38 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [DeC. 3, 



over the first crest of the neighhouring mountains. Yet if we ascend 

 to the hne of break, which passes through the Scar Limestone, al- 

 though we find unequivocal marks of dislocation, we do not find any 

 very great change of level between the limestone beds on the oppo- 

 site sides of the break. Here, therefore, the great downcast at Brough, 

 although connected with the Pennine fault, is produced mainly by the 

 change of dip, and not by any great downcast at the line of break. 



Again, I may appeal to the Black Burton* coal-field, the beds of 

 which exist at a level of 1600 or 1800 feet below that of the top of 

 Ingleborough. It might be said, that in their more natural position 

 they ought to be one or two thousand feet above the top of that 

 mountain ; and hence it has been sometimes asserted that the fault 

 which passes at the base of Ingleborough must have produced a 

 downcast of more than 2000 feet. In a certain sense this may be 

 true ; for the present anomalous position of the Black Burton coal- 

 field may have been, and probably was, produced by the same kind 

 of disturbing forces which produced the Craven fault. But, in the 

 miner's sense, there is no very great fault at the immediate base of 

 Ingleborough. There are the unequivocal marks of a fracture, and 

 there is a great change of dip on the western side of the line of frac- 

 ture ; but immediately on the opposite sides of the break, there is no 

 great change of level in the corresponding beds. In fact, the position 

 of the coal-field arises from a complication of nearly contemporaneous 

 movements, which have been admirably described by Professor Phil- 

 lips f, and belong not to the discussions of this paper ^. 



I have extended the section above-noticed (fig. 1) across the low 

 country between Brough and Kirkby Stephen, to show the effects both 

 of the Pennine and Craven faults : but I have drawn the line in such 

 a manner as to leave out some very confused masses of carboniferous 

 rocks which have been thrown down, in most perplexing confusion, 

 into the upper part of the valley, near the intersection of the two 

 lines of fracture. And I may here remark, as I have done in a former 

 paper, that the magnesian conglomerates, close to Brough, have been 

 tilted, by the action of the Pennine fault, in the same manner as the 

 carboniferous beds on which they rest ; whilst the same conglome- 

 rates near Kirkby Stephen rest almost horizontally on the edges of 

 the beds which have been tilted by the action of the Craven fault : 

 and hence we may conclude, that the two faults, although both pro- 



* See Sections, Trans. Geol. Soc. 2nd Ser. vol. iv. pi. 5. fig. 3 ; and Phil. Geol. 

 Yorksh. pi. 24. fig. 1; and Map of the Craven District, Trans. Geol. Soc. 2nd Ser. 

 vol. iii. pi. 2. 



t See Illust. Geol. Yorkshire, Part 2. p. 126 et seq. ; and Section No. 1. pi. 24. 



X I have been informed by some of the old miners in the Black Burton coal- 

 field, that many years since, vs^hen they attempted to push their works tov^^ards 

 Ingleton, the beds became utterly confused and broken, and that in one place they 

 became nearly perpendicular, and were consequently deserted. Professor Phillips 

 has indeed proved that this coal-field takes not its dip and rise from the limestone 

 immediately on the west side of the Craven fault, but from another highly inclined 

 calcareous chain (Report Lancaster Mining Company, 4to, 1837). There are se- 

 veral great breaks and downcasts between Ingleton and Black Burton, consider- 

 ably to the west of the great Craven fault. 



