LAMPLUGH : GLACIAL SECTIONS. 
33 
with the other pebbles. I have ah-eady mentioned that it some- 
times passes upwards into the beds above ; where this takes place 
it is generally thick, and sandy throughout. Downwards, its 
junction with the boulder clay is most irregular and peculiar. The 
general section and enlarged sections 1 and 2 will illustrate this 
better than a verbal description, and I would also refer to the 
account I gave last year* of very similar appearances to the north 
of the town. 
The Purple Boulder -Clay (3). This boulder-clay answers 
closely to my description of the same bed in the above-cited 
paper, being a dark brownish-purple clay, containing a great 
variety of boulders, and a few shell-fragments. The chief point 
of interest in this section lies in the existence of a well-stratifi- 
ed portion, (oc), which occurs along one horizon, and thus forms 
a band running thread-like throughout the section. 
This stratified band varies in thickness from a few inches to 
three feet ; it does not differ much from the rest of the clay 
except in being bedded, but is rather more earthy, (which causes 
it to weather faster), and also contains a sprinkling of small 
chalk pebbles, and these are rare in the clay below it, and not 
plentiful above. It contains scratched blocks like the rest of the 
boulder clay, but flat pebbles are nearly always laid horizontally. 
The bedding is sometimes very distinct and almost fine enough to 
be called lamination ; at others it is almost, or quite lost, though 
the state of the cliff has something to do with this, as it is after 
the washing of a heavy sea that the bedding is best brought out. 
There are often reddish, whitish, or greenish streaks at its base, 
which seem to be the remains of crushed masses of soft rocks. 
Its junction with the boulder-clay below is sharply defined, 
but upwards it is sometimes vague. As will be seen from the 
section, it rests on, and follows the inequalities of, an extremely 
imeven surface, rising and sinking in the cliff continually, varying 
* Proc. York. Geol. and Polyt Soc, 1881, p. 384. 
