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1997

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Articles 211 - 240 of 255

Full-Text Articles in Earth Sciences

Fillmore County Test Hole Logs, Raymond R. Burchett, Scott E. Summerside Jan 1997

Fillmore County Test Hole Logs, Raymond R. Burchett, Scott E. Summerside

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Resource News-Winter 1996-97 Jan 1997

Resource News-Winter 1996-97

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Structural Contour Map On Top Of The Lansing Group (Pennsylvanian) In Dundy County, Nebraska, R. R. Burchett Jan 1997

Structural Contour Map On Top Of The Lansing Group (Pennsylvanian) In Dundy County, Nebraska, R. R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Herbicides And Their Metabolites In Rainfall: Origin, Transport, And Deposition Patterns Across The Midwestern And Northeastern United States, 1990-1991, Donald Goolsby, E. Michael Thurman, Michael Pomes, Michael Meyer, William Battaglin Jan 1997

Herbicides And Their Metabolites In Rainfall: Origin, Transport, And Deposition Patterns Across The Midwestern And Northeastern United States, 1990-1991, Donald Goolsby, E. Michael Thurman, Michael Pomes, Michael Meyer, William Battaglin

United States Geological Survey: Staff Publications

Herbicides were detected in rainfall throughout the midwestern and northeastern United States during late spring and summer of 1990 and 1991. Herbicide concentrations exhibited distinct geographic and seasonal patterns. The highest concentrations occurred in midwestern cornbelt states following herbicide application to cropland. Volume-weighted concentrations of 0.2-0.4 μg/L for atrazine and alachlor were typical in this area during mid-April through mid-July, and weighted concentrations as large as 0.6- 0.9 μg/L occurred at several sites. Concentrations of 1-3 μg/L were measured in a few individual samples. Atrazine was detected most often followed by alachlor, deethylatrazine, metolachlor, cyanazine, and deisopropylatrazine. The high ratio …


Correlation Of Late-Pleistocene Lake-Level Oscillations In Mono Lake, California, With North Atlantic Climate Events, Larry Benson, Steve P. Lund, James W. Burdett, Michaele Kashgarian, Timothy P. Rose, Joseph P. Smoot, Martha Schwartz Jan 1997

Correlation Of Late-Pleistocene Lake-Level Oscillations In Mono Lake, California, With North Atlantic Climate Events, Larry Benson, Steve P. Lund, James W. Burdett, Michaele Kashgarian, Timothy P. Rose, Joseph P. Smoot, Martha Schwartz

United States Geological Survey: Staff Publications

Oxygen-18 (18O) values of sediment from the Wilson Creek Formation, Mono Basin, California, indicate three scales of temporal variation (Dansgaard-Oeschger, Heinrich, and Milankovitch) in the hydrologic balance of Mono Lake between 35,400 and 12,900 14C yr B.P. During this interval, Mono Lake experienced four lowstands each lasting from 1000 to 2000 yr. The youngest low stand, which occurred between 15,500 and 14,000 14C yr B.P., was nearly synchronous with a desiccation of Owens Lake, California. Paleomagnetic secular variation (PSV) data indicate that three of four persistent low stands occurred at the same times as Heinrich events …


Spatial Distribution Of Lead In Soil And Sediment In Iqaluit, Northwest Territories And Links With Human Health, Liisa Ann Peramaki Jan 1997

Spatial Distribution Of Lead In Soil And Sediment In Iqaluit, Northwest Territories And Links With Human Health, Liisa Ann Peramaki

Theses and Dissertations (Comprehensive)

The Baffin Regional Health Board has recently expressed concern over lead poisoning in Iqaluit, NWT, manifested by low haemoglobin levels in children. Several studies in temperate regions have demonstrated links between environmental lead and human health. However, little is known about these links in a permafrost environment. While humans are exposed to lead via a number of different pathways, soils and sediments are two major pathways. The purpose of this study is to determine the spatial distribution of soil and sediment-associated lead in Iqaluit and to assess probable pathways between high lead levels and children. The research hypothesis is that …


Fluid Patterns, Sediment Pathways And Woody Obstructions In The Pine River, Angus, Ontario, John T. Beebe Jan 1997

Fluid Patterns, Sediment Pathways And Woody Obstructions In The Pine River, Angus, Ontario, John T. Beebe

Theses and Dissertations (Comprehensive)

The objective of this research was to determine the effects that woody obstructions have on flow patterns and sediment pathways in a sand-bed river in Central Ontario. The Pine River near Angus, a tributary of the Nottawasaga River, was chosen because it contained a number of woody obstructions to flow from which to choose study sites. Two reaches, one containing a trunk oriented in the direction of flow, were chosen as the study reaches. Sampling of fluid speeds through the study reaches showed that the cross-stream obstruction acted to slow fluid as it approached and exited the obstruction zone, while …


Soil Information Sheets For The Northern Agricultural Areas, Natural Resources Assessment Group, Agriculture Western Australia, Landcare Western Australia Jan 1997

Soil Information Sheets For The Northern Agricultural Areas, Natural Resources Assessment Group, Agriculture Western Australia, Landcare Western Australia

Agriculture reports

These soil information sheets are produced for farmers in the Northern Wheatbelt. Each sheet summaries information on the particular soil's characteristic properties and associated land use suitability and management. A photograph of a representative profile is provided for each soil. Technical terms are defined in the glossary. Information is presented under the following headings: Soil series and group, occurrence, native vegetation, soil profile description, characteristic soil properties, soil classification (Australian Soil Classification and Northcote Principal Profile Form).


Timing Of Basaltic Volcanism Along The Mesa Butte Fault In The San Francisco Volcanic Field, Arizona, From 40Ar/39Ar Dates: Implications For Longevity Of Cinder Cone Alignments, F. M. Conway, David A. Ferrill, Chris M. Hall, Alan P. Morris, John A. Stamatakos, Charles B. Connor, Alex N. Halliday, Christopher Condit Jan 1997

Timing Of Basaltic Volcanism Along The Mesa Butte Fault In The San Francisco Volcanic Field, Arizona, From 40Ar/39Ar Dates: Implications For Longevity Of Cinder Cone Alignments, F. M. Conway, David A. Ferrill, Chris M. Hall, Alan P. Morris, John A. Stamatakos, Charles B. Connor, Alex N. Halliday, Christopher Condit

School of Geosciences Faculty and Staff Publications

Using high‐precision stepwise‐heating 40Ar/39Ar methods, we dated volcanic products of at least 12 vents cropping out along the northern segment of the Mesa Butte Fault in the San Francisco Volcanic Field, Arizona, where the relationship between fault and vent alignment is unambiguous. The 40Ar/39Ar isochron dates indicate that the Mesa Butte Fault hosted five episodes of volcanism over a 1 million year interval, from 1400 to 300 ka. The first episode occurred 1 km northwest of the trace of the Mesa Butte Fault, whereas the next two episodes were centered near the intersection of the Mesa Butte and Cedar Ranch …


Regulation Of Algal Blooms In Antarctic Shelf Waters By The Release Of Iron From Melting Sea Ice, Peter N. Sedwick, Giacomo R. Ditullio Jan 1997

Regulation Of Algal Blooms In Antarctic Shelf Waters By The Release Of Iron From Melting Sea Ice, Peter N. Sedwick, Giacomo R. Ditullio

OES Faculty Publications

During summer 1995-96, we measured iron in the water column and conducted iron-enrichment bottle-incubation experiments at a station in the central Ross Sea (76°30'S, 170°40'W), first, in the presence of melting sea ice, and 17 days later, in ice-free conditions. We observed a striking temporal change in mixed-layer dissolved iron concentrations at this station, from 0.72-2.3 nM with sea ice present, to 0.16-0.17 nM in ice-free conditions. These changes were accompanied doubling of algal (diatom) biomass. Our incubation experiments suggest that conditions were iron-replete in the presence of sea ice, and iron-deficient in the absence of sea ice. We surmise …


An Assessment Of Hydrological Process And Landform Change: Slave River Delta, Northwest Territories, Ronald Brad Hill Jan 1997

An Assessment Of Hydrological Process And Landform Change: Slave River Delta, Northwest Territories, Ronald Brad Hill

Theses and Dissertations (Comprehensive)

The Slave River Delta, 61˚15'N, 113˚30'W, is located at the mouth of the Slave River in the southeast arm of Canada's Great Slave Lake. Although the delta itself lies some 1600 km downstream from the W.A.C. Bennett Dam at Hudson's Hope, British Columbia, the mean annual discharge and sediment load of the Slave River have decreased by 16% and 33% respectively since regulation. Such alterations in the Slave River flow regime have significant implications for the growth of the River Delta since the transfer of sediment to the delta front is one of the most important factors in the landform’s …


The Impact Of Glacier Recession Upon The Discharge Of The Bow River Above Banff, Alberta, 1951-1993, Christopher Dennis Hopkinson Jan 1997

The Impact Of Glacier Recession Upon The Discharge Of The Bow River Above Banff, Alberta, 1951-1993, Christopher Dennis Hopkinson

Theses and Dissertations (Comprehensive)

Three methods have been used to explore the volumetric change of glaciers in the Bow Basin above Banff for the years 1951 to 1993. Using aerial photography, the extent of glacier covers for the two years were mapped at a scale of 1:50,000. The first volumetric calculation of glacier loss was based on inventory criteria; the second a hyposgraphic curve method based on Young’s investigations in Mistaya Basin (1991) and the third stereo air photogrammetry and DEM comparisons using computer software. These methods were applied to the highly glacierized Hector Lake catchment within the Bow Valley and then extrapolated up …


Reexamination Of Scarp Development Along The Niagara Escarpment, Ontario, Canada, David Walter Hintz Jan 1997

Reexamination Of Scarp Development Along The Niagara Escarpment, Ontario, Canada, David Walter Hintz

Theses and Dissertations (Comprehensive)

The Niagara Escarpment is generally viewed as a relict landform which shows ancient structural features and the effects of glaciation. Since it was realized that the Escarpment was not a fault, but instead a feature of erosional origin, little interest has been paid to development of the steep cliffed section of the Niagara Escarpment. This research project has several objectives. The first is an examination of the relationship between the morphology of the Escarpment and its geological units. This will include analysis of the structure and lithology of each and the geochemistry, especially, of the Queeston Formation. Associated with the …


Les Deux Faces De La Pensée De E. A. Martel, Jacques Choppy Jan 1997

Les Deux Faces De La Pensée De E. A. Martel, Jacques Choppy

International Journal of Speleology

Réunion de textes de Martel: 1 - Extraits du Nouveau Traité des Eaux Souterraines (1921), donnant l’essentiel de la pensée de l’auteur sur l’hydraulique et la morphologie du karst. 2 - En opposition à cette vision, rappelée de nombreuses fois par l’auteur, extraits de diverses publications (de 1894 à 1930), admettant qu’un fonctionnement en régime noyé était possible: Martel est donc l’un des tout premiers ayant observé des formes de creusement en régime noyé, et les ayant interprétées comme telles.


Are Troglobitic Taxa Troglobiomorphic? A Test Using Phylogenetic Inference, Laure Desutter-Grandcolas Jan 1997

Are Troglobitic Taxa Troglobiomorphic? A Test Using Phylogenetic Inference, Laure Desutter-Grandcolas

International Journal of Speleology

Obligate cave dwelling organisms are frequently characterised by a peculiar morphological syndrome, named troglomorphosis or troglobiomorphosis. This hypothesis, which deals with the evolutionary influence of the subterranean environment on cave organisms is far from being universally accepted. Yet it has been adopted by many authors and is often included in the definitions of the current classification of cave taxa. In this paper I present a test of the troglobiomorphosis hypothesis, using the case study of the cricket clade Amphiacustae (Orthoptera, Grylloidea, Phalangopsidae). Such a test preliminarily requires that observations of the habitat of the taxa (achieved on present-day populations) are …


The Hawaiian Cave Planthoppers (Homoptera: Fulgoroidea: Cixiidae) - A Model For Rapid Subterranean Speciation?, Hannelore Hoch Jan 1997

The Hawaiian Cave Planthoppers (Homoptera: Fulgoroidea: Cixiidae) - A Model For Rapid Subterranean Speciation?, Hannelore Hoch

International Journal of Speleology

After the successful colonization of a single ancestral species in the Hawaiian Islands, planthoppers of the cixiid genus Oliarus underwent intensive adaptive radiation resulting in 80 described endemic species. Oliarus habitats range from montaneous rain forests to dry coastal biotopes and subterranean environments. At least 7 independant evolutionary lines represented by different species have adapted to lava tubes on Molokai (1), Maui (3), and Hawaii Island (3). Behavioral and morphological studies on one of these evolutionary lines on Hawaii Island, the blind, flight- and pigmentless Oliarus polyphentus have provided evidence for reproductive isolation between allopatric populations which may in fact …


Geographic Variation And Genetic Relationships In Populations Of The Androniscus Dentiger Complex From Central Italy (Isopoda, Oniscidea, Trichoniscidae), Gabriele Gentile, Giuliana Allegrucci Jan 1997

Geographic Variation And Genetic Relationships In Populations Of The Androniscus Dentiger Complex From Central Italy (Isopoda, Oniscidea, Trichoniscidae), Gabriele Gentile, Giuliana Allegrucci

International Journal of Speleology

Androniscus dentiger is a terrestrial isopod distributed from Great Britain to North Africa, inhabiting humid edafic environments, superficial underground compartments and both natural and artificial caves. In this study allozyme data have been used to investigate the geographic variation and the genetic relationships of several populations of A. dentiger from Central Italy, using as outgroups populations from four congeneric species, A. calcivagus, A. cfr. subterraneus, A. spelaeorum, and A. degener. Multivariate analysis of A. dentiger allele frequencies indicates the existence of a group of populations (group A) distributed in a wide geographic area which are genetically …


Genetic Divergence And Evolutionary Times: Calibrating A Protein Clock For South-European Stenasellus Species (Crustacea Isopoda), Valerio Ketmaier, Roberto Argano, Marina Cobolli, Elvira De Matthaeis Jan 1997

Genetic Divergence And Evolutionary Times: Calibrating A Protein Clock For South-European Stenasellus Species (Crustacea Isopoda), Valerio Ketmaier, Roberto Argano, Marina Cobolli, Elvira De Matthaeis

International Journal of Speleology

We studied genetic divergence in a group of exclusively stygobiont isopods of the family Stenasellidae. In particular, we assessed evolutionary relationships among several populations of Stenasellus racovitzai and Stenasellus virei. To place this study in a phylogenetic context. we used another species of Stenasellus, S. assorgiai, as an outgroup. S. racovitzai occurs in Corsica, Sardinia and in the fossil islands of the Tuscan Archipelago, while S. virei is a polytypic species widely distributed in the central France and Pyrenean area. This vicariant distribution is believed to be the result of the disjunction of the Sardinia-Corsica microplate from …


Long Term Stability Of A Terrestrial Cave Community, Claudio Di Russo, Gianmaria Carchini, Mauro Rampini, Marco Lucarelli, Valerio Sbordoni Jan 1997

Long Term Stability Of A Terrestrial Cave Community, Claudio Di Russo, Gianmaria Carchini, Mauro Rampini, Marco Lucarelli, Valerio Sbordoni

International Journal of Speleology

We report data on the spatial structure and seasonal variation of the community of Valmarino cave, a medium sized sandstone cave, located a few kilometres from the coast line, in Central Italy. Due to both its habitat features and its relatively recent geological history, Valmarino cave is only inhabited by terrestrial, troglophilic elements, i.e facultative cave dwellers. By means of monthly censuses and density plot estimates we have investigated species abundance, diversity and their spatial organization, by considering separately samples from different cave sectors. Homogeneous sampling design allowed to compare series of samplings performed in 1974 and 1994. On the …


Martel's Links With Usa, Trevor R. Shaw Jan 1997

Martel's Links With Usa, Trevor R. Shaw

International Journal of Speleology

Of the 29% foreign members in the Société de Spéléologie, five lived in the USA. They were Luella Owen (the only woman member of the Société), R. Ellsworth Cali, H.C. Hovey, E Van Epps and C. R. Blackall. E.S. Balch, though not a member, also knew Martel. These members, between them, published ten papers in Spelunca, which also reviewed their other work. The activities of these six, and their links with France, are discussed. Martel actively encouraged cave work in America, as elsewhere, and Hovey, who had been with him during the survey of Aven Armand, he knew quite well. …


Fernandez Bay, San Salvador, Bahamas: A Natural Laboratory For Assessment Of The Preservation Of Coral Reef Community Structure, Benjamin J. Greenstein, Lora A. Harris, H. Allen Curran Jan 1997

Fernandez Bay, San Salvador, Bahamas: A Natural Laboratory For Assessment Of The Preservation Of Coral Reef Community Structure, Benjamin J. Greenstein, Lora A. Harris, H. Allen Curran

Geosciences: Faculty Publications

Reprinted from: James L. Carew (ed.), Proceedings of the 8th Symposium on the Geology of the Bahamas: San Salvador, Bahamian Field Station


Guide To Bahamian Ichnology: Pleistocene, Holocene, And Modern Environments: A Field Trip Guide, H. Allen Curran, Brian White, Mark A. Wilson Jan 1997

Guide To Bahamian Ichnology: Pleistocene, Holocene, And Modern Environments: A Field Trip Guide, H. Allen Curran, Brian White, Mark A. Wilson

Geosciences: Faculty Publications

This guide was prepared for the Fourth International Ichnofabric Workshop (IIW- 4) to be hosted by the Bahamian Field Station and held on San Salvador Island on March 15-22, 1997. About 35 scientists representing 15 countries are registered to attend the workshop.

The focus of discussion in the infonnal scientific sessions will be the uses of ichnofabric analysis in sedimentary geology. An ichnofabric is the texture or internal structure created within a sedimentary substrate from the bioturbating activity of organisms. Ichnofabric analysis is a new and emerging area of ichnology (the study of trace fossils), and its methods are proving …


Chemistry And Environmental Implications Of Thio-Red And 2,4,6-Trimercaptotriazine Compounds, Kevin R. Henke Jan 1997

Chemistry And Environmental Implications Of Thio-Red And 2,4,6-Trimercaptotriazine Compounds, Kevin R. Henke

Theses and Dissertations

Many compounds, including Thio-Red® and 2,4,6-trimercaptotriazine, trisodium salt (TMT-55), have been marketed to precipitate mercury and other heavy metals from water, including contaminated ground waters. For the products to be effective, information is needed on the chemistry of the products, how they precipitate metals from aqueous solutions, and the chemistries and stabilities of the precipitates.

CS32-, HS-, and S2- are the dominant sulfur species in Thio-Red®. They precipitate heavy metals from water as sulfides (e.g., HgS, PbS, and ZnS). Thio-Red® also contains traces of poisonous carbon disulfide (CS2). Additional CS2 could form from reactions between dissolved heavy metals and CS32-. …


Knickpoint Analysis Of Streams In North Dakota, South Dakota, And Nebraska, Trent D. Hubbard Jan 1997

Knickpoint Analysis Of Streams In North Dakota, South Dakota, And Nebraska, Trent D. Hubbard

Theses and Dissertations

Analysis of stream profiles, seismic reflection studies, engineering studies, and historical earthquakes indicates uplift in south-central South Dakota and north-central Nebraska over the last 5-10 ma. The purpose of this study was to determine if this uplift could be detected by constructing topographic profiles along, and in close proximity to several streams in this region. The Cannonball River, ND, was used to compare the streams in South Dakota and Nebraska to a stream beyond the affected area.

Data for the profiles were collected from 7 .5 minute topographic maps as well as GPS surveys. Abrupt changes in slope (irregularities) were …


The Characterization Of An Amiid Species From The Fort Union Rock Formation Of The Early Paleocene, Alexis Penot Jan 1997

The Characterization Of An Amiid Species From The Fort Union Rock Formation Of The Early Paleocene, Alexis Penot

Honors Capstone Projects and Theses

No abstract provided.


Nearly Synchronous Climate Change In The Northern Hemisphere During The Last Glacial Termination, Larry V. Benson, James Burdett, Steve Lund, Michaele Kashgarian, Scott Mensing Jan 1997

Nearly Synchronous Climate Change In The Northern Hemisphere During The Last Glacial Termination, Larry V. Benson, James Burdett, Steve Lund, Michaele Kashgarian, Scott Mensing

United States Geological Survey: Staff Publications

The climate of the North Atlantic region underwent a series of abrupt cold/warm oscillations when the ice sheets of the Northern Hemisphere retreated during the last glacial termination (17,700–11,500 years ago). Evidence for these oscillations, which are recorded in European terrestrial sediments as the Oldest Dryas/Bølling/ Older Dryas/Allerød/Younger Dryas vegetational sequence, has been found in Greenland ice cores. The geographical extent of many of these oscillations is not well known, but the last major cold event (the Younger Dryas) seems to have been global in extent. Here we present evidence of four major oscillations in the hydrological balance of the …


Fractured-Aquifer Hydrogeology From Geophysical Logs; The Passaic Formation, New Jersey, Roger H. Morin, Glen B. Carleton, Stephane Poirier Jan 1997

Fractured-Aquifer Hydrogeology From Geophysical Logs; The Passaic Formation, New Jersey, Roger H. Morin, Glen B. Carleton, Stephane Poirier

United States Geological Survey: Staff Publications

The Passaic Formation consists of gradational sequences of mudstone, siltstone, and sandstone, and is a principal aquifer in central New Jersey. Ground-water flow is primarily controlled by fractures interspersed throughout these sedimentary rocks and characterizing these fractures in terms of type, orientation, spatial distribution, frequency, and transmissivity is fundamental towards understanding local fluid-transport processes. To obtain this information, a comprehensive suite of geophysical logs was collected in 10 wells roughly 46 m in depth and located within a .05 km2 area in Hopewell Township, New Jersey. A seemingly complex, heterogeneous network of fractures identified with an acoustic televiewer was …


Statistical Modeling Of Agricultural Chemical Occurrence In Midwestern Rivers, William A. Battaglin, Donald A. Goolsby Jan 1997

Statistical Modeling Of Agricultural Chemical Occurrence In Midwestern Rivers, William A. Battaglin, Donald A. Goolsby

United States Geological Survey: Staff Publications

Agricultural chemicals in surface water may constitute a human health risk or have adverse effects on aquatic life. Recent research on unregulated rivers in the midwestern USA documents that elevated concentrations of herbicides occur for 1–4 months following application in late spring and early summer. In contrast, nitrate concentrations in unregulated rivers are elevated during fall, winter, and spring months. Natural and anthropogenic variables of river drainage basins, such as soil permeability, amount of agricultural chemicals applied, or percentage of land planted in corn, affect agricultural chemical concentration and mass transport in rivers.

Presented is an analysis of selected data …


Three-Dimensional Upper Crustal Velocity Structure Beneath San Francisco Peninsula, California, Tom Parsons, Mary Lou Zoback Jan 1997

Three-Dimensional Upper Crustal Velocity Structure Beneath San Francisco Peninsula, California, Tom Parsons, Mary Lou Zoback

United States Geological Survey: Staff Publications

This paper presents new seismic data from, and crustal models of the San Francisco Peninsula. In much of central California the San Andreas fault juxtaposes the Cretaceous granitic Salinian terrane on its west and the Late Mesozoic/Early Tertiary Franciscan Complex on its east. On San Francisco Peninsula, however, the present-day San Andreas fault is completely within a Franciscan terrane, and the Pilarcitos fault, located southwest of the San Andreas, marks the Salinian-Franciscan boundary. This circumstance has evoked two different explanations: either the Pilarcitos is a thrust fault that has pushed Franciscan rocks over Salinian rocks or the Pilarcitos is a …


Hands-On Geology For Navajo Nation Teachers, Russell Frank Dubiel, Stephen Tom Hasiotis, Steven Christian Semken Jan 1997

Hands-On Geology For Navajo Nation Teachers, Russell Frank Dubiel, Stephen Tom Hasiotis, Steven Christian Semken

United States Geological Survey: Staff Publications

The Navajo Nation comprises the largest land area and the largest population of any Native American community in the United States, and it hosts some of earth's most spectacular geology.