Paper No. 1
Presentation Time: 12:00 AM


PIERCE, Courtney N.1, HAWKES, Andrea D.2, TEDICK, Amanda M.1, DONNELLY, J.3, EVANS, Rob L.3, ASHTON, Andrew D.3 and LANE, Chad4, (1)Geography and Geology, University of North Carolina Wilmington, 601 South College Road, Wilmington, NC 28403, (2)Geography and Geology, University of North Carolina Wilmington, 5600 Marvin K. Moss Lane, Wilmington, NC 28409, (3)Geology and Geophysics, Woods Hole Oceanographic Institution, 360 Woods Hole Rd, Woods Hole, MA 02543, (4)Geography and Geology, University of North Carolina Wilmington, 601 S. College Rd, Wilmington, NC 28403,

A 5000-year record showing relative sea-level rise was reconstructed using fossil foraminiferal assemblages found in a salt marsh bordering Choctawhatchee Bay, in the panhandle area of Florida. The relative sea-level record will be developed from a continuous 3 m peat core and 5 basal peats overlying a basal sand deposit. Peats retrieved from basal contacts are unlikely to have been significantly vertically displaced by autocompaction and age dating similar depth basal peats and long cored peat horizons can be used to derive whether autocompaction has occurred in the long core.

Modern transects spanning from the upland to the intertidal zone will be used to determine the distribution of modern foraminifera relative to the duration and frequency of tidal inundation (elevation). The modern dataset will be used to quantitatively estimate former elevations of fossil foraminiferal assemblages found in the long peat core and basal peats sections to reconstruct past relative sea level. Foraminiferal assemblages and radiocarbon dated in situ plant macrofossils within the salt marsh peats will be used to identify the timing and magnitude of changes in the rates of relative sea level over the past 5000 years. Geochemical data (C and N) will be used to corroborate the paleo-environment over the same time span of the relative sea-level record.

This region suffers from a paucity of valid sea-level index points, discrepancies between existing sea-level records, and temporal and spatial gaps in the existing records. Mid to late Holocene rates of relative sea-level rise of 0.6 mm/yr accelerate in the later Holocene to over 2 mm/yr. This foraminiferal-based sea-level reconstruction will alleviate prior discrepancies and data gaps and provide a solid mid through late Holocene sea-level record for the Florida Panhandle region.