17. 



are particularly common in the axis. The prevalence of 

 unconsolidated fine grained sediments with the limited 

 exposure of rock supports the theory that Baltimore Canyon 

 is an area of active sediment deposition. 



The substrate distribution pattern in Lydonia Canyon is 

 somewhat more complex than that seen in Baltimore Canyon. 

 Silty sediment predominates on the flanks and walls of the 

 canyon with occasional rock outcrops. Rock outcrops are more 

 numerous in the axis of the canyon. Dredged material from 

 these outcrops indicates that they are composed of a dark 

 grey to black micaceous siltstone of mid to late Cretaceous 

 age. Silty sediment in the thalweg of the canyon is rippled 

 along most of its length. On the west wall and flank there 

 are outcrops of consolidated clay as well as of rock. None 

 of this material was recovered in dredges, so the lithology 

 and geologic age of these outcrops is unknown. Above 400 

 meters on the east wall and flank of the canyon are large 

 deposits of glacial erratics, mostly cobbles and pebbles with 

 some shell hash. In general Lydonia Canyon appears to 

 represent an area of active erosion of sediments, particularly 

 within the canyon axis. 



Oceanographer Canyon is the most deeply incised of the 

 three canyons studied and also shows the greatest substrate 

 variability. Silty sediment predominates on the lower 



