Physical Sciences and Mathematics Commons^™

Modeling The Impacts Of Sea Level Rise In Coastal Virginia At Multiple Scales, George Murray Mcleod Iv

OES Theses and Dissertations

Relative sea level is increasing along the Mid-Atlantic coast of the United States and the rate of relative sea level rise (ΔRSL) for Coastal Virginia is approximately double the rate of global sea level rise (ΔSLRG)(1). The potential impacts posed to communities by ΔRSL are best understood by examining the spatial relationship between the upper limits of ocean-connected waters and the geographic positioning of critical natural and societal assets. This research examines this problem at three spatial scales to quantify the impacts of ΔRSL and storm flooding events on (i) structural and transportation infrastructure for the tide-influenced coastal zone of …

Organic Copper Binding Ligands And Thiol Compounds Produced By Bacteria And In The Elizabeth River, Virginia, Christina Louise Dryden

OES Theses and Dissertations

This dissertation presents work focusing on copper and organic copper binding ligands in laboratory cultures and the Elizabeth River, Virginia. Laboratory cultures of the marine bacterium Vibrio parahaemolyticus were used to demonstrate the influence of elevated copper concentrations on copper-complexing ligand and thiol production. Copper-complexing ligands similar in binding strength to the strongest natural ligands were detected in V. parahaemolyticus cultures (log K′_CuL = 11.8–13.2). A strong correlation (r² = 0.973) was found between total thiol and copper-complexing ligand concentrations at all copper concentrations examined.

A yearlong seasonal study was undertaken in a heavily polluted estuary to ascertain …

Evaluating The Contribution Of Groundwater To Wetland Water Budgets Central Piedmont Virginia, Kerby Morgan Dobbs

OES Theses and Dissertations

In the Piedmont region of Virginia, development pressures are increasing the demand for mitigation wetlands but appropriate construction sites are relatively scarce due to local topography and geology. Many existing water budget models used for planned mitigation sites exhibit considerable error when estimating groundwater fluxes, particularly for historical years that lack hydraulic head data. This difficulty has led many planners to neglect or underestimate the contribution of groundwater to wetland water budgets, resulting in mitigation sites that fail to create the appropriate hydrology for the desired vegetation community. However, reliable estimations of groundwater input contributing to wetland water budgets can …

Fecal Indicator Bacteria In Knitting Mill Creek With A Comparison Of Methods Used To Enumerate E. Coli, Manju Nagarajan

OES Theses and Dissertations

This research seeks to evaluate the impact of an urban, multi-use neighborhood on the bacteriological quality of water in Knitting Mill Creek, a blind arm of the Lafayette River, a sub-estuary of the lower Chesapeake Bay. A principal objective was to determine the effects of rainfall, a surrogate for run-off, on water-column concentrations of fecal-indicator bacteria (FIB). I collected water samples weekly (September 2009-December 2010) and biweekly (January 2010-December 2011) at a storm-sewer outfall and a nearby marina and quantified their E. coli and enterococci concentrations using Colilert-18 and Enterolert, most-probable-number assays. In addition, I took monthly samples for these …

Hydrologic Variations Within Created And Natural Wetlands In Southeastern Virginia, Aaron Dyer Despres

OES Theses and Dissertations

The hydrology of wetlands, particularly how wetland soils collect, store, and redistribute water strongly affects how wetland systems function. In created wetlands, construction processes and materials influence the hydrology and consequently, the potential for successful reestablishment of target vegetation communities. During .2002- 2004, the Virginia Department of Transportation constructed large mitigation wetlands on two different Quaternary aged surfaces with very similar hydrogeomorphic conditions. The Sandy Bottom Nature Park site (SBNP) located in Hampton, VA and rests on the sandy loam Tabb Formation while the Charles City Wetland site (CCW) lies on the older and clay-rich Shirley Formation. This study documents …

Inner Shelf Circulation In Coastal Virginia: A Data Assimilation Approach, Hector Hito Sepulveda

OES Theses and Dissertations

The primary objective of this dissertation is to describe the tidal and subtidal flow patterns over the inner shelf of the Delmarva Peninsula, located in the Mid-Atlantic Bight of the United States (36.6–38.0 N), north of the Chesapeake Bay. The objective is pursued with a combination of direct measurements and numerical assimilative techniques. The dynamic balance of the study area is little known, and the distribution of tidal properties has not been described for this area since very rough descriptions in the 1950's. Hydrographic and current velocity profiles from four regional cruises in the inner shelf were used to study …

Stratal Architecture In A Prograding Shoreface Deposit, Eastern Shore, Va: Relationship To Grain Size, Permeability, And Facies Distribution, Andrew C. Miller

OES Theses and Dissertations

A fundamental concern of the stratigrapher is to develop predictive models of stratigraphic organization. In sedimentology one of the most significant problems that has yet to be resolved is the fact that there is a lack of quantitative information regarding the relationship between geometry of beds, thickness of beds, grain size and sedimentary structures in sandy environments, especially shallow marine deposits. Scientists have also realized the need to correlate quantitative permeability to sedimentary structures and scales of stratigraphic organization. The purpose of the study is to investigate the scales of stratigraphic organization that control the variation of grain size and …

The Impacts Of External Nutrient Sources On Marine Phytoplankton In An Eastern Shore Sea-Side Estuary, Claudette Lajoie Jenkins

OES Theses and Dissertations

The Eastern Shore of Virginia (Greens Creek) as well as a large portion of the North Atlantic coastline is characterized by estuarine systems not dominated by large river systems. Instead, small freshwater creeks influence many coastal systems yet little information has been documented on their ecological significance. The focus of this research is to identify the biogeochemical and physical interactions within an estuarine water-column and understand the importance of freshwater sources in governing phytoplankton production. The hypothesis of this research is that increases in external nutrient loading into Greens Creek will not result in an increase in primary production. The …

Non-Volatile Dissolved Organic Iodine In Marine Water, Xianhao Cheng

OES Theses and Dissertations

An analytical scheme for the determination of marine DOI has been established. The concentration of DOI is estimated as total iodine (TI) minus total inorganic iodine (TII). The concentration of total iodine is determined as [special characters omitted] after DOI has been oxidized to inorganic iodine quantitatively by intensive UV-irradiation and all the inorganic iodine in the samples had been converted to [special characters omitted] by the addition of NaClO.

Production of DOI in seawater can be via both non-phytoplankton and phytoplankton related processes. In the former, iodide is converted to DOI. In the latter, most likely, iodate is converted …

The Influence Of Saprolite Composition Texture And Structure On Groundwater Flow In The Piedmont Province Henry County Virginia, John Thomas Russell

OES Theses and Dissertations

At a 500 acre site in Henry County, Virginia, differences in vertical hydraulic conductivity (K_V) and lateral hydraulic conductivity (K_H) measured in saprolites formed from the Fork Mountain biotite gneiss and the Leatherwood granite reflect the control of the fabric, texture, and structure of the parent rock preserved within the saprolite horizon. Using subsurface data collected from approximately 350 boreholes in conjunction with published information enabled various maps to be generated that identify the spatial relationships between geology and topography and their influence on the nature of the saprolite aquifer.

Measurements of K_H determined from …

Quaternary Seismic Stratigraphy Of The Inner Shelf And Coastal Zone, Southern Delmarva Peninsula, Virginia, Anthony M. Foyle

OES Theses and Dissertations

The Pleistocene stratigraphic record beneath the Virginia inner shelf is largely unknown. On the adjacent lower Atlantic Coastal Plain of southeastern Virginia, the Pleistocene record consists of seven stacked transgressive sequences, while on the southern Delmarva Peninsula, a series of three transgressive to highstand sequences are developed. Reconstruction of the mid-Atlantic basin margin response to high-frequency Quaternary glacioeustasy is limited by this sparse record of late transgressive through early regressive deposition. Knowledge of high-frequency depositional sequence architecture, developed under conditions of low subsidence (to net uplift) and low sediment input, is also incomplete. The Atlantic inner shelf and coastal zone, …

Paleocene To Miocene Foraminifera From A Well Near Gloucester, Virginia, Nelson Stanley Ford

OES Theses and Dissertations

Lithologic analysis of twenty-one core samples from a well near Gloucester, Virginia, when compared to published descriptions of formations occurring in the study area, indicates the presence of five formations. From oldest to youngest these units are the Aquia (late Paleocene), Nanjemoy (early Eocene), Chickahominy (late Eocene), Old Church (late Oligocene and early Miocene), and Eastover (late Miocene) formations. Comparison of the stratigraphic ranges of key planktic and benthic foraminifera from each of the core samples shows chronological agreement with previously published ages for each of these formations.

Paleoenvironmental analysis of each of the formations in the well is based …

Ground Water Investigation Of The Petersburg Granite In Chesterfield County, Virginia, Michael W. Bennett

OES Theses and Dissertations

Yields of new water wells in areas underlain by the Petersburg Granite in Chesterfield County, Virginia should improve if procedures for site selection and well construction follow the new guidelines proposed. These guidelines integrate analyses of aerial photo linears and drainage patterns, survey of bedrock joints and shallow geophysical properties and techniques using several statistical methods.

Throughout the study area, fracture traces form in nearly the same orientation as bedrock fractures. The dominant N-S and E-W trending bedrock joints also corresponded to aerial photo linears of similar orientation.

Across one large fracture zone, both gamma-ray and electrical resistivity surveys reveal …

Evaluation Of Late Mesozoic And Cenozoic Tectonism: Atlantic Inner Coastal Plain Margin Near Richmond, Virginia, Andrew A. Gremos

OES Theses and Dissertations

A combined geologic, geophysical, and geomorphic analysis of the Virginia Inner Coastal Plain margin near Richmond was conducted to investigate the presence of basement structures and to evaluate their influence on the overlying sedimentary package and present-day landscape. Basement structures identified included north-northeast and northwest oriented faults that appear to bound and transect a north-northeast trending early Mesozoic basin or basins and other pre-existing zones of weakness. Observed offsets are propagated upward through the pre-Miocene strata in the form of reverse faults and flexuring. Fracture sets measured in the Petersburg Granite and overlying Coastal Plain units, stream drainage lines, and …

The Geomorphology Of Alluvial Fan Deposits On The West Flank Of The Blue Ridge, Augusta County, Virginia, Debra Lynn Duffy

OES Theses and Dissertations

Large coalescing alluvial fans mantle the carbonate and shale formations west of the Blue Ridge mountains near Stuarts Draft, Virginia. Fan sediments are predominantly boulder and cobble gravels derived from the Antietam Quartzite, The fan complex consists of three alluvial units of significantly different ages. The surface of each fan unit was mapped using relative geomorphic position, soil color, clay content and thickness of Bt horizons, clast weathering, and degree of removal of depositional surfaces by stream incision. A five-category quartzite clast weathering scale developed for this study was very effective as a measure to distinguish map units. Stratigraphic data …

A Geophysical And Geological Study Of The Farmville Triassic Basin, Charles G. James Jr.

OES Theses and Dissertations

The Farmville basin is one of many Triassic basins which are found along the eastern coast of North America, and is the largest of the central string of basins in Virginia. Meta-volcanic and metasedimentary rocks of the Chopawamsic Formation, as well as felsic intrusives are the primary lithologies surrounding the basin. A detailed gravity survey was conducted along six roads that trend approximately NW-SE, across the basin. Geologic, gravity, magnetic, and radiometric data were used to develop a kinematic model. Gravity anomalies were isolated using two-dimensional harmonic analysis methods to isolate the local, and regional anomalies. This analysis indicates that …

A Geophysical Study Of The Easternmost Piedmont: Brunswick County, Virginia, Mark A. Corbin

OES Theses and Dissertations

Gravity and magnetic models indicate that a steeply dipping, mylonitic shear zone recognized by reconnaissance mapping in the easternmost Piedmont of Brunswick County, Virginia is a listric fault. A pronounced 3 to 5 mgal Bouguer anomaly high is associated with the fault zone. A band of N10° trending aeromagnetic anomalies delineate the areal extent of the fault zone. The fault zone flattens eastward over a short distance to a depth of 15 kms where it joins a near horizontal surface that cuts across the region. This surface is herein interpreted to be a decollement. The fault zone of this study …

The Geomorphology And Surficial Geology Of The West Flank Of The Blue Ridge, Sherando Area, Virginia, Derek Weston Ryter

OES Theses and Dissertations

The west flank of the Blue Ridge near Sherando, Virginia (Augusta County) consists of many landforms including talus slopes, bedrock cliffs, boulder streams, colluvial slopes, residual knobs, and debris fans. The purpose of this study is to describe the geomorphic history of the area by understanding the spatial and temporal relationships between landforms on the hillslopes.

Boulder streams (maximum 30 m wide, 400 m long, 6.1 m thick) exhibit a gently dipping imbricated fabric and basal shear stresses of 0.1 to 0.4 bars.

Debris fans in Group L (lower) and Group U (upper) are distinguished by topographic position, degree of …

Trace Elements In Northern Virginia Middle Ordovician Carbonates: Implications For Diagenesis, Ruth Ann Strauss

OES Theses and Dissertations

Ninety-three carbonate rock samples collected from four of the major lithofacies types present in the Middle Ordovician limestone sequence of northwestern Virginia were analyzed to investigate whether the lithofacies bear the geochemical signature of the depositional and/or the diagenetic environment. Significant variations in Cr, Fe, Mg, Mn and Sr concentrations exist among the major lithofacies types. Low levels of Sr in both New Market lithofacies are indicative of an open system during diagenesis. Dissimilar Fe and Mn concentrations between these, however, reflect water chemistry differences in the depositional environment. Increasingly greater Cr, Fe, Mn, and Sr concentrations in the Lincolnshire …

Holocene Geology And Migration Of A Low-Profile Barrier Island System, Metompkin Island, Virginia, Mark R. Byrnes

OES Theses and Dissertations

Analysis of historical shoreline position, cross-island profile change, and stratigraphic data provided a shoreline response model for low-profile barrier island systems. Historical shoreline data illustrates continuous, shore-parallel retreat between 1852 and 1957, at which time the island narrowed to a width of approximately 200 m. Between 1957 and 1981, ephemeral inlet breaching along southern Metompkin Island disrupted longshore sediment transport, increased the rate of shoreline recession, and resulted in differential rates of retreat associated with an abrupt break in backbarrier morphology. By 1981, a 400 m offset had formed at a position midway along Metompkin Island, suggesting that ephemeral inlet …

Economic Considerations For Artificial Reef Development In Coastal Virginia, Dean Thomas Devereaux

OES Theses and Dissertations

The contingent valuation method, recommended by the U. S. Water Resources Council, was used to estimate the economic value of sport fishing and diving at the Chesapeake Light Tower Artificial Reef. The study is based on a random sample of 170 anglers and 33 divers who participated in telephone, personell and mail-in surveys in 1985 and 1986.

The average user value (consumer surplus) was $21.13, $110,75, and $13.30 for head boat anglers, private boat anglers and sport divers, respectively, who claimed to have used the reef in 1985. Variation in consumer surplus was statistically affected by trip expense, distance from …

Discrimination Of Subparallel Beach Ridges Using Detrital Ilmenite Composition And Fourier Shape Analysis, Allen E. Evans Jr.

OES Theses and Dissertations

Elemental composition (Fe, Ti, Mn, Mg, V, Cu, Ni, Zn, and Cr) and Fourier shape analysis of magnetically separated detrital ilmenite from seven Pleistocene and modern beach sand deposits of the Southeastern Virginia Coastal Plain were used to distinguish each deposit. Geomorphic expression, crosscutting relationships and proximity to the present shoreline differentiates the relative age of the seven sampled beach deposits. Analysis of ilmenite elemental composition, independent of geomorphic expression, distinguished beach sands of

different age and was successful in determining that each beach contained ilmenite similar in composition. Of the seven beach ridges tested, subtle yet significant differences in …

Phytoplankton Dynamics In The Very Low Salinity Region Of The James River Estuary, Virginia, U.S.A., Changho Moon

OES Theses and Dissertations

During summer and autumn discharge from the James River estuary, Virginia, was less than 120 _m³sec^-1. There was a peak phytoplankton biomass in the very low salinity region (defined as the location where surface salinity measured less than 0.5$ 0/00) and this peak represented five to ten times greater biomass than adjacent waters. The peak biomass occurred independent of the tidal state and the location of nutrient inputs. It disappeared during winter and spring, and nutrient limitation was not responsible for the low phytoplankton biomass, indicating there were physical, not chemical controlling factors.

The peak biomass …

Depositional And Diagenetic History Of The Middle Ordovician Carbonates Of The Shenandoah Valley, Northern Virginia, Lynn Ellen Weyenberg

OES Theses and Dissertations

An examination of the Middle Ordovician carbonates in northwest Virginia has revealed a particularly sensitive record of deposition and subsidence. Two-hundred acetate peels from six measured stratigraphic sections in Shenandoah County, Virginia were examined to interpret the depositional and diagenetic history. Two major lithofacies have been recognized within the New Market Limestone and three have been recognized in the Lincolnshire Formation. These five lithofacies represent an overall transgressive sequence. This transgression was not uniform but paused several times to allow carbonate deposition to reach sea-level. These shoaling events suggest a slowly subsiding basin in this region. The carbonate rocks within …

Conodont Biostratigraphy Of The Cambrian-Ordovician Boundary Interval In The Northern Shenandoah Valley Of Virginia, U.S.A., Randall C. Orndorff

OES Theses and Dissertations

Conodonts collected from two measured sections in the northern Shenandoah Valley of Virginia indicate that locally the Cambrian-Ordovician boundary is within the upper part of the Conococheague Formation and that the Conococheague-Stonehenge formational contact as defined in this study, is diachronous in relation to the boundary. Using the generally accepted definition of the CambrianOrdovician boundary as at the base of the trilobite Missisguoia Zone or within the conodont Hirsutodontus hirsutus Subzone of the Cordylodus proavus Zone, it is found here that the boundary is 230 ft (70 m) below the formational contact at the Narrow Passage Creek section. Several North …

A Geophysical Model Of The Gravity-Magnetic High, Virginia Coastal Plan, Gordon Everett Davison

OES Theses and Dissertations

The coastal plain province of Virginia is characterized by a coincidental gravity and magnetic high separating Appalachian-trend geophysical signatures to the west from non-Appalachian signatures to the east. Two cross-trend gravity and magnetic profiles, one on the Northern Neck of Virginia and one along Interstate Highway 64, were used to interpret the anomalous high. The profile models suggests that the anomaly is characterized by high-density, variably magnetic, east-dipping (60°) crustal blocks. Further information from well-logs indicate that the anomaly is due to meta-mafic rocks of oceanic origin, flanked by low-density, lower susceptibility, granitic units. This suggests that the anomalous gravity-magnetic …

Sedimentologic And Stratigraphic Significance Of Boulder Layers In The Outer Coastal Plain Of Southeastern Virginia, Robert C. Mcdaniel

OES Theses and Dissertations

In southeastern Virginia one to two discontinuous boulder layers occur at the base of the Pleistocene Norfolk Formation. The sediments, heavy minerals and microfossils within the boulder layers in addition to boulder lithologies, dimensions and orientations were studied to determine the origin of these layers. These data indicate the boulder layers were separated into two similar yet distinct layers.

The ancestral James River with sea-level 100 meters lower than today probably had the capacity to entrain 70-80 percent of the clasts in the boulder layers, but probably not the capacity to entrain the larger cobbles and boulders in the boulder …

Phytoplankton Ecology And Dynamics In The James River Estuary Virginia, U. S. A., Margaret J. Filardo

OES Theses and Dissertations

Autotrophic biomass and productivity as well as nutrient distributions and phytoplankton cell populations in the James River estuary, Virginia, from Newport News Shipyard to the 0 o/oo isohaline, were sampled on a monthly basis from August of 1981 to December of 1982. Particular emphasis was placed on the very low salinity region (defined as the location where surface salinity measured between 0.0 and 0.75 o/oo based on conductivity) in order to determine the fate of fresh water phytoplankters upon being advected into the estuary because of their suspected role in the biogeochemical cycling that occurs there.

Both chlorophyll a and …

A Description And Analysis Of The Timing Of Virginia's Weakfish Fishery, Bruce William Hill

OES Theses and Dissertations

The seasonality of Virginia's weakfish fishery is quantitatively defined by providing a mean time of catch and variance of catch for the years 1960 - 1981. On the average. the central half of the population is available for harvest from mid-May through September in all of Virginia's waters and the mean date of harvest is July 20th • The 22 year average variance of catch for Virginia's waters is 3.97. In Virginia's Chesapeake Bay tributaries the mean date of harvest is July 17th and the 22 year average variance of catch is 2.50. There is evidence for an inverse relationship …

Timing Of The Blue Crab Fisheries Of Virginia And Its Application To Harvest Management, J. Dale Shively

OES Theses and Dissertations

The timing of a fishery is a quantitative expression of the composite behaviors of harvesters, markets, animals and climatic events. A quantitative description of the timing of the blue crab (Callinectes sapidus) fisheries of Virginia was established using the time density model of Mundy (1979). Blue crab catch statistics supplied by the National Marine Fisheries Service and the Virginia Marine Resource Commission were divided into two fisheries based on gear type; the summer and winter fisheries. Average performance curves were then constructed using average cumulative proportions of catch. Annual yield estimates were also made and timing in five …