74fi 



HEEZEN 



[chap. 27 



(Figs. 4 and 5). The thickness of the bed was nearly identical with that cal- 

 culated by Kuenen (1952) on the basis of the slopes and observed velocities. 



This bold challenge to the concept of the motionless, pristine abyss was 

 immediately attacked. Shepard (1954) based his objections largely on the claim 



A180-1 



A180-2 



iX 



S4^ 



A ''"l-'-V-'ic 



(.-///'/'•fA' . 



2m. 



3 m 



MO 052 mm 

 00(4 0.43(4 



Well-sorted 



sill. 



upper port 



graded 



► MD 0.082 mm 

 0D(4 0.35 (iS 



MD 0.062 mm 

 00(4 0.35(4 

 Shorply defined 

 contoct 



MD 0.019 mm 

 00(4 1.50 



Groyistv-brown Sllty 



" foromir^iferol lutilt 



^Fine muddy sond 



^Groyisti-brown silty 

 forominiferol lutite 



Position: 



39° 07' 30" N 

 5<1<'32'30"W 

 Deptti: 

 5190m 

 2840 fm 



m. 



-'y;^^.-^?i^?i 



Position: 

 39° 06' N 

 54° ll'w 



Deptti: 

 5190m 

 2840 fm 



pT 



A^^ 



Fig. 4. Logs of cores 180-1 and 180-2 from the Sohm Abyssal Plain south of the cable 

 break area. Note the upper layer of graded silt in both cores, deposited by the 1929 

 Grand Banks turbidity current. (After Heezen, Ericson and Ewing, 1954.) 



that the velocities of 10-50 knots were larger than could be expected, but 

 offered no more serious objections. Kullenberg (1954), misled by some erroneous 

 soundings, claimed that Heezen and Swing's explanation required the turbidity 

 current to run uphill and over a range of hills, an ability which, he correctly 



