212 THE ANTIQUITY OF MAN 
may well represent one of the sub-Arctic oscillations 
which are attributed to the Chellean period. However 
that maybe, it is quite evident that the great layer of chalky 
boulder clay, and the thick bed of glacial sands which lie 
under the boulder clay, are very much older than the 
deposits of the Hoxne valley, for the valley had been 
carved out of these deposits by a stream which no longer 
exists. Any remains of man or of his works found in or 
under undisturbed chalky boulder clay belong to a much 
older period than any we have dealt with in former 
chapters. 
The boulder clay, which forms a thick sheet over a 
great part of East Anglia, is regarded by geologists as a 
pelatt deposit 
Fig. 74. — Section of the Pleistocene deposits near Cromer, Norfollc 
(Sir Charles Lyell). 
product of the most severe of all the glacial cycles. It 
is important for our present inquiry to ascertain the 
position of the chalky boulder clay in the series of 
deposits laid down at an early part of the Pleistocene 
period. The accompanying illustration (fig. 74) is 
copied from the first edition of Sir Charles Lyell's 
Antiquity of Man (1863). In that illustration the Rev. 
S. W. King represents a section of a cliff, on the coast 
of Norfolk, a few miles to the east of Cromer. The 
cliff is there 35 feet high. The section is similar to that 
at Hoxne. An ancient valley is seen in the section, 
filled with various deposits. The valley has been cut 
in the boulder clay, which is here capped by a stratum 
of "contorted drift" and a layer of gravel. The mid- 
glacial sands, seen at Hoxne, are absent. In their place 
