LAMPLUGH : NOTES ON THE WHITE CHALK OF YORKSHIRE. 69 
(Appendix, p. 82) on the western side, and its absence from the eastern 
side of the gap; while that there is much vertical displacement in the 
opposite direction is also rendered improbable by the discovery by 
Mr. J. W. Stather of a single specimen of that fossil in the chalk 
immediately to the east of tlie valley. 
I think, therefore, we may safely conclude that the value of any 
fault existing at this point cannot be great, and that its only possible 
elfect can be slightly to increase the apparent thickness of the strata. 
Westward from Danes Dike the prevalent gentle south-easterly 
dip becomes rather more pronounced, and there is consequently a 
more rapid rise of the layers into the cliff, so that in the distance of 
one mile which intervenes before the South Sea Landing is reached, 
the detailed measurements record a further thickness of 214 feet of 
Flintless Chalk. Blake mentions that beyond Danes Dike he measured 
130 feet " as far as it was safe to go," and apparently stopped about 
midway between the above-mentioned places. There is, however, 
neither danger nor difficulty, excepting from the roughness of the 
way, in going along the beach at low- water, or even at half-tide, not 
only from Sewerby to South Sea Landing, but also for nearly two 
miles farther, to the extremity of the headland, where on the south 
side of High Stacks a rather steep but perfectly easy path leads up 
into the fields above. 
At South Sea the line of section is again interrupted by a deep 
hollow which has been excavated in the Chalk down to sea-level in 
pre-glacial or glacial times and afterwards filled in with drift. The 
low-water scars are, however, very nearly continuous across the 
little bay, and so far as can be seen there is no sign of any change in 
the regularity of the strata in traversing it. 
Farther east there is an unbroken cliff-section extending for 
nearly two miles, quite to the extremity of the headland,, in which 
the Chalk throughout is flintless. In this area there is, however, 
a slight change in the direction of the dip, which here inclines 
towards the south, and occasionally even a little to the westward of 
south, and at an angle rarely reaching so much as 4 degrees ; and as 
the effect of this is to bring the line of strike very nearly into coin- 
cidence with the cliff-line, the strata retain their position in the 
