LAMPLUGH : NOTES ON THE WHITE CHALK OF YORKSHIRE. 179 
middle distance, witli the cavernous eastern side of Great Thornwick, 
shown in a nearer view on Phite G, in tlie background. 
The stratification of the chalk is beautifully brouglit out in this 
picture, as also the tendency of the rock to become broken and rubbly 
immediately beneath the drifts. Its hardness and solidity, as com- 
pared with the more usual type of English Chalk, is well indicated 
by the deeply indented profile of the v\\\Y<. It may be advisable to 
mention that the dark tint of the lower part of the cliffs, so apparent 
in this and other pictures of the series, is merely superficial staining 
from organic agencies, marking the limit of the waves. 
5. Thornwick and Bempton Cliffs. 
This, like the third view, looks westward. The ridges seen in 
the last plate fill the middle of the picture, the point of view being 
on the eastern side of Great Thornwick. In the middle distance the 
Bempton Cliffs are again seen, their straight massive outline scarcely 
suggesting stratified material. Staple Nook lies in the recess 
between the most distant and the next nearer headlands. The 
Middle or Flinty Chalk is alone in sight. In the corner of the 
little bay in the foreground it is rather rich in gigantic Iiwcerami. 
The change which takes place in the contour of the coast in the 
nearer cliffs, from a simple or only slightly wavering line to any 
intricate tracery of deep inlets and narrow headlands, showing on the 
map like the suture-lines on an ammonite, cannot fail to strike the 
observer. The characteristic irregularity is retained from this place 
to the most easterly point of the headland, two miles distant. As 
there is no corresponding change in the hardness of the rock we 
must seek some other cause to account for it. This cause is, I think, 
revealed very clearly in the plates. 
It has already been mentioned that the Bempton Valley lies a 
little way inland from the edge of the great cliffs, from Speeton east- 
ward. The northern cliff-line of the headland cuts the land slightly 
obliquely to the course of this ancient valley, so that eastward from 
Bempton the northern side of the hollow is more and more deeply 
carved until near Thornwick this side of the valley has almost 
disappeared. The hollow is of preglacial date, and its lower portion 
is so choked with drift as to be nearly obliterated as a surface- 
