19, 
This is regarded as amounting to proof that the zones in question 
are due to important changes in ecological conditions during the Pleisto- 
cene, and not to purely local concentrations of the empty tests by various 
kinds of bottom scour, 
Vertical distribution of G. men, in the cores gives no evidence 
of a southern shift of the current system during Pleistocene glacial 
stages. Instead, drastic reduction of volume of flow or even complete 
cessation of flow is indicated by the simultaneous disappearance of G, men, 
throughout the North Atlantic, ‘ 
In order to check the record of climatic changes as inferred from 
planktonic foraminifera paleotemperature determinations by the oxygen 
isotope method are being made of several of the Capiisen cores at the 
Institute for Nuclear Studies, the University of Chicago, under the direc- 
tion of Dr, Harold C. Urey, and Dr, Cesare Emiliani, 
The isotope analyses of core Al72-6 (See figure 3) gave the 
following results: 
Sample Analysis Temperature 
0/00 °c 
Top -0.99 20.9 
10 cm, +1, 16 21,6 
200 cm. +0,41 (+0, 42) 14,7 (14, 6) 
900 cm, -0, 58 19,1 
These results confirm the relative temperatures inferred from 
the foraminiferal assemblages.!; Oxygen isotope temperature determina- 
tions on samples from other cores have also been in reasonably good 
agreement with the relative temperatures deduced from the foraminifera, 
