Southeastern Section–56th Annual Meeting (29–30 March 2007)

Paper No. 9
Presentation Time: 10:40 AM


OERTEL II, George F., Ocean, Earth and Atmospheric Sciences, Old Dominion Univ, Elkhorn Av, Norfolk, VA 23529, ALLEN, Thomas R., Geography, East Carolina University, Greenville, NC 27858, FOYLE, Anthony M., School of Science, Penn State Erie - The Behrend College, Station Road, Erie, PA 16563-0203 and MCLEOD, George, Ocean, Earth and Atmospheric Sciences, Old Dominion University, Norfolk, VA 23528,

A major offset in the Virginia coastline exists between Assateague Island and Wachapreague Island. The offset produces a broad bight anchored by the cape-like southern tip of Assateague Island and the northern tip of Parramore Island. The bight is located directly south of Chincoteague Island and Chincoteague Bay and is hereby designated as the "Chincoteague Bight".

Several explanations involving differential rates of erosion linked to wave-energy distribution have been offered for the creation of Chincoteague Bight. We believe that other factors may have had a strong influence on the development of this part of the Virginia coast. Seismic and geomorphic data suggest the offset might be explained by the strong influence of antecedent drainage patterns on transgressive processes. Watersheds along the northern margin of the Chesapeake Bay have spatial characteristics that were used to reconstruct transgressed systems on the continental shelf. Paleochannels beneath the inner shelf were used to orient the transgressed watersheds, and to locate and define paleo-drainage characteristics.

The Chincoteague Bight is believed to be partially controlled by the oblique intersection of the Chincoteague Paleovalley and the Atlantic coastline. The axis of Chincoteague Bay is on a bearing of (23º- 203º) and has an average flooded valley width of about 9.25 km. The coastline has a bearing of about 213º. Projecting the coastline across Chincoteague Bay produces a "stretched" valley-section that is about 4.5 times the width of a perpendicular section. Since the width of Chincoteague Bight is comparable to the width of the stretched valley section, we believe that the Bight is at least partially influenced by the unique intersection of the coastline and the paleovalley. South of Chincoteague Bight, seismic tributary patterns flow northeast providing additional validation for valley location.