Date of Award
Spring 2026
Abstract
Modern hydrographic surveys can reveal paleolandscapes on the continental shelf that have remained preserved since their inundation by post-glacial sea-level rise following the Last Glacial Maximum (LGM) ~20,000 years ago. This study investigates a submerged paleolandscape preserved on the continental shelf east of Frying Pan Shoals in Onslow Bay, North Carolina by utilizing modern high-resolution multibeam bathymetry ranging from 60 cm to 4 m resolution, acoustic backscatter, surficial bottom samples, interpreted core and seismic stratigraphy, and ICE-6G_C glacial isostatic adjustment (GIA) models. The high-resolution bathymetry reveals geomorphic features such as an elongated escarpment, paleochannels, exposed bedrock, fractures, bedding, scours, and modern sand waves. Backscatter characterization and bottom samples indicate the preserved geomorphic features are associated primarily with coarse, shell-rich quartz sand, gravel, and exposed or near-exposed bedrock. Comparison with GIA-modeled shorelines shows that the continuous, elongated escarpment aligns most closely with the 8,500 cal yr BP model, supporting its interpretation as a preserved paleoshoreline that marks the last subaerially exposed surface before rapid sea-level rise. Also delineated is a paleoshoreline at 9,000 cal yr BP and 9,500 cal yr BP, which correspond to geomorphic features in the study area, allowing us to constrain these relict features in time. Collectively, delineation of these features reveals a well-preserved, karst-controlled coastal plain paleolandscape developed in limestone and sandstone bedrock, including preserved shorelines, complex meandering paleochannel networks, and hundreds of depressions interpreted as former ponds, lakes, or bays. This study provides a paleogeomorphic reconstruction of a relict coastal plain landscape on the North Carolina continental shelf, with broader implications for critical habitat mapping, assessing sand resources, and identifying areas of archaeological importance.
Document Type
Master's Thesis
First Advisor
Joel E Johnson
Second Advisor
Larry G Ward
Third Advisor
M. Scott Harris
Department or Program
Earth Sciences
Degree Name
Master of Science
Recommended Citation
Lawrence, Alexandra Dawson, "A PALEOGEOMORPHIC RECONSTRUCTION OF A PRESERVED LANDSCAPE ON THE CONTINENTAL SHELF EAST OF FRYING PAN SHOALS, ONSLOW BAY, NORTH CAROLINA" (2026). Master's Theses and Capstones. 2083.
https://scholars.unh.edu/thesis/2083