KENDALL ■ THE GLACIATION OF YORKSHIRE. 
311 
in a valuable paper* gave some details of the section in the more 
southerly moraine at Escrick, aud mentioned that the beds of sand, 
gravel, &c., dipped strongly to the south-west. 
A section in the more northerly moraine, seen by myself, just to 
the north of the village of Bilbrough, displayed a series of sands and 
gravels dipping somewhat east of south. In the village I found a 
boulder of Shap granite. A general examination which I made of 
the boulders at this place agreed closely in its results with those 
yielded by my studies of sections in and about York. There was a 
great preponderance of boulders of various rocks from the Carboni- 
ferous series, especially Mountain Limestone. 
One feature in the general disposition of the drift deposits at 
York deserves mention. The two moraines, that of York and that of 
Escrick, are joined together by a high ridge of coarse gravel, which 
from its position and relation to the flow of the glacier may be safely 
pronounced to be an esker. 
So far all has been straightforward and simple, but 1 have now 
to propound the first problem : — Which moraine is the older, that 
upon which York stands, or the more southerly one at Escrick ? The 
first impulse would, I have no doubt, be to declare the proposition 
self-evident, the Escrick moraiue being further from the source of the 
glacier would be the older, and the York moraine would be a 
" moraine of retrocession." There are some facts, however, which 
seem to me to be worthy of consideration, which might lead one to 
the opposite conclusion, and these I put forward in a note communi- 
cated to the Glacialists' Association on September 24th, 1892. 
An examination of the Geological Survey Maps shows that each 
of the two great moraines consists of a central strip of sand and 
gravel flanked by outcrops of boulder clay. Now, so far as I am 
aware, tough stony clay has never been observed amongst the 
materials discharged upon the free edge of a modern glacier so as to 
form the substance of its terminal moraine ; and, indeed, the rarity of 
the occurrence of boulder clay in association with modern glaciers or 
their deposits, has led many geologists to deny the direct glacial 
origin of the material and to ascribe to it a marine origin,! but, 
* Proc. Yorks. Geol. and Polyt. Soc, 1877. 
t Dawkin's Early Man : Bulman, Geol. Mag. 1893. 
D 
