1868.] nrLL — lines of elevation. 331 



fault" hero presents itself; for this "fault" not only dislocates the 

 Permian strata, but those of the New lied Sandstone also, near Mac- 

 clesfield and Conglcton ; and it might hence be inferred that the fault 

 is of later date than both of these formations. My answer to this 

 objection is that there have been two periods of vertical movement 

 along the line of the fault — one before the Triassic period, another 

 after. Such cases (where the demonstration is perfect) arc not un- 

 known, and I can point to that of the boundary fault of the Coleorton 

 coal-field in Leicestershire, along which there have been two distinct 

 vertical movements in opposite directions, in post-Carboniferous and 

 post-Triassic times. I have also already referred to the case of the 

 *^ anticlinal fault " at its southern extremity and at Leek as a case 

 of a double vertical movement. 



The objection, therefore, which might be urged against the view of 

 identity in age of the " Red-Eock " and " anticlinal " faults, owing 

 to the displacement by the former of beds of Triassic age, seems to 

 me to fall to the ground. Their parallelism and evident connex- 

 ion with the system of flexures which range in north and south 

 lines seem to me to point to identity of age, from which I draw 

 the conclusion that the age of the " anticlinal " fault and of the 

 upheaval of the Pennine chain is that which intervened between 

 the close of the Permian and the commencement of the Trias — 

 in other words, that it belongs to that period of general strati- 

 graphical disturbance which marked the close of the Palaeozoic age. 



This is a conclusion, indeed, which has often been assumed, but 

 it is not by any means so easily proved. 



If, then, my reasoning be admitted, it follows that the Pendle 

 range and the Pennine range belong to two entirely different lines 

 of disturbance — different in direction, different in age — the former 

 being referable to the close of the Carboniferous, the latter to 

 the close of the Permian age. To these two periods Professor 

 Sedgwick refers the Craven and Pennine faults of Yorkshire ; and 

 looking at the parallelism in direction of the great fault which 

 forms the boundary between the Carboniferous and Silurian rocks 

 of the central valley of Scotland with that of the Pendle range, 

 it seems highly probable that this great depression is also refer- 

 able to the close of the Carboniferous period*. 



To recapitulate in a few words — it appears, then, that immediately 

 upon the close of the Carboniferous period the northern limits of the 

 Lancashire and Yorkshire coal-fields were determined bj^ the upheaval 

 and denudation of the beds along east and west lines, while the coal- 

 fields themselves remained in their original continuity across the 

 region now formed of the Pennine hills from Skipton southwards, and 

 that at the close of the Permian period these coal-fields were dis- 

 severed by the uprising of the area now formed of the Pennine range 

 by lines of upheaval ranging from north to south, nearly at right 

 angles to the former — this perpendicularity being of itself an evidence 

 of difference of age. 



* This great fracture has been traced by my colleagues of the Geological Survey 

 of Scotland for many miles along the southern boundary of the coal-fields. 



