107-1 THE BELL SYSTEM TECHNICAL JOUKNAL, SEPTEMBER 1957 



Fig. 15 — Seamount photographs taken near summit of seamount on Bermuda 

 Rise at 34°38'N, 56°53'W at depth of 1,370 fathoms. The two photos were taken 

 about 100 feet apart, indicating the rapid alternation of ooze and rock bottom over 

 short distances. 



The crest of the Mid-Atlantic Ridge is similar, as a bottom type, to j 

 the seamounts previously described. Dredge hauls have brought up | 

 mostly basalt, although a few fragments of limestone have also been | 

 retrieved. The photographs shown in Fig. 16 were taken about 60 feet ' 

 apart on the Mid-Atlantic Ridge. They illustrate a change from smooth 

 to rocky conditions in this short distance. 



Fig. 16 — Mid-AtLantic Ridge photographs (1,500-fathom depth at 48°30'N, 

 28°48'W). The two pictures were taken about 60 feet apart. Out of 60 photographs 

 taken at simihir intervals in this location three were similar to that on the left and 

 the remainder resembled that on the right. The dark l)and in the right-hand pic- 

 ture is probably composed of gravel and sand of the dark-colored rock of the peaks, 

 while the white underlying layer is clay or ooze. The dark bantl was produced by 

 a current which swept the dark material over the light-colored material. 



