Geology Commons^™

Foraminiferal Paleoenvironments Of The Eastover Formation (Upper Miocene Virginia), Joann H. Goshorn

OES Theses and Dissertations

Sixty-two taxa representing 29 genera from 39 foraminiferal sample pairs have been documented and analyzed in a paleoenvironmental study of the Eastover Formation in southeastern Virginia. The Eastover Formation consists of a lower Claremont Manor Member, a silt fine-grained sand and an upper Cobham Bay Member, a shelly fine grained sand. Planktonic specimens were rare and indicated a late Miocene to early Pliocene age for the Eastover Formation. Benthics were used to interpret paleoenvironments by comparison with data from the distribution of Recent foraminifera, species diversity, planktonic to benthic ratios, and sediment analyses. The foraminifera indicate that the Eastover Formation …

The Use Of Ilmenite Element Composition For The Determination Of Provenance, Yu W. Tsang

OES Theses and Dissertations

Fifty three samples were taken from three major rivers and their tributaries in Virginia: the James, Roanoke. and Potomac-Shenandoah Rivers. Samples were obtained from the Valley and Ridge. Blue Ridge and Piedmont provinces. The possible source rock types for these samples were determined by comparison of tributary ilmenite composition with drainage basin rock types. Ilmenite element concentration varied with different rock types. Ti was usually high for the ilmenite derived from non-mafic igneous rocks. Mg and Cr were high for the ilmenite from mafic igneous rocks. Zn was low for metamorphic ilmenite. The ilmenite from sedimentary rocks tended to have …

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 …

Tectonic Implications Of Late Tertiary Strata Exposed Along The Piankatank River, Eastern Virginia, Daniel Stephen Lane

OES Theses and Dissertations

Biostratigraphic analysis of Late Miocene and Pliocene strata along the Piankatank River in eastern Virginia exposes a juxtaposition of the Eastover and Yorktown Formations. This structure is situated on a NE trending alignment of geological, geomorphic, and geophysical features which run from southern Virginia to northern Delaware. Tectonic jointing in isolated sandstone bodies and fracture controlled drainage patterns provide further evidence of post-middle Pliocene tectonism in the region. The lateral spacing of this structure from the Stafford and Brandywine fault zones and other linear features on the Coastal Plain strongly implies that a structural similarity exists between the Piankatank structure …

Stratigraphy And Textural Analyses Of A Beach Ridge Complex, Cape Henry, Virginia, Daniel Leland Oyler

OES Theses and Dissertations

Eight lithological units, documented from the analyses of 26 boreholes, comprise five laterally extensive horizons in the subsurface of Cape Henry, Virginia. Interpretations of the environments of deposition for those units are based upon textural and compositional features, fossils, thickness and distribution of strata, and previous reports about late Tertiary and Quaternary deposits in nearby areas. The incised, Pliocene Chowan River Formation (Unit H) underlies Pleistocene Units F and G which are concentrated in a buried river valley beneath Cape Henry. Estuarine Units D and E resulted from a marine transgression of the study area during the early Holocene. The …

Trace-Elements In Ilmenite - A Way To Discriminate Provenance Or Age In Coastal Sands, Dennis A. Darby

OES Faculty Publications

Trace elements and Ti percentage in ilmenite grains magnetically separated from modern and late Pleistocene coastal sands of southeastern Virginia and northwestern North Carolina were used to distinguish different deposits. Multivariate analysis of ilmenite composition (Ti, Mn, Mg, Cr, V, Ni, and Cu) from coastal deposits and potential source rivers enabled the identification of dominant source rivers. Using the trace element content of one mineral instead of heavy-mineral suites eliminated most of the hydraulic sorting, selective weathering, and intrastratal solution problems that often obscure heavy-mineral provenance determinations. Most ilmenite grains lacked exsolution or twinning, which are common to ilmenite; however, …

Cluster Analysis Of Grain Size Parameters From A Beach Ridge Complex, Cape Henry, Virginia, Amy T. Robbins, G. Richard Whittecar

OES Faculty Publications

Cape Henry is a Holocene beach ridge complex at the mouth of the Chesapeake Bay. Analyses of cross-cutting relationships visible on aerial photographs divide the complex into five geomorphic zones. Low, arcuate beach ridges, ornamented in places with small dunes, characterize the four oldest zones. The youngest zone consists of large irregular-shaped dunes which bury the margins of all older zones. Locations of 102 samples taken from 1 m depths on ridge crests were based upon a random stratified sampling grid covering all of Cape Henry. The use of half-phi size data generated standard sediment parameters. Weighted-pair cluster analyses of …

Stratigraphy And Depositional Environments Of A Late Pleistocene Barrier Island Complex, Southeastern Virginia, Alan K. Jasper

OES Theses and Dissertations

The Norfolk, Kempsville, and Sand Bridge Formations beneath the HIckory Scarp of southeastern Virginia are reinterpreted as representing one glacio-eustatic transgressive cycle. The timing of this transgressive event is set during the earliest Wisconsinan. The formations were previously interpreted as unconformable overlying one another. The Norfolk-Kempsville unconformity is actually a diagenetic boundary. Evidence is presented which indicates that the Kempsville Scarp area should be reduced to member status or dropped entirely.

Geomorphology And Dynamics Of A Sand Wave In Lower Chesapeake Bay, Virginia, Gerardo Miguel Eduardo Perillo

OES Theses and Dissertations

A single, more or less isolated, sand wave in a sand wave field recently discovered in the lower Chesapeake Bay, Virginia, was studied intensively for morphology, sedimentology and in terms of dynamic processes. The morphologic investigation consisted of bathymetric surveys of the sand wave field and the specific sand wave. Twenty-five grab samples and four box cores were obtained from different segments of the feature studied. Textural parameters of the samples were determined, and a multivariate technique was utilized to identify subenvironments on the feature. The box cores provided information on the internal structure of the sand wave.

Observations of …

The Distribution Of Several Metals And Cation Exchange Capacity In Sediment Fractions From An Artificial And Natural Marsh, James River, Virginia, William Nivens

OES Theses and Dissertations

In order to examine the mechanisms by which Fe, Mn, Ca, Zn, Cu, Ni and Pb are bound in sediments, a sequential selective extraction procedure was employed on sediment samples collected at an experimental dredge disposal marsh and a neighboring natural marsh located near Windmill Point, James River, Va. The metal concentrations were determined in six phases, interstitial water, exchangeable, easily reducible (oxides of Mn), organic, moderately, reducible (oxides of Fe), and residual fractions. In addition, the cation exchange capacity (CEC) of the sediments was determined as well as the actual role of organics and colloidal iron coatings as they …

Sediment Interstitial Dissolved Mercury And Carbon Relationships In An Artificial And Natural Marsh, James River, Virginia, Apostolos Katsaounis

OES Theses and Dissertations

Thirty six sediment cores were collected during August, 1976 and January, 1977 in order to examine the relationships between dissolved organic carbon and total dissolved mercury in the interstitial water of two marshes located near Windmill Point, James River, 16 km downstream from Hopewell, Virginia. The Windmill Point marsh development site is a dredged material disposal island in the James River. The reference marsh which does not contain dredged material, is located 2.3 km upstream at Ducking Stool Point.

The concentrations of dissolved organic carbon and total dissolved mercury showed no significant difference between the two marshes. Trends in the …

The Effects Of Dredging On The Stability Of An Ebb-Tidal Delta, Lynnhaven Inlet, Virginia, Donald Keith Riggenbach

OES Theses and Dissertations

A channel was dredged in 1965 through the ebb-tidal delta of Lynnhaven Inlet, Virginia. The purpose of this study was to determine if this channel has affected the morphological configuration of the delta. It was proposed that the channel caused the dynamically stable delta to become unstable and change its morphology.

Bathymetric comparisons of seven surveys during the last 122 years, including one conducted during this investigation, show that prior to 1962 and the dredging operations, the delta had become dynamically stable. The present survey shows that the delta has changed its shape in response to the interaction of the …

Stability And Local Effects Of An Offshore Sand Storage Mound, Dam Neck Disposal Site, Virginia Inner Continental Shelf, William Joslyn Saumsiegle

OES Theses and Dissertations

From 1967 to 1974 medium to coarse sand dredged from the Chesapeake Bay was stockpiled approximately three miles offshore of Dam Neck, Virginia in hopes that the sand could be recovered for local beach renourishment projects. The resulting mound was surveyed over a two year period to determine if the sand is being removed by wave and current action and if the creation of a new feature on the ocean bottom changes the wave refraction patterns and perhaps creates local erosion.

Bathymetric profiles across the storage mound show some apparent morphological changes, but a detailed analysis of this data is …

Topography, Shallow Structure, And Sedimentary Processes Of The Atlantic Continental Slope Off The Carolina Coast, Robert Michael Fitchko

OES Theses and Dissertations

Analysis of 58 closely-spaced bathymetric and seismic profiles of the Carolina continental slope from the northern Blake Plateau to the vicinity of the North Carolina-Virginia state line (latitude 32• 30 'N to 36• 30 'N) indicates sharp contrasts in quantity of slumping and outcrop ledge continuity.

Terrestrial progradation and a relatively gentle slope characterize the area south of Cape Lookout, especially between Cape Romain and Cape Fear where sediment mantling is the greatest. Submarine canyons, slumps, and a steep slope are characteristic Between Cape Lookout and Cape Hatteras. North of Cape Hatteras, canyons and slumps are also common, though sediment …

Processes Controlling The Distribution Of Methane In The Cariaco Tranch, Venezuela, Denis A. Wiesenburg

OES Theses and Dissertations

Abstract unavailable.

An Investigation Of Littoral Transport Between Virginia Beach And Sandbridge, Virginia, Richard C. Cunningham Jr.

OES Theses and Dissertations

A method for calculating littoral transport, direct determination of the sediment flux, has been proposed and evaluated. Three sampling stations, located between Virginia Beach and Sandbridge, Virginia, were occupied for a period of thirteen months (September, 1972 to September, 1973). Measurements include velocity of the littoral current, cross-sectional area of the surf zone, and in situ samples of suspended and bottom sediment load. Observations of sea and atmospheric conditions were obtained. Two ways of calculating littoral transport were derived from the same basic method, thus two sets of transport values were generated. Two annual littoral transport values were calculated by …

Evolution Of Platt Shoals Northern North Carolina Shelf: Inferences From Areal Geology, Philip C. Sears

OES Theses and Dissertations

The evolution of Platt Shoals, a complex ridge and trough system on the south side of the Albemarle Shelf Valley, was determined and the modern hydraulic regime was inferred. The methods used were surficial grain size, 11 vibracores, seismic profiling and bathymetric maps. Platt Shoals developed in a three step process. The first, step was the formation of a substrate of late Pleistocene regressive deposits from 15,000 to 30,000 yr B. P. The second step, occurring approximately 11,000 yr B. P., was the formation of estuary mouth shoals of the ancestral Albemarle River. Between 4,4.00 to 5,000 yr B. P., …

Seismic Refraction Study Of Post-Pliocene Stratigraphy, Dismal Swamp, Virginia, William Brian Fraser

OES Theses and Dissertations

This study examines Pliocene-Pleistocene lithostratigraphy and the Yorktown unconformity within the Dismal Swamp by means of remote sensing analysis, Wyrobek-Gardner seismic refraction profiling and split-spoon coring. Pre-Sangamon fluvial/tidal channel deposits are not present and the Yorktown unconformity dips irregularly southeastward at 0.35 meters/kilometer (2 feet/mile) from a high at 4 meters above sea level to a low of -1 meter (+12 to -2 ft) below sea level. The marker velocity for the Yorktown Formation is 1600 mps (5250 fps) and regression of seismic depths of the Yorktown Formation with corresponding split-spoon depths yields a high correlation. Short line upper layer …

Grain Size Reconnaissance Of The Virginia-North Carolina Inner Shelf Analysis By Settling Technique, Robert Bailey Sanford Jr.

OES Theses and Dissertations

The 2-fold purpose of this study is to calibrate a Rapid Sediment Analyzer and to use it to aid in the determination of the genesis of sediment on the inner continental shelf between Cape Henry and Cape Hatteras. Rapid Sediment Analyzer calibration was conducted by comparison of sieving and settling results of similar sands.

The study area was divided into sediment provinces by both a qualitative procedure (grain size and topography) and a quantitatively procedure (factor-vector analysis). Qualitative provinces are beach and surf, upper shore face, lower shore face, sea floor, and terminal shoals. The berm fines from each terminal …

A Fluorescent Tracer Study At A Tidal Inlet (Rudee Inlet, Virginia), James W. Bunch

OES Theses and Dissertations

Patterns and approximate rates of littoral transport south of Rudee Inlet. Virginia were investigated with fluorescent tracers. Sand movement was traced under a variety of longshore current and wave conditions. Patterns of tracer dispersal reflected the importance of wave height, breaker angle, and longshore current velocity on modes of littoral transport. A direct relationship between angle of breaker incidence. generated longshore current. and direction of tracer sand movement was found. Onshore offshore paths were taken by tracer material during periods of weak longshore currents and small breaker angles while alongshore paths were followed by tracer material during strong longshore currents …