MAN FROM THE FARTHEST PAST 
Canada and found nearly corresponding results. Going 
still further back, these investigators have shown that 
certain well-defined pulsations of ice advance and retreat 
occurred both in America and in Europe. Summing up 
all the evidence, Doctor Antevs concludes as follows: 
Thus there was correspondence between the ice retreat in North 
America and in Europe in several of the larger features, but topographic 
and climatic differences seem to have limited the agreement. Since 
the correspondence was not perfect even in the larger features, agree- 
ment in the smaller features in details, such as relative summer tem- 
perature and varve graphs, cannot be expected. 
Our present knowledge of the geologic history of the two areas does 
not permit any other correlation. If the one outlined is correct and 
the estimates of the time represented by zones in which the ice retreat 
is not chronologically determined are fair, the last ice sheets had their 
greatest extent and began to wane about 40,000 years ago. This figure 
may be less than 10,000 years too large or too small—a fact of impor- 
tance because of the interest that has recently sprung up in the absolute 
Quaternary chronology. 
Thus for the first time we have before us, in results 
attained since 1920, an actual chronology in years cover- 
ing the period since the peak of the last glaciation, and 
we can say with some confidence that it reached its 
greatest intensity about 40,000 years ago and, after a 
long and fluctuating period of retreat, finally ended, in 
western Europe at least, about 8000 or 10000 B.c. This 
much is fairly definite. 
[70 ] 
