120 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [DeC. 17, 



Vale of St. John westward to Keswick, bound the Skiddaw slates of 

 this portion of Cumberland. 



The southern portion of this area rarely exhibits the rocks in situ. 

 The Skiddaw slates in this district occupy Flaseow Moor, a large 

 tract of barren country lying between the Keswick and Penrith lload 

 on the north, and the base of the hills just referred to on the south. 

 Two streams, having their origin among the greenish-grey rocks on 

 the south, intersect this moory district in their course to the Glen- 

 dermaken River, which flows into the Greta near Threlkeld. The 

 most easterly of these streams, called Troutbeck, after passing over 

 the greenish-grey rocks, reaches the moory country, and begins to 

 exhibit in its course the Skiddaw slates. In a small brook which 

 flows into Troutbeck from the west, these slates are considerably 

 contorted, but have predominant S.S.E. dips. A short distance 

 above the hamlet of Troutbeck this inclination is well seen, the 

 angle being 40°; and a gritty quartz-rock, strongly impregnated 

 with iron-pyrites, is here seen associated with the Skiddaw slates. 

 For a considerable distance below this hamlet, through the moor, 

 no exposures of rock occur ; but when the stream reaches near to 

 the Keswick Road, parallel to which it flows for some distance, we 

 have good sections of the Skiddaw slates, principally on the line of 

 strike. The stream in this portion of its course is called Gills-beck, 

 and here the Skiddaw slates, which are thin-bedded and of a dark 

 colour, have prevailing N.N.W. dips. Intercalated with the strata 

 are masses possessing the structure known as cone-in- cone, a feature 

 which accompanies the Skiddaw slates in some other localities. In 

 some portions of this section there are great contortions in the bed- 

 ding, and quartz-veins are abundant, running along the lines of the 

 contortions. 



N.N.W. 



Fig. 3. — Section from Matterdale to Uldale (12 miles). 



S.S.E> 



a. Skiddaw Slates, b. Granite, c. Green slate and porphyry. 

 d. Felspathic Traps. e. Carboniferous rocks. 



Westward from this stream we have the Skiddaw slates exhibited 

 in the course of another brook, which also traverses Flascow Moor 

 from the south. This, which is known as Mosedale-beck, rises from 

 the northern flank of Great Dod, and its upper portion is likewise 

 over the greenish-grey rocks. The junction of these with the Skid- 

 daw slates in the course of this brook is not seen, in consequence of 



