840 



ERICSON 



[chap. 31 



cores pass through the flexuosa zone and into sediment which was probably 

 deposited during the last interglacial, we conclude that deep circulation in this 

 part of the North Atlantic has remained essentially constant in both direction 

 and velocity during the late Pleistocene. 



Canaries Cores 



AI80-39 



3470 m 

 25°50'N. I9°I8'W 



R5-54 



32 95 m 

 25°52.3'N, I9°03.3'W 



I007o Left 

 Warm 



100% Right 

 ^^ 28 km- 



^ Climotic Variation 



2m 



Coiling of Globoro folia 

 truncatulinoides 



Fig. 4. The Canaries cores. 



D. The Muir Seamount Cores 



The location of the Muir Seamount is shown in Fig. 1 . The positions of the 

 cores with respect to the seamount, the coiling curves of Globorotalia truncatu- 

 linoides and the positions of the flexuosa zone in the cores are shown in Fig. 5. 

 Here again, as in the case of the Canaries cores, we find a marked contrast in 

 rates of sediment accumulation within a short distance, 15 km. Sediment 

 samples from the top of the mount are almost devoid of fine fraction. Presum- 

 ably this is due to winnowing by a deep current of sufficient velocity to prevent 

 fine material from coming to rest on the top of the mount. Percentages of fine 

 fraction ( < 74 [j.) in the cores are shown in Fig. 5. In the zone between the top 

 of the flexuosa zone and the base of the post-glacial zone in core A 164-44, the 



