Mississippi and Illinois show that the composi- pretations, using paleosols, are reliable climofunctions tion of the parent material is similar in the northern and southern for modern soils, which give an understanding of soil parts of the valley. We hypothesized that in …


Inhibition Of Erythrocyte Δ- Aminolevulinic Acid Dehydratase (Alad) Activity In Fish From Waters Affects By Lead Smelters, Christopher J. Schmitt, Colleen A. Caldwell, Bill Olsen, Dave Serdar Jan 2001

Inhibition Of Erythrocyte Δ- Aminolevulinic Acid Dehydratase (Alad) Activity In Fish From Waters Affects By Lead Smelters, Christopher J. Schmitt, Colleen A. Caldwell, Bill Olsen, Dave Serdar

United States Geological Survey: Staff Publications

We assessed the effects on fish of lead (Pb) released to streams by smelters located in Trail, BC (Canada), E. Helena, MT, Herculaneum, MO, and Glover, MO. Fish were collected by electrofishing from sites located downstream of smelters and from reference sites. Blood from each fish was analyzed for δ-aminolevulinic acid dehydratase (ALAD) activity and hemoglobin (Hb), and samples of blood, liver, or carcass were analyzed for Pb, zinc (Zn), or both. Fish collected downstream of all four smelters sites had elevated Pb concentrations, decreased ALAD activity, or both relative to their respective reference sites. At E. Helena, fish from …


Remnant Colloform Pyrite At The Haile Gold Deposit, South Carolina: A Textural Key To Genesis, Nora Foley, Robert A. Ayuso, Robert R. Seal Ii Jan 2001

Remnant Colloform Pyrite At The Haile Gold Deposit, South Carolina: A Textural Key To Genesis, Nora Foley, Robert A. Ayuso, Robert R. Seal Ii

United States Geological Survey: Staff Publications

Auriferous iron sulfide-bearing deposits of the Carolina slate belt have distinctive mineralogical and textural features—traits that provide a basis to construct models of ore deposition. Our identification of paragenetically early types of pyrite, especially remnant colloform, crustiform, and layered growth textures of pyrite containing electrum and pyrrhotite, establishes unequivocally that gold mineralization was coeval with deposition of host rocks and not solely related to Paleozoic tectonic events. Ore horizons at the Haile deposit, South Carolina, contain many remnants of early pyrite: (1) fine-grained cubic pyrite disseminated along bedding; (2) finegrained spongy, rounded masses of pyrite that may envelop or drape …


2,3,7,8-Tetrachlorodibenzo-P-Dioxin Induces Apoptotic Cell Death And Cytochrome P4501a Expression In Developing Fundulus Heteroclitus Embryos, Barbara Holland Toomey, Susan Bello, Mark E. Hahn, Susannah Cantrell, Peggy Wright, Donald E. Tillitt, Richard T. Di Giulio Jan 2001

2,3,7,8-Tetrachlorodibenzo-P-Dioxin Induces Apoptotic Cell Death And Cytochrome P4501a Expression In Developing Fundulus Heteroclitus Embryos, Barbara Holland Toomey, Susan Bello, Mark E. Hahn, Susannah Cantrell, Peggy Wright, Donald E. Tillitt, Richard T. Di Giulio

United States Geological Survey: Staff Publications

Fundulus heteroclitus embryos were exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during early development using nanoinjection or water bath exposure. TCDD caused developmental abnormalities that included hemorrhaging, loss of vascular integrity, edema, stunted development and death. The LC50 and LD50 of TCDD for Fundulus embryos were ~19.7 ± 9.5 pg TCDD/µl (water bath) and 0.25 ± 0.09 ng TCDD/g embryo (nanoinjection). To identify a possible cause for these developmental abnormalities we analyzed the effects of TCDD on apoptotic cell death and cytochrome P4501A (CYP1A) expression in the embryos. TCDD exposure increased apoptotic cell death in several tissues including brain, …


Fluvial Processes And Passive Rehabilitation Of The Lisbon Bottom Side-Channel Chute, Lower Missouri River, Robert B. Jacobson, Mark S. Laustrup, Michael D. Chapman Jan 2001

Fluvial Processes And Passive Rehabilitation Of The Lisbon Bottom Side-Channel Chute, Lower Missouri River, Robert B. Jacobson, Mark S. Laustrup, Michael D. Chapman

United States Army Corps of Engineers, Omaha District

Multiple large floods in 1993-1997 on the Lower Missouri River carved a side-channel chute through the river bottom at Lisbon, Missouri. Although similar in some respects to engineered side-channel chutes designed for habitat rehabilitation projects, the Lisbon Bottom chute has been unique in that it was allowed to evolve for more than four years with minimal stabilization. During the wet years, 1996-1999, the chute was subjected to abnormally high discharges and passed as much as 20% of the total discharge of the Missouri River. Relatively unrestrained fluvial processes during this time created a wide channel with highly diverse habitats. The …


Origin Of Late Quaternary Dune Fields On The Southern High Plains Of Texas And New Mexico, Daniel R. Muhs, Vance T. Holliday Jan 2001

Origin Of Late Quaternary Dune Fields On The Southern High Plains Of Texas And New Mexico, Daniel R. Muhs, Vance T. Holliday

United States Geological Survey: Staff Publications

Mostly stabilized late Holocene eolian sands on the Southern High Plains of the United States were studied to determine their origins and to assess whether present dune stability depends more strongly on sediment supply, sediment availability, or transport limitations. Geomorphic, sedimentological, and geochemical trends indicate that late Holocene dunes formed under westerly paleowinds, broadly similar to those of today. Mineralogical and geochemical data indicate that the most likely source for the sands is not the Pecos River valley, but the Pleistocene Blackwater Draw Formation, an older, extensive eolian deposit in the region. These observations suggest that new sand is supplied …


Vegetation And Paleoclimate Of The Last Interglacial Period, Central Alaska, Daniel R. Muhs, Thomas A. Ager, James E. Begét Jan 2001

Vegetation And Paleoclimate Of The Last Interglacial Period, Central Alaska, Daniel R. Muhs, Thomas A. Ager, James E. Begét

United States Geological Survey: Staff Publications

The last interglacial period is thought to be the last time global climate was signi"cantly warmer than present. New stratigraphic studies at Eva Creek, near Fairbanks, Alaska indicate a complex last interglacial record wherein periods of loess deposition alternated with periods of soil formation. The Eva Forest Bed appears to have formed about the time of or after deposition of the Old Crow tephra (dated to ~ 160 to ~ 120 ka), and is therefore correlated with the last interglacial period. Pollen, macrofossils, and soils from the Eva Forest Bed indicate that boreal forest was the dominant vegetation and precipitation …


Evolution Of Soils On Quaternary Reef Terraces Of Barbados, West Lndies, Daniel R. Muhs Jan 2001

Evolution Of Soils On Quaternary Reef Terraces Of Barbados, West Lndies, Daniel R. Muhs

United States Geological Survey: Staff Publications

Soils on uplifted Quaternary reef terraces of Barbados, ~125,000 to ~700,000 yr old, form a climo-chronosequence and show changes in physical, chemical, and mineralogical properties with terrace age. Parent materials are dust derived from the Sahara, volcanic ash from the Lesser Antilles island arc, and detrital carbonate from the underlying reef limestone. Although some terrace soils are probably eroded, soils or their remnants are redder and more clay-rich with increasing terrace age. Profile-average Al2O3 and Fe2O3 content increases with terrace age, which partially reflects the increasing clay content, but dithionite-extractable Fe also increases with …


Comparison Of Instream Methods For Measuring Hydrolic Conductivity In Sandy Streambeds, Matthew K. Landon, David L. Rus, F. Edwin Harvey Jan 2001

Comparison Of Instream Methods For Measuring Hydrolic Conductivity In Sandy Streambeds, Matthew K. Landon, David L. Rus, F. Edwin Harvey

United States Geological Survey: Staff Publications

Streambed hydraulic conductivity (K) values were determined at seven stream transects in the Platte River Basin in Nebraska using different instream measurement techniques.


The Pacific Island Mapping Program Of The Us Geological Survey, Frank C. Whitmore Jr. Jan 2001

The Pacific Island Mapping Program Of The Us Geological Survey, Frank C. Whitmore Jr.

United States Geological Survey: Staff Publications

A little-known aspect of the U.S. Geological Survey history is its involvement in preparing terrain intelligence reports during World War II. The Survey's Military Geology Unit was in charge of compiling these reports on areas of possible military operations. Maps were the main part of' these studies; they were compiled from existing maps, geologic and soils literature, aerial and ground photographs, and travelers' accounts. Compiled geologic anti soils maps served as basic data for interpretative maps on such subjects as construction materials. water supply, road and airfield siting and construction, and cross-country movement by tanks.


Evidence For Millennial-Scale Climate Change During Marine Isotope Stages 2 And 3 At Little Lake, Western Oregon, U.S.A., Laurie D. Grigg, Cathy Whitlock, Walter E. Dean Jan 2001

Evidence For Millennial-Scale Climate Change During Marine Isotope Stages 2 And 3 At Little Lake, Western Oregon, U.S.A., Laurie D. Grigg, Cathy Whitlock, Walter E. Dean

United States Geological Survey: Staff Publications

Pollen and geochemical data from Little Lake, western Oregon, suggest several patterns of millennial-scale environmental change during marine isotope stage (MIS) 2 (14,100–27,600 cal yr B.P.) and the latter part of MIS 3 (27,600–42,500 cal yr B.P.). During MIS 3, a series of transitions between warm- and cold-adapted taxa indicate that temperatures oscillated by ca. 2±–4±C every 1000–3000 yr. Highs and lows in summer insolation during MIS 3 are generally associated with the warmest and coldest intervals. Warm periods at Little Lake correlate with warm sea-surface temperatures in the Santa Barbara Basin. Changes in the strength of the subtropical high …


Occurrence Of Cyanazine Compounds In Groundwater: Degradates More Prevalent Than The Parent Compound, Dana Kolpin, E. Michael Thurman, S. Michael Linhart Jan 2001

Occurrence Of Cyanazine Compounds In Groundwater: Degradates More Prevalent Than The Parent Compound, Dana Kolpin, E. Michael Thurman, S. Michael Linhart

United States Geological Survey: Staff Publications

A recently developed analytical method using liquid chromatography/mass spectrometry was used to investigate the occurrence of cyanazine and its degradates cyanazine acid (CAC), cyanazine amide (CAM), deethylcyanazine (DEC), and deethylcyanazine acid (DCAC) in groundwater. This research represents some of the earliest data on the occurrence of cyanazine degradates in groundwater. Although cyanazine was infrequently detected in the 64 wells across Iowa sampled in 1999, cyanazine degradates were commonly found during this study. The most frequently detected cyanazine compound was DCAC (32.8%) followed by CAC (29.7%), CAM (17.2%), DEC (3.1%), and cyanazine (3.1%). The frequency of detection for cyanazine or one …


Effect Of Scale On The Behavior Of Atrazine In Surface Waters, Paul Capel, Steven Larson Jan 2001

Effect Of Scale On The Behavior Of Atrazine In Surface Waters, Paul Capel, Steven Larson

United States Geological Survey: Staff Publications

Field runoff is an important transport mechanism by which agricultural pesticides, including atrazine, move into the hydrologic environment. Atrazine is chosen because it is widely used, is transported in runoff relatively easily, is widely observed in surface waters, and has relatively little loss in the stream network. Data on runoff of atrazine from experimental plot and field studies is combined with annual estimates of load in numerous streams and rivers, resulting in a data set with 408 observations that span 14 orders of magnitude in area. The load as a percent of use (LAPU) on an annual basis is the …


Effects Of Landsat 5 Thematic Mapper And Landsat 7 Enhanced Thematic Mapper Plus Radiometric And Geometric Calibrations And Corrections On Landscape Characterization, James E. Vogelmann, Dennis Helder, Ron Morfitt, Michael J. Choate, James W. Merchant, Henry Bulley Jan 2001

Effects Of Landsat 5 Thematic Mapper And Landsat 7 Enhanced Thematic Mapper Plus Radiometric And Geometric Calibrations And Corrections On Landscape Characterization, James E. Vogelmann, Dennis Helder, Ron Morfitt, Michael J. Choate, James W. Merchant, Henry Bulley

United States Geological Survey: Staff Publications

The Thematic Mapper (TM) instruments on board Landsats 4 and 5 provide high-quality imagery appropriate for many different applications, including land cover mapping, landscape ecology, and change detection. Precise calibration was considered to be critical to the success of the Landsat 7 mission and, thus, issues of calibration were given high priority during the development of the Enhanced Thematic Mapper Plus (ETM+). Data sets from the Landsat 5 TM are not routinely corrected for a number of radiometric and geometric artifacts, including memory effect, gain/bias, and interfocal plane misalignment. In the current investigation, the effects of correcting vs. not correcting …


Basicranial Anatomy Of The Living Linsangs Prionodon And Poiana (Mammalia, Carnivora, Viverridae), With Comments On The Early Evolution Of Aeluroid Carnivorans, Robert M. Hunt Jr. Jan 2001

Basicranial Anatomy Of The Living Linsangs Prionodon And Poiana (Mammalia, Carnivora, Viverridae), With Comments On The Early Evolution Of Aeluroid Carnivorans, Robert M. Hunt Jr.

Department of Earth and Atmospheric Sciences: Faculty Publications

The living Asian linsang, Prionodon pardicolor, shares marked anatomical similarities in basicranium and dentition with the extinct Oligocene aeluroid, Palaeoprionodon lamandini, from the Quercy fissures, France. The living African linsang, Poiana richardsoni, is similar yet slightly more derived in basicranial traits relative to Prionodon pardicolor, and also has basicranial and dental features indicating a relationship to the living genets (Genetta). The basicranial and auditory anatomy of a series Palaeoprionodon-Prionodon-Poiana can be interpreted as a morphocline showing the progressive alteration of the form of the petrosal and auditory bulla from the plesiomorphic aeluroid state in …


Population Characteristics And Food Habitats Of White Perch (Morone Americana) In Branched Oak, Nebraska, Cara Hodking Jan 2001

Population Characteristics And Food Habitats Of White Perch (Morone Americana) In Branched Oak, Nebraska, Cara Hodking

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Field Trip Guide (For The Nebraska Well Drillers Association) Western Nebraska Geology, J. Cannia, D. Weinert, D. Brost, C. Miller, D. Carlson Jan 2001

Field Trip Guide (For The Nebraska Well Drillers Association) Western Nebraska Geology, J. Cannia, D. Weinert, D. Brost, C. Miller, D. Carlson

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Resource Notes-Academic Year 2000-01 Jan 2001

Resource Notes-Academic Year 2000-01

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


The Great Plains Natural Resources And Environmental Change Survey Report, D. C. Gosselin, R. Levy, D. Geise Jan 2001

The Great Plains Natural Resources And Environmental Change Survey Report, D. C. Gosselin, R. Levy, D. Geise

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Logan County Test Hole Logs, Perry B. Wigley Jan 2001

Logan County Test Hole Logs, Perry B. Wigley

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Results Of Whole-Rock Organic Geochemical Analyses Of The Crp-3 Drillcore, Victoria Land Basin, Antarctica, Richard M. Kettler Jan 2001

Results Of Whole-Rock Organic Geochemical Analyses Of The Crp-3 Drillcore, Victoria Land Basin, Antarctica, Richard M. Kettler

Department of Earth and Atmospheric Sciences: Faculty Publications

Sediments and rocks recovered in CRP-3 coring operations contain minute amounts of organic matter (average 0.3% TOC). TOC contents and C:N ratios are zoned systematically: those rocks encountered at depths greater than 330 meters below sea floor (mbsf) contain less organic matter and have higher TOC:N ratios (after correcting for inorganic N) than do shallower rocks. The only two samples that have TOC values greater than 1% also contain abundant granule to silt-sized particles of coal. The total sulphur contents of these rocks is very low and indicates either that only small amounts of deposited organic matter were labile, or …


Facies Architecture Of The Crp-3 Drillhole, Victoria Land Basin, Antarctica, Christopher R. Fielding, T. R. Naish, K. J. Woolfe Jan 2001

Facies Architecture Of The Crp-3 Drillhole, Victoria Land Basin, Antarctica, Christopher R. Fielding, T. R. Naish, K. J. Woolfe

Department of Earth and Atmospheric Sciences: Faculty Publications

The Cenozoic Victoria Land Basin (VLB) stratigraphic section penetrated by CRP-3 is mostly of Early Oligocene age. It contains an array of lithofacies comprising fine-grained mudrocks, interlaminated and interbedded mudrocks/sandstones, mud-rich and mud-poor sandstones, conglomerates and diamctites that are together interpreted as the products of shallow marine to possibly non-marine environments of deposition, affected by the periodic advance and retreat of tidewater glaciers. This lithofacies assemblage can be readily rationalised using the facies scheme designed originally for CRP-2/2A, and published previously. The uppermost 330 metres below sea floor (mbsf) shows a cyclical arrangement of lithofacies also similar to that recognised …


Laser-Derived Particle Size Data From Crp-3, Victoria Land Basin, Antarctica: Implications For Sequence And Seismic Stratigraphy, Christopher R. Fielding, G. B. Dunbar, S. M. Bryce Jan 2001

Laser-Derived Particle Size Data From Crp-3, Victoria Land Basin, Antarctica: Implications For Sequence And Seismic Stratigraphy, Christopher R. Fielding, G. B. Dunbar, S. M. Bryce

Department of Earth and Atmospheric Sciences: Faculty Publications

Seven hundred and nineteen samples from throughout the Cainozoic section in CRP-3 were analysed by a Malvern Mastersizer laser particle analyser, in order to derive a stratigraphic distribution of grain-size parameters downhole. Entropy analysis of these data (using the method of Woolfe & Michibayashi, 1995) allowed recognition of four groups of samples, each group characterised by a distinctive grain-size distribution. Group 1, which shows a multi-modal distribution, corresponds to mudrocks, interbedded mudrock/sandstone facies, muddy sandstones and diamictites. Group 2, with a sand-grade mode but showing wide dispersion of particle size, corresponds to muddy sandstones, a few cleaner sandstones and some …