Silurian Rocks of Westmoreland and North Lancashire. 535 



of Professor Sedgwick ; a bed only found in two localities, at Meer 

 Beck and a wood behind Low Hall, on the east of the road from 

 Ireleth to Kirkby Ireleth, where it is a dark-blue limestone very 

 like that of Coniston, dipping east 40°, of which only about a thick- 

 ness of twelve feet is laid open ; and at Turtle-bank Heights, south- 

 west of Blawith, where it has been quarried near the top of the 

 south-east face of the hill, and is a dark gray limestone, twenty feet 

 thick, striking north-east and dipping perpendicularly; from this 

 spot it runs by Cockin's-hill to the side of Coniston Water, half a 

 mile north of Water Gate. The fossils found by Mr. Marshall in 

 this bed near Blawith were identified as Lower Silurian species. 



5th. Flagstones and Slates of Kirkby Ireleth. — These are placed 

 by Professor Sedgwick below the Blawith limestone, No. 4, but 

 as Mr. Sharpe considers erroneously : nevertheless, although no 

 fossils have been found in them, he considers them to be the upper- 

 most bed of the Lower Silurian series, because they are always con- 

 formable to the undoubted Lower Silurian beds below them, and are 

 not equally conformable to the bedsabove. As this southern edge forms 

 the boundary line of the Lower Silurian formation, Mr. Sharpe traced 

 them carefully along their whole course, from their first appearance 

 rising from under the mountain limestone, on the east of Ireleth, till 

 they are hidden by the old red sandstone of Birkbeck-beck. Near 

 Ireleth it is only used for building- stone, but at Kirkby Ireleth are 

 quarries extending for a mile and a half along the range of the bed, 

 supplying dark-blue slates of very good quality. At Horse Spital 

 Quarry the beds dip south-east 80°, and the cleavage dips south-east 

 55°, both sets of planes striking north-east : this coincidence in the 

 strike of the bedding and cleavage planes is common in all this 

 district; yet at Lord Quarry, close to the last-mentioned, the beds 

 dip N.N.E. 20°, while the cleavage dips S.S.E. 70°. Further east 

 the rock is of inferior quality, and is rarely worked for roofing- slate: 

 its usual course is north-east, passing by Suberthwaite, Blawith, 

 Nibthwaite, at the foot of Coniston Water, where much building- 

 stone has been quarried, and the rock is well exposed, being a dark- 

 blue flagstone streaked with gray : between Oxen Park and Satter- 

 thwaite it dips north 50°, and N.N.W. 70°, and is lighter and more 

 striped than usual ; at Force Mill it strikes E.N.E. and dips N.N.W. 

 65°, and the cleavage has the same strike but is perpendicular : at 

 Satterthwaite the dip is north 45° : between Esthwaite and the 

 Ferry on Windermere the road runs near the upper edge of the bed, 

 which is well exposed close to the Ferry House, north of which spot 

 it reaches more than a mile up the shore of the lake. On the east 

 side of the lake it has been quarried north of Bowness. 



Eastward of Bowness, Mr. Sharpe corrects an error which he 

 committed in laying down this line too far south : he now traces it 

 nearly E.N.E. by Ing's Chapel, Row Gill, and Hugill Hall, dip 

 south-east 60° ; Monument Hill on the west side of Kentmere, dip 

 S.S.E. 80° to Fellfoot in Kentmere. The flagstone crosses Long 

 Sleddale at the Chapel, where it was found not worth working for 

 slate : at Bonnisdale-head Farm it gives a slate of fair quality, the 



