1862.] HAEKNESS SKJDDAW SLATE SEEIES. 121 



the peaty nature of the country at the base of the crags of the green- 

 ish-grey rocks. Below this peaty interval the Skiddaw slates occur, 

 and are seen in Moscdale-beck, consisting of contorted black shales, 

 like those of Gills-beck, having the cone-in-cone masses imbedded 

 among them. 



The Skiddaw slates in the course of this stream have a prevailing 

 N.JNT.W. inclination. They yield Graptolites Sagittarius *. 



The interval of country between the Keswick Road on the south 

 and the Glendermaken River on the north affords no exposures of 

 rock. In the Glendermaken, as it flows along the eastern base of 

 Souter-fell and south from Mungrisdale, the Skiddaw slates, of a 

 dark colour, are seen at intervals dipping S.S.E. At Mungrisdale 

 these Skiddaw slates are worked, and have a well-marked cleavage ; 

 but the surfaces of some of the strata very frequently show distinct 

 tracks. Tracks similar to those of Mungrisdale also occur at Two- 

 seats, near Threlkeld, on the south base of Saddle-back, which is on 

 the line of strike of the Mungrisdale beds. The strata at Mungris- 

 dale, some of which are flaggy, dip towards the S.S.E. at 55°. 



With reference to the Souter-fell ridge, which lies between Mun- 

 grisdale and Saddle-back, on its south side it has a very regular slope, 

 while on the north side it is more abrupt and marked by escarpments, 

 from which results a considerable development of " Screes." 



Among these " Screes," tracks are found resembling those of 

 Mungrisdale, and the rocks which produce the " Screes " dip S.S.E. 

 about 30°. On the opposite side of the valley of the Glendermaken, 

 north of Souter-fell, the ridge known as Bannerdale-fell is seen. 

 In the south spur of this ridge a considerable mass of chiastolite- 

 slate makes its appearance, and has been extensively wrought here. 



The first appearance of this mineral in the Skiddaw slates is 

 marked by the occurrence of chiastolite in the form of very small 

 dots, and some of the rocks so marked contain tracks. Following 

 the southern spur of Bannerdale-fell northwards, the chiastolite is 

 seen to become more abundant, and, on the higher portions of the 

 hill, obtains to such an extent as to constitute chiastolite-rock ; and 

 rocks of this nature form the ridges which occupy the southern side 

 of the Caldew valley. A southern spur from Bowscale-fell, called 

 Tongue, parallel to the southern spur of Bannerdale-fell, exhibits 

 similar rocks to those just described. 



Following the Glendermaken, between Souter-fell and Banner- 

 dale-fell, to its source, tracks occur, on the south-west flank of 

 Bannerdale-fell, in the unchanged Skiddaw slates which dip S.S.E. 

 Towards the north these slates become more black and glossy, and 

 have spots of chiastolite in them. A short distance brings on the 

 chiastolite- slates, and at the summit of the low ridge connecting 

 Bannerdale-fell and Saddle-back the chiastolite-rock occurs. 



* The streams which intersect Flascow Moor cut through a fine mass of glacial 

 debris, consisting of sandy clays containing imbedded boulders of the several 

 rocks which occur in the northern portion of the Lake-area. These boulders are 

 often very beautifully striated ; and on the surface of the moor large erratic 

 blocks are very common. 



