1 88 Kimeridge Clay. 



this great escarpment as far north as Kowde, near 

 Devizes, where it is again overlapped by the uncon- 

 formable Cretaceous strata, to reappear at Calne, from 

 whence, on the north-east, it comes on in great force, 

 covering a broad tract of country by Swindon and 

 Longcott. A little east of Longcott, a great tongue 

 of Lower Grreensand, running out to Farringdon, over- 

 laps the Kimeridge Clay. Escaping from this overlap, 

 the clay runs eastward by Abingdon, Netley, Quainton, 

 and the south end of Stewkley, between which and 

 Leighton Buzzard it is again overlapped by broad- 

 spreading strata of Grault and Lower Grreensand. 

 Between this area and the fens of Lincolnshire it 

 doubtless lies deep underground, well to the east of the 

 Chalk escarpment, for it is well known to underlie 

 much of the marshes on either side of the Wash, from 

 whence it trends north in a strip at the base of the 

 Lincolnshire Wolds as far as the Humber, where it is 

 again unconformably overlapped by the Cretaceous 

 strata of the Yorkshire Wolds, to reappear in great 

 force in and around the Vale of Pickering, between 

 Hambleton Hills and Filey Bay in Yorkshire. 



The Kimeridge Clay is in places from 500 to 600 

 feet in thickness, but of late, in a great experimental 

 boring in the Weald of Kent, after passing through the 

 Purbeck and Portland Limestones and Sand, it was 

 pierced to the depth of 921 feet, below which came clays 

 supposed to be the Coral Rag and Oxford Clay, the base 

 of which was not reached at 1 ,906 feet when for financial 

 reasons the boring was abandoned. The meaning of 

 this seems to be, that whereas these clays, in their range 

 from Dorsetshire to Yorkshire, were deposited in com- 

 paratively shallow areas not very far from land, in the 

 Kent area they were laid down in a much deeper sea. 



