170 



A little study of the figure will, I think, make the following points 

 clear, i. That the Carboniferous strata were deposited in the form of 

 a great series of alternating sheets of various kinds of sediment, whose 

 aggregate thickness must have originally amounted to at least two 

 miles. 2. That these Carboniferous rocks consist, in ascending order 

 of — i. The Basement Beds, not separately shewn ; ii. The Moun- 

 tain Limestone A ; iii. The Yoredale Rocks B ; iv. The Millstone 

 Grit C ; and, v. The Coal Measures D. 3. That this great pile of 

 marine accumulations has been originally distributed over a very 

 large extent of country consisting of older rocks whose surface only 

 accidentally bore anything more than the remotest relation to the 

 original surface of deposition. 4. That after these Carboniferous 

 rocks had been deposited, and before the commencement of the 

 next period we have any local evidence of, they were, in their turn, 

 very much disturbed and folded, and the continuity of the original 

 sheets of rock interrupted by great lines of fracture. 5. That they 

 were then exposed for untold geological periods to the action of 

 various denudants, which gradually stripped off thousands of feet 

 of rock from some parts, with the result of completely severing the 

 continuity of the once-extensive deposits. 6. That on the remnants 

 of these strata accidentally preserved from denudation were suc- 

 cessively piled up several other great series of accumulations, 

 which, in their turn, were also deranged and denuded like the 

 older strata. And, finally, that the ultimate outcome of this 

 complex series of changes has been the present form of the surface, 

 variously shaped out of all the older parts of the Neozoic, and the 

 newer portions of the Pateozoic series of rocks. 



If I have succeeded thus far in imparting a general idea of the 

 nature and origin of the complicated phenomena that characterise 

 this part of the district, the reader will now be prepared to under- 

 stand the brief description of the actual lie of the rocks that 

 follows. 



It is in the comparatively low ground in the neighbourhood of 

 Harcla, near Kirkby Stephen, that the Pennine Fault changes its 

 throw from a net result of a downthrow on the south-east to a net 

 result of a downthrow on the side opposite. On the .east side of 



