32 



W, GUNN AND C. T. CLOUGH ON THE 



As far as the evidence goes, too, there would appear to be a 

 difference in dip between these Pencil-mill beds and the Carbonife- 

 rous rocks of the neighbourhood. We have already stated that the 

 true dip of the beds cannot be precisely determined, but that it 

 appears to be at high angles and in various directions. Now the 

 higher Carboniferous beds in the neighbourhood are either lying 

 horizontally, or else, under the influence of the Burtreeford Dyke, 

 they are dipping steeply and uniformly to the E.N.E. ; and the 

 conglomerates &c. resting on the Pencil-beds are lying horizon- 

 tally. 



We have now given the main points that occur to us as being 

 likely to help to settle the question. We think that, taken alto- 

 gether, they form a mass of cumulative evidence which is over- 

 whelming. 



Taking, then, our conclusion as proved, we proceed to mention, 

 very briefly, a point in which this discovery is of great theoretical 

 interest. 



Prom the bottom of the Whin Sill on Cronkley Scar to the top of 

 the Pencil-bed there is a vertical distance of 165 feet. The beds 

 occurring in this space are probably somewhat as below, in descend- 

 ing order : — 



feet 

 Limestone ,.. 100 



( In places very impure, sandy and shaly 

 bands coming in and dying out very 

 irregularly. Probably in the lower 50 

 feet the limestone bands are subordinate 

 to the sandy and shaly bands. 



Conglomerates 65 With quartz and clay-slate pebbles. 



We cannot give the section as very trustworthy in respect of 

 details, because the lower portion of Cronkley Scar is so covered by 

 tumbled whin that the lower beds are very rarely to be seen ; but, 

 judging by better sections to be seen on either hand, it is probable 

 that it is roughly correct. There can be no doubt that the limestone 

 in the section must represent in part the Melmerby-Scar Limestone 

 of the Pennine escarpment. Now in this escarpment we have 

 beneath this limestone an enormous thickness of Carboniferous beds. 

 At Roman Pell, about eight miles from the Pencil -mill in a S.S.W. 

 direction, these Lower Carboniferous beds are no less than 1500 

 feet thick, according to our colleague Mr. Goodchild. 



The two sections we have here brought together for comparison 

 must be taken as really representing the different developments of 

 the Lower Carboniferous beds in the two districts. It is impossible 

 to explain away the difference by supposing that in Teesdale the 

 Pencil-bed is caught in between two enormous faults or any thing of 

 that kind, and this for two reasons : in the first place, as has been 

 said, conglomerate beds can be seen resting directly on the Pencil- 

 bed; in the second place, the sections on the Pell-sides around are 

 too good to allow of any such faults having escaped our observation. 



