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2006

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Articles 61 - 90 of 172

Full-Text Articles in Geology

Mineral-Scale Sr Isotopic Study Of Plagioclase In The Mafic Dikes Of The North American Wall And The Diorite Of The Rockslides, Yosemite Valley, California., Wendy Rae Nelson Mar 2006

Mineral-Scale Sr Isotopic Study Of Plagioclase In The Mafic Dikes Of The North American Wall And The Diorite Of The Rockslides, Yosemite Valley, California., Wendy Rae Nelson

Theses and Dissertations

The North American Wall mafic dikes and the diorite of the Rockslides mafic complex in the intrusive suite of Yosemite Valley show evidence of mixing with their host granites as well as with earlier components. Whole rock major element variation diagrams indicate the mafic rocks mixed with a more silicic component, but extrapolating to the silica end member does not yield the same result with each element. Trace element concentrations show a wide variation in concentration of Cr and Ni, with two samples showing enrichment in Cr (>300 ppm) and Ni (~44 ppm) compared to other samples (Cr =13-94 …


A Multidisciplinary Approach To Reservoir Characterization Of The Coastal Entrada Erg-Margin Gas Play, Utah, Will D. Monn Mar 2006

A Multidisciplinary Approach To Reservoir Characterization Of The Coastal Entrada Erg-Margin Gas Play, Utah, Will D. Monn

Theses and Dissertations

World-class outcrops of an outermost erg-margin can be observed within the Middle Jurassic Entrada Sandstone near Capitol Reef National Park, Utah. These erg-margin deposits contain isolated reservoir quality sandstone bodies that transition into a muddy tidal flat facies. These high quality reservoirs are dominated by eolian-influenced facies interbedded with sandy interdune facies. They are sealed vertically by muddy and silty facies of associated tidal flat deposits that act as excellent stratigraphic traps in the subsurface. A variety of approaches were used to characterize these Entrada erg-margin reservoirs including: annotated panoramas of outcrops, measured sections, scintillometer measurements of field sections, facies …


Unresolved Problems Involving The Hydrogeology And Sequence Stratigraphy Of The Wasatch Plateau Based On Mapping Of The Wattis 7.5 Minute Quadrangle, Carbon And Emery Counties, Utah: Insights Gained From A New Geologic Map, David O. Alderks Mar 2006

Unresolved Problems Involving The Hydrogeology And Sequence Stratigraphy Of The Wasatch Plateau Based On Mapping Of The Wattis 7.5 Minute Quadrangle, Carbon And Emery Counties, Utah: Insights Gained From A New Geologic Map, David O. Alderks

Theses and Dissertations

The Wattis 7.5 Minute Quadrangle is located in central Utah, in the transition zone between the Basin and Range province and the Colorado plateau. Two small grabens, located in the quadrangle, are the easternmost evidence of Basin and Range faulting. Sedimentary units exposed are mainly Cretaceous in age and deposited in the Western Cretaceous Interior Seaway. This area is of economical importance due to its large coal deposits, coal bed methane, and groundwater. The Wattis Quadrangle provided an ideal opportunity to test, at a small scale, the applicability of a new groundwater model for stratified mountainous terranes. Water samples had …


Induced-Polarization Measurements On Unconsolidated Sediments From A Site Of Active Hydrocarbon Biodegradation, Gamal Z. Abdel Aal, Lee D. Slater, Estella A. Atekwana Mar 2006

Induced-Polarization Measurements On Unconsolidated Sediments From A Site Of Active Hydrocarbon Biodegradation, Gamal Z. Abdel Aal, Lee D. Slater, Estella A. Atekwana

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

To investigate the potential role that indigenous microorganisms and microbial processes may play in altering low frequency electrical properties, induced-polarization (IP) measurements in the frequency range of 0.1 to 1000 Hz were acquired from sediment samples retrieved from a site contaminated by hydrocarbon undergoing intrinsic biodegradation. Increased imaginary conductivity and phase were observed for samples from the smear zone (contaminated with residual-phase hydrocarbon), exceeding values obtained for samples contaminated with dissolved-phase hydrocarbons, and in turn, exceeding values obtained for uncontaminated samples. Real conductivity, although generally elevated for samples from the smear zone, did not show a strong correlation with contamination. …


Lessons Learned From The St. Francis Dam Failure, J. David Rogers Mar 2006

Lessons Learned From The St. Francis Dam Failure, J. David Rogers

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The St. Francis Dam (Fig. 1), a curved concrete gravity structure 209-feet high, located in the mountains about 35 miles north of downtown Los Angeles, failed catastrophically near midnight just before March 12, 1928. The failure released 36,180 acre-feet of water down San Francisquito Canyon on a turbulent 55-mile journey to the Pacifica Ocean near Ventura, killing 450 people. As the deadliest American civil engineering failure of the 20th century, the city of Los Angeles paid more than $7 million in restitution to the victims' families and affected landowners. The sudden failure of a new concrete dam constructed by a …


The Earth All Around Us Selected Building Stone In Lincoln, Nebraska, William J. Wayne Mar 2006

The Earth All Around Us Selected Building Stone In Lincoln, Nebraska, William J. Wayne

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Long-Term Mechanical Behavior Of Yucca Mountain Tuff And Its Variability, Jaak J.K. Daemen, Lumin Ma, Guohua Zhao Mar 2006

Long-Term Mechanical Behavior Of Yucca Mountain Tuff And Its Variability, Jaak J.K. Daemen, Lumin Ma, Guohua Zhao

Publications (YM)

The study of the long term mechanical behavior of Yucca Mountain tuffs is important for several reasons. Long term stability of excavations will affect accessibility (e.g. for inspection purposes), and retrievability. Long term instabilities may induce loading of drip shields and/or emplaced waste, thus affecting drip shield and/or waste package corrosion. Failure of excavations will affect airflow, may affect water flow, and may affect temperature distributions. The long term mechanical behavior of “hard” rocks remains an elusive topic, loaded with uncertainties. A variety of approaches have been used to improve the understanding of this complex subject, but it is doubtful …


A Geologic Record Of Competing Sulfate-Depletion Processes Within Continental-Rise Sediments Overlying Methane Gas Hydrates Of The Blake Ridge Region (Continental Rise, Offshore Southeastern United States), Walter S. Borowski, Kathryn G. Takacs, Matthew K. Thompson Mar 2006

A Geologic Record Of Competing Sulfate-Depletion Processes Within Continental-Rise Sediments Overlying Methane Gas Hydrates Of The Blake Ridge Region (Continental Rise, Offshore Southeastern United States), Walter S. Borowski, Kathryn G. Takacs, Matthew K. Thompson

EKU Faculty and Staff Scholarship

Geochemical signals locked within sediments and sedimentary rocks record geochemical processes through geologic time. Sulfide minerals (elemental sulfur, iron monosulfides, and pyrite) are formed within marine sediments as dissolved sulfide is produced by various geochemical processes, which include sulfate reduction and anaerobic methane oxidation (AMO). The concentration and sulfur isotopic composition (d34S) of sulfide minerals gives clues about the relative importance of these competing geochemical processes, and consequently about sedimentation rates and upward methane transport.

Marine sediments of the Blake Ridge(offshore South Carolina and Georgia) contain sulfide minerals that point to AMO as an important diagenetic process both …


Serial Ruptures Of The San Andreas Fault, Carrizo Plain, California, Revealed By Three-Dimensional Excavations, Jing Liu-Zeng, Yann Klinger, Kerry Sieh, Charles Rubin, Gordon Seitz Feb 2006

Serial Ruptures Of The San Andreas Fault, Carrizo Plain, California, Revealed By Three-Dimensional Excavations, Jing Liu-Zeng, Yann Klinger, Kerry Sieh, Charles Rubin, Gordon Seitz

All Faculty Scholarship for the College of the Sciences

It is poorly known if fault slip repeats regularly through many earthquake cycles. Well‐documented measurements of successive slips rarely span more than three earthquake cycles. In this paper, we present evidence of six sequential offsets across the San Andreas fault at a site in the Carrizo Plain, using stream channels as piercing lines. We opened a latticework of trenches across the offset channels on both sides of the fault to expose their subsurface stratigraphy. We can correlate the channels across the fault on the basis of their elevations, shapes, stratigraphy, and ages. The three‐dimensional excavations allow us to locate accurately …


Results Of Chemical Analyses For Alcove 8/ Niche 3 Tracer Studies, Jeanette Daniels, Amy J. Smiecinski Feb 2006

Results Of Chemical Analyses For Alcove 8/ Niche 3 Tracer Studies, Jeanette Daniels, Amy J. Smiecinski

Publications (YM)

This is the final report detailing the analyses performed under ORD-FY04-011 "Chemical Analyses for Alcove 8/Niche 3 Tracer Studies," The work was performed under The University and Community College System of Nevada (UCCSN) and the Department of Energy (DOE) Cooperative Agreement DE-FC28-04RW12232, This task provided method development and analytical support for the Alcove 8/Niche 3 Tracer Studies in the Exploratory Studies Facility (ESF). Concentrations of tracers as well as major anions and cations were reported for samples provided by Lawrence Berkeley National Laboratory (LBNL) and the US Geological Survey (USGS). Samples were analyzed using High Performance Liquid Chromatography (HPLC) and …


Effect Of Water Ice Content On Excavatability Of Lunar Regolith, Leslie S. Gertsch, Robert Gustafson, Richard E. Gertsch Feb 2006

Effect Of Water Ice Content On Excavatability Of Lunar Regolith, Leslie S. Gertsch, Robert Gustafson, Richard E. Gertsch

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The amount of water ice contained within prepared samples of JSC-1 lunar regolith simulant strongly affects the excavatability of the material. As part of a NASA Phase I SBIR project, load-penetration testing of JSC-1 lunar regolith simulant was performed at water ice concentrations ranging from zero to 11% by mass (approximately saturated), after compaction and cooling to simulate probable lunar conditions. After mixing dry JSC-1 simulant with the appropriate amount of water, the samples were individually compressed into containment rings under 48 MPa of pressure. Thermocouples embedded in the samples monitored internal temperature while they were cooled in a bath …


Southern African Crustal Evolution And Composition: Constraints From Receiver Function Studies, Shaji K. Nair, Stephen S. Gao, Kelly H. Liu, Paul G. Silver Feb 2006

Southern African Crustal Evolution And Composition: Constraints From Receiver Function Studies, Shaji K. Nair, Stephen S. Gao, Kelly H. Liu, Paul G. Silver

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Stacking of approximately 1500 radial receiver functions recorded at about 80 broadband seismic stations deployed in southern Africa reveals systematic spatial variations in the ratio of crustal P and S wave velocities (Φ), crustal thickness (H), and the amplitude of the converted Moho phases (R). The eastern Zimbabwe and the southern Kaapvaal cratons are characterized by small H (~38 km), small Φ (~1.73), and large R (~0.15) values, suggesting that the relatively undisturbed Archean crust beneath southern Africa is separated from the mantle by a sharp Moho and is felsic in composition. The Limpopo belt, which was created by a …


A Stable Isotopic Investigation Of A Polar Desert Hydrologic System, Mcmurdo Dry Valleys, Antarctica, Michael N. Gooseff, W. Berry Lyons, Diane M. Mcknight, Bruce H. Vaughn, Andrew G. Fountain, Carolyn Dowling Feb 2006

A Stable Isotopic Investigation Of A Polar Desert Hydrologic System, Mcmurdo Dry Valleys, Antarctica, Michael N. Gooseff, W. Berry Lyons, Diane M. Mcknight, Bruce H. Vaughn, Andrew G. Fountain, Carolyn Dowling

Geology Faculty Publications and Presentations

The hydrologic system of the coastal McMurdo Dry Valleys, Antarctica, is defined by snow accumulation, glacier melt, stream flow, and retention in closed-basin, ice-covered lakes. During the austral summers from 1993-1996 and 1999-2000 to 2002-2003, fresh snow, snow pits, glacier ice, stream water, and lake waters were sampled for the stable isotopes deuterium (D) and 18O in order to resolve sources of meltwater and the interactions among the various hydrologic reservoirs in the dry valleys. This data set provides a survey of the distribution of natural water isotope abundances within the well-defined dry valley hydrologic system in Taylor Valley, which …


Effects Of Carbonation On The Mineral Composition Of Cement Kiln Dust, Cecilia P. Anderson Jan 2006

Effects Of Carbonation On The Mineral Composition Of Cement Kiln Dust, Cecilia P. Anderson

Dissertations, Master's Theses and Master's Reports - Open

Due to their relatively high calcium oxide content, industrial mineral oxide wastes are potential candidates for mineral sequestration of carbon dioxide (CO2). Cement kiln dust (CKD), a byproduct of cement manufacturing contains 20-60% CaO making it a possible candidate for CO2 sequestration. In this study, three types of CKD are characterized, before and after carbonation, using environmental scanning electron microscopy and energy dispersive x-ray microanalysis to determine the mineralogical and morphological changes occurring due to carbonation. The reactants, products, and precipitation mechanisms were investigated to enhance understanding of the governing processes and allow better utilization of CKD …


Base-Level Buffers And Buttresses: A Model For Upstream Versus Downstream Control On Fluvial Geometry And Architecture Within Sequences, John M. Holbrook, Robert W. Scott, Francisca Oboh-Ikuenobe Jan 2006

Base-Level Buffers And Buttresses: A Model For Upstream Versus Downstream Control On Fluvial Geometry And Architecture Within Sequences, John M. Holbrook, Robert W. Scott, Francisca Oboh-Ikuenobe

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The effects of downstream base-level control on fluvial architecture and geometry are well explored in several broadly similar sequence-stratigraphic models. Cretaceous Dakota Group strata, U.S. Western Interior, have characteristics reflecting combined downstream and upstream base-level controls that these models cannot address. Particularly, three layers of amalgamated channel-belt sandstone within this group thicken and are continuous for distances (≤ 300 km) along dip that stretch the reasonable lengths for which these models are intended to apply. As well, architecture in up-dip reaches records repeated valley-scale cut-and-fill cycles. This contrasts with equivalent strata down dip which record channel-scale lateral migration with no …


The Climate Of Hays, Kansas, From 1867 To 1999: Variability, Trends, And Influences, John Heinrichs Jan 2006

The Climate Of Hays, Kansas, From 1867 To 1999: Variability, Trends, And Influences, John Heinrichs

Fort Hays Studies Series

Data for a number of possible regional and global climate influences were compared with Hays climate data to characterize the relationships. The analysis of possible influences on Hays climate provided a rich and complex pattern of relationships.


Cave Levels, Marine Terraces, Paleoshorelines, And The Water Table In Peninsular Florida, Lee J. Florea, H L. Vacher Jan 2006

Cave Levels, Marine Terraces, Paleoshorelines, And The Water Table In Peninsular Florida, Lee J. Florea, H L. Vacher

Earth, Environmental, and Atmospheric Sciences Faculty Publications

Levels of passages are a common feature of many cave systems around the world. Likewise, coastal and marine terraces are common in coastal plain settings. This paper extends the discussion of cave levels from traditional research sites in the interior lowlands of the United States to the Atlantic Coastal Plains, namely peninsular Florida. Are there levels in Florida caves, and is there a link between the elevation of cave levels, marine terraces, paleoshorelines, and thus the water table, above and below present sea level in peninsular Florida?


Origin Of Gabbroic Xenoliths Within The Lone Mountain Dacite Intrusion, Big Sky, Montana: A Field And Petrographic Analysis, Emily Clement Jan 2006

Origin Of Gabbroic Xenoliths Within The Lone Mountain Dacite Intrusion, Big Sky, Montana: A Field And Petrographic Analysis, Emily Clement

Undergraduate Review

No abstract provided.


Microstructural Analysis Of A Drill Core From The Rhode Island Formation: Upper 750 Feet, Ashlee Kirkwood Jan 2006

Microstructural Analysis Of A Drill Core From The Rhode Island Formation: Upper 750 Feet, Ashlee Kirkwood

Undergraduate Review

No abstract provided.


The Sparrow Surface Water-Quality Model: Theory, Application And User Documentation, G. E. Schwarz, A. B. Hoos, R. B. Alexander, R. A. Smith Jan 2006

The Sparrow Surface Water-Quality Model: Theory, Application And User Documentation, G. E. Schwarz, A. B. Hoos, R. B. Alexander, R. A. Smith

United States Geological Survey: Publications

SPARROW (SPAtially Referenced Regressions On Watershed attributes) is a watershed modeling technique for relating water-quality measurements made at a network of monitoring stations to attributes of the watersheds containing the stations. The core of the model consists of a nonlinear regression equation describing the non-conservative transport of contaminants from point and diffuse sources on land to rivers and through the stream and river network. The model predicts contaminant flux, concentration, and yield in streams and has been used to evaluate alternative hypotheses about the important contaminant sources and watershed properties that control transport over large spatial scales.

This report provides …


Taxonomic Considerations In Listing Subspecies Under The U.S. Endangered Species Act, Susan M. Haig, Erik A. Beever, Steven M. Chambers, Hope M. Draheim, Bruce D. Dugger, Susie M. Dunham, Elise Elliott-Smith, Joseph B. Fontaine, Dylan C. Kesler, Brian J. Knaus, Iara F. Lopes, Pete Loschl, Thomas D. Mullins, Lisa M. Sheffield Jan 2006

Taxonomic Considerations In Listing Subspecies Under The U.S. Endangered Species Act, Susan M. Haig, Erik A. Beever, Steven M. Chambers, Hope M. Draheim, Bruce D. Dugger, Susie M. Dunham, Elise Elliott-Smith, Joseph B. Fontaine, Dylan C. Kesler, Brian J. Knaus, Iara F. Lopes, Pete Loschl, Thomas D. Mullins, Lisa M. Sheffield

United States Geological Survey: Staff Publications

The U.S. Endangered Species Act (ESA) allows listing of subspecies and other groupings below the rank of species. This provides the U.S. Fish and Wildlife Service and the National Marine Fisheries Service with a means to target the most critical unit in need of conservation. Although roughly one-quarter of listed taxa are subspecies, these management agencies are hindered by uncertainties about taxonomic standards during listing or delisting activities. In a review of taxonomic publications and societies, we found few subspecies lists and none that stated standardized criteria for determining subspecific taxa. Lack of criteria is attributed to a centuries-old debate …


Conserving Biodiversity In Human-Dominated Landscapes, Dale D. Goble, J. Michael Scott, Frank W. Davis Jan 2006

Conserving Biodiversity In Human-Dominated Landscapes, Dale D. Goble, J. Michael Scott, Frank W. Davis

United States Geological Survey: Staff Publications

The two volumes of The Endangered Species Act at Thirty look backward to evaluate the effectiveness of the act over its first three decades (Wilcove and McMillan 2006; Scott et al. 2006, chap. 2; Goble, this volume; Svancara, this volume; Callicott, this volume; Norton, this volume) and also forward to suggest how it can be used as a cornerstone for conserving biological diversity in increasingly human-dominated landscapes (Davis et al. 2006; Bean 2006). The chapters in part 2 of this volume, for example, appraise the science of the 1990s and 2000s at both the large scale (Lomolino, this volume; Naeem …


Endangered Species Time Line, Leona K. Svancara, J. Michael Scott, Dale D. Goble, Frank W. Davis, Donna Brewer Jan 2006

Endangered Species Time Line, Leona K. Svancara, J. Michael Scott, Dale D. Goble, Frank W. Davis, Donna Brewer

United States Geological Survey: Staff Publications

The Endangered Species Act (ESA) is embedded in a web of statutes designed to regulate relationships between humans and other species that stretch back nearly a millennium (Goble, this volume; Goble and Freyfogle 2002). This chapter presents a time line of federal actions taken to protect wildlife beginning with passage of the Land and Water Conservation Fund Act in 1963 (Act of May 28, 1963). Earlier laws to protect wildlife are discussed elsewhere (Goble, this volume). The time line emphasizes federal actions that conserve species at risk of extinction and significant events in the course of implementing the Endangered Species …


Isotope Sourcing Of Prehistoric Willow And Tule Textiles Recovered From Western Great Basin Rock Shelters And Caves: Proof Of Concept, Larry V. Benson, E. M. Hattori, H. E. Taylor, S. R. Poulson, E. A. Jolie Jan 2006

Isotope Sourcing Of Prehistoric Willow And Tule Textiles Recovered From Western Great Basin Rock Shelters And Caves: Proof Of Concept, Larry V. Benson, E. M. Hattori, H. E. Taylor, S. R. Poulson, E. A. Jolie

United States Geological Survey: Staff Publications

Isotope and trace-metal analyses were used to determine the origin of plants used to manufacture prehistoric textiles (basketry and matting) from archaeological sites in the western Great Basin. Research focused on strontium (87Sr/86Sr) and oxygen (18O/16O) isotope ratios of willow (Salix sp.) and tule (Schoenoplectus sp.), the dominant raw materials in Great Basin textiles. The oxygen-isotope data indicated that the willow and tule used to produce the textiles were harvested from the banks of rivers or in marshes characterized by flowing water and not from lakes or sinks. The strontium-isotope …


The Agricultural Productivity Of Chaco Canyon And The Source(S) Of Pre-Hispanic Maize Found In Pueblo Bonito, Larry Benson, John Stein, Howard Taylor, Richard Friedman, Thomas C. Windes Jan 2006

The Agricultural Productivity Of Chaco Canyon And The Source(S) Of Pre-Hispanic Maize Found In Pueblo Bonito, Larry Benson, John Stein, Howard Taylor, Richard Friedman, Thomas C. Windes

United States Geological Survey: Staff Publications

Agricultural productivity estimates suggest that the core area of Chaco Canyon could have sustained only a few hundred individuals. Modern analogues of existing Pueblo populations and their domestic habitations with Chaco structures suggest that Chaco at times had a resident population exceeding 2000 people. These data suggest that maize would have had to be imported to feed permanent residents and those visiting Chaco during ritual–political gatherings and those who participated in the accelerated construction and modification of great houses between AD 1030 and 1130. Comparison of strontium-isotope and trace-element ratios of synthetic soil and natural waters from sites within the …


Unraveling The Geologic History Of The Avalon Terrane In Ma, Erin Nevens Jan 2006

Unraveling The Geologic History Of The Avalon Terrane In Ma, Erin Nevens

Undergraduate Review

No abstract provided.


Field, Petrographic, And Geochemical Characteristics Of Price Creek, Russ Mccormack Jan 2006

Field, Petrographic, And Geochemical Characteristics Of Price Creek, Russ Mccormack

Undergraduate Review

No abstract provided.


Microstructural Analysis Of The Rhode Island Formation, Narragansett Basin, Ma, Elizabeth Connell Jan 2006

Microstructural Analysis Of The Rhode Island Formation, Narragansett Basin, Ma, Elizabeth Connell

Undergraduate Review

No abstract provided.


Implications Of Climate Change And Tephra Accumulation On The Lacustrine Environment In A Volcanic Caldera In Michoacan, Mexico, Tabitha Trosper Jan 2006

Implications Of Climate Change And Tephra Accumulation On The Lacustrine Environment In A Volcanic Caldera In Michoacan, Mexico, Tabitha Trosper

Undergraduate Honors Theses

La Alberca is a volcanic caldera in the Michoacan-Guanajuato volcanic field of central Mexico. The oldest known burial ( ~5000 yrs BP) in the state of Michoacan was discovered beneath prehispanic cliff paintings on the caldera wall. The stratigraphy of fluvial and lacustrine sediments exposed in trenches in the caldera floor record environmental changes that have implications for the type of human use of the site. La Alberca is a closed system with an alluvial fan that extends from the northeastern wall into the lowest southern comer of the caldera floor. Paricutin eruption in 1943-52 and other earlier eruptions deposited …


Sequence Of Tuffs Between The Kbs Tuff And The Chari Tuff In The Turkana Basin, Kenya And Ethiopia, Francis H. Brown, Bereket Haileab, Ian Mcdougall Jan 2006

Sequence Of Tuffs Between The Kbs Tuff And The Chari Tuff In The Turkana Basin, Kenya And Ethiopia, Francis H. Brown, Bereket Haileab, Ian Mcdougall

Geology Faculty Work

No abstract provided.