52 



because, although not so proved, any intervening strata which 

 exist must be of trifling thickness. 



I have had some difficulty in arriving at the thickness of 

 the pennant in constructing the present section. Buckland 

 has estimated it at from 400 to 500 feet, and another writer 

 puts it at 600 feet ; but both seem to be far short of the 

 truth. Even in the Gloucestershire end of the basin its 

 thickness has been clearly ascertained to be not less than 

 1,840 feet, and every circumstance which has come to my 

 knowledge seems to go to prove that in the southern or 

 Somersetshire end of the field its thickness is much greater. 

 In the vicinity of Pensford 2,000 yards of its outcrop may 

 be seen, exhibiting an average inclination of J 8 degrees, 

 which is equal to a vertical depth of 1,880 feet ; and even 

 there the under part of it is covered by the overlying strata. 

 At Temple Cloud its outcrop may be traced fi-om Highbuiy 

 Hill to a point nearly a mile to the west, the dip varjang from 

 10 to 25 degrees, equal to a vertical depth of 1,700 feet ; but 

 here again we do not see the under part of it, as it is covered 

 by the new red sandstone. At Holcombe church its outcrop 

 is traceable for upwards of 1,000 yards, at an angle of 50 

 degrees, equal to a vertical thickness of 2,500 feet ; but 

 there also we only see part of it. 



In deciding the depth for the purpose of this section, I 

 have chiefly been guided by another section, which I have had 

 occasion to construct across the parishes of Stratton and 

 Midsomer Norton ; which, by taking the lowest vein of the 

 upper division and its inclination in connection with the 

 upper vein of the under di-\dsion and its inclination, has led 

 me to the conclusion that the thickness cannot be less than 

 3,000 feet. This you must bear in mind is only an estimate, 

 and a margin of 500 feet must be allowed either way for 

 error ; but it is the nearest approach I have been enabled to 

 make to the truth. 



