525 
Quartz Rock of the Lickey Hill , &c. 
along this valley of denudation at Clay don and Cherwelton, near 
the sources of the Cherwell, having been drifted into this indenture 
or low lip of the oolite escarpment, though not in such quantities 
as those which entered by the vale of Moreton into that of the 
Evenlode, where the current was stronger in consequence of the 
projecting horn of the Campden Hills. The lowness of the oolite 
escarpment at the lip or gap above Banbury, appears still further 
from its having been selected as the point by which the Oxford 
Canal is conducted out into the sandstone plains of Warwickshire. 
Miss Morland (to whose exertions in the cause of geology I am 
under extensive obligations,) has traced the Warwickshire quartzose 
pebbles mixed with chalk flints and slightly rounded oolitic gravel 
down the valley of the Cherwell, from Steeple Aston to Heyford, 
Rowsham, Kirtlington, and Kidlington, four miles on the north of 
Oxford ; at Kidlington there occur mixed with them numerous 
shells of gryphites rolled to pebbles and probably drifted in from 
the lias beds of Warwickshire. She has also found similar quartzose 
pebbles at Long Hanborough, in the valley of the Evenlode, and 
below Oxford in the plains that flank the valley of the Thames 
between Dorchester and Abingdon. In the Abingdon gravel pits, 
and also in Bagley Wood, there are pebbles of porphyritic green- 
stone and greenstone slate, usually decomposed and probably 
derivative from the neighbourhood of Mount Sorrel in Leicester- 
shire. 
If we examine the geological structure of that large portion of 
England which lies south-east of the line of the great escarpment 
of the oolite formation, along its whole extent, from the coast of 
Dorset to that of Yorkshire, we shall find in it no one stratum that 
has the smallest resemblance to the quartzose pebbles which are 
accumulated near Oxford, and over the other districts which I have 
