and extends from the South Carolina border through Long Bay, Frying Pan 

 shoals, and Onslow Bay to Cape Lookout (Fig. 1). Based on survey density, 

 the study area is divided into two segments: the main survey area, which 

 extends about 13 kilometers (7 nautical miles) offshore and lies between 

 the South Carolina border and New River Inlet in Onslow Bay (Figs. 2 and 

 3), and the reconnaissance area (Fig. 4). The main survey area contains 

 the most detailed data coverage; the reconnaissance area is covered by 

 widely spaced seismic reflection profiles and cores. Data obtained by 

 the ICONS survey in the Cape Fear region consist of 824 kilometers (445 

 nautical miles) of seismic reflection profiles and 124 cores ranging from 

 0.6 to 6.1 meters (2 to 20 feet) in length. These data are supplemented 

 by pertinent scientific and techincal literature and National Ocean Survey 

 (NOS) hydrographic data. 



3. Geologic Setting . 



The Atlantic Continental Shelf bordering North Carolina is a submerged 

 extension of the southeast Atlantic Coastal Plain Province. Both the 

 coastal plain and shelf in the study area are topographically subdued and 

 slope gently southeastward. The mainland shore is fringed by barrier 

 islands sheltering a belt of coastal lagoons and marshes. Seaward of the 

 beach a relatively steep shoreface slopes to depths of -9 to -18 meters 

 (-30 to -60 feet) mean low water (MLW) where the gradient flattens into 

 the characteristic gentle seaward dip of the shelf floor. The shelf floor 

 is a wide submarine plain extending 102 kilometers (55 nautical miles) 

 offshore where at a depth of about -45.7 meters (-150 feet) MLW the shelf 

 edge begins. 



Coastal plain rock units that crop out on the emerged coastal plain 

 adjacent to the study area consist primarily of marine quartzose and 

 biogenic carbonate sediments and rocks of Cretaceous, Paleocene, Eocene, 

 Miocene, Plio-Pleistocene , and Quaternary age. Preliminary analyses of 

 lithology and fauna in the cores collected from the study area indicate 

 that the inner part of the shelf is closely underlain by sediments of 

 Cretaceous, Paleocene, Eocene, Oligocene, Miocene, and Plio-Pleistocene 

 age. These units crop out on the sea floor in many places; elsewhere 

 they are usually within 4.6 meters (15 feet) of the surface. Quaternary 

 sediments are thus thin and discontinuous throughout much of the study 

 area. 



The stratigraphic framework of Atlantic Coastal Plain rocks from 

 North Carolina to New York was discussed in Brown, Miller, and Swain 

 (1972) . Instead of using traditional stratigraphic subdivisions applied 

 to Atlantic Coastal Plain rocks, they proposed a modified framework based 

 on 17 chronostratigraphic units. For the Cenezoic section, these units 

 were based on an extension of current gulf region chronostratigraphic 

 boundaries and nomenclature into the Atlantic region. For Mesozoic rocks, 

 informal chronostratigraphic units were designated by the letters A to I . 

 Seven of the units proposed by Brown, Miller, and Swain occur at or near 

 enough below the inner shelf of the Cape Fear region to be within range 

 of cores or seismic reflection data used in this report. These seven 

 units and the formations generally recognized in the coastal plain rocks 



