1862.] HARKNESS SKLDDAW SLATE SERIES. 129 



On the south side of Scaleborrow, in Rossgill-beck, which flows 

 into the stream draining Swinedale, the Skiddaw slates are again 

 seen; and here they were formerly worked for slate-pencils. In 

 this locality the slates, which are somewhat shaly, are, by cleavage 

 and fine jointing, cut up into long thin pieces. Intercalated with 

 them are masses possessing the cone-in-cone structure, and which on 

 decomposing produce abundance of hydrated peroxide of iron, show- 

 ing their affinity in composition to iron-stone. The strata here are 

 much contorted, but on the whole dip S.S.E. 



Higher up Swinedale than the junction of Eossgill-beck, where 

 the rocks become prominent on both sides of the dale, they consist 

 of the hard greenish-grey grits, equally without distinct bedding 

 with those lying northwards, and to such an extent cut by vertical 

 joints that they have a columnar aspect. This exposure of the Skiddaw 

 slates in Eossgill-beck is doubtless the result of another anticlinal, 

 which, like that before alluded to, has a W.S.W. strike. 



In the course of the River Lowther, southwards from the junction 

 of Swinedale-beck, no rock is seen for a considerable distance. On 

 the east side of the river occurs the Carboniferous series, which 

 bounds the Silurians on the east. The lower part of the Carboni- 

 ferous rocks is well seen in the escarpment on the east side of the 

 Lowther, immediately above the ruins of Shap Abbey ; here also the 

 equivalents of the green slates and porphyries are seen in the 

 stream, and, in consequence of having been stained by the beds of 

 the Carboniferous series, they present a purple colour. 



Above Shap Abbey, a small stream enters the Lowther opposite 

 to the hamlet of Keld, and is called Keld-gill. Between this and 

 the Abbey there are abundant exhibitions of rock in the course of 

 the Lowther, all of which possess the greenish-grey colour and an 

 imperfectly bedded character. 



Southwards from Keld-gill, over that portion of Rafland Moor 

 which lies between this and another small stream, called Thornship- 

 gill, no good exposures of rock occur ; and this remark applies also 

 to the Eiver Lowther in the interval between the junctions of these 

 streams. 



The lower part of the course of Thornship-gill is over gravel 

 composed of small rounded fragments of Skiddaw slates; and on 

 following up the stream for a short distance, these rocks are seen in 

 situ. They consist of dark-coloured, shaly beds, like those of Ross- 

 gill and Eggbeck, enclosing masses which have also the cone-in-cone 

 structure. The strata here are much contorted, but the prevailing 

 dip is N.N.W. Quartz-veins intersect the beds, and have a N.W. 

 and S.E. strike. The slates here, like those of Rossgill, are much 

 broken up by cleavage and jointing ; and they have also been exten- 

 sively wrought for slate-pencils. This locality also affords fossils, 

 among which we have Graptolites Sagittarius, the branching forms, and 

 others too imperfect to determine. In one locality on the N.E. side of 

 Thornship-gill, porphyry is seen, which, from the dip of the slates, 

 must overlie the latter, and here consequently we have the same 

 sequence of strata that occurs at Eggbeck. 



VOL. XIX. PART I. K 



