details o£ the bedding. Cores are set up for splitting on a wooden 

 trough. A circular power saw moionted on a base which is designed to 

 ride along the top of the trough is set to cut just through the liner. 

 By making a cut in one direction and then reversing the saw base and 

 making a second cut in the opposite direction, a 120-degree segment of 

 the liner is cut. The sediment above the cut line is then removed with 

 a spatula, and the core is logged, sampled and photographed. 



Samples from cores are examined under a binocular microscope, and 

 described in terms of gross lithology, mineralogy, and the type and 

 abundance of skeletal fragments of organisms. 



3. Scope 



Continuous marine seismic reflection profiles and sediment cores 

 were obtained by the contractor for an area of sea floor lying in lower 

 Chesapeake Bay and the Atlantic Ocean in the general vicinity of Cape 

 Charles and Cape Henry (Fig. 1) . The exploration program consisted of 

 a detailed survey covering 180 square miles in the Chesapeake Bay En- 

 trance area adjacent to the Capes and a reconnaissance survey of the 

 nearshore continental shelf off the southern Virginia Coast between 

 Cape Henry and False Cape. Only that portion of the survey covering 

 the Chesapeake Bay Entrance is reported in detail. (A report on the 

 reconnaissance area will be made in the future when sufficient addi- 

 tional data is available for adequate analysis.) 



During field operations, 290 statute miles of shallow and medium 

 penetration seismic reflection survey of the bottom and subbottom under- 

 lying the report area were obtained (Figs. 2a. and 2b.). A total of 

 sixty-one 4-inch diameter sediment cores up to 20 feet long were taken 

 in the survey area by a pneumatic vibrator-hammer type coring apparatus. 

 Additional data was obtained in 1970 from similar cores collected by 

 the Norfolk District of the Corps of Engineers for a dredging survey. 



