139 



In order to give a clear idea of this extraordinary disloca- 

 tion, I have constructed a cross section of the strata affected. 

 (See Section No. I. api^ended, which is a reduction from the 

 original.) The section begins a httle to the north of Tyning 

 pit, passes through the fault at right angles, and shows its 

 effect on the upper series. The extreme extent of the overlap 

 would be found in the centre of the village a httle farther to 

 the west, but I have selected the line indicated partly because 

 at present there are more particulars obtainable there than at 

 any other point in the manor, and partly to take in the two 

 smaller faults which I have already mentioned. You will 

 observe that the veins have been moved bodily forward, the 

 letters AA, BB, and so on indicating the fractured ends, now 

 far apart, but which were once united. The maximum amount 

 of overlap may be estimated as follows : — 



On the Great Vein 120 yards 



„ Top Little Vein uncertain 



„ Middle Vein, not less than ... 1 60 yards 

 but the full extent not ascertained. 



„ SlyvingVein 291 „ 



„ Under Little Vein 308 „ 



„ Bull Vein 330 „ 



Some may be disposed to ask whether there may not be 

 some mistake about this forward movement, and to inquire 

 whether the strata may not have been originally deposited as 

 we find them ; but in reply I would explain that each vein 

 possesses so many distinctive features of tliickness, sub- 

 division, and surrounding strata as to render its identifica- 

 tion easy and mistake impossible. 



I have classed the overlap in the catalogue of true faults, 

 because it does not consist of a folding of the strata, but, hke 

 all dislocations properly so called, it possesses a clear, well- 

 defined line of fi-acture. In vertical faults the Hues of fi-acture 

 have originally formed chasms or crevices which have 



