E. Wilson — Age of the Pennine Chain. 503 



explorations for Coal at South Scarle, Lincolnshire, the Permian 

 rocks proved to be much more developed than in West Notts. At 

 Scarle the Lower Magnesian Limestone and Marl-slates together 

 amount to a thickness of 219 feet, at Bestwood to 95 feet, and at 

 Kimberley to from 53 to 33 feet only, while west of the Erewash no 

 Permians are found, and Triassic rocks repose directly on various 

 members of the Carboniferous formation. 



III. Coincidently with this attenuation the Magnesian Limestone 

 becomes intermingled with sedimentary materials on the west. The 

 Lower Magnesian Limestone, though no thicker on the east than 

 on the west, is a very different rock. Under Lincolnshire, it is a pure 

 cream-coloured compact limestone; while in West Notts it is instead 

 a coarse granular dolomite, interleaved with seams of marl and 

 micaceous sand, and may become gritty, and even conglomeratic. 

 These phenomena would seem to indicate the shallowing of the 

 waters, and the vicinity of land on the west in Zechstein times. 



IV. Mountain Limestone pebbles are said to have been found in 

 Permian rocks on the east, and certainly occur in Permian breccias 

 west of the Pennine Chain. The basement Permian breccia of 

 Notts is largely composed of the debris of Coal-measure rocks. 

 Such fragmental materials could only have been derived from the 

 denudation of a central tract of land composed of Carboniferous 

 rocks in Permian times, and clearly indicate not only that the 

 Pennine Chain had come into existence in Pre-Permian times, but 

 also that denudation had supervened to such an extent, that rocks so 

 low down as the Mountain Limestone were then laid bare in that 

 range. 



V. Though the Bunter Sandstone of West Notts and East Derby- 

 shire contains numerous fragments of Carboniferous rocks, — Lime- 

 stone, chert, and Millstone Grit, — no fragments of Permian rocks are 

 to be found in that or any other member of the Trias. This fact, 

 though negative, and therefore inconclusive, would seem to show 

 that the Permians were formed subsequently to the elevation of the 

 Pennine Chain, and consequently were not uplifted so as to be 

 exposed to denudation on the flanks of that range in Triassic times. 



VI. The absence of Permian outliers, at any distance west of the 

 Magnesian Limestone escarpment, taken in conjunction with the 

 absence of fragments of Permian rocks in the Triassic rocks of the 

 neighbourhood, indicates that the original margin of the Magnesian 

 Limestone waters did not lie very far west of the present escarpment. 



VII. There is no similarity either in character, thickness, or 

 succession of the Permians on the opposite sides of the Pennine 

 Chain. In Lancashire and Cheshire the Lower Permians are re- 

 presented, according to the Government Surveyors, by a mass of 

 unfossiliferous red sandstone, estimated to attain a maximum of 

 1500 feet (near Stockport), while the Upper Permians of South 

 Lancashire consist of from 100 to 250 feet of red calcareous marls 

 with thin bands of earthy limestone and gypsum. 1 



1 See Geological Survey Memoirs of the district. 



