484 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 2, 



of one mile and a half from the valley of the Coin. At or near its 

 entrance, the base of the Great Oolite (a), resting on the Fuller's 

 Earth (b), nearly reaches the bed of the brook. As we ascend towards 



Fig 



4. — Chedworth Valley. 

 (Section at the entrance.) 



/^Y= 



T~^^ 



ZT) 



/ " « 



/I } J , 





o 



Level of Brook. 



the village, lower beds successively arrive at the' surface ; until after 

 passing over about 30 feet of Fuller's Earth, we reach the Inferior 

 Oolite (c). At the village, about 50 feet of this formation compose 



Fig. 5. — Chedworth Valley. 

 (Section through the centre.) 



a. Great Oolite. 



Level of Brook. 

 b. Fuller's Earth. 



c. Inferior Oolite. 



the banks of the brook ; whence continuing our course, we meet with 

 higher beds, until at the top of the gorge we again reach the Great 

 Oolite. It is therefore evident that in the centre there exists a 

 dome-shaped structure of the strata ; the brook forming a datum- 

 line slightly inclined. 



Valleys in lines of dislocation. — A third class of valleys are those 

 which have originated in, or the directions of which have been locally 

 marked out by, lines of fault. In this place it would be superfluous 

 to describe the manner of the formation of such valleys. It will be 

 sufficient to enumerate several localities where they occur. They 

 are as follows : — Cranham, west of Painswick Hill ; Painswick Slade, 

 Cubberley, Winston Wood, Eyeford, Hawling Lodge near Naunton, 

 and Burford. When no valley occurs along a line of fault, a feature 

 is generally present, formed of a ridge of the harder beds along the 

 upcast side. 



There is a fourth kind of valley, represented by a few narrow 

 ravines, especially in the districts occupied by the Great Oolite, the 

 origin of which cannot be referred to any of the above causes. Some 

 of these contain brooks which are dry throughout the greater part 

 of the year, and are too insignificant to be supposed capable of having 

 excavated any portions of the gorges through which they run. The 

 formation of these, and indeed all the valleys of the Cotteswold Hills, 

 must be considered as entirely due to marine agency acting at several 

 successive periods ; the most ancient dating, perhaps, as far back as 

 the period of the upheaval of the Chalk, when about to form basins 



