A-15, 



the slope. Sandy sediment is generally confined to the 

 shelf, the upper slope and canyon heads. It is also inter- 

 mittently found on canyon walls and in their axes. Consol- 

 idated clay outcrop is found in canyons and on the lower 

 continental slope. Loose hard substrates, such as cobbles 

 and glacial erratics, are primarily found in the heads and 

 on the walls of the northern canyons. Rock outcrops are 

 usually restricted to canyon axes, with occasional outcrops 

 on the canyon walls. 



The continental shelf and upper slope (100-350 m) of 

 the mid-Atlantic region is characterized by a sandy sub- 

 strate with shell fragments and coral debris. From 350 to 

 500 meters depth the substrate is silty with occasional 

 cobble patches and boulders. The lower continental slope 

 (850-2550) of the mid-Atlantic region consists mainly of 

 silty substrate with occasional minor consolidated clay 

 outcrops below 1000 meters. 



Data was obtained for the depth intervals of 1050 to 

 1600 meters and 2150 to 2350 meters in the axis of Norfolk 

 Canyon. The predominant substrate is a silty sediment. 

 Substantial outcrops were seen in the depth interval from 

 1050 to 1500 meters, while only occasional outcrop was seen 

 deeper. The head of Carteret Canyon is characterized by 

 predominantly sandy sediment with occasional shell fragments 

 on its north flank (150-350 m) . Outcrop of consolidated 

 Pleistocene clay is found at a depth of 250 meters on the 



