330 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [April 8, 



hood of Collie on the north to Leek and Wetley on the south, a dis- 

 tance of 55 miles ; and in the memoir above referred to have termed 

 it " the anticlinal fault," because it is nearly everywhere accom- 

 panied by a reversal of the dip. 



Commencing on the north at Colne, " the anticKnal fault " tra- 

 verses the western slopes of Boulsworth and Black Hambledon; 

 crossing the Yale of Todmorden, it follows the margin of the high 

 moorlands of West Yorkshire, throwing off the Millstone and Yore- 

 dale beds to the east and to the west. It then passes along the 

 "western base of Blackstone Edge, and follows the centre of Saddle- 

 worth Yalley, and the moorland slopes east of Staleybridge, to Harrop 

 Edge, accompanied by a sharp reversal of the dip. From this point 

 it continues its course by Compstall, Disley, and along the anticlinal 

 axis of Saltersford Yalley, onward to Leek in Staffordshire ; and here 

 it passes below undisturbed beds of the Kew Eed Sandstone, which 

 lie in the centre of an old palaeozoic trough. To the southward of 

 this outlier it reappears, passing along the vertical beds of " AYetley 

 rocks," and ultimately forms a junction with another fault, which 

 traverses both Carboniferous and Triassic beds. 



Kow here we have the curious case of the same fault passing 

 below the beds of the ISTew Eed Sandstone at one point without frac- 

 turing them, and coalescing with another fault which does fracture 

 the beds of this formation. It would therefore appear as if the an- 

 ticlinal fault was of two periods. I wish to draw special attention 

 to this fact, because it is necessary to my argument. 



The position and relations of the anticlinal fault with reference to 

 the IS'ew Eed Sandstone at Leek show that the primary and main 

 fracture, and the great upheaval of the rocks of the Pennine chain 

 which accompanied it, was of older date than that formation ; but 

 now we must endeavour to ascertain its relation to the Permian beds. 



Throughout a great part of its course from Staleybridge southward, 

 the anticlinal fault is accompanied by several parallel fractures and 

 foldings of the strata, such as the well-knoAvn Groyt trough of Earey. 

 These foldings are all closely connected, both by parallelism and other 

 circumstances, with the anticlinal fault, which may be regarded as 

 the axis of distui^bance of the whole*. Amongst these parallel lines 

 of disturbance, ranging from north to south, is the " Eed-Eock fault " 

 — an important fracture — forming the boundary between the Car- 

 boniferous and more recent formations, from Eredbury and Poynton, 

 in Cheshire, southward for several miles. East of Stockport this 

 fault is a downthrow of the Permian sandstone against the Carboni- 

 ferous beds, and is therefore clearly of later date than the Permian for- 

 mation itself; and if I am justified in assuming that the " Eed-Eock 

 fault " is contemporary with " the antichnal fault," it is clear, by 

 implication, that '^the anticlinal fault" is also of later date than the 

 Permian fonnation. 



An objection to the view of the pree-Tiiassic age of the " Eed-Eock 



^ Sections illustrating the relations of these flexures will be found in the paper 

 above quoted, by Mr. Green and myself, in the Journal of the Society, vol. xs. 



