The Department of Geology and Environmental Science proudly presents the

2008 Student Research Symposium

April 25, 2007
9:30 AM - 3:00 PM Memorial Hall 6125

A FAUNAL AND PALEOCOMMUNITY ANALYSIS OF THE YORKTOWN FORMATION
Holly Fitzgibbon & Dr. Lynn Fichter

A faunal and paleocommunity analysis was conducted for the Lieutenants Run outcrop of the Pliocene Yorktown Formation (4.2 Ma) behind A.P. Hill Elementary School in Petersburg , Virginia (37°12'17”N 77°24'48”W; 96 feet elevation.) Study area was a roughly 900 foot drainage gully. Present are three members of the Yorktown Formation: Rushmere, Morgarts Beach , and Moore House. The highly fossiliferous Rushmere is a cohesive clay, brownish-grey or copper colored when weathered, gunmetal grey on fresh surface, containing dense communities of Turritella. Up section the Turritella decrease and larger predatory animals began to appear. The Rushmere Member grades into the fine sandy/clayey Morgarts Beach Member, rich tan or white in color; containing the majority of the fossils, including many large and small bivalves. The section is capped by the Moore House Member composed of sand and rounded pebbles with few or no fossils. Thirty-eight species of invertebrate fossils were found from the Rushmere and Morgarts Beach Members, including:

Preservation varied greatly; the large, common, bivalves, such as Chesapecten madisonius and Mercenaria tridacnoides rileyi (both from the Morgarts Beach Member) were among the best preserved and most abundant. The predatory snails Ecphora quadricostata and Busycon maximum were among the most uncommon, and were also among the least well preserved. The species collected from both members fall into a range of feeding strategies and comprise only a small fraction of all the fossils documented from the Yorktown Formation. The clayey Rushmere Member was deposited in the middle neritic zone in several meters of calmer water. The fine sandy, very fossiliferous Morgarts Beach Member was deposited in a shallower more energetic environment such as the inner neritic zone. The well washed and fossil sparse sandy/cobbly Moore House Member was deposited in a shallow environment with strong and/or steady currents. These members of the Yorktown formation at this locality trace a regressive sequence of the ocean off of Virginia 's coastal plain.

HURRICANE IVAN: A CASY STUDY OF LARGE STORM-GENERATED WAVES
Thomas Fortune and Dr. Stan Ulanski

Using data from the National Data Buoy Center (NDBC) buoys in the Gulf of Mexico, this study examines the extreme waves generated by Hurricane Ivan.—a powerful category V hurricane . In particular, I will summarize the wave properties, including height and period, on the left and right sides of the hurricane to determine if there is a significant difference in these properties as a function of the hurricane's track. Wave-generating factors to be studied include the following: wind speed, direction, duration, fetch, and hurricane translational speed. Each of these factors will be analyzed in depth to isolate their relative importance in causing sea conditions that are of major importance to military operations and civilian coastal zone management.

THE IMPACT OF URBAN DEVELOPMENT AND TIDAL INTERACTION ON THE AQUEOUS GEOCHEMISTRY OF THE CHESAPEAKE BAY ESTUARINE ENVIRONMENT IN NORFOLK , VA.
Jennifer L. Shelburne and Steve J. Baedke

Estuary environments in populated areas are vulnerable; the connection between the open sea and industrially influenced river waters contribute to their susceptibility. Urban runoff discharged into an estuary system cause huge problems; pollution in the surface water is transported to the ocean where these sensitive ecosystems are damaged. Contaminated waters moving into the estuary have a negative effect not just on water quality itself, limiting consumption, but also on the aesthetics of the area, such as when pollutants cause bacteria to proliferate at accelerated rates. When pollutants enter these systems recreation is hindered, wildlife suffers, and commercial interests diminishes as a result of biological contamination to sea life.
The Chesapeake Bay is an example of a locality that is both naturally impaired due to the coastal nature of the estuary, as well as being impaired by anthropogenic influences. Differentiating between human caused versus natural impairment, though, is often problematic. For instance, in 2006, the Department of Environmental Quality designated 2,212 square miles of the Chesapeake Bay as being impaired, with 351 square miles being recently impaired but the causes of the impairment are difficult to measure. This research examines how the water quality of the Chesapeake Bay area around Norfolk , Virginia , is impacted by urbanization. Water samples have been collected from eight different locations along the eastern branch of the Lafayette River . Anion and cation concentrations of the water samples will be compared with historical water quality data in hopes of establishing a relationship between the tidal changes, land uses, and the over all water chemistry.

THE USE OF AQUEOUS GEOCHEMISTRY AS AN INDICATOR OF FLOW SYSTEM INTERACTION WITHIN A BEACH-RIDGE COMPLEX OF LAKE HURON
HODGES, Amanda L. 1 , DEGRAZIA, Lisa C. 1 , BAEDKE, Steve J. 1 , THOMPSON, Todd A. 2 , and WILCOX, Douglas A. 3 , (1) Dept. of Geology and Environmental Science, James Madison University, MSC 6903, Harrisonburg, VA 22807, degrazlc@jmu.edu, (2) Indiana Geological Survey, Indiana University, 611 North Walnut Grove, Bloomington, IN 47405, (3) Great Lakes Science Center, U.S. Geol Survey, 1451 Green Road, Ann Arbor, MI 48105

The interaction between groundwater and surface-water systems is a fundamental component of the hydrology, development, and persistence of wetlands found within beach-ridge filled embayments around the Great Lakes . The nature and type of interactions between these flow systems can be viewed as occurring within a hydrologic continuum between local (shallow) flow systems and regional (deep) flow systems. We collected 70 samples from “wetland” surface water and shallow groundwater wells driven into the upper aquifer in Albert E. Sleeper State Park near Caseville , Michigan . The samples were distributed along a transect of 55 beach ridges originating at Lake Huron and extending approximately 1500 meters inland to ridges of Nipissing age. All 70 samples collected have been analyzed in the field for parameters of specific conductance, temperature, pH, Eh, and alkalinity. The samples are also being analyzed for major ions of K⁺, Na⁺, Ca²⁺, Mg²⁺, F^-, NO^3-, SO₄^2-, Cl^-, PO₄^3- , and isotopes of oxygen and deuterium.

Mercury Contamination of Floodplain Soils along the South River, Shenandoah Valley, Virginia
Alyssa K. Melberg, Steve J. Baedke, and L. Scott Eaton

Mercury contamination has resulted in the declared impairment of over 8,500 bodies of water across the United States . Although low levels of mercury are deposited from natural emissions, the main source of environmental contamination is anthropogenic activity, which contributes thousands of pounds of mercury into the water and atmosphere each year. Over time, aerially transported mercury is deposited onto the Earth's surface where it bioaccumulates and endangers the health of aquatic ecosystems.

Mercury contamination of the South Fork of the Shenandoah River, and its tributary, the South River is a direct result of the use of mercury in the production of fibers at E.I. du Pont de Nemours in Waynesboro, VA. The use of mercury at Dupont spanned from 1929 to 1950, releasing an estimated thousands of pounds of mercury into the South River . Following the discovery of the contamination in 1976, preliminary samples were collected that found the levels of mercury in fish exceeded the EPA's limit. In addition to mercury within the organisms, the contamination was spread throughout the surrounding soil and floodplains.

Studies conducted by the State Water Control Board (now known as Virginia Department of Environmental Quality) are supported by a trust fund established by Dupont in 1984. The two organizations collaborated to develop the 100-year sampling plan to monitor the contamination with the intention that mercury concentrations would dissipate over time. Soil sampling was conducted in 1980, 1987, and 1997 and confirmed the presence and persistence of contamination along the South River and the South Fork Shenandoah River with the greatest concentrations residing in the floodplains immediately downstream of the Dupont plant. Despite a slight decrease in concentrations between 1980 and 1987, there has been no general decreasing trend from 1987 to 1997, suggesting that much of the contamination is immobile.

Soil samples have been collected from several transects along the South River , beginning upstream at Waynesboro to Port Republic . The samples will be acid digested and analyzed for total mercury concentration. Results of the analysis will be compared to mapped soil survey data to determine the control of grain size on the retention of mercury, and thus, distribution of mercury in floodplain sediments. In addition, downstream mercury concentrations will be mapped and compared to historical data.

SUBSURFACE STRATIGRAPHY AND AQUEOUS GEOCHEMISTRY AS INDICATORS OF HYDROLOGY IN BEACH-RIDGE COMPLEXES: A CASE STUDY FROM THE UPPER GREAT LAKES  
Sean Porse and Dr. Steve Baedke  

Surface-water and groundwater systems can be viewed as representing end members of a hydrologic continuum that exists between local (shallow) flow systems and regional (deep) flow systems. In beach-ridge filled embayment throughout the Great Lakes , the extent to which these flow systems interact is a primary control on hydrology. The linkages between these flow systems, however, are poorly understood and conventional methods of investigation (including groundwater modeling and water level measurements) may fail to quantify these interactions.   We have used an integrated approach of water sampling for aqueous chemical indicators and groundwater flow modeling to study Lake Superior State Forest in St.Vitals Bay, MI. Samples from surface water and groundwater wells installed into the upper aquifer were analyzed for field parameters and major ions (specific conductance, temperature, pH, Eh, and alkalinity).Samples were distributed along transects originating at the Lake Huron beach and extending 1800 meters inland. Final results from work at St. Vitals Bay shows that we can identify end members of the hydrologic continuum at each site using water chemistry indicators. Furthermore, the distribution of flow systems is influenced by the presence or absence of low conductivity zones (clay layers) that are indicated by data collected from ground penetrating radar, vibracores, continuously recorded pressure transducers, and aqueous geochemistry.

PRACTICAL APPLICATIONS AND PROBLEMS USING DELTANU ® PORTABLE RAMAN SPECTROMETER FOR MINERAL ANALYSIS
J. L. Yakob and L. E. Kearns

A portable Raman spectrometer was recently developed by DeltaNu ® to provide a new resource for the field mineralogist. This instrument provides nondestructive identification of minerals. The spectrometer measures the shift in energy (Raman shift) between the 785 nm wavelength laser beam and reflected light due to interactions with the mineral's structure. Minerals can be identified by comparing the acquired Raman pattern to standard patterns in a mineral database. The device's small size allows for the user to analyze samples of various positions and shapes.

A total of 597 mineral samples were analyzed using the DeltaNu ® portable Raman spectrometer. The purpose of this study was to determine which mineral groups can be accurately identified with high confidence using this particular Raman spectrometer. Analyses include samples from the following classes or subclasses: carbonates, halides, sulfates, nesosilicates, sorosilicates, cyclosilicates, inosilicates, phyllosilicates, and tectosilicates. In addition, outcrop-style specimens were analyzed. Phenocrysts and porphyroblasts in hand samples of rock were analyzed to simulate outcrop conditions.

Results show that some mineral groups are identified more consistently than others. Reasons for misidentifications include induced sample fluorescence, micro-inclusions, exsolution, symmetry, structural anomalies, chemical zoning, specimen polarization, and the absence of a mineral species in the database. In some cases, a mineral may be correctly identified but with poor confidence. Misidentified minerals are typically matched to spectral patterns in the database having a low signal-to-noise ratio without distinctive peaks. For minerals whose patterns are not in the database, their spectra can be added to the database. However, adding the spectra should only be done if the spectrum has a relatively high signal-to-noise ratio. The addition of spectra to the database may increase the number of correctly identified minerals.

WATER CONTENTS OF YELLOWSTONE MAGMAS ESTIMATED FROM HYDROXYL CONCENTRATIONS IN FELDSPAR PHENOCRYSTS
SHEPHERD, Hannah V. and JOHNSON, Elizabeth A.

The water contents of five eruptions of Yellowstone Volcano, Wyoming, (Headquarters Flow, Blue Creek Flow, Lava Creek Tuff, Biscuit Basin Flow, and Canyon Flow) were estimated using measurements of structurally incorporated hydroxyl (OH) in feldspar phenocrysts. Hydroxyl concentrations were shown to be related to magmatic water concentrations in a previous study of feldspars from the 1980-81 eruptions of Mount St. Helens (Johnson 2005 GCA 69:A743).

Feldspars from the Yellowstone samples were separated from the rock matrix by crushing and picking individual crystals, and were identified using an optical microscope. The feldspar phenocrysts were prepared for infrared analysis by creating two perpendicular doubly-polished thick sections of each crystal. Polarized infrared spectra were obtained at 4 cm -1 resolution using the microscope accessory on the Varian Digilab Excalibur FTS 3000 Fourier-Transform Infrared (FTIR) spectrometer in the Department of Mineral Sciences at the National Museum of Natural History, Smithsonian Institution, Washington, D.C. Hydroxyl concentrations were determined using the calibration from Johnson and Rossman (2003; Am Min v.88, 901-911).

Formation of layered manganese oxide stream deposits near the Skyline coal mine complex, southeastern Tennessee
Kathy Bordwell and Dr. Elizabeth Johnson

The Skyline coal mining company began strip mining operations in southeast Tennessee near Fall Creek Falls State Park in 1987. The mines were shut down for three days in 1992 due to a noticeable change in the color of the water in nearby streams. The mines ceased operation in 1999. Thick, layered manganese oxide deposits were found in Spring Branch Creek below the mines. We studied the layers in the black crusts to see if they recorded a history of the water chemistry in the area. Two thick sections of the manganese oxide crust were characterized using digital images obtained on a petrographic microscope, powder X-ray diffraction, and Scanning Electron Microscopy ( SEM ). Water chemistry data were collected upstream and downstream of the manganese oxide crusts by Brent Means from the Office of Surface Mining, Harrisburg , PA. A series of distinct bands is repeated in each layer of the manganese oxide crusts. Light colored bands contain calcite that grew in a coarse grained radial texture. Thin dark bands contain a calcium-rich manganese oxide mineral called buserite, and graded bands contain a mixture of calcite and buserite as well as clay minerals. A sequence of light and dark bands is repeated about seven times, the number of years of active mining after 1992. The thin manganese rich layers contain imprints of diatoms. If we can determine the species of diatom, we might learn more about the timing of mineral deposition in the stream. The pH was the same at the top and bottom of the stream and the Mn concentration in the stream water increased from top to bottom. Changes in water chemistry, maybe caused by interaction between groundwater and mine drainage, likely caused the bands of calcite and manganese oxides to form.

CHEMICAL ANALYSIS OF MARS SURFACE MATERIALS
Kaitlyn Ruvel and Dr. Eric Pyle

Specific data collected from NASA's Mars Exploration Rover (MER) Mission website reveals much about the surface materials of the planet. Mars' surface was thought to be composed of dust and volcanic rocks, however research from the MER analysis toolkit has shown evidence for a variety of sedimentary material. The two rovers, Spirit and Opportunity , landed on Mars on the 3 rd and 24 th of January in 2004 at different locations. Spirit landed in Gusev Crater and Opportunity landed in Meridiani Planum. Data, collected from an alpha proton x-ray spectrometer (APXS), returned major element oxides and is defined as either rock surface, abraded rock surface (using the Rock Abrasion Tool, or RAT), or soil. The information gathered can be used for comparing Mars' surface materials to that of Earth, as well as identifying possible relationships in the evolution of surface materials. Harker variation diagrams were generated, plotting oxides versus silica, and were used for comparison with the data collected throughout the first 701 sols. With these diagrams of major oxide analysis, it is possible to distinguish different surface materials on Mars. Distinctive clusters of data of the RAT rock surfaces are visible for both rovers. These abraded surfaces provide the clearest data, providing a fresh, unweathered surface. The soil data collected should resemble the rock surface data gathered, but this determination cannot be made until more data is released.

Application of Sub-surface Instruments in Search of Historical Foundations Related to Meriwether Lewis and Family in Charlottesville, Virginia
Blair Benson and Dr. Mike Harris

Current research is being done in hopes of finding the old foundation of the carriage house or ice house at the original Meriwether Lewis house in Charlottesville , VA. This research is using two forms of sub-surface applications: ground penetrating radar (GPR) data and magnetometer data. These geophysics survey techniques have become valuable new tools in the archaeology field, since they allow researchers to survey sites without disturbing the ground. Five separate grids have been explored using the GPR, along with two grids using the magnetometer. Analysis of the data so far suggests that: (1) the foundation of the ice house may not have been constructed out of materials other than packed soil, hay, etc. and so therefore there may not be any evidence of its existence anymore besides disturbed soil; (2) there is an anomaly roughly 10-12 meters long alongside the southwest border of the section being measured whose intensity ranges around 52,500 – 53,000 nT. This anomaly is possibly linked to the existence of an old carriage house or ice house foundation, most likely an old pipe used for drainage. This is an important discovery, because it may be the only evidence left of any old foundations or structures that used to exist in this area. Overall, the magnetometer has proved very useful for initial surveying of a site, but the Ground Penetrating Radar is best for a more detailed or in depth look to what's below the surface.