ON THE STOCKDALE SHALES. 



683 



Ac 4. The highest beds consist of the blue mudstones, which 

 occur between the sjnnigerus-zone and the Browgill Jieds ; these are 

 here ten feet in thickness, and contain a calcareous nodular band of 

 the usual description, ten inches thick, and at a distance of three 

 feet from the base. No fossils have been found here in these mud- 

 stones of the erinaceus-zone, and their passage up into the Browgill 

 Beds has been already described. 



The section in Stockdale Beck below the cascade over the Coniston 

 Limestone is, so far as the Skelgill Beds are concerned, quite like 

 that occurring at the rake in Browgill ; for we get the convolutus- 

 beds as the lowest zone developed, and above it the remaining zones 

 of the Middle Skelgill, and all the zones of the Upper Skelgill Bods 

 occur just as there, so that further description is unnecessarj'. The 

 strike-fault below the shales of the convolutus-zone is marked by a 

 depression down which a rivulet trickles from a swamp in the field 

 above, and this fault appears to bring the convolutus -beds actually 

 against the Coniston Limestone, though there is a short interspace, 

 marked by the above hollow, in which no rock is seen. 



Stile End. 



The Stockdale Shales are apparently shifted to a slight extent by 

 a dip-fault, or probably a complex of such faults, running down the 

 Long Sleddale valley ; but as the lower parts of the valley are here 

 occupied by alluvium and drift, no section of the beds is seen until 

 after mounting the hill on the west side of the valley for a con- 

 siderable distance. About halfway up the Stile End Pass, shales 



Fig. 4. — Section near Stile End. (Scale 12 feet to 1 inch.) 



Abo 



A6 6 



belonging to the Dimorphograptus-zone are seen cropping up on the 

 moorland ; but the exposure is a small one and of little interest. 

 Still higher up, and a very short distance below the summit of the 

 pass, on the Long Sleddale side, a section of the Skelgill Beds is 

 found on the right bank of a small stream to the south of the path 

 (see fig. 4-). 



The base of the AshgiU-Shales series occupies the left bank of the 



