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PKOCEEDmeS OF THE GEOLOGICAL SOCIETY. [April 8, 



the evidence is clear, and may be considered conclusive. It can be 

 shown that they are the effects of the earliest of the three consecutive 

 periods of disturbance, to which all the principal flexures and faults 

 of the district may he referred. 



Fig. 2. — Diagram of Flexures, Mid-Lancashire. 



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If we glance at a map of Yorkshire on which the flexures to the 

 North of the Yorkshire coal-field are laid down*, we find that those of 

 the Pendle range are but the extension of others in the region to the 

 east ; and I have already remarked that the Clitheroe anticlinal is 

 continuous with that which ranges by Skipton into the Forest of 

 Knaresborough. The uprising of the Millstone and Yoredale series, 

 along the northern margin of the Yorkshire coal-field, can only be 

 regarded as a result of the same movements which have originated 

 the flexures in the Clitheroe and Pendle districts of Mid-Lancashire ; 

 and as the Permian beds pass across denuded edges of the Carboni- 

 ferous rocks, the flexures by which they are influenced are conse- 

 quently anterior to the Permian period. This is, of course, a fact 

 long since established ; but it is necessary to my argument to repeat 

 * I refer particularly to Phillips's map in the ' Geology of Yorkshire.' 



