Vol. 55.] AGGLOMEKATES AND TUFFS OF CONGLETON EDGE. 



555 



into a grit-and-shale series above and a shale series below, and with 

 no demonstrable reduplication of any one bed, render this unlikely. 

 Beyond indications of the strata having been considerably squeezed 

 we find no evidence for the complicated system of faulting, represented 

 on the Geological Survey map as surrounding the limestone-inlier. 

 The fault on the Survey map represented as cutting off the limestone 

 series to the east does not exist, and was probably introduced to 



Fig. 5. — Section along GH (see map, fig. l^p. 548) on the scale of 

 4 inches to the mile. 



Eed Astbury 

 Rock Lime- 

 Fault, works. 



Quarry 

 Fossils. 



Third 

 Grit. 



a = Limestone. 

 b-f = Shales, limestones, agglome- 

 rates, tuffs, and grit. 



g — Shales and thin earthy limestones. 

 h = Shales and grit. 

 i = Third Grit. 



account for the absence of the great thickness of strata assumed to 

 exist elsewhere between the limestone and the Third Grit. Towards 

 the north-western portion of the inlier, as already stated (p. 552), 

 minor folds exist in proximity to the Eed Rock Fault, and in the 

 stream a little farther north the shales are much disturbed, but in 

 some cases this is due to the different resistance offered to tangential 

 pressure by the more massive beds, whether limestone or grit, and 

 the thin fissile shales. 



So far as the evidence goes, there seems no reason for placing the 

 strata between the limestone and the Third Grit in the Yoredale 

 division, while, on the contrary, the fauna of the marine band and 

 the presence of numerous grits of Millstone Grit type, containing 

 plant-remains, point to their connexion with the Grit Series of the 

 Carboniferous system. 



5. Summary and Conclusion. 



The occurrence of contemporaneous volcanic action towards the 

 extreme summit of the Carboniferous Limestone exposed in the small 

 inlier on Congleton Edge is interesting, as it brings the rocks into 

 close relationship with the similar rocks in Derbyshire. Whatever 

 opinion is held regarding the position of the vent, or the age of the 

 beds lying between the Third Grit and the main limestone, there 

 is no doubt that the volcanic tuff fell into the Carboniferous sea at 

 the time when the main oscillatory movements which characterized 

 the later Carboniferous period began. 



