Figs 2 
- CORRELATION BY COILING DIRECTION of Globorotalia truncatulinoides 
A18)9-39 R5-54 
3470 meters 3295 meters 
West East 
27.7 Km WUHAN e Left 
<< (15 miles) “i 
175 meters 
Left 50/50 Right ) 
50 
ee ed 
yp: 1 meter 
ih 50 
Se na 
_2 meters 
Location; 220 km or 120 miles SSW of Hierro, Canary Islands, and 
400 km or 215 miles WNW of Oro River, Rio de Oro. 
From the correlation: it is obvious that the upper 180 cm section of A1l80-39 is 
the time equivalent of the upper 100 cm in R5-54, In other words, the rate of depo- 
sition at A180-30 has been 1. 8 times as fast as that at R5-54. 
Both sections are composed of uniform foraminiferal lutite, quite without any 
silt or sand layers, Thus there is no obvious évidence of turbidity current deposi- 
tion which might explain the difference in rates of deposition. 
Evidently the difference in rate is not a consequence of relative distance from 
the source of terrigenous sediment because the more rapid deposition has taken place 
at that station which is more remote from the African coast. 
. There is no evidence for greater productivity of lime secreting organisms at 
A180-39, Not only is the CaCO 3 content of the two sections very nearly the same, 
but foram tests ectually make up a larger fraction of the sediment in R5-54 where 
deposition has been slower. 
That the more rapid deposition has taken place at the deeper station suggests that 
turbid water flowing along the ocean floor has been channeled by local topography. 
Whether the greater density of the water so flowing is due to the turbidity itself, or 
to higher salinity, lower temperature, or a combination of all three is a question. 
Whatever the cause, a low velocity is indicated by absence of well sorted layers, and 
tairly continuous flow, by the lack of distortion in the coiling curve of A180-39 as 
sompared with that of R-54, 
4he importance of this process of transportation and deposition as a possible ex- 
planation for the extraordinarily smooth and nearly level plains of sediment known to 
fill many depressions in the North Atlantic basin needs no emphasis. 
