LAMPLUGH : GLACIAL SECTIONS NEAR BRIDLINGTON. 
287 
stoney Boulder-clay, which thickens considerably in one direction, 
and passes into the normal lower Boulder-clay, and in the other tapers 
away and disappears between stratified beds. It is most instructive 
to find that in this, the only instance in which we have been able to 
study the shell-bearing patches in full section, and to see the base of 
the drifts below, that though there are stratified beds lower in the 
series these are quite different in character from the fossiliferous 
sand, contain no fossils, and are probably not of marine origin, 
thus lending no countenance to the view that the shelly patches have 
been derived from beds immediately underlying the Boulder-clay. A 
full description of this interesting section will be found in a recent 
number of the Geological Magazine. 
From the South Sea Landing the Basement Clay may be followed 
eastward almost step by step to the Lighthouses at the most easterly 
point, where it is largely made up of the debris of the Speeton Clay,''' 
sometimes indeed without other admixture, and thence, turning west- 
ward we trace it, with curious local aberrations, through the buried 
valleys of the North Sea Landing and Thornwick Bay. Beyond Thorn- 
wick, however, when we reach the rising ground which leads to the 
high cliffs of Bempton, Buckton, and Speeton, we find the lower clay 
grows thin and indefinite, with a constant tendency to pass into 
gravels, but on descending at Speeton there is little difficulty 
in again identifying it, and in following it northward across Filey 
Bay : and 1 believe that it extends, with some local interruptions, 
past Scarbro', Whitby, and Sal tb urn. I have not yet examined the 
sections lying north of the Tees. Thus we find that in most of the 
clifi' sections of the Yorkshire Coast there is a bed with well-marked 
characteristics, which, though beds of glacial origin occasionally occur 
below it, is the lowest of the series which can be called a boulder 
clay ; and this bed is therefore well-described by the term Basement 
Clay. Before giving the inferences to which I have been led in 
studying this clay, I will add a few notes on its contained boulders. 
Boulders of the Basement Clay. — There are decidedly fewer 
large boulders in the Basement Cla}* than in the Purple, but the 
number of small stones is quite as great, and these present an extra- 
* Proc. Yorksh. Geol. and Polyt. Soc, vol. vii., p. 244. 
