Earth Sciences Commons^™

Isotopic Signature Of Burial Diagenesis And Primary Lithological Contrasts In Periplatform Carbonates (Miocene, Great Bahama Bank), Tracy D. Frank, Karin Bernet

Department of Earth and Atmospheric Sciences: Faculty Publications

The stable isotope geochemistry of Miocene sediments from the leeward margin of the Great Bahama Bank was examined to investigate burial diagenetic processes in periplatform carbonates. Data indicate that, in addition to differences in bulk proportions of neritic and pelagic carbonate along the slope, rhythmic variation in primary carbonate content has controlled patterns of burial diagenesis and associated geochemical signatures throughout much of the succession examined. The present study focuses on Ocean Drilling Program Sites 1006 and 1007, the most distal of five sites drilled from marginal to deep basin environments during Leg 166. These Miocene sections are characterized by …

Investigating Ground And Surface Water In The Republican River Basin Of Nebraska Using Water Chemistry And Environmental Isotopes, Jennifer J. Schellpeper

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

Recent legal battles concerning water use initiated an investigation of the stream/aquifer relationships in the Republican River Basin located in southwest Nebraska. Ground and surface water was analyzed for tritium, deuterium, ¹⁸O, and major ions. Temperature, pH, conductivity and alkalinity were determined on-site. Samples were collected during 1997 and 1998 from irrigation wells throughout the entire basin. Localized interactions between groundwater and surface water were examined during twenty-four hour pump tests performed on the irrigation wells screened in the alluvium along the river valley and its tributaries. These data show there are differences between the ground and surface waters …

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.

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.

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, …

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 …

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. …

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.

Interannual Variations In Snowmelt Onset And Links To 500 Hpa Atmospheric Anomalies Over The Arctic, Sheldon D. Drobot, Mark R. Anderson

Department of Earth and Atmospheric Sciences: Faculty Publications

Interannual variations in the melt onset of snow provide a mechanism to observe climatic fluctuations. Timing of initial ablation is associated with certain poorly defined overlying atmospheric conditions. This paper investigates the spatial and temporal patterns in melt onset dates and associated 500 hPa height anomalies over the Arctic region from 1982 to 1992. Melt onset dates are derived from Scanning Multichannel Microwave Radiometer (SMMR) and Special Sensor Microwave Imager (SSM/I) data, while 500 hPa height anomalies are computed from the National Centers for Environmental Protection (NCEP) reanalysis models. Results indicate significant interannual variations in the spatial pattern and timing …

Molybdenum Accumulation In Cariaco Basin Sediment Over The Past 24 K.Y.: A Record Of Water-Column Anoxia And Climate, Walter E. Dean, David Z. Piper, Larry C. Peterson

United States Geological Survey: Staff Publications

Molybdenum (Mo) concentrations in a sediment core from the Cariaco basin on the Venezuelan continental shelf can be partitioned between a marine fraction and a terrigenous fraction. The accumulation rate of the marine fraction of Mo increased abruptly 15 000 calendar years ago (15 ka), from <0.5 mg • cm^-2 • yr^-1 to >4 μg • cm^-2 • yr^-1, and then decreased abruptly at 9 ka. The accumulation rate remained high throughout this 6 k.y. period, but exhibited maxima at 15–14 and 12.5 ka, corresponding in time to meltwater pulse IA into the Gulf of Mexico and the onset …

Close-Range And Satellite Remote Sensing Of Algal Biomass In The Iowa Great Lakes, Eric A. Wilson

Department of Geography: Dissertations, Theses, and Student Research

The utility of both close-range and satellite remote sensing for assessing inland water quality was examined in the Iowa Great Lakes. The water quality of this system is of considerable interest because of its status as an environmental, recreational, and therefore, economic resource. The broad range of optical conditions present in the lakes and the wealth of literature on the system make it an ideal environment for water quality remote sensing research. The goal of this research was to survey the water quality of the Iowa Great Lakes via remote sensing, evaluate different predictive algorithms, and map the distribution of …

Cheyenne County Test-Hole Logs: Nebraska Water Survey Test-Hole Report No. 17, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

In 1930, the Conservation and Survey Division (CSD) of the University of Nebraska and the United States Geological Survey began a program of cooperative groundwater studies in Nebraska. Since then test drilling by use of rotary drilling equipment has been an integral part of that program. This report contains logs of all the test-holes drilled in the county under the program as well as those drilled by the Conservation and Survey Division with financial assistance from other government agencies. Also included are logs of test-holes drilled by cooperators with the South Platte Natural Resources District.

The maps in this report …

Tectonic Forcings Of Maastrichtian Ocean-Climate Evolution, Tracy D. Frank, Michael A. Arthur

Department of Earth and Atmospheric Sciences: Faculty Publications

A global compilation of deep-sea isotopic records suggests that Maastrichtian ocean-climate evolution was tectonically driven. During the early Maastrichtian the Atlantic intermediate-deep ocean was isolated from the Pacific, Indian, and Southern Oceans; deep water formed in the high-latitude North Atlantic and North Pacific. At the early/late Maastrichtian boundary a major reorganization of oceanic circulation patterns occurred, resulting in the development of a thermohaline circulation system similar to that of the modem oceans. A combination of isotopic and plate kinematic data suggests that this event was triggered by the final breaching of tectonic sills in the South Atlantic and the initiation …

Deuel County Test-Hole Logs: Nebraska Water Survey Test-Hole Report No. 25, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

In 1930, the Conservation and Survey Division (CSD) of the University of Nebraska and the United States Geological Survey began a program of cooperative groundwater studies in Nebraska. Since then test drilling by use of rotary drilling equipment has been an integral part of that program. This report contains logs of all the test holes drilled in the county under the program as well as those drilled by the Conservation and Survey Division with financial assistance from other government agencies.

The map in this report shows the location of all test holes drilled in the county since 1942.

Present techniques …

Mountain Evolution And Environmental Changes Of Huangshan (Yellow Mountain), China, Pei-Hua Huang, Robert F. Diffendal Jr., Min-Qing Yang, Patricia E. Helland

Department of Earth and Atmospheric Sciences: Faculty Publications

Huangshan (Yellow Mountain) is located in southern part of the lower reaches of the Yangtze River. The highest Lotus Flower peak is 1,864 m above sea level. Formative ages of the Huangshan and its granite, process of mountain geomorphic evolution from the Eocene to Quaternary, environmental changes of Quaternary, formative origin of beautiful peaks and fascinating rocks were studied and the questionable “Pleistocene glaciation” was also discussed in this paper.

Long-Term Prairie Falcon Population Changes In Relation To Prey Abundance, Weather, Land Uses, And Habitat Conditions, Karen Steenhof, Michael Kochert, Leslie B. Carpenter, Robert N. Lehman

United States Geological Survey: Staff Publications

We studied a nesting population of Prairie Falcons (Falco mexicanus) in the Snake River Birds of Prey National Conservation Area (NCA) from 1974-1997 to identify factors that influence abundance and reproduction. Our sampling period included two major droughts and associated crashes in Townsend's ground squirrel (Spermophilus townsendii) populations. The number of Prairie Falcon pairs found on long-term survey segments declined significantly from 1976-1997. Early declines were most severe at the eastern end of the NCA, where fires and agriculture have changed native shrubsteppe habitat. More recent declines occurred in the portion of canyon near the Orchard …

Test-Hole Drilling Program In Nebraska, Duane R. Mohlman

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Geology And Ground Water, Garden County, Nebraska, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

All of Garden County (Nebraska) is underlain by the Brule Formation. This formation is tightly cemented and yields sufficient water to wells only in areas where the siltstone has been fractured. In most places the Brule Formation forms an impermeable seal that prevents water from moving downward from the overlying aquifers. The Arikaree Group is unimportant as an aquifer in the county, but the younger Ash Hollow Formation is important, particularly beneath the Cheyenne Tableland. Most, if not all, of the domestic and livestock wells on the tableland tap this aquifer. The thickness of the Ash Hollow Formation is 100 …

Geochemistry, Toxicity, And Sorption Properties Of Contaminated Sediments And Pore Waters From Two Reservoirs Receiving Acid Mine Drainage, D. Kirk Nordstrom, Charles N. Alpers, Jennifer A. Coston, Howard E. Taylor, R. Blaine Mccleskey, James W. Ball, Scott Ogle, Jeffrey S. Cotsifas, James A. Davis

United States Geological Survey: Staff Publications

Acid mine waters from the Iron Mountain Superfund Site, Shasta County, California, flow through Spring Creek Reservoir and into Keswick Reservoir on the Sacramento River. In Keswick Reservoir, the acid mine waters have neutralized on mixing with neutral-pH lake water, producing fine-grained, metalrich sediments. Sediment cores were collected during 1997 from both reservoirs for characterization and pore waters were extracted under anoxic conditions. Chemical composition, mineralogical identification, redox chemistry, sorption properties, and toxicity were determined on several samples. Metal concentrations in sediment ranged from 4 to 47 % for Fe, 200 to 4,800 mg/kg (milligrams per kilogram) for Cu, and …

Classification Of Explosives Transformation Products In Plant Tissue, Steven L. Larson, Robert P. Jones, Lynn Escalon, Don Parker

United States Army Corps of Engineers, Omaha District

Explosives contamination in surface or groundwater used for the irrigation of food crops and phytoremediation of explosives-contaminated soil or water using plant-assisted biodegradation have brought about concerns as to the fate of explosives in plants. Liquid scintillation counting, high-performance liquid chromatography, and gel permeation chromatography were utilized to characterize explosives (hexahydro-1,3,5-trinitro-1,3,5-triazine and trinitrotoluene) and their metabolites in plant tissues obtained from three separate studies. Analyzing tissues of yellow nutsedge (Cyperus esculentus), corn (Zea mays), lettuce (Lacuta sativa), tomato (Lyopersicum esculentum), radish (Raphanus sativus), and parrot feather (Myriophyllum aquaticum) …

Mercury Contamination From Hydraulic Placer-Gold Mining In The Dutch Flat Mining District, California, Michael P. Hunerlach, James J. Rytuba, Charles N. Alpers

United States Geological Survey: Publications

Mercury contamination at historic gold mining sites represents a potential risk to human health and the environment. Elemental mercury (quicksilver) was used extensively for the recovery of gold at both placer and hardrock mines throughout the western United States. In placer mine operations, loss of mercury during gold recovery was reported to be as high as 30 percent. In the Dutch Flat mining district located in the Sierra Nevada region of California, placer mines processed more than 100,000,000 cubic yards of gold-bearing gravel. The placer ore was washed through mercury-charged ground sluices and drainage tunnels from 1857 to about 1900, …

Areas Susceptible To Irrigation-Induced Selenium Contamination Of Water And Biota In The Western United States, Ralph L. Seiler, Joseph P. Skorupa, Lorri A. Peltz

United States Geological Survey: Publications

The U.S. Department of the Interior (DOI) studied contamination induced by irrigation drainage in 26 areas of the Western United States during 1986–95. Comprehensive compilation, synthesis, and evaluation of the data resulting from these studies were initiated by DOI in 1992. Soils and ground water in irrigated areas of the West can contain high concentrations of selenium because of (1) residual selenium from the soil’s parent rock beneath irrigated land; (2) selenium derived from rocks in mountains upland from irrigated land by erosion and transport along local drainages, and (3) selenium brought into the area in surface water imported for …

Trace-Element Concentrations In Streambed Sediment Across The Conterminous United States, Karen Rice

United States Geological Survey: Staff Publications

Trace-element concentrations in 541 streambed-sediment samples collected from 20 study areas across the conterminous United States were examined as part of the National Water-Quality Assessment Program of the U.S. Geological Survey. Sediment samples were sieved and the <63-μm fraction was retained for determination of total concentrations of trace elements. Aluminum, iron, titanium, and organic carbon were weakly or not at all correlated with the nine trace elements examined: arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, and zinc. Four different methods of accounting for background/ baseline concentrations were examined; however, normalization was not required because field sieving removed most of the background differences between samples. The sum of concentrations of trace elements characteristic of urban settings-copper, mercury, lead, and zinc-was well correlated with population density, nationwide. Median concentrations of seven trace elements (all nine examined except arsenic and selenium) were enriched in samples collected from urban settings relative to agricultural or forested settings. Forty-nine percent of the sites sampled in urban settings had concentrations of one or more trace elements that exceeded levels at which adverse biological effects could occur in aquatic biota.

Merrick County Test Hole Logs, Frank A. Smith

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Howard County Test Hole Logs, Vincent H. Dreeszen

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Abrupt Along-Strike Change In Tectonic Style: San Andreas Fault Zone, San Francisco Peninsula, Mary Lou Zoback, Robert C. Jachens, Jean A. Olson

United States Geological Survey: Staff Publications

Seismicity and high-resolution aeromagnetic data are used to define an abrupt change from compressional to extensional tectonism within a 10- to 15-km-wide zone along the San Andreas fault on the San Francisco Peninsula and offshore from the Golden Gate. This 100-km-long section of the San Andreas fault includes the hypocenter of the M_w= 7.8 1906 San Francisco earthquake as well as the highest level of persistent microseismicity along that ~470-km-long rupture. We define two distinct zones of deformation along this stretch of the fault using well-constrained relocations of all post- 1969 earthquakes based a joint one-dimensional velocity/hypocenter inversion …

Kearney County Test Hole Logs, Scott E. Summerside

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Groundwater-Level Changes In Nebraska 1996, Abraham H. Chen, Mohan J. Khisty

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.