LAMPLUGH : GLACIAL SECTIONS. 
31 
into the sand below, and certainly in more than one place there is 
that appearance, but in all the cases I have examined except one, 
1 found this appearance to be deceptive, being due to seams of 
sand in the cross-bedded gravel coming in contact with the under- 
lying sand. The exception is at D in Fig. !2. where the gravel 
thins out ; and here as the gravel is much weathered and confus- 
ed, matters are not so clear. 
I can give no certain information as to the manner in which 
the chalky gravel under the marls in the northern part of my 
section dies out southward, as my section of 1877 is unfortunately 
by no means clear on this point ; at that time I confined my 
attention almost wholly to the boulder-clay, especially the ' Base- 
ment,' and have grouped the beds above the Purple Clay as ' clay, 
sand and gravel ;' but from what I can gather from my notes, and 
from the now much obscured section, it seems to overlap the 
edges of the denuded sand and warp which forms the slope at 0 ; 
the upper part of the sand and warp, however, contains much 
gravel here, and is also cross bedded. One hundred yards north of 
the north end of Fig. 1 a drain, which has just been cut, showed, 
at the surface, two feet of chalky gravel, resting directly on 
Purple Boulder clay. The marls had thinned out. 
The Sand and Clay Series. (2a). This series, called by 
Prof. Phillips* ' the Warp beds,' is the chief component of the 
section. The upper part consists of fine yellow sand with clay 
partings, generally passing downward gradually into almost 
pure clay, in varying reddish-brown and greenish stripes ; but 
in a few places there is a sharp line between the sand and clay. The 
whole series is finely laminated, and full of beautiful ripple-marking ; 
cross-bedding is also of frequent occurrence, and in three or four 
places the sandy beds are crumpled and twisted in a curious 
manner along certain lines. This crumpling has been ascribedf 
* Geology of Yorkshire, 3rd edition, p. 82. 
t J. R. Dakins, Proc. Yorks. Geol. and Polyt. Soc., 1879 p. 126. 
