LUMINESCENCE AGES FOR SUFFOLK SHORELINE IN NORTHEASTERN NORTH CAROLINA

The north-south trending Suffolk Shoreline (SS) is a prominent geomorphic feature in northeastern North Carolina and southeastern Virginia. Although it is an erosional scarp near the type locality in Suffolk, Virginia, the majority of the SS in North Carolina is a constructional shoreline complex dominated by sandy deposits. The toe of the SS occurs at ca. 6 m above present MSL and its crest reaches an elevation of ca. 12 m. This study used optically stimulated luminescence (OSL) data obtained from drill cores and outcrops to determine the timing of deposition and sea-level history of the SS in northeastern North Carolina. OSL data indicate that SS deposits are dominantly MIS 5a in age with some underlying MIS 5c ages and none that are definitively MIS 5e. East of the SS, age data indicate that the late Quaternary section is dominated by shelly marine deposits associated with MIS 5a that are overlain by tidally laminated sand and mud associated with MIS 3. OSL data from the SS indicate that relative sea level in the study area during MIS 5a was at least ca. 6 m above present (the elevation of the toe of the SS) while eustatic records for the same time indicate that sea level was ca. 20 m lower. This substantial deviation from the eustatic sea-level record for MIS 5a is further evidence that intermediate-field glacioisostatic adjustment has played an important role in sedimentation in the northeastern North Carolina.