The goal of this investigation was to determine whether highly accurate sampling and dating methods could be employed to develop a high-resolution history of barrier evolution and sea-level change. The focus of the study was St. Vincent Island, an undeveloped barrier island beach ridge plain in the northeastern Gulf of Mexico. The island consists of more than 100 beach ridges organized into a dozen groups or sets based on their topographic expression and geographic pattern. These ridges represent sequential paleo-shoreline positions over the 4000+ year history of the island. Given the long-term tectonic stability of the northern Gulf of Mexico throughout the Quaternary, the island holds the potential for a unique high-resolution chronology of mid- to late-Holocene sea-level change. The sampling of the beach ridges by means of trenches, rather than just cores, allowed for the collection of basal deposits as well as visual confirmation of the origin and structure of the ridges. Ground penetrating radar (GPR) profiles confirmed the origin and structure of the ridges. Based on these techniques it is evident that the beach ridges on the island were built by swash processes rather than by storms. The direct dating of quartz grains collected from the base of several of the islands beach ridges via optically stimulated luminescence dating (OSL) provided an accurate measure of the depositional ages of the ridges. The ridges on St. Vincent Island have ages ranging from zero to 4,100 years, with the oldest ridges on the north side of the island and the youngest ridges on the southeast side of the island. These ages can be correlated with the most recent sea level curve produced for the northern Gulf of Mexico. These ages have also been used in conjunction with topographic maps, leveling or topographic profile surveys and LIDAR data, to calculate the rates of beach ridge plain progradation and beach ridge formation over time. Results show that during times of sea level fall, the progradation rates on St. Vincent Island were relatively fast while during times of sea level rise, rates were considerably slower. The result of this project is a better and more detailed understanding of the influence of sea-level change on barrier island development. / A Dissertation submitted to the Department of Geological Sciences in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Spring Semester, 2007. / April 2, 2007. / Sea Level, St. Vincent Island, Barrier Island Evolution, Beach Ridges, Gulf of Mexico, Sea Level, Holocene / Includes bibliographical references. / Joseph F. Donoghue, Professor Directing Dissertation; Philip N. Froelich, Outside Committee Member; Sherwood W. Wise, Committee Member; Sergio Fagherazzi, Committee Member; Stephen A. Kish, Committee Member; Alan W. Niedoroda, Committee Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_182544 |
| Contributors | Forrest, Beth M. (Beth Margaret), 1978- (authoraut), Donoghue, Joseph F. (professor directing dissertation), Froelich, Philip N. (outside committee member), Wise, Sherwood W. (committee member), Fagherazzi, Sergio (committee member), Kish, Stephen A. (committee member), Niedoroda, Alan W. (committee member), Department of Earth, Ocean and Atmospheric Sciences (degree granting department), Florida State University (degree granting institution) |
| Publisher | Florida State University, Florida State University |
| Source Sets | Florida State University |
| Language | English, English |
| Detected Language | English |
| Type | Text, text |
| Format | 1 online resource, computer, application/pdf |
| Rights | This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). The copyright in theses and dissertations completed at Florida State University is held by the students who author them. |
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