FOX-STRANGWAYS : FILEY BAY AND BRIGG. 
343 
one time burnt for making lime, but tliese beds being just at the top 
of the vertical part of the cliff they are not easy to examine. 
On the shore, at low-water mark, close to the left-hand corner, 
the Kellaways Rock and Cornbrash may be observed when the tide 
is out, so that here we have one of the most complete sections of the 
lower part of the Middle Oolites in this part of the country. Most 
of the ammonites obtained from the Oxford Clay of Yorkshire have 
been found in blocks that have fallen from this cliff. 
The contrast between the vertical and overhanging cliff of 
Calcareous Grit and the more gentle slopes formed by the Oxford 
Clay and Drift is well illustrated in this view. The numerous joints 
in the Calcareous Grit have caused the rock to weather into the 
buttress-like projections seen in this part of the cliff. 
Before closing this short description of the rocks shown in 
Mr. Godfrey Bingley's excellent photographs, it may be as well to 
offer a few remarks on their geological history or the physical 
conditions under which they were laid down. During a portion of 
the period that immediately preceded the deposition of the rocks 
shown in these cliffs, there existed in this area a condition of dry 
land and large estuaries on which flourished the plant beds forming 
the coal seams of the Lower Oolite. 
Towards the close of this period the land sank, more on this 
side than to the west, and the thin fossiliferous bed of the Corn- 
brash was laid down in a comparatively shallow sea, where in course 
of time its prolific fauna was overwhelmed by the great inrush of 
sands and sandy mud that formed the Kellaways Rock, here 
however probably reaching nearly their eastern limit. The source 
of these sands appears to have been from some ancient land away to 
the west of Thirsk, where the rock attains its maximum development, 
while the shales of the Oxford Clay above become very thin if they 
do not entirely disappear. The curious interlacing of these 
formations in the west leads to the idea that they are to a certain 
extent contemporaneous, and it is probable that the deeper water 
about Gristhorpe led to the deposition of the argillaceous beds of 
the Oxford Clay here, while more sandy beds were being formed 
nearer the shore line to the west. 
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