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Articles 25951 - 25980 of 29959
Full-Text Articles in Geology
Mcpherson County Test Hole Logs, James W. Goeke
Mcpherson County Test Hole Logs, James W. Goeke
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Webster County Test Hole Logs, Scott E. Summerside
Webster County Test Hole Logs, Scott E. Summerside
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Review Of Geologic Factors Affecting Underground Limestone Mining In The U.S. And An Overview Of Underground Limestone Mining In Nebraska, R. M. Joeckel
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Genetic Identification Of Spotted Owls, Barred Owls, And Their Hybrids: Legal Implications Of Hybrid Identity, Susan M. Haig, Thomas D. Mullins, Eric D. Forsman, Pepper W. Trail, Liv Wennerberg
Genetic Identification Of Spotted Owls, Barred Owls, And Their Hybrids: Legal Implications Of Hybrid Identity, Susan M. Haig, Thomas D. Mullins, Eric D. Forsman, Pepper W. Trail, Liv Wennerberg
United States Geological Survey: Staff Publications
Recent population expansion of Barred Owls (Strix varia) into western North America has led to concern that they may compete with and further harm the Northern Spotted Owl (S. occidentalis caurina), which is already listed as threatened under the U.S. Endangered Species Act (ESA). Because they hybridize, there is a legal need under the ESA for forensic identification of both species and their hybrids. We used mitochondrial control-region DNA and amplified fragment-length polymorphism (AFLP) analyses to assess maternal and biparental gene flow in this hybridization process. Mitochondrial DNA sequences (524 base pairs) indicated large divergence between …
Subspecific Relationships And Genetic Structure In The Spotted Owl, Susan M. Haig, Thomas D. Mullins, Eric D. Forsman
Subspecific Relationships And Genetic Structure In The Spotted Owl, Susan M. Haig, Thomas D. Mullins, Eric D. Forsman
United States Geological Survey: Staff Publications
Hierarchical genetic structure was examined in the three geographically-defined subspecies of spotted owl (Strix occidentalis) to define relationships among subspecies and quantify variation within and among regional and local populations. Sequences (522 bp) from domains I and II of the mitochondrial control region were analyzed for 213 individuals from 30 local breeding areas. Results confirmed significant differences between northern spotted owls and the other traditional geographically defined subspecies but did not provide support for subspecific level differences between California and Mexican spotted owls. Divergence times among subspecies estimated with a 936 bp portion of the cytochrome b gene …
A Holocene Pollen Record Of Persistent Droughts From Pyramid Lake, Nevada, Usa, Scott A. Mensing, Larry Benson, Michaele Kashgarian, Steve Lund
A Holocene Pollen Record Of Persistent Droughts From Pyramid Lake, Nevada, Usa, Scott A. Mensing, Larry Benson, Michaele Kashgarian, Steve Lund
United States Geological Survey: Staff Publications
Pollen and algae microfossils preserved in sediments from Pyramid Lake, Nevada, provide evidence for periods of persistent drought during the Holocene age. We analyzed one hundred nineteen 1-cm-thick samples for pollen and algae from a set of cores that span the past 7630 years. The early middle Holocene, 7600 to 6300 cal yr B.P., was found to be the driest period, although it included one short but intense wet phase. We suggest that Lake Tahoe was below its rim for most of this period, greatly reducing the volume and depth of Pyramid Lake. Middle Holocene aridity eased between 5000 and …
Quaternary Sea-Level History Of The United States, Daniel R. Muhs, John F. Wehmiller, Kathleen R. Simmons, Linda L. York
Quaternary Sea-Level History Of The United States, Daniel R. Muhs, John F. Wehmiller, Kathleen R. Simmons, Linda L. York
United States Geological Survey: Staff Publications
In the past 30 years, there have been tremendous advances in our understanding of Quaternary sea-level history, due directly to developments in Quaternary dating methods, particularly uranium-series disequilibrium and amino acid racemization. Another reason for this progress is that coastline history can now be tied to the oxygen-isotope record of foraminifera in deep-sea cores. Furthermore, both records have been linked to climate change on the scale of glacial-interglacial cycles that are thought to be forced by changes in Earth-Sun geometry, or “orbital forcing” (Milankovitch, 1941).
Sedimentological And Geochemical Characterization Of East Pond, Belgrade Lakes Watershed, Central Maine, Robin H. Nesbeda
Sedimentological And Geochemical Characterization Of East Pond, Belgrade Lakes Watershed, Central Maine, Robin H. Nesbeda
Honors Theses
The present study focuses on East Pond, the head of the lake-chain system. East Pond is roughly oval in shape with several coves along the margins; it has an average 3 depth of 4.5 m, a maximum depth of 7.3 m, and a total volume of 26.35 x 10 6 m . The lake is surrounded by North temperate hardwood forest and a marshy outlet to the other lakes exists in the northwest comer. East Pond has suffered severe yearly algal blooms during the late summer and into the fall since 1993. This project aims to develop a baseline for …
Spectacular Recovery In The Ord River Catchment, A L. Payne, I W. Watson, P E. Novelly
Spectacular Recovery In The Ord River Catchment, A L. Payne, I W. Watson, P E. Novelly
Agriculture reports
Regeneration work on severely damaged country in what is now known as the Ord River Regeneration Reserve (ORRR) commenced in 1960. The ORRR is in the East Kimberley area of Western Australia with an associated small area in the Northern Territory. The work included strip contour cultivation and seeding (which proceeded at various levels of intensity during the 1960s, 1970s and 1980s), fencing and destocking of cattle by mustering over many years, and the eradication of donkeys.
Discontinuities In The Icebox Formation (Ordovician), Williston Basin, North Dakota And Montana, Aaron J. Ulishney
Discontinuities In The Icebox Formation (Ordovician), Williston Basin, North Dakota And Montana, Aaron J. Ulishney
Theses and Dissertations
The Ordovician Winnipeg Group is composed of three formations; in ascending order, the Black Island Formation, the Icebox Formation, and the Roughlock Formation. The Icebox Formation is largely composed of shale. This work shows that discontinuities and coarser facies exist within the Icebox Formation and that they are traceable throughout the subsurface of North Dakota and eastern Montana. This work also illustrates possible sea-level changes during the deposition of the Icebox Formation along with probable source areas providing detrital sediments into the study area.
Gamma-ray wireline logs were used to distinguish the formations of the Winnipeg Group from each other, …
Magnetic Susceptibility For The Paleocene-Eocene Boundary: Correlation Among Three Egyptian Sections, Kelli Willson
Magnetic Susceptibility For The Paleocene-Eocene Boundary: Correlation Among Three Egyptian Sections, Kelli Willson
Honors Capstones
No abstract provided.
Application Of Well Log Tomography To The Dundee And Rogers City Limestones, Michigan Basin, Usa, Mellisa A. Le M.
Application Of Well Log Tomography To The Dundee And Rogers City Limestones, Michigan Basin, Usa, Mellisa A. Le M.
Dissertations, Master's Theses and Master's Reports - Open
The Michigan Basin is located in the upper Midwest region of the United States and is centered geographically over the Lower Peninsula of Michigan. It is filled primarily with Paleozoic carbonates and clastics, overlying Precambrian basement rocks and covered by Pleistocene glacial drift. In Michigan, more than 46,000 wells have been drilled in the basin, many producing significant quantities of oil and gas since the 1920s in addition to providing a wealth of data for subsurface visualization.
Well log tomography, formerly log-curve amplitude slicing, is a visualization method recently developed at Michigan Technological University to correlate subsurface data by utilizing …
Geometric And Kinematic Evolution Of The Bessemer Transverse Zone, Alabama Alleghanian Thrust Belt, Margaret Colette Brewer
Geometric And Kinematic Evolution Of The Bessemer Transverse Zone, Alabama Alleghanian Thrust Belt, Margaret Colette Brewer
University of Kentucky Doctoral Dissertations
Transverse zones are important syn-kinematic components of thrust belt development. Various scales of data were utilized to develop three-dimensional geometric and kinematic models for the Bessemer transverse zone (BTZ) of the Alabama Alleghanian thrust belt.
Regional analysis of the BTZ began with the examination of geologic maps (1:250,000, 1:48,000, and 1:24,000 scales), seismic reflection profiles, well data, and previous stratigraphic research. All Paleozoic-age stratigraphic contacts, major thrust faults and associated folds, and various unnamed minor structures were compiled to create two strike-perpendicular, and five-strike parallel, cross sections transecting the extent of the BTZ at a scale of 1:100,000. The balanced …
A Holocene Record Of Changing Arctic Ocean Ice Drift Analogous To The Effects Of The Arctic Oscillation, Dennis A. Darby, Jens F. Bischof
A Holocene Record Of Changing Arctic Ocean Ice Drift Analogous To The Effects Of The Arctic Oscillation, Dennis A. Darby, Jens F. Bischof
OES Faculty Publications
The Arctic Oscillation (AO) controls the configuration of the Transpolar Drift (TPD). If thicker ice from the Beaufort Gyre were exported, the volume of fresh water/sea ice in the Nordic seas would significantly increase, decreasing the formation of North Atlantic deep water. This would cool large parts of the Northern Hemisphere and affect global climate. Therefore, in order to understand how the global climate system functions, it is imperative to know how the TPD changed over the last millennium or more. The provenance of grains in a sediment core located near the confluence of the TPD and the Beaufort Gyre …
In-Situ Apparent Conductivity Measurements And Microbial Population Distribution At A Hydrocarbon-Contaminated Site, Estella A. Atekwana, D. Dale Werkema, Joseph W. Duris, Silvia Rossbach, Eliot A. Atekwana, William A. Sauck, Daniel P. Cassidy, Jay Means, Franklyn D. Legall
In-Situ Apparent Conductivity Measurements And Microbial Population Distribution At A Hydrocarbon-Contaminated Site, Estella A. Atekwana, D. Dale Werkema, Joseph W. Duris, Silvia Rossbach, Eliot A. Atekwana, William A. Sauck, Daniel P. Cassidy, Jay Means, Franklyn D. Legall
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
We investigated the bulk electrical conductivity and microbial population distribution in sediments at a site contaminated with light nonaqueous-phase liquid (LNAPL). The bulk conductivity was measured using in-situ vertical resistivity probes; the most probable number method was used to characterize the spatial distribution of aerobic heterotrophic and oil-degrading microbial populations. The purpose of this study was to assess if high conductivity observed at aged LNAPL-impacted sites may be related to microbial degradation of LNAPL. The results show higher bulk conductivity coincident with LNAPL-impacted zones, in contrast to geoelectrical models that predict lower conductivity in such zones. The highest bulk conductivity …
Ammonite Biostratigraphy Of The Jurassic Of Tanzania, S Kapilima
Ammonite Biostratigraphy Of The Jurassic Of Tanzania, S Kapilima
Tanzania Journal of Science
The present paper summarizes the previous biostratigraphical researches and incorporates the recent research findings on the Jurassic rocks in the coastal basin of Tanzania. The ammonites used for the biostratigraphical classification are from two sub-basins along the coastal belt of Tanzania: Mandawa (south) and Ruvu- Tanga (north). The oldest known ammonites from these basins are of Aalenian age. The biostratigraphical classification of the Jurassic sequence, on the basis of the vertical and horizontal distributions of the ammonite assemblages, permits the erection of eight sub stages of Jurassic: Upper Aalenian (Concavum-Zone), Bajocian (Humphrieasianum-Zone), Middle Callovian (Coronatum-Jason Zone), Upper Callovian (Lamberti-Athleta Zone), …
Petrology And Lithogeochemistry Of The Mineralized Tanzanite-Grossular Bearings Rocks In The Merelani-Lelatema Area, Northeastern Tanzania, Ep Malisa
Tanzania Journal of Science
The Merelani-Lelatema area, which is occupied by late Proterozoic metasedimentary rocks, lies along the Lelatema fault zone. The rocks are mainly pelitic and semi-pelitic gneisses, psammitic gneisses, hydrothermally altered rocks, crystalline dolostones, pegmatites and quartz veins. The occurrence of gem-quality tanzanite and grossular has been found to occur mainly in boudinaged pegmatitic veins and hydrothermal fracture fillings. These fracture fillings occur in brecciated and hydrothermally altered graphite-bearing gneiss in a mineral association containing glass-clear quartz, diopside, zoisite, graphite and calcite. The psammitic gneisses are more siliceous and enriched in feldspars. They are grouped into graphite-kyanite gneiss with thin interlayers of …
Metal Concentrations In Sediment And Fish Of Lake Victoria Near And Away From Catchments With Gold Mining Acctivities, Jf Machiwa
Tanzania Journal of Science
Concentrations of metals in sediment and fish as well as organic matter contents of sediment from Lake Victoria were investigated. The objective of the study was to compare levels of metals in sediment and fish from areas of the lake that are within and outside catchments with gold mining activities.The results showed that the concentration of As was less than 6 mg g-1 dw and Cd was below 1.9 mg g-1 dw in sediment samples. Lead, zinc and copper concentrations were highest (58.1±17.6 mg g-1 dw, 101.9±20.6 mg g-1 dw and 32.6±2.8 mg g-1 dw respectively) in sediment samples that …
Lewis And Clark And The Geology Of Nebraska And Parts Of Adjacent States, Robert F. Diffendal Jr., Anne P. Diffendal
Lewis And Clark And The Geology Of Nebraska And Parts Of Adjacent States, Robert F. Diffendal Jr., Anne P. Diffendal
School of Natural Resources: Faculty Publications
Meriwether Lewis and William Clark undertook their journey with the Corps of Discovery in 1804–1806 in order to explore the area that the United States had purchased from France in 1803. Then known as Louisiana, this region included almost everything west of the Mississippi to the continental divide (illustrated below). In order to find the best route across the continent, President Thomas Jefferson charged Lewis to follow the Missouri River to its headwaters and then locate rivers flowing down the west side of the Rocky Mountains to the Columbia River and into the Pacific Ocean. Jefferson's written instructions further specified …
Delineation Of Mass Movement Prone Areas By Landsat 7 And Digitial Image Processing, Shiloh Marie Howland
Delineation Of Mass Movement Prone Areas By Landsat 7 And Digitial Image Processing, Shiloh Marie Howland
Theses and Dissertations
The problem of whether Landsat 7 data could be used to delineate areas prone to mass movement, particularly debris flows and landslides, was examined using three techniques: change detection in NDVI (Normalized Difference Vegetation Index), change detection in band 5, and the tasseled cap transformation. These techniques were applied to areas that had recently experienced mass movement: Layton, Davis County and Alpine, Spanish Fork Canyon and Santaquin, Utah County. No distinctive spectral characteristics were found with any of these techniques with two possible explanations: 1. That despite improved spatial resolution in Landat 7 over its predecessors and improved digital image …
Lewis And Clark And The Geology Of The Great Plains, Robert F. Diffendal Jr., Anne P. Diffendal
Lewis And Clark And The Geology Of The Great Plains, Robert F. Diffendal Jr., Anne P. Diffendal
School of Natural Resources: Faculty Publications
Meriwether Lewis and William Clark undertook their journey with the Corps of Discovery in 1804-1806 in order to explore the area that the United States had purchased from France in 1803. Then known as Louisiana, this region included almost everything west of the Mississippi to the continental divide. In order to find the best route across the continent, President Thomas Jefferson charged Lewis with following the Missouri River to its headwaters and then locating rivers flowing down the west side of the Rocky Mountains to the Columbia River and into the Pacific Ocean. Jefferson's written instructions further specified that the …
Laboratory Testing Of Select Geotextiles As Biointrusion Barriers And Sediment Filters, David R. Beck
Laboratory Testing Of Select Geotextiles As Biointrusion Barriers And Sediment Filters, David R. Beck
Masters Theses
It has been proposed that placing a geotextile over sediments with adsorbed contaminants can prevent bioaccumulation of the contaminants in larger animals by isolating the benthic organisms living within these sediments from fish. In conjunction with a field study carried out at Gull Creek, a laboratory study testing two geotextiles as biointrusion barriers and sediment filters was conducted.
Constant-head permeameters were run for seven days using cores from the field study area with a geotextile placed over the cores. For biointrusion barrier tests, medium sand was placed over the geotextile and spiked with nutrients. Following each trial, benthic organisms in …
Current Perspectives On Energy And Mass Fluxes In Volcanic Arcs, William Leeman, Jon Davidson, Tobias Fischer, Anita Grunder, Mark Reagan, Martin J. Streck
Current Perspectives On Energy And Mass Fluxes In Volcanic Arcs, William Leeman, Jon Davidson, Tobias Fischer, Anita Grunder, Mark Reagan, Martin J. Streck
Geology Faculty Publications and Presentations
Volcanoes of the Pacific Ring of Fire and other convergent margins worldwide are familiar manifestations of nature's energy, account for about 25% of global volcanic outputs, dominate volcanic gas emissions to the atmosphere, and pose significant physical threats to a large human population. Yet the processes behind this prolific activity remain poorly understood.
An international "State of the Arc" (SOTA) conference was held in August on the slopes of Mt. Hood, Oregon, to address current views on the energy and mass fluxes in volcanic arcs. This meeting brought together some 90 leading experts and students of subduction zones and their …
Using Cesium 137 To Understand Recent In Cave Sedimentation In The Tongass National Forest, Southeast Alaska, William Curry
Using Cesium 137 To Understand Recent In Cave Sedimentation In The Tongass National Forest, Southeast Alaska, William Curry
Masters Theses & Specialist Projects
Removal of vegetation and subsequent erosion in karst regions such as central Kentucky or southeastern Alaska often leads to increased sedimentation in karst features such as caves and dolines. This sedimentation can impact the ground water by altering flow paths and the bio-geochemistry of the karst aquifer itself. Various methodologies have been used to obtain quantitative erosion and sedimentation rates for surface areas in karst and non-karst settings, but few quantitative studies have taken place in caves. The purpose of this study is to examine the effects of timber harvesting and development upon the caves and karst of southeastern Alaska …
Field-Scale Estimation Of Volumetric Water Content Using Ground-Penetrating Radar Ground Wave Techniques, Katherine R. Grote, Susan Sharpless Hubbard, Yoram N. Rubin
Field-Scale Estimation Of Volumetric Water Content Using Ground-Penetrating Radar Ground Wave Techniques, Katherine R. Grote, Susan Sharpless Hubbard, Yoram N. Rubin
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
Ground-penetrating radar (GPR) ground wave techniques were applied to estimate soil water content in the uppermost ∼10 cm of a 3 acre California vineyard several times over 1 year. We collected densely spaced GPR travel time measurements using 900 and 450 MHz antennas and analyzed these data to estimate water content. The spatial distribution of water content across the vineyard did not change significantly with time, although the absolute water content values varied seasonally and with irrigation. The GPR estimates of water content were compared to gravimetric water content, time domain reflectometry, and soil texture measurements. The comparisons of GPR-derived …
Sulfide Mineralization In Deep-Water Marine Sediments Related To Methane Transport, Methane Consumption, And Methane Gas Hydrates, Matthew K. Thompson, Walter S. Borowski, Charles K. Paull, William Ussler Iii
Sulfide Mineralization In Deep-Water Marine Sediments Related To Methane Transport, Methane Consumption, And Methane Gas Hydrates, Matthew K. Thompson, Walter S. Borowski, Charles K. Paull, William Ussler Iii
EKU Faculty and Staff Scholarship
Patterns of sulfide sulfur concentration and sulfur isotopic composition (d34S) are perhaps related to upward methane transport, especially in sediments underlain by methane gas hydrate deposits. Increased methane delivery augments the affect of anaerobic methane oxidation (AMO) occurring at the sulfate-methane interface (SMI). Sulfate and methane co-consumption results in production of dissolved sulfide at the interface that is eventually sequestered within sulfide minerals (elemental sulfur, iron monosulfide, pyrite).
We examine the sediments of two piston cores collected over the Blake Ridge gas hydrate deposits (offshore southeastern North America) by extracting total sedimentary sulfide using chromium reduction. We use …
Mantle Layering Across Central South America, Kelly H. Liu, Stephen S. Gao, Paul G. Silver, Yongkai K. Zhang
Mantle Layering Across Central South America, Kelly H. Liu, Stephen S. Gao, Paul G. Silver, Yongkai K. Zhang
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
Imaging of seismic velocity discontinuities along a 3000 km profile across central South America at 20°S suggests that the depth variations of the 410-km (d410) and 660-km (d660) discontinuities are closely associated with the high-velocity Nazca slab and juxtaposed low-velocity oceanic mantle beneath the slab. The mantle transition zone thickness ranges from 220 km in the oceanic mantle to 270 km in a 600-km-wide area occupied by the deflected Nazca slab. The slab deflection has also been suggested by previous studies of seismic tomography and seismicity. This 50 km difference in the thickness corresponds to a lateral temperature variation of …
Ancient Maize From Chacoan Great Houses: Where Was It Grown?, Larry Benson, Linda Cordell, Kirk Vincent, Howard E. Taylor, John Stein, G. Lang Farmer, U.S. Geological Survey
Ancient Maize From Chacoan Great Houses: Where Was It Grown?, Larry Benson, Linda Cordell, Kirk Vincent, Howard E. Taylor, John Stein, G. Lang Farmer, U.S. Geological Survey
United States Geological Survey: Staff Publications
In this article, we compare chemical (87Sr/86Sr and elemental) analyses of archaeological maize from dated contexts within Pueblo Bonito, Chaco Canyon, New Mexico, to potential agricultural sites on the periphery of the San Juan Basin. The oldest maize analyzed from Pueblo Bonito probably was grown in an area located 80 km to the west at the base of the Chuska Mountains. The youngest maize came from the San Juan or Animas river floodplains 90 km to the north. This article demonstrates that maize, a dietary staple of southwestern Native Americans, was transported over considerable distances in …
Integrated Hydrologic And Hydrochemical Observations Of Hidden Creek Lake Jökulhlaups, Kennicott Glacier, Alaska, Suzanne P. Anderson, Joseph S. Walder, Robert S. Anderson, Erin R. Kraal, Michelle Cunico, Andrew G. Fountain, Dennis C. Trabant
Integrated Hydrologic And Hydrochemical Observations Of Hidden Creek Lake Jökulhlaups, Kennicott Glacier, Alaska, Suzanne P. Anderson, Joseph S. Walder, Robert S. Anderson, Erin R. Kraal, Michelle Cunico, Andrew G. Fountain, Dennis C. Trabant
Geology Faculty Publications and Presentations
Hidden Creek Lake (HCL), an ice-marginal lake impounded by Kennicott Glacier, Wrangell Mountains, Alaska, fills annually to ~20 to 30 x ~10⁶ m³ and then drains subglacially within 2 to 3 days. During the 1999 and 2000 jökulhlaups, we carried out a series of planned observations around the lake and in the Kennicott River, which drains the glacier. Approximately 20% of the lake volume was contained within a subglacial water ‘‘wedge’’ beneath the ice dam. The entire volume of the lake drains through the wedge; hydraulic head loss through this constriction may be responsible for the fairly symmetrical shape of …
Geogram 2003, David J. Keeling Editor, Wku Department Of Geography And Geology
Geogram 2003, David J. Keeling Editor, Wku Department Of Geography And Geology
Earth, Environmental, and Atmospheric Sciences Publications
No abstract provided.