Digital Commons Network^™

Numerical Simulation Of Double‐Diffusive Finger Convection, Joseph D. Hughes, Ward E. Sanford, H. L. Vacher

School of Geosciences Faculty and Staff Publications

A hybrid finite element, integrated finite difference numerical model is developed for the simulation of double‐diffusive and multicomponent flow in two and three dimensions. The model is based on a multidimensional, density‐dependent, saturated‐unsaturated transport model (SUTRA), which uses one governing equation for fluid flow and another for solute transport. The solute‐transport equation is applied sequentially to each simulated species. Density coupling of the flow and solute‐transport equations is accounted for and handled using a sequential implicit Picard iterative scheme. High‐resolution data from a double‐diffusive Hele‐Shaw experiment, initially in a density‐stable configuration, is used to verify the numerical model. The temporal …

Assembly Focuses On Volcanism And Societal Impacts, Anita Grunder, Stephen R. Mcnutt

School of Geosciences Faculty and Staff Publications

With a theme of “Volcanism and Its Impact on Society,” the November 2004 meeting of the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) held in Pucón, Chile, brought together experts to discuss many aspects of volcanology.

The five‐day IAVCEI meeting was the association's largest, attracting 940 participants from 44 countries. U.S. participants constituted one third. The meeting consisted of over 1100 abstracts presented in 12 theme sessions, and reflected a diversity of disciplines and techniques encompassed by volcanic studies.

Diurnal Water-Pressure Fluctuations: Timing And Pattern Of Termination Below Bench Glacier, Alaska, Usa, T. J. Fudge, Joel T. Harper, Neil Humphrey, W. Tad Pfeffer

Geosciences Faculty Publications

Observations from basal water-pressure sensors along the length of Bench Glacier, Alaska, USA, show that diurnal fluctuations of water pressure are seasonal and restricted to summer. Most notable about these fluctuations is their disappearance in the late summer and early autumn, long before the seasonal end of diurnal meltwater input. Here we present data documenting the end of diurnal water-pressure fluctuations during the 2002 and 2003 melt seasons. The end of diurnal fluctuations occurred abruptly in multiple boreholes spaced meters to kilometers apart. There was no obvious spatial progression of termination events, and a clear correlation with meteorological forcing or …

Reevaluation Of Species Concepts Of Uppermost Cretaceous Unionidae (Mollusca: Bivalvia) : Hell Creek Formation, Montana, U.S.A., Marron J. Bingle

Theses and Dissertations

Species are the basic units of life relative to taxonomy, and a practical definition of species is imperative to paleontology in order to promote reproducible, unambiguous criteria for accurately interpreting past species relationships. The need for a well-defined rubric for identifying species is evident in the freshwater mussel assemblage (Family Unionidae) in the Hell Creek Formation. The Hell Creek Formation unionid species were first described by Whitfield in 1903 and 1907. His descriptions were often based on differences of a single trait. In 1976, Russell reevaluated the original species descriptions, I but still based the classification of species on only …

Isotopic Tracers As Evidence Of Denitrification In The Karlsruhe Aquifer, Eben J. Spencer

Theses and Dissertations

The Karlsruhe Aquifer of north-central North Dakota has experienced considerable nitrate contamination sparking an investigation by the North Dakota State Water Commission. Certain portions of the aquifer have experienced nitrate-N concentrations of up to seven times the drinking water standard. Although contamination is evident it is possible the NO₃¯ is naturally being eliminated by denitrification, whereby bacteria reduce NO₃¯ to nitrogen gas. Evidence of denitrification may be illustrated by accelerated reduction of NO₃¯ relative to the conservative tracer Cl¯ coupled with an increase in the heavy isotopes of 15N and 18O within the NO₃¯ ion. Such an increase is not …

Unruly Complexity: Ecology, Interpretation, Engagement, Peter Taylor

Curriculum and Instruction Faculty Publication Series

Ambitiously identifying fresh issues in the study of complex systems, Peter J. Taylor, in a model of interdisciplinary exploration, makes these concerns accessible to scholars in the fields of ecology, environmental science, and science studies. Unruly Complexity explores concepts used to deal with complexity in three realms: ecology and socio-environmental change; the collective constitution of knowledge; and the interpretations of science as they influence subsequent research.

For each realm Taylor shows that unruly complexity-situations that lack definite boundaries, where what goes on "outside" continually restructures what is "inside," and where diverse processes come together to produce change-should not be suppressed …

The Early To Middle Ordovician Graptolite Faunal Succession Of The Trail Creek Region, Central Idaho, U.S.A., Jörg Maletz, Daniel Goldman, M. Cone

Department of Earth, Environment and Sustainability Faculty Publications

The Middle Ordovician graptolite biostratigraphy of the Trail Creek region of Idaho is reviewed and revised. The oldest known fauna belongs to the Didymograptellus bifidus Biozone. The Isograptus victoriae lunatus, I. victoriae maximodivergens, Oncograptus, Undulograptus austrodentatus and Holmograptus lentus Biozones can be differentiated. Pseudophyllograptus archaios (Braithwaite) is found for the first time in the Trail Creek region. This species represents a conspicuous North American mid-continent faunal element and enables the correlation of the endemic P. archaios-C. flexilis Biozone of Utah with the D. bifidus Biozone of the Pacific faunal realm, thus, providing an important tool for the correlation of endemic …

Step-Pool Morphology Of A Wilderness Headwater Stream Of The Buffalo River, Arkansas, Aaron M. Nickolotsky

Graduate Theses/Dissertations

Step-pool and cascade morphology reflect the geological and climatic factors affecting channels in mountain watersheds. This study uses longitudinal and cross-section surveys of a headwater stream in the Boston Mountains of the Ozarks Plateau region in northwest Arkansas to describe channel form and develop quantitative models for comparisons with other regions. The Bowers Hollow Creek watershed (3.5 km2) is located within the boundaries of the Forest Service’s Upper Buffalo Wilderness Area. Step-pool morphology varies with the influence of lithology and sediment supply in the Boston Mountains. However, step height and wavelength relationships are generally similar to other regions. Distribution of …

Geospatial Analysis Of Gravel Bar Deposition And Channel Migration Within The Ozark National Scenic Riverways, Missouri (1955-2003), Derek J. Martin

Graduate Theses/Dissertations

Historical land clearing is believed to be responsible for present-day channel instability in main stem reaches in the Ozark National Scenic Riverways (ONSR) in south-central Missouri. The nature of instability is related to the delivery of excess amounts of gravel sediment to stream channels and higher rates of lateral bank erosion. These conditions are of concern to resource managers because of the potential damaging effects on recreational facilities and aquatic habitat. The purpose of this study is to develop a geographic information systems (GIS)/remote sensing (RS) based methodology to monitor spatial patterns of gravel deposition and lateral channel migration within …

Level And Source Of Supplemental Selenium For Beef Steers, Scott Fry, Elizabeth B. Kegley, M. Ellen Davis, Michael D. Ratcliff, Douglas L. Galloway, Ron A. Dvorak

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Selenium (Se) is deficient in many Arkansas soils; therefore, an experiment was conducted on steers to evaluate the effects of two supplemental Se sources on performance, blood metabolites, and immune function. Thirty Angus-crossbred steers were blocked by weight and assigned within block to one of 15 pens (two steers/pen). Pens were assigned randomly within blocks to one of three dietary treatments consisting of a corn-soybean meal supplement devoid of supplemental Se (negative control, NC) or corn-soybean meal supplements providing 1.7 mg supplemental Se/d as sodium selenite (inorganic Se, ISe) or as Se yeast (organic Se, OSe). Steers were offered fescue …

Petrography And Petrology Of The Calc-Alkaline Sarıhan Granitoid (Ne Turkey): An Example Of Magma Mingling And Mixing, Zafer Arslan

Turkish Journal of Earth Sciences

There are many acidic intrusions of varying age in the northern and southern zones of the eastern Pontides, NE Turkey, and the Sarıhan Granitoid is one of these. The Maastrichtian Sarıhan Granitoid was emplaced into the pre-Permo-Carboniferous Pulur Massif, generally comprising medium-grade metamorphic rocks; the Liassic Hamurkesen Formation, that begins with the Dikmetaş conglomerate and continues upward into volcano-sedimentary rocks; and the Malm-Lower Cretaceous Hozbirikyayla Formation, comprising limestone and sandy limestones. The Sarıhan Granitoid crops out in an area of approximately 40 km2, has an ellipsoidal shape, and comprises mainly quartz monzodiorite, granodiorite and lesser quartz diorite. The pluton contains …

Investigation Of Safe And Sustainable Yields For The Sandy Complex Aquifer System In The Ergene River Basin, Thrace Region, Turkey, Şebnem Ökten, Hasan Yazicigi̇l

Turkish Journal of Earth Sciences

This study aims to determine the safe and sustainable yields for the Sandy Complex aquifer system in Ergene River basin in northwestern Turkey. A numerical ground-water flow model was developed for the Sandy Complex aquifer, which is the most productive and the most widespread aquifer in the basin. The finite difference ground-water model was used to simulate steady and unsteady flow in the aquifer. The model was calibrated in two steps: a steady-state calibration, by using the observed ground-water levels of January 1970; then a transient calibration, by using the observed ground-water levels for the period of January 1970 and …

X-Ray Bursts Associated With Leader Steps In Cloud-To-Ground Lightning, Joseph R. Dwyer, Hamid K. Rassoul, M. Al-Dayeh, Lee Caraway, A. Chrest, Brian F. Wright, E. Kozak

Aerospace, Physics, and Space Science Faculty Publications

X-ray and electric field measurements were made during five nearby negative natural lightning strikes in north central Florida during the summer of 2004. The observed X-ray emission typically was detected ∼1 ms before the first return stroke, during the stepped-leader phase, and had energies extending up to a few hundred keV. The X rays were produced in discrete, intense bursts emitted in coincidence with the formation of the leader steps, demonstrating unambiguously that the source of lightning X rays is closely related to the stepping process. The X-ray emission from lightning stepped leaders is found to be remarkably similar to …

Chinese City Design: Searching History In Order To Find A Balanced And Sustainable Future, Andrew Armbruster

Senior Honors Theses and Projects

The Chinese city faces a crisis. As development on a scale unprecedented in human history consumes this country, little care is being taken to ensure the survival of age-old traditions and the concrete principles that accompany those traditions. Western ideas seep into the country, and this produces an effect of imbalance [see Figure A]. This imbalance is not only cultural but is accompanied with all of the derivatives pertaining thereto: physical disharmony, economic imbalance, environmental unsustainability. Considering this, what needs to change within the contemporary Chinese city? To this question one must answer that the fundamental bases which underlie the …

Geomechanics Applied To Reservoir Development In The Coso Geothermal Field, Andrew J. Nygren

Theses and Dissertations

The Coso geothermal field is located approximately 220 kilometers north of Los Angeles, CA. In 2002, a project began to develop the east flank of the Coso geothermal field into an enhanced geothermal system (EGS); in such a system water is injected via injection well(s) into hot dry basement rock through naturally occurring or stimulated fractures. The injected water gathers heat from the reservoir rock before being extracted for direct use or energy production. To develop such a reservoir, adequate understanding of the reservoir geomechanics is necessary. This thesis investigates the state of stress and rock fractures, the existing permeable …

The Twiggs Clay: Mineralogy, Origin, And Industrial Properties Of An Upper Eocene Opaline Claystone In The Coastal Plain Province Of Georgia, U.S., Lori G. Eversull

LSU Doctoral Dissertations

The Twiggs Clay is an upper Eocene claystone found as discontinuous deposits downdip of the Fall Line in the Coastal Plain Province of eastern and central Georgia. A distinctive facies of the Twiggs is found in two lenses near the town of Wrens. The nature, origin, and potential commercial application of this resource are examined. Four strata and two mineralogic assemblages are recognized in the Wrens deposit. The lower three strata are near white in color and very low in density. These strata are mineralogically similar and are composed predominantly of disordered silica and smectite. The smectite is dioctahedral, and …

Carbonate Records Of Submarine Hydrocarbon Venting: Northern Gulf Of Mexico, Matthew S. Hackworth

LSU Doctoral Dissertations

Hydrocarbon seep sediments are examined from 3 sites in the Gulf of Mexico (Green Canyon Lease Blocks 232, 185, and 272) to relate the effects of gas hydrates and hydrocarbons on microbial process, pore fluid chemistry, and the processes of authigenic carbonate formation. Hydrocarbon-fueled microbial reactions result in pore fluids with lowered SO₄^2- (all consumed by –10 cm) and enrichments in H₂S, alkalinity, and DIC (up to 20 mmol, 30 meq/L, and 18 mmol/L, respectively) which promote carbonate formation. Pore fluid d¹³C_DIC (PDB) is influenced by thermogenic hydrocarbons and crude oil in GC …

Diagenesis Of Mudstones, Offshore Texas And Southwestern Louisiana, Maria Antonieta Pacheco

LSU Master's Theses

Predicting the effects of mudstone diagenesis on reservoir quality is an important component of successful petroleum exploration and production programs. A regional study using chemical analyses from mudstone core cuttings and SP logs from 15 wells from the western Gulf of Mexico, including the Matagorda, Brazos, Mustang offshore areas, indicates that chemical changes with depth such as overall depletion of quartz and calcite; the illite-smectite conversion; and K2O enrichment occur in the mudstone Miocene interval of the study area. Mixing of depositional sources has been suggested to be the cause of similar chemical and mineralogical changes observed in Paleocene-Eocene and …

Chromian Spinel–Olivine Phase Chemistry And The Origin Of Primitive Basalts Of The Southern Washington Cascades, Diane R. Smith, W. P. Leeman

Earth and Environmental Geosciences Faculty Research

Geochemically diverse basalts occur in an ~160-km-wide transect that stretches across the Quaternary southern Washington Cascades (SWC) volcanic arc. Two fundamental groups of SWC basalts can be identified on the basis of major and trace element chemistry. On primitive mantle-normalized “spidergrams”, Group I lavas resemble within-plate basalts, whereas Group II lavas exhibit chemical characteristics (e.g., Nb, Ta, and Ti depletions) typical of subduction-related magmas. The primitive nature of many SWC basalts is indicated by their high MgO (>6.5 wt.%, up to 9.5 wt.%), Ni (>85 ppm) and Cr (>180 ppm) contents. Electron microprobe analyses of olivine–spinel pairs …

Bedrock Geology Of Rogers Quadrangle, Benton County, Arkansas, Jon C. Dowell, Camille M. Hutchinson, Stephen K. Boss

Journal of the Arkansas Academy of Science

A digital geologic map of Rogers quadrangle was produced at 1:24,000 scale using the geographic information system (GIS) software Maplnfo. Data regarding stratigraphic relations observed in the field were digitized onto the United States Geological Survey (USGS) digital raster graphic (DRG) of Rogers quadrangle. The geology of Rogers quadrangle consists of sedimentary rocks of the Ordovician, Devonian, and Mississippian systems. The Cotter, Powell, and Everton formations represent the Ordovician System. The Clifty and Chattanooga formations represent the Devonian System. The St.Joe and Boone formations represent the Mississippian System. This mapping effort represents the first time stratigraphy of Rogers quadrangle was …

Monsoon-Driven Biogeochemical Processes In The Arabian Sea, Jerry D. Wiggert, Raleigh Hood, Karl Banse, John Kindle

Faculty Publications

Although it is nominally a tropical locale, the semiannual wind reversals associated with the Monsoon system of the Arabian Sea result annually in two distinct periods of elevated biological activity. While in both cases monsoonal forcing drives surface layer nutrient enrichment that supports increased rates of primary productivity, fundamentally different entrainment mechanisms are operating in summer (Southwest) and winter (Northeast) Monsoons. Moreover, the intervening intermonsoon periods, during which the region relaxes toward oligotrophic conditions more typical of tropical environments, provide a stark contrast to the dynamic biogeochemical activity of the monsoons. The resulting spatial and temporal variability is great and …

Transient Detection And Modeling Of Continuous Geodetic Data, Walter Michael Szeliga

All Master's Theses

Transient surface deformation has been observed by continuously operating Global Positioning System stations in the Puget Sound area during the past decade. This surface deformation is associated with processes occurring on or near the subducting plate boundary between the Juan de Fuca and North American plates. This thesis is composed of two studies of transient deformation along the Cascadia plate margin and a discussion of the methodologies employed in these studies. We model one 7-week episode of transient deformation that occurred during 2003 beneath the Puget Sound area. Additionally, we utilize a combination of continuous Global Positioning System and seismic …

The Role Of Geomorphic Features And Hydrologic Processes On Sediment Clusters In Gravel-Bed Rivers, Washington: A Field-Based Approach, Ross Richard Hendrick

All Master's Theses

This project investigated the movement and evolution of sediment clusters after four separate flood events at two geomorphically different sites along the Entiat River, Washington. Clusters are defined as an obstacle or anchor clast(s) that impede the progress of two or more sediment particles, and are believed to be an important characteristic of the variable bed topography of gravel-bed rivers. Detailed field descriptions and digital photographs of clusters were used to determine the characteristics of clusters at chosen locations on gravel bars regularly covered by high flow events. Data were collected during low-flow conditions, and clusters were re- examined and …

Geotectonic Setting And Origin Of The Youngest Kula Volcanics (Western Anatolia), With A New Emplacement Model, Murat Tokçaer, Samuele Agostini, Mehmet Yilmaz Savaşçin

Turkish Journal of Earth Sciences

The Quaternary Kula volcanics are Na-dominant in character while all the older volcanic rocks of western Anatolia are generally definitive K-dominant rocks. As a unique example in western Anatolia, the existence of a huge amount of plateau basalts at Kula indicates rapid uplift of mantle material, as confirmed by new geochemical data. Based on our field observations, the oldest Kula volcanics are the plateau basalts with more than one main lava flow. At the beginning of volcanic activity (first-period plateau basalts), this plateau was vast. Subsequently, parts of the first-period plateau basalts were uplifted and partly eroded while other parts …

Evolution Of And Factors Controlling Eocene Sedimentation In The Darende-Balaban Basin, Malatya (Eastern Turkey), Kemal Gürbüz, Murat Gül

Turkish Journal of Earth Sciences

Collision of the Arabian and Anatolian plates affected evolution of basins located along the southern flank of the Anatolian Plate. The Darende-Balaban foreland basin is one such basin – a basin filled with Upper Cretaceous and Eocene sediments, accumulated unconformably and transgressively above ophiolitic and carbonate basement rocks. This basin is locally surrounded, to the north and south, by Late Jurassic–Early Cretaceous structural highs created by tectonic elements during the collision of Arabia and Anatolia. This paper aims to describe the factors controlling and evolution of the Eocene sedimentation in the Darende-Balaban basin. The basin fill comprises two distinct sequences …

Wagin-Woodanilling (Zone 5) : Catchment Appraisal 2005, K Ohlsen, T Schulz, T W. Mathwin, Gina Pemberton, Henry Brockman, J Firth, Mitchell Davies, Heather M. Percy

Resource management technical reports

The aim of this report is to assess the current extent of salinity and other natural resource degradation issues and provide landholders with the best current management options to address natural resource management issues and enhance sustainable agricultural production.

Natural Resource Management Issues For The South Coast Regional Strategy, B Nicholas

Resource management technical reports

This report has been prepared by the Agricultural Resource Management Program of the Department of Agriculture to assist SCRIPT (South Coast Regional Initiative Planning Team) in preparing the regional strategy. It records the key natural resource management issues threatening agricultural land on the south coast of Western Australia. Managing agricultural land effectively should be a priority in reducing the risks of land degradation on all assets-productive agricultural land, biodiversity and waterways.

Upper Yilgarn Catchment Appraisal 2005, Keith Ohlsen, Susan Murphy-White

Resource management technical reports

Soil degradation on farmland reduces agricultural production and will often lead to damage to natural resources such as remnant vegetation and waterways, as well as to infrastructure, including roads and townsites. This report provides current information on the land degradation status for the Upper Yilgarn Catchment area in Western Australia by outlining: condition of the soils, hydrology, natural vegetation, farming systems and agricultural production and risks to natural resources.

Native Or Introduced? Fossil Pollen And Spores May Say. An Example From The Azores Islands, Jacqueline F.N. Van Leeuwen, Hanno Schäfer, W. O. Van Der Knapp, Tammy M. Rittenour, Svante Björck, Brigitta Ammann

Geosciences Faculty Publications

Aim: Among the various possible approaches to assess whether a species is native or introduced, the analysis of subfossil pollen and spores from natural archives is a valuable tool. Requirements include a sufficiently high taxonomic resolution of the pollen morphology, as well as sufficient temporal and spatial resolution. The aim of this study is to show the usefulness of this method in solving whether the taxon is native or introduced.

Location: The results are derived from two islands of the Azores: Flores and Pico. Methods: Analysis of pollen and spores in lake sediments; radiocarbon dating of the studied sediments.

Results: …

Calcareous Nannoplankton Response To Late Albian Oceanic Anoxic Event 1d In The Western North Atlantic, David K. Watkins, Matthew J. Cooper, Paul A. Wilson

Department of Earth and Atmospheric Sciences: Faculty Publications

Well-preserved nannofossil and stable isotope records from the mid-Cretaceous of Ocean Drilling Project Leg 171B (western North Atlantic) indicate cyclical, productivity-based variations in surface water characteristics, suggesting orbitally paced changes in upwelling intensity and the strength of deep mixing associated with oceanic anoxic event (OAE)1d. Paleontologic and isotopic evidence suggest that collapse of upper water column stratification associated with OAE1d was preceded by approximately 1 m.y. of progressively decreasing water column stability and increasing surface water fertility. Thirteen species went extinct during a short (ca. 200 k.y.) interval associated with OAE1d. Nine of these have morphological characters suggesting adaptation to …