Abstract: Shallow Framework of Inner Continental Shelf of Cape Fear Region, North Carolina

Edward P. Meisburger

Seismic-reflection profiles and cores from the Continental Shelf off North Carolina between Cape Lookout and South Carolina were studied to determine the geologic framework of the inner shelf to 25 km offshore. Reflection profiles show that most of this area is underlain by three extensive reflection units distinguished by bounding reflectors and characteristic internal reflection patterns. One unit underlies the area from Lockwoods Folly Inlet to South Carolina and is up to 30 m thick. It is characterized by southward-dipping internal reflectors suggesting foreset bedding. Cores of the upper 6 m contain muddy sand with abundant Late Cretaceous foraminifers. A second unit underlying the shelf from south of Cape Fear to New River Inlet also is typified by foreset-type internal reflectors dipping southeast and is up to 80 m thick. Cores of the upper 6 m contain uniform fine quartz sand wit foraminifers indicating Oligocene age. A third unit is present chiefly as fill in large channels incised in the fine sand unit and off the Cape Fear River entrance. The cored upper part of this unit consists of biogenic calcarenite of probable late Tertiary age. Post-Tertiary sediments overlying these units are thin and discontinuous in most places; thus the units are accessible to relatively short coring devices. This accessibility plus the probable progradational origin of the two larger units suggests that detailed chronologic samples could be obtained by sequential sampling of the units in the direction of growth.

AAPG Search and Discovery Article #90968©1977 AAPG-SEPM Annual Convention and Exhibition, Washington, DC