Earth Sciences Commons^™

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 …

Analysis Of Lunar Basalt Flows In Oceanus Procellarum Using Clementine Data, Noel William Jackson

OES Theses and Dissertations

Remote sensing analyses of data set taken by Clementine in 1994 permit new observations about mineral distribution on the lunar surface, basalt flow stratigraphy, and thus the geologic evolution of the Moon. The northern section of Oceanus Procellarum contains numerous impact craters which penetrated the basalt and thus can be used as natural probes to estimate the number and thicknesses of flows.

I constructed a mosaic taken in three frequencies ( 415 nm, 750 nm, 950 nm), and a Ratio Image (750/415 = red, 750/950 = green, 415/750 = blue). On such an image, red indicates the iron-poor mature highland …

Effects Of Organic Matter And Iron-Rich Clay On Mobility Of Trace Metals From Flue Dust Contaminated Soil, Scott Ephraim Lewis

OES Theses and Dissertations

The enhanced leaching of trace metals through soil becomes a concern for human health if dissolved trace metals reach groundwater and migrate into a public water system. A serial batch extraction procedure was implemented to determine the effects of Vitagrow © organic matter and Fe-Rich TM clay on the mobility of trace metals (Zn, Pb, and Cd) from a flue dust treated (0, 600, 1200, and 2400 μgig Zn) Appling soil.

The addition of an organic matter (OM) amendment to the Appling soil enhanced Pb mobility and reduced soluble Zn and Cd. In general, average solution concentrations of trace metals …

Physical Control Of Biological Processes In The Central Equatorial Pacific: A Data Assimilative Modeling Study, Marjorie Anne Macwhorter Friedrichs

OES Theses and Dissertations

A five-component data assimilative ecosystem model is developed in order to investigate the effects of physical processes encompassing a wide range of space and time scales, on the lower trophic levels of the highly dynamic central equatorial Pacific (140°W). Many of the biological processes included in the ecosystem model respond to environmental fluctuations with time scales between one and ten days, which are not typically resolved by basin to global scale circulation models. Therefore, the ecosystem model is forced using daily observations from the TAO mooring array. Model simulations successfully reproduce data collected both during and after the 1991–92 El …

Limitation Of Algal Growth By Iron Deficiency In The Australian Subantarctic Region, Peter N. Sedwick, Giacomo R. Ditullio, David A. Hutchins, Philip W. Boyd, F. Brian Griffiths, A. Clive Crossley, Thomas W. Trull, Bernard Queguiner

OES Faculty Publications

In March 1998 we measured iron in the upper water column and conducted iron- and nutrient-enrichment bottle-incubation experiments in the open-ocean Subantarctic region southwest of Tasmania, Australia. In the Subtropical Convergence Zone (∼42°S, 142°E), silicic acid concentrations were low (< 1.5μM) in the upper water column, whereas pronounced vertical gradients in dissolved iron concentration (0.12-0.84 nM) were observed., presumably reflecting the interleaving of Subtropical and Subantarctic waters, and mineral aerosol input. Results of a bottle-incubation experiment performed at this location indicate that phytoplankton growth rates were limited by iron deficiency within the iron-poor layer of the euphotic zone. In the Subantarctic water mass (∼46.8°S, 142°E), low concentrations of dissolved iron (0.05-0.11nM) and silicic acid (< 1μM) were measured throughout the upper water column, and our experimental results indicate that algal growth was limited by iron deficiency. These observations suggest that availability of dissolved iron is a primary factor limiting phytoplankton growth over much of the Subantarctic Southern Ocean in the late summer and autumn.

The Geomorphological History Of An Alluvial Fan Complex In Nelson County, Virginia, Melinda Ann Youngblood

OES Theses and Dissertations

An alluvial fan complex blankets a portion of the Rockfish Valley in Nelson County Virginia, located along the eastern slope of the Blue Ridge Mountains. The seven-km² field area contains three mappable relict alluvial surfaces (Qf1, Qf2, and Qf3) and one modern surface (Qa1), each of which is underlain by fluvial deposits dominated by greenstone and charnokite cobbles. The four surfaces were mapped according to topographic position and degree of stream dissection. Alluvial deposits underlying each surface were characterized using a 3-part clast weathering scale based on greenstone clast weathering rinds and using soil development criteria (clay content, Munsell …

A Paleoenvironmental Study Of A Middle Wisconsinan Biota Site, Russell County, Virginia, Thomas C. Wynn

OES Theses and Dissertations

The study area lies in a first-order valley on the northwestern slope of Clinch Mountain that drains into Moccasin Creek. The deposit is 50 m long, 25 m wide and approximately 10 m thick and overlies the Ordovician Moccasin Formation. Preserved within the deposit are mammoth and mastodon bones, logs, and plant macrofossils. Radiocarbon analyses indicate the age of the organic-rich sediments ranges from 29, I 00 BP to >44,000 BP, a time period with no fossil remains reported in this region of the Appalachians. Analyses of field observations, textural data, organic carbon content, and plant macrofossils indicate the organic-rich …

Heat And Salt Changes On The Continental Shelf West Of The Antarctic Peninsula Between January 1993 And January 1994, John M. Klinck

CCPO Publications

Hydrographic measurements from four cruises between January 1993 and January 1994 over the continental shelf west of the Antarctic Peninsula allow analysis of seasonal changes in heat and salt content of this region. Changes above the permanent pycnocline (about 150 m) follow a seasonal pattern of cooling and increasing in salt from summer to winter and warming and freshening from winter to summer. These near-surface changes expressed as net heating or salting rate, were above 80 W m(-2) and 4 mg salt m(-2) s(-1). The year to year difference was small compared to the seasonal changes. There was no seasonal …

A Geochemical Study Of Marine Sediments From The Mac. Robertson Shelf, East Antarctica: Initial Results And Palaeoenvironmental Implications, Peter N. Sedwick, P. T. Harris, L. G. Robertson, G. M. Mcmurtry, M. D. Cremer, P. Robinson

OES Faculty Publications

Sediments from the Antarctic continental margin may provide detailed palaeoenvironmental records for Antarctic shelf waters during the late Quaternary. Here we present results from a palaeoenvironmental study of two sediment cores recovered from the continental shelf off Mac. Robertson Land, East Antarctica. These gravity cores were collected approximately 90 km apart from locations on the inner and outer shelf. Both cores are apparently undisturbed sequences of diatom ooze mixed with fine, quartz-rich sand. Core stratigraphies have been established from radiocarbon analyses of bulk organic carbon. Down-core geochemical determinations include the lithogenic components Al and Fe, biogenic components opal and organic …

The Biogeochemical Cycling Of Dissolved Organic Nitrogen In Estuarine Sediments, David J. Burdige, Shilong Zheng

OES Faculty Publications

Benthic fluxes and pore-water profiles of dissolved organic nitrogen and carbon (DON and DOC, respectively) were determined in seasonal studies at contrasting sites in Chesapeake Bay. Pore-water dissolved organic matter (DOM) concentrations were elevated over bottom-water values, generally increased with depth, and ranged from 15 to similar to 160 μM for DON and ~200-2000 μM for DOC. Pore-water DOM concentrations and the C:N ratio of this material showed spatial (depth) and temporal changes that varied among the sites studied. These trends appeared to be related to differences in the types of sediment organic matter (SOM) undergoing remineralization, as well as …

Iron In Ice Cores From Law Dome, East Antarctica: Implications For Past Deposition Of Aerosol Iron, R. Edwards, Peter N. Sedwick, Vin Morgan, C. F. Boutron, S. Hong

OES Faculty Publications

Total-dissolvable iron has been measured in sections of three ice cores from Law Dome, East Antarctica, and the results used to calculate atmospheric iron deposition over this region during the late Holocene and to provide a preliminary est. of aerosol iron deposition during the Last Glacial Maximum (LGM). Ice-core sections dating from 56-2730 BP (late Holocene) and ∼18 000 BP (LGM) were decontaminated using trace-metal clean techniques, and total-dissolvable iron was determined in the acidified meltwaters by flow-injection analysis. Our results suggest that the atmospheric iron flux onto the Law Dome region has varied significantly over time-scales ranging from seasonal …

Lead Isotopes And Selected Metals In Ice From Law Dome, Antarctica, K. J. R. Rosman, W. Chisholm, C. F. Boutron, S. Hong, R. Edwards, Vin Morgan, Peter N. Sedwick

OES Faculty Publications

The isotopic composition. of Pb and the concentrations of Pb, Ba and Bi were measured in selected ice-core samples from Law Dome, East Antarctica, to a depth of 1196 m. The range of concentrations found in decontaminated ice was 0.03-1.5 pg g^-1 for Pb, 0.9-6.1 pg g^-1 for Ba and 0.4-17 fg g^-1 for Bi, excluding the deepest sample which contained ∼1 ppm of rock dust. The abundances of all four stable lead isotopes were measured and gave ²⁰⁶Pb/²⁰⁷Pb ratios ≤ ∼1.23. A value of ²⁰⁸Pb/²⁰⁷Pb = 2.78 was measured in …

The Study Of Wave-Blocking And Current Effects On Nonlinear Interactions Of Shallow-Water Waves Using Advanced Boussinesq Models, Qin Chen

Civil & Environmental Engineering Theses & Dissertations

The first part of this work focuses on the derivation of enhanced Boussinesq-type equations for the combined motion of waves and currents in shallow water areas.

The strategy proposed in this work is to couple two known methods which are the sponge layer concept suitable for short waves and Sommerfeld radiation condition for currents. This coupling method provides satisfactory non-reflective boundaries for the simulation of fully coupled wave/current motion as demonstrated by the numerical experiments. We verify the model against the well known solutions based on the existing theories and good agreement has been observed. The numerical results confirm the …

Biostratigraphic Analysis Of Southern Florida's Plio-Pleistocene Shell Beds, Dalton L. Rasmussen

OES Theses and Dissertations

Four molluscan assemblage zones in southern Florida corresponding to the Pinecrest Sand Member of the Tamiami Formation, and the Caloosahatchee, Bermont and Fort Thompson shell beds were identified following quantitative and qualitative analyses of the fossil molluscan fauna. Twenty-eight bulk sediment samples collected from 16 localities across southern Florida were processed for fossil material, and yielded nearly 60,000 specimens belonging to 311 species. A Q-mode cluster analysis compared sediment samples on the basis of 188 species whose abundances had been converted to binary presence-absence form. The cluster analysis was run four times using the Jaccard and Dice similarity coefficients as …

Ice Transport In The Queen Elizabeth Islands, Canadian Arctic Using Detrital Fe Oxide Grain Composition, Duan Li

OES Theses and Dissertations

Nine Fe oxide mineral types (45pm-250pm) separated from 54 glacial and glaciomarine sediment samples from the Queen Elizabeth Islands (QEI) of Canada were analyzed for 12 elements by electron microprobe to determine the dispersal patterns of ice rafted debris in this area. Both cluster analysis and discriminant function analysis (DFA) on the chemical compositions were used to match each detrital Fe oxide grain to a source The entire QEI area can be subdivided into eight unique areas based on the elemental composition of the Fe oxide minerals. These subdivisions are similar to the source areas based on the assemblage of …

Elevation As A Control Of Boulder Stream Formation In The Blue Ridge Province Of Virginia, Marc D. Zamkotowicz

OES Theses and Dissertations

Within four study areas in the Blue Ridge Mountains of Virginia, boulder streams formed by periglacial processes carpet the bottoms of most high-altitude first-order valleys. The geomorphic indicators of periglacial formation in these long, linear accumulations of bouldery colluvium - the presence of vertical clasts, gradational upper contacts with talus deposits, confinement within valleys, and hump-like cross sectional profiles - were present in all areas mapped and in most individual boulder streams. The minimum critical elevation for boulder stream formation increases from north to south across Virginia, from 150 m in elevation in northern Virginia to 1500 m in southwestern …

The Effects Of Organic Matter Rich Topsoil On The Germination Growth And Metal Uptake Of Corn (Zea Mays) Grown In Flue Dust Contaminated Soil, Christopher Allen Impellitteri

OES Theses and Dissertations

The large biomass of corn (Zea mays) and promising results from a previous experiment (Chlopecka and Adriano, 1995) concerning metal uptake by corn indicate that corn may be a good candidate for phytoremediation of trace metal contaminated soil. Appling soil (acid, thermic, typic paleudult) was treated with increasing levels of a metal rich flue dust based on Zn concentration (0, 150, 300, 600, 1200, and 2400 mg/kg). Four replicates at each Zn treatment level were either limed to pH 6.3-6.5 and covered with a two inch thick layer of organic matter rich topsoil (OM), unlimed and covered with …

40Ar/39 Ar Geochronology Of The Lowland Creek Volcanic Field And Its Temporal Relations With Other Eocene Volcanic Areas, Vladimir Olegovich Ispolatov

OES Theses and Dissertations

Exposures of the Eocene Lowland Creek Volcanics (LCV) cover an area of 2000 km² in southwestern Montana, and consist of basal elastic deposits, felsic tuffs, and felsic and intermediate lavas with an aggregate thickness of about 2 km. New ⁴⁰Ar/³⁹Ar dates show that volcanic activity lasted for at least 4.2 million years (52.7- 48.5 Ma), or even longer (4.5-4.7 million years: from 53.0-53.2 Ma to 48.5 Ma). During evolution of the volcanic field, early explosive volcanism was gradually replaced by extrusive activity. During the transition period (52.7-51.5 Ma), the two volcanic styles coexisted.

The evolution of …

Middle Shoreface Intervals: Evidence Of Barred Nearshore Systems In He Stratigraphic Record, James V. Gravette

OES Theses and Dissertations

An interpretation for middle shoreface (MSF) intervals was developed by comparing MSF intervals from the Upper Cretaceous (Campanian) Blackhawk Formation, east-central Utah, with conceptual models proposed for modern nearshore areas. Specifically, MSF intervals identified within the Sunnyside Member were compared with MSF intervals identified within the Spring Canyon (Kamola and Van Wagoner, 1995) and the Aberdeen (Kamola, unpublished data) members.

A comparison of MSF interval data revealed that MSF intervals occur stratigraphically between upper and lower shore face deposits, disrupting the standard vertical succession for nearshore marine deposits (consisting of offshore, lower shore face, upper shore face, and foreshore deposits). …

Fluxes Of Copper-Complexing Ligands From Estuarine Sediments, Stephen A. Skrabal, John R. Donat, David J. Burdige

OES Faculty Publications

Most studies of the organic complexation of Cu in natural waters have focused on distributions and processes in the water column, where a significant fraction of Cu-complexing ligands may be biologically produced. We present direct evidence for a flux of Cu-complexing ligands from estuarine sediments, demonstrating that sediments are a significant, yet previously unrecognized source of the ligands. Fluxes of Cu-complexing ligands from Chesapeake Bay sediments range from 300 to 1,200 nmol m^-2 d^-1, exceeding fluxes of total dissolved Cu by 3->40-fold, suggesting that any Cu fluxing from the sediments is likely to be organically complexed. …

Regulation Of Algal Blooms In Antarctic Shelf Waters By The Release Of Iron From Melting Sea Ice, Peter N. Sedwick, Giacomo R. Ditullio

OES Faculty Publications

During summer 1995-96, we measured iron in the water column and conducted iron-enrichment bottle-incubation experiments at a station in the central Ross Sea (76°30'S, 170°40'W), first, in the presence of melting sea ice, and 17 days later, in ice-free conditions. We observed a striking temporal change in mixed-layer dissolved iron concentrations at this station, from 0.72-2.3 nM with sea ice present, to 0.16-0.17 nM in ice-free conditions. These changes were accompanied doubling of algal (diatom) biomass. Our incubation experiments suggest that conditions were iron-replete in the presence of sea ice, and iron-deficient in the absence of sea ice. We surmise …

Depositional Environment And Sequence Stratigraphic Interpretation Of Miocene St. Marys Formation, Calvert County, Maryland, John J. Blandin

OES Theses and Dissertations

The Miocene St. Marys Formation at Calvert Cliffs, Maryland is divided into four depositional packages made up of marine fades representing shallow shelf through intertidal conditions. These depositional packages are separated by five laterally persistent surfaces and were defined based on detailed depositional fades analysis of 24 measured sections, averaging 17 meters thick. These four packages make up two marine sequences, stratigraphic units bound above and below by surfaces of sea level fall. The lower sequence is composed of a single depositional package, while the upper sequence is composed of three upward-shallowing depositional packages (i.e. para-sequences). A fifth depositional package …

Comprehensive Conjunctive-Use Management Of Connected Surface Water Groundwater Systems Using Stochastic Inputs And Uncertainties, Seshadri Suryanarayana

Civil & Environmental Engineering Theses & Dissertations

A comprehensive conjunctive-use management model is developed. The dynamics of flow and solute transport processes in connected surface water groundwater systems are integrated by a dual programming management model. The governing aquifer flow parameters and streamflows are treated as stochastic random processes. Multiple realizations of the random field are generated and are explicitly incorporated in a non-linear optimization model along with other system, environmental, and management constraints. To facilitate management of large aquifer systems, a linked simulation-optimization approach is used. The simulation program generates the response matrices for flow and transport processes. The management model then determines optimal well discharges …

A One-Dimensional Model For Storm Breaching Of Barrier Islands, Cheol Shik Shin

Civil & Environmental Engineering Theses & Dissertations

A set of numerical models is developed for simulating the four stages of barrier breaching characterized by one horizontal spatial dimension.

The SBEACH model is employed for the first stage of dune/beach erosion. The Lax-Wendroff two-step explicit scheme for Stage II is developed to simulate initiation of ocean flood propagation on initially dry barrier islands and the method of characteristics (MOC), is employed to compute additional boundary data. The development of the Preissmann implicit scheme for water motion and a forward time centered space explicit scheme for sediment motion in Stages III and IV provide a tool to study the …

Observation Of Shelfwater Overrunning The Southern Slope Sea, Ajoy Kumar

OES Theses and Dissertations

Analyses of two years (1992 and 1993) of high resolution (1.47 km²) sea surface temperature satellite images of the southern Mid-Atlantic Bight (MAB), showed that unusually extensive overhang of shelf water occurs episodically, and coherently over along shelf distances of several hundred kilometers. These episodes are dubbed overrunning of the Slope Sea by shelf water. The overrunning volume has a "face" and a "back" (southern and northern limit). It transports substantial quantities of shelf water southward, and does not retreat onto the shelf, but eventually joins the western edge of the Gulf Stream in the vicinity of Chesapeake …

Factors Affecting Nitrogen Fixation Rates In Termites (Isoptera: Rhinotermitidae: Reticulitermes) And Termite Nitrogen Contributions Of Forest Ecosystems, Anthony Duane Curtis

Biological Sciences Theses & Dissertations

Termites host symbiotic bacteria that fix atmospheric nitrogen, which makes termites important in the biogeochemical cycling of nitrogen in ecosystems. The objective of this study was to estimate annual nitrogen contributions by termites by examining seasonal rates of nitrogen fixation, seasonal abundance of different termite castes and their nitrogenase activity, the effects of dietary nitrogen on nitrogenase activity, and low oxygen and high carbon dioxide atmospheres on termite nitrogenase activity, and the accuracy of mark-recapture studies to estimate termite population size.

Termite nitrogen fixation rates were monitored monthly for 10 Reticulitermes Holmgren colonies from June, 1993, to December, 1995. Rates …

A Coupled, Non-Linear, Steady State Model For Early Diagenetic Processes In Pelagic Sediments, Surya P. Dhakar, David J. Burdige

OES Faculty Publications

A steady state, coupled, non-linear model has been developed for early diagenetic processes in pelagic and hemi-pelagic marine sediments. Model results show that the occurrence of oxic and sub-oxic diagenetic processes is significantly affected by variations in parameters such as the sedimentation rate, bioturbation coefficient, sediment porosity, and organic matter flux to the sediments. Increases in the sedimentation rate or the bioturbation coefficient increase organic matter oxidation by sub-oxic processes, whereas an increase in sediment porosity decreases organic matter oxidation by sub-oxic processes. Sediment data from three contrasting MANOP sites are fit reasonably well with the model. The resulting best-fit …

Biogenic Matter Diagenesis On The Sea Floor: A Comparison Between Two Continental Margin Transects, William M. Berelson, Jim Mcmanus, Kenneth H. Coale, Kenneth S. Johnson, Tammy Kilgore, David J. Burdige, Cynthia Pilskaln

OES Faculty Publications

Benthic chamber measurements of the reactants and products involved with biogenic matter diagenesis (oxygen, ammonium, nitrate, silicate, phosphate, TCO₂, alkalinity) were used to define fluxes of these solutes into and out of the sediments off southern and central California. Onshore to offshore transects indicate many similarities in benthic fluxes between these regions. The pattern of benthic organic carbon oxidation as a function of water depth, combined with published sediment trap records, suggest that the supply of organic carbon from vertical rain can just meet the sedimentary carbon oxidation + burial demand for the central California region between the …

Copper Complexation Capacity And Copper Speciation In Freshwater Lakes (Lake Western Branch And Lake Prince), Rachide Ibrahimo Abdul Sultana

Chemistry & Biochemistry Theses & Dissertations

This research examines the copper complexation capacity, copper speciation and dissolved copper concentrations in Lake Western Branch (WB) and Lake Prince (LP) both located in Suffolk, Virginia. These lakes are drinking water reservoirs for the cities of Suffolk and Norfolk, and they experience blooms of algae which can deplete them of oxygen and affect treatment of their waters for drinking. Copper sulfate has regularly been added to control the algae, but the effectiveness of these additions is uncertain. For environmental management implications, knowledge of speciation (i.e., the concentrations of the various chemical forms) is important in studying the effects of …

"A Geological Interpretation Of The Stanley Fault And Other Thrust Faults In Page County, Virginia", Michael James Sarros

OES Theses and Dissertations

Paleozoic carbonate rocks flooring Page Valley (within Page County) are overthrust by Precambrian to Cambrian elastic rocks of the Blue Ridge to the east of the study area. King (1950) recognized that the Cambrian carbonate sequence of Page Valley, near Stanley, Virginia, is broken by a large transverse fault which he named the Stanley fault. King (1950) interpreted the Stanley fault as a high-angle reverse fault with oblique-slip displacement. However, detailed mapping and structural data collected in this study indicate the Stanley fault is a low angle thrust fault which cuts all pre-Alleghanian and Early Alleghanian structures.

Two previously unrecognized …