S. A. Nicholson — On the Lahe District. Ill 



less than a mile to the east. The north-eastern extremity, therefore, 

 of Eycott Hill rests upon the lower beds of the Skidclaw Slates. From 

 the above description it will be seen that there is the most complete 

 discordance between the two formations ; the strike of the two being 

 at variance by as much as nearly 80°, whilst the dip of the lower 

 formation is nearly double that of the superior. 



(II.) Shiddaw Slates and Green Slates beneath the Penine Bange. — 

 Commencing at the north-western extremity of the Lower Silurian 

 area beneath the Penine chain, the lower beds of the Skiddaw Slates 

 are seen at Mickle Aw Fell and in various parts of Eake Beck, near 

 Melmerby, dipping S.S.E. at from 50° to 65°. Similar hard and 

 flaggy beds are seen right under the base of Caterpellct Hill, dipping 

 in the same direction at 65°, and directly surmounted by a green 

 felspathic trap which forms the base of the Green Slates. This trap 

 forms the mass of Caterpellet and rises on the N.E. into Cuns Fell, 

 where it also reposes upon the lower beds of the Skiddaw Slates. 

 On the south-eastern side of Cuns Fell, in Ousby-dale Beck, the 

 upper, shaly beds of the Skiddaw Slates are seen dipping N.N.W. at 

 70° ; and lower down the stream, immediately to the south-east 

 of Caterpellet, similar beds are seen dipping N. at 65°. Tliese are 

 directly overlaid by a light-brown felspathic trap, containing crystals 

 of felspar, which form the ridges to the S.E. of Ousby-dale. The 

 appearance of the Skiddaw Slates in Ousby-dale Beck is probably 

 due to a sharp anticlinal, but may possibly be produced by a fault. 

 Be this as it may, it is clear that to the N.W. of Caterpellet, the trap 

 which forms the base of the Green Slates rests upon the loioer beds 

 of the Skiddaw Slates, whereas to the S.E. of Caterpellet the same 

 trap reiDOses iipon the upper, shaly beds of the same. Further to the 

 S.E. a similar felspathic trap is seen in Ashlock Syke, and again in 

 Ardale Beck, resting upon the upper, shaly beds of the Skiddaw 

 Slates, which appear to have a nearly vertical inclination. Still 

 further to the S.E. the Skiddaw Slates are found occupying the 

 Westmorland side of Crowdundale Beck, and extending from this 

 stream to Knock-ore-gill Beck. In Crowdundale, and in its tributary 

 Ellengill Beck, the upper, shaly beds of the Skiddaw Slates dip 

 N.N.W. at 70°, and are overlaid by the porphyries of Moray and 

 Grumpley Hills on the north. To the south the strata fold over, 

 and in Knock-ore-gill Beck, on the S.E. side of Burney Hill, similar 

 shaly beds are seen dipping nearly S. at froin 50° to 60°. These are 

 succeeded by the yellowish -brown felspathic trap of Knock Pike, 

 which is in turn succeeded by a series of flaggy shales, which occupy 

 Swindale Beck, and dip S.S.E. at about 45°. The remainder of the 

 Lower Silurian area beneath the Penine chain offers nothing which 

 bears specially upon the relations between the Green Slates and 

 Poi-phyries and the Skiddaw Slates. 



(III.) Skiddaio Slates near the foot of Ullesivater. — In a small area 

 close to the foot of Ulleswater, the upper shaly beds of the Skiddaw 

 Slates are seen in the lower part of Aik Beck, dipping S.S.E. at 

 angles of from 50° to 60°. In the higher part of the stream, these 

 are overlaid by the inferior portion of the Green Slate series, some 



