Holocene inner continental shelf stratigraphy, micropaleontology and paleoenvironmental change off the Outer Banks, North Carolina / by Christopher Stanton.
| Author/creator | Stanton, Christopher author. |
| Other author | Culver, Stephen J., degree supervisor. |
| Other author | Mallinson, David J., degree supervisor. |
| Other author | East Carolina University. Department of Geological Sciences. |
| Format | Theses and dissertations |
| Production | 2008. |
| Description | 182 leaves : illustrations (some color), maps (some color) ; 29 cm |
| Supplemental Content | Access via ScholarShip |
| Subjects |
| Summary | Holocene paleoenvironmental change of the inner continental shelf east of the Outer Banks, North Carolina was investigated using lithological, foraminiferal, chronological (AMS radiocarbon age estimates) and geochemical data from 23 vibracores. Four litho/biofacies were identified in six approximately shore-perpendicular transects between Oregon Inlet and Cape Hatteras, North Carolina. These data were considered within a shallow seismic framework. An open marine, inner continental shelf facies, characterized by muddy and shelly sand, contains a normal marine foraminiferal assemblage dominated by Elphidium excavatum with abundant Elphidium subarcticum, Nonionella atlantica. Ammonia parkinsoniana and Hanzawaia strattoni. A second normal marine, inner shelf sand facies was also dominated by Elphidium excavatum, but contained abundant Quinqueloculina seminula, Quinqueloculina lamarkiana and Quinqueloculina jugosa. A high salinity estuarine facies characterized by muddy sediments contained a foraminiferal assemblage dominated by Elphidium excavatum and Ammonia parkinsoniana with Elphidium galvestonense and Haynesina germ̀nica as secondary taxa. A fourth facies, characterized by Elphidium excavatum or Elphidium galvestonense, or both, was interpreted based on lithology. Muddy lithology indicated a high brackish estuary; sandy lithology indicated a normal nearshore, inner shelf facies. Seismic profiles revealed a relict drainage system which became an estuarine system as Holocene sea level rose. Five of the 23 vibracores contained muddy estuarine deposits associated with the drainage system. AMS radiocarbon age estimates on oyster shells found in muddy estuarine sediments indicate that initial flooding of the relict drainage occurred approximately 11,000 yrs BP. Seismic data within the study area show chaotic, high amplitude reflections associated with relict river profiles, as well as, the high amplitude reflection of the ravinement surface of a transgressive systems tract. Litho/biofacies data of five cores correlated with the low amplitude reflections within the channel infill and were indicative of estuarine conditions and interbedded mud associated with flooded river evolution. Overall trends from geochemical analysis of four cores indicate a system with terrestrial and marine influences that show increasing marine dominance through time. All 23 vibracores have a sand cap that correlates with high amplitude seismic reflections associated with the sediment water interface. The reflector ranges between 0.5 and 1 meter in depth (average), the base of which is interpreted as the Holocene ravinement surface due to the litho/biofacies and geochemical data taken from surficial samples that indicate dominant normal marine, inner shelf facies. Lithologic, foraminiferal, geochemical and geophysical data indicate that a latest Pleistocene fluvial system existed on the current inner continental shelf off the northern Outer Banks. As sea level rose, the system flooded around 11,000 yrs BP and became estuarine for approximately 4,000 yrs before open marine, inner shelf conditions prevailed. This drainage system was not an extension of paleo-Pamlico Creek that underlies modem Pamlico Sound, but rather a separate latest Pleistocene drainage that evolved to become an estuary prior to and eastward of Pamlico Sound. |
| General note | Presented to the faculty of the Department of Geological Sciences. |
| General note | Advisor: Stephen J. Culver |
| General note | Advisor: David J. Mallinson |
| Dissertation note | M.S. East Carolina University 2008 |
| Bibliography note | Includes bibliographical references (leaves 108-125). |
| Genre/form | dissertations. |
| Genre/form | Academic theses. |
| Genre/form | Academic theses. |
| Genre/form | Thèses et écrits académiques. |
Availability
| Library | Location | Call Number | Status | Item Actions |
|---|---|---|---|---|
| Joyner | University Archives | ASK AT SPECIAL COLLECTIONS DESK | ✔ Available | Request Material |
| Electronic Resources | Access Content Online | ✔ Available |