Digital Commons Network^™

Local And Landscape Factors Affecting Nest Site Selection And Nest Success Of Burrowing Owls In Western Nebraska, Rebecca T. Ekstein

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Ecology Of Elk In Northwestern Nebraska: Demographics, Effects Of Human Disturbance, And Characteristics Of Calving Habitat, Bruce A. Stillings

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Calibration, Installation Techniques, And Initial Measurements For Vertical Resistivity Probes Used In Hydrogeologic Investigations, Jeffrey Mark Groncki

Masters Theses

Vertical Resistivity Probes (VRPs) are being increasingly used in a variety of applications where detailed vertical resistivity information in both the vadose and saturated zones is needed. All the different possible array types and spacings must be calibrated for the effect of the 2" (outer diameter) insulating PVC cylinder on which the electrodes are mounted. Apparent resistivities must be corrected by calibration factors. Varying the installation parameters greatly influences the measured apparent resistivity because of the disturbed annulus and the composition of the backfill materials. Bentonite slurry is necessary for the installations to keep the electrodes in good contact with …

Late Quaternary Fossil Mammals And Last Occurrence Dates From Caves At Barahona, Puerto Rico, Donald A. Mcfarlane

WM Keck Science Faculty Papers

Puerto Rico supported at least five genera of endemic terrestrial mammals in the late Quaternary, all of which are extinct. Whether these animals died out in the late Pleistocene, the mid-Holocene, or in post-Columbian time has not been established. This paper is the first attempt at radiometrically dating the 'last occurrences' of these taxa, together with the first unambiguous descriptions of localities reported by previous workers. Last occurrence dates for Nesophontes, Elasmodontomys and Heteropsomys are shown to be mid-Holocene and overlap with Amerindian occupation of the island. Acratocnus is known only from the late Pleistocene. No Puerto Rican taxon has …

Stratigraphic Analysis Of Diamicton Units In North-Central St. Joseph County, Michigan, Andrew C. Flint

Masters Theses

Seven subsurface glacial diamicton units, including a paleosol, have been characterized from two borings in north-central St. Joseph County, Michigan. These units have been characterized in terms of their clay mineralogy, texture, color, and stratigraphic position. t-Tests confirm that each unit displays a significant difference in mean 7A/10A peak height ratio from all other units.

Unit 4, informally called the Gray Marker tilt has been correlated between borings in this study and to the findings of others (Gardner, 1997, Nicks, in preparation). The Newbury till described by the Indiana Geological Survey (unpublished data) may also correlate to Unit 4, raising …

The Effect Of Divalent Cations On The Prophenoloxidase Enzyme Cascade Activity In The Freshwater Crayfish Cambarus Latimanus, Hans Skailand Eikaas

Theses and Dissertations

The effect of divalent cations such as cadmium, calcium, copper, lead and magnesium upon the prophenoloxidase system (proPO) was studied in hemocytes of the crayfish Cambarus latimanus. It was demonstrated that cadmium, calcium, copper and lead increased proPO activity significantly, whereas magnesium had no statistically significant effect on the system. Also, the molecular weight of the proPO enzyme was estimated using SDS-PAGE and found to be approximately 76 kDa.

Structural And Stratigraphic Relationships Of Ortho- And Paragneisses Southwest Of Marion, North Carolina, Brendan Richardson Bream

Masters Theses

This thesis examines the stratigraphic and structural relationships in the western Inner Piedmont of several orthogneisses and a paragneiss sequence. Detailed mapping was completed for an area slightly larger than one 7.5-minute quadrangle and is located southwest of Marion, North Carolina, at the northeast outcrop termination of the main Henderson Gneiss unit. From bottom to top, the stratigraphy of the study area consists of the Tallulah Falls Formation, Poor Mountain Amphibolite, and Poor Mountain Quartzite. Amphibolites and amphibole gneisses of the Tallulah Falls Formation, Poor Mountain Formation, and Dysartsville gneiss are interpreted as tholeiitic basalts related to rifting along the …

Mineral Paragenesis And Ore Fluids At The Turquoise Ridge Gold Deposit, Nevada, Michiko Shigehiro

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this study, mineral assemblages and related fluid inclusions at the Turquoise Ridge Carlin-type gold deposit were examined to answer the following questions: (1) What is the ore-stage mineral paragenesis? (2) At what pressures and temperatures did the deposits form? (3) What are the sources of ore fluids?

Pyrite with gold, jasperoid quartz, stibnite, orpiment, realgar, and calcite were successively deposited at Turquoise Ridge. Microthermometric data and isotopic ratios of inclusion fluids in ore-related minerals indicate entrapment of multiple generations of fluids in pre-ore, ore-, and late-ore stage minerals. Primary fluid inclusions in an ore-stage jasperoid quartz crystal have salinities …

Alteration Associated With Gold Deposition At The Getchell, Carlin-Type Gold Deposit, North-Central Nevada, Tracy Lynn Cail

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alteration at the Getchell deposit was examined to determine the effects of ore-bearing fluids on host lithologies and the relationship between K-bearing alteration minerals and Au deposition. The geochemistry of unaltered to highly altered and mineralized rocks from the Getchell deposit was quantified for 54 samples collected along 14 transects in calcareous siltstone, carbonaceous limestone, and a rhyodacitic dike. Each transect was collected along a single homogeneous bed that could be followed from visibly unaltered waste rock into high-grade ore.

Calculated elemental gains and losses record an increase in the concentrations of Au, Hg, Sb, Se, Si, Te, Tl, and …

Runoff From Fescue Plots Treated With Trimec, Cristopher G. Moss, Dwayne R. Edwards, Stephen R. Workman, R. Michael Williams

Biosystems and Agricultural Engineering Faculty Publications

Runoff of herbicides can promote adverse impacts in receiving waters. The objective of this study was to assess the effects of rainfall delay, herbicide application rate, rainfall intensity, and pre-application rainfall on runoff of TRIMEC (a combination of 2,4-D, dicamba, and mecoprop), a herbicide that is commonly used in central Kentucky. The levels of rainfall delay were 0, 2, and 4 d following application; and the levels of herbicide application rate were 0, 0.5, 1 and 2 times the recommended rate. Simulated rainfall was applied at intensities of 64, 102, and 140 mm h^-1; and the depths of …

Geosciences Newsletter- 1999, Department Of Geosciences

Geological and Environmental Sciences News

Vol.1, No. 24

• Dear Alumni and Friends
• Faculty News
• Graduate Student News
• Student News
• Alumni News
• Donations

Vegetation Trend In The East Kimberley Region : An Analysis Of Ground Monitoring Data From 1991-1998, Noelene Duckett, Paul Novelly, Ian Watson

Research Reports

This document summarises the analyses carried out on the ground monitoring data from the Kimberley region of Western Australia as part of the Natural Heritage Trust project 953024 - ‘'Development of Information Products for Reporting Rangeland Changes.”

A New Numerical Model Of Coupled Inland Ice Sheet, Ice Stream, And Ice Shelf Flow And Its Application To The West Antarctic Ice Sheet, Christina L. Hulbe, D. R. Macayeal

Geology Faculty Publications and Presentations

We have developed a dynamic/thermodynamic finite element numerical model that couples inland ice sheet, ice stream, and ice shelf dynamics. This new model stands apart from other whole ice sheet models in its explicit treatment of ice stream flow. Additionally, the model accounts for both horizontal and vertical advection and diffusion of temperature in the flowing ice. In present day simulations of the West Antarctic Ice Sheet (WAIS), modeled ice velocity agrees well with observed ice flow. In particular, the model reproduces the pattern of speed variation across ice streams although the continuous downstream speed up of ice flow cannot …

Climate Variability In The Andes Of Ecuador And Its Relation To Tropical Pacific And Atlantic Sea Surface Temperature Anomalies, Mathias Vuille, Raymond S. Bradley, Frank Keimig

Raymond S Bradley

The main spatiotemporal modes of seasonal precipitation and temperature variability in the Andes of Ecuador (1N–4S) and their relation to tropical Pacific and Atlantic sea surface temperature anomalies (SSTAs) between 1963–92 are identified based on rotated principal component analysis and cross-correlation techniques. Outgoing longwave radiation composites are analyzed during periods of strong oceanic forcing to confirm the proposed physical mechanisms. Despite the close proximity to the Pacific, precipitation variability in the Andes of Ecuador is not related to SSTA in the tropical Pacific domain alone. The El Nin˜o–Southern Oscillation influence is most dominant in the northwestern part of the Andes …

Sensitivity Of The North Atlantic Basin To Cyclic Climatic Forcing During The Early Cretaceous, Walter E. Dean, Michael A. Arthur

United States Geological Survey: Staff Publications

Striking cyclic interbeds of laminated dark-olive to black marlstone and bioturbated white to light-gray limestone of Neocomian (Early Cretaceous) age have been recovered at Deep Sea Drilling Project (DSDP) and Ocean Drilling Project (ODP) sites in the North Atlantic. These Neocomian sequences are equivalent to the Maiolica Formation that outcrops in the Tethyan regions of the Mediterranean and to thick limestone sequences of the Vocontian Trough of France. This lithologic unit marks the widespread deposition of biogenic carbonate over much of the North Atlantic and Tethyan seafloor during a time of overall low sealevel and a deep carbonate compensation depth. …

Earth In Four Dimensions: Development Of The Ideas Of Geologic Time And History, Robert F. Diffendal Jr.

School of Natural Resources: Faculty Publications

Changes in ideas and in technology can come about as slow incremental modifications, as well as by major paradigm shifts. In the case of the development of the ideas of geologic history and time, I will try to present these changes broadly and then look at how some of these have affected interpretation of Nebraska geology. Changes of view on three fronts were important in the development of geologic history and time concepts. First is the question of the nature of time. Is time cyclic or is it linear? The Greco-Oriental cultures had a world view based on cosmic cycles, …

Earth In Four Dimensions: Development Of The Ideas Of Geologic Time And History, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Changes in ideas and in technology can come about as slow incremental modifications, as well as by major paradigm shifts. In the case of the development of the ideas of geologic history and time, I will try to present these changes broadly and then look at how some of these have affected interpretation of Nebraska geology. Changes of view on three fronts were important in the development of geologic history and time concepts.

First is the question of the nature of time. Is time cyclic or is it linear? The Greco-Oriental cultures had a world view based on cosmic cycles, …

Observations Of Shallow Groundwater Contamination Due To Leakage Of Dairy Effluent Ponds On The Swan Coastal Plain, Wa, Richard J. George Dr, D L. Bennett, J R M Bell, Roger Wrigley

Resource management technical reports

In response to the risk of pollution of surface water from farm runoff, dairy farmers have been encouraged to install effluent storage ponds. Previous research has indicated that leachate from these storages can contribute to groundwater contamination. This project assessed the performance of storages at eight sites on the Swan Coastal Plain (SCP), WA. Groundwater conditions were monitored for over three years to study the influence of soil type, water table depth and waste water characteristics.

Diagenesis Of Lower Cretaceous Pelagic Carbonates, North Atlantic: Paleoceanographic Signals Obscured, Tracy D. Frank, Michael A. Arthur, Walter E. Dean

Department of Earth and Atmospheric Sciences: Faculty Publications

The stable isotope and minor element geochemistry of Neocomian (Lower Cretaceous) pelagic carbonates of the North Atlantic Basin (Deep Sea Drilling Project Sites 105, 367, 387, 391, and 603) was examined to develop a diagenetic model for pelagic limestones. In particular, we hoped to test the fidelity of whole-rock geochemical records as paleoceanographic indicators for pelagic deposits of pre-Aptian age, in which individual microfossils are not available for analysis. Data indicate that in addition to depth of burial, rhythmic variations in primary carbonate content have strongly controlled diagenetic patterns and associated geochemical signatures in these Neocomian sequences. Samples become increasingly …

Earth News, Fall 1999, Department Of Earth Science, University Of Northern Iowa.

Earth News

Inside this issue:

--- Earth Science Staff Activities
--- Faculty Research, Publications, and Recognition
--- Profile: Wayne Anderson
--- PRISMS Helps Physic Students "See"
--- UNI Meteorology Students "Chase" Tornadoes in Des Moines
--- Technology Takes classes, teachers into the Next Millenium
--- Gifts to the Department of Earth Science
--- Volcanology Students Study Volcanoes in Italy, Sicily and the Aeolian Islands
--- Spring Trip 2000
--- Gifts to the Department of Earth Science
--- 1999-2000 Scholarship and Award Recipients
--- Earth Science Seminar Series
--- 1999 Earth Science Graduates
--- Student Research Presentations
--- Earth Science Majors
--- Alumni …

Investigations Of Offshore Beach Sands : Virginia Beach And Sandbridge, Virginia, C. S. Hardaway, C. H. Hobbs Iii, D. A. Milligan

Reports

The City of Virginia Beach is faced with an ongoing problem of erosion along its ocean beaches. The "Resort Strip," the backbone of beach-going tourism in the Commonwealth, must be renourished annually. Steel bulkheads or seawalls have been constructed along most of the 7 km (4.5 mile) ocean shoreline of Sandbridge, a semi-private, ocean-side community. The City is looking for beach material to reestablish its sandy coast. Maintaining a protective and recreational beach is the_primary goal in both locales.

Previous sources of sand for the "Resort Strip" have been upland borrow pits that either have closed or are located too …

Regional Hydrology Of The Dixie Valley Geothermal Field, Nevada: Preliminary Interpretations Of Chemical And Isotopic Data, Gregory Nimz, Cathy Janik, Fraser Goff, Charles Dunlap, Mark Huebner, Dale Counce, Stuart Johnson

Charles Dunlap

Chemical and isotopic analyses of Dixie Valley regional waters indicate several distinct groups ranging in recharge age from Pleistocene (<20 ka) to recent (<50a). Valley groundwater is older than water from perennial springs and artesian wells in adjacent ranges, with Clan Alpine range (east) much younger (most <50a) than Stillwater range (west; most > 1OOOa).Geothermal field fluids (-12-14 ka) appear derived from water similar in composition to non-thermal groundwater observed today in valley artesian wells (also -14 ka). Geothermal fluid interaction with mafic rocks (Humboldt Lopolith) appears to be common, and significant reaction with granodiorite may also occur. Despite widespread occurrence of carbonate rocks, largescale chemical interaction appears minor. Age asymmetry of the ranges, more extensive interaction with deep- seated waters in the west, and distribution of springs and artesian wells suggest the existence …

Maximum Temperature Trends In The Himalaya And Its Vicinity: An Analysis Based On Temperature Records From Nepal For The Period 1971-94, Arun B. Shrestha, Camerson P. Wake, Paul Andrew Mayewski, Jack E. Dibb

Earth Science Faculty Scholarship

Analyses of maximum temperature data from 49 stations in Nepal for the period 1971-94 reveal warming trends after 1977 ranging from 0.06° to 0.12°C yr¹ in most of the Middle Mountain and Himalayan regions, while the Siwalik and Terai (southern plains) regions show warming trends less than 0.03°C yr¹. The subset of records (14 stations) extending back to the early 1960s suggests that the recent warming trends were preceded by similar widespread cooling trends. Distributions of seasonal and annual temperature trends show high rates of warming in the high-elevation regions of the country (Middle Mountains and Himalaya), …

Modeling Surface And Subsurface Pesticide Transport Under Three Field Conditions Using Przm-3 And Gleams, Robert W. Malone, Richard C. Warner, Stephen R. Workman, Matt E. Byers

Biosystems and Agricultural Engineering Faculty Publications

Contaminant transport models should be evaluated over a wide range of conditions to determine their limitations. The models PRZM and GLEAMS have been evaluated many times, but few studies are available in which predicted movement in runoff and percolate were simultaneously evaluated against field data. Studies of this type are essential because pesticide leaching and runoff are mutually dependent processes. For this reason, PRZM-3 and GLEAMS were evaluated for their ability to predict metribuzin concentrations in runoff, sediment, subsurface soil, and pan lysimeters under three field conditions (yard waste compost amended, no-till, and conventional-till) on a Lowell silt loam soil. …

Results Of The Improved Soil Management & Cropping Systems For Waterlog-Prone Soils Project, Derk Bakker, G J. Hamilton, Peter I. Tipping, Cliff Spann, Doug Rowe

Resource management technical reports

No abstract provided.

Antarctic's Role Pursued In Global Climate Change, Paul Andrew Mayewski, I. Goodwin

Earth Science Faculty Scholarship

The impact of Antarctica on global climate change and the impact of global climate change on Antarctica are the focal points of a current series of expeditions there, and an international, interdisciplinary array of researchers met this past spring to go over the expeditions' progress. Advances were reported in describing the impact of the seasonal cycle, semiannual oscillation, and the El Niño-Southern Oscillation (ENSO) cycle on Antarctic accumulation in recent decades.

Difficulties still remain, however, in explaining fully the history and forcing of the Antarctic climate and the links between tropical forcing and high-latitude response. The difficulties arise largely because …

Soil Moisture Within The Windbreak/Crop Interface And A Comparison Of Three Types Of Sensors For Measuring Soil Water Content, Qingjiang Hou

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Central Platte River Forests: Breeding Birds And Woody Vegetation, Barbara K. Good

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Modeling Macrophytes Of The Columbia Slough, Oregon, Chris Berger, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

The Columbia Slough is a tidally influenced freshwater system of wetlands, channels, and lakes located within the Portland, Oregon metropolitan area at the confluence of the Willamette and Columbia Rivers. It is a eutrophic water body susceptible to algae blooms and crashes and periods of high pH which violate water quality standards. High nutrient loads from groundwater principally controls algae productivity. Past structural changes to the Columbia Slough have included filling of wetlands and lakes and the construction of levees, dikes, culverts and irrigation channels. These changes have altered the natural flow dynamics creating an environment more conducive to eutrophication. …

Behavior Of Oceanic Crustal Magnetization At High Temperatures: Viscous Magnetization And The Marine Magnetic Anomaly Source Layer, Julie A. Bowles, H. Paul Johnson

Geosciences Faculty Articles

Although the source layer for marine magnetic anomalies has been assumed to be the extrusive basalts of uppermost ocean crust, recent studies indicate that lower crustal rocks may also contribute. Because the temperature at which magnetization of crustal rocks achieves long-term stability is crucial to any source layer contribution, we undertook high-temperature VRM (viscous remanent magnetization) experiments on samples of basalt, dike and gabbroic sections. Samples were heated at temperature intervals up to T_c, while a magnetic field was applied for periods between 6 hours and 28 days. Results show that the dike and gabbro samples achieve maximum …