diameter) in granular- type Continental Shelf sediments. The apparatus 

 consists of a standard steel core barrel, plastic inner liner, shoe and 

 core catcher, and a pneumatic driving head attached to the upper end of 

 the barrel. These elements are enclosed in a tripodlike frame with artic- 

 ulated legs which allow the assembly to rest on the sea floor during the 

 coring operation. The detachment of the core device from the surface 

 vessel has the advantage of allowing limited motion of the vessel during 

 the actual coring process. Power is supplied to the pneumatic vibrator 

 head by a flexible hoseline connected to a large- capacity air compressor 

 mounted on the deck of the ship. After coring is complete, the assembly 

 is winched on board the vessel, the liner containing the core is removed, 

 capped at both ends, adequately marked, and stored. A review of the 

 historical development of vibratory coring equipment is discussed by 

 Tirey (19 72). 



d. Processing of Data . Seismic records are visually examined to 

 establish the principal bedding and geologic features in the subbottom 

 strata. After analyses are complete, record data are reduced to detailed 

 geologic cross-sectional profiles showing the primary reflective inter- 

 faces within the subbottom. Selected acoustic reflectors are then mapped 

 to provide areal continuity of horizons considered significant because of 

 their extent and relationship to the general structure and geology of the 

 study area. Where possible, the topmost reflectors are correlated with 

 cored sediment to provide a measure of continuity between cores. 



Cores are visually inspected and described aboard the recovery ship. 

 After delivery to CERC, the cores are sampled at close intervals by drill- 

 ing through the liners and removing parts of representative material. 

 After preliminary analysis, representative cores are split longitudinally 

 to show details of the bedding and changes in stratigraphy. Cores are 

 split using a wooden trough arrangement fabricated at CERC shop facilities, 

 A circular powersaw, mounted on a base designed to ride along the top of 

 the trough, is adjusted to cut just through the plastic liner and not dis- 

 turb the core sediment. By making a second longitudinal cut in the oppo- 

 site direction, a 120°-segment of the liner is cut and can be removed. 

 The sediment above the cut is then scraped away to remove altered and 

 disturbed sediment and the core is carefully logged, sampled at closer 

 intervals, photographed, and resealed. 



Samples from the cores are then examined using a plane light binocu- 

 lar microscope and described in terms of gross lithology, color, mineral 

 composition, and the type and abundance of skeletal fragments of marine 

 organisms. Granulometric parameters (e.g., mean size, sorting) for the 

 sand fraction of many samples are also obtained by using the CERC Rapid 

 Sand Analyzer (RSA) which is analogous to that described by Zeigler, 

 Whitney, and Hays (1960) and Schlee (1966). 



3. Scope . 



The study area (Fig. 1) covers about 800 square miles (2,072 square 

 kilometers) of the Long Island Atlantic inner shelf from East Rockaway 



10 



