ANCIENT GLACIERS IN EASTERN HEMISPHERE. 177 



which it again protrudes 

 on the western side of 

 the valley of the Ouse, 

 and however the drift 

 between there and the 

 Pennine water - shed 

 may be interpreted, it 

 shows not a sign of ma- 

 rine origin ; but, even 

 granting that it did, we 

 find that it does not 

 reach within a thousand 

 feet of the water-shed. 

 When the water-shed is 

 crossed, however, abun- 

 dant glacial deposits are 

 met with which are not 

 to be differentiated from 

 others at slightly lower 

 levels which contain 

 shells. 



" If we suppose that 

 the line of our traverse 

 crosses the Pennine 

 Chain at Heald Moor, 

 we shall find that on 

 the eastern side no 

 traces of drift occur 

 above about 300 feet ; 

 while the very summit 

 of the water-shed is oc- 

 cupied by boulder-clay, 

 and thence downward 

 the trace is practically 

 continuous, and at about 

 1,000 feet and down- 



