HR: 11:40h
AN: OS32C-02    [Abstracts]
TI: Defining the Chronostratigraphic and Seismic Stratigraphic Framework of the Albemarle Embayment: A Passive Margin Record of Quaternary Sea Level Changes
AU: * Mallinson, D J
EM: mallinsond@mail.ecu.edu
AF: Dept. of Geology, East Carolina University, Graham Bldg., Greenville, NC 27858 United States
AU: Culver, S
EM: culvers@mail.ecu.edu
AF: Dept. of Geology, East Carolina University, Graham Bldg., Greenville, NC 27858 United States
AU: Riggs, S
EM: riggss@mail.ecu.edu
AF: Dept. of Geology, East Carolina University, Graham Bldg., Greenville, NC 27858 United States
AU: Thieler, E R
EM: rthieler@usgs.gov
AF: United States Geological Survey, Coastal and Marine Program 384 Woods Hole Rd., Woods Hole, MA 02543 United States
AU: Foster, D
EM: dfoster@usgs.gov
AF: United States Geological Survey, Coastal and Marine Program 384 Woods Hole Rd., Woods Hole, MA 02543 United States
AU: Wehmiller, J
EM: jwehm@udel.edu
AF: Dept. of Geology, University of Delaware, Newark, DE 19716 United States
AU: Farrell, K
EM: kathleen.farrell@ncmail.net
AF: North Carolina Geological Survey, 4100-A Reedy Creek Rd. , Raleigh, NC 27607 United States
AB: New seismic and core data, combined with amino acid racemization age data, radiocarbon age data, and optically stimulated luminescence age data are being used to define the Quaternary fill history of a passive margin coastal embayment; the Albemarle Embayment on the U.S. mid-Atlantic margin. Data reveal multiple depositional sequences with varying degrees of preservation and varying characteristics (thickness, extent, geometry, etc.) which are a function of age and depth within the embayment. A distinct change in depositional character occurs in the middle Pleistocene, possibly in response to a change in sea level periodicity and amplitude. A structure of particular significance is an early Pleistocene paleotopographic high and possible lowstand coastal deposit beneath Cape Hatteras. The high is designated the Cape Hatteras High (CHH), and appears to exert a control on the trend of the modern shoreline. Seismic and foraminiferal paleoenvironmental data indicate a regressive coastal facies consisting of inner shelf sand that was deposited on the eastern flank of the CHH. The depth and location of this shoreline suggest that this system is an early Pleistocene mainland-attached lowstand strandplain shoreline. An open-shelf paleo-embayment occurred to the north of the CHH, and was filled during middle to late Pleistocene sea-level highstands. A complex system of valley-fill is evident in the southern portion of the study area, indicating dissection of the CHH multiple times during middle to late Pleistocene sea-level lowstands.
DE: 3002 Continental shelf and slope processes (4219)
DE: 3025 Marine seismics (0935, 7294)
DE: 3045 Seafloor morphology, geology, and geophysics
SC: Ocean Sciences [OS]
MN: Fall Meeting 2005