Yol. 6S.] TEE GLACIATION OF THE BLACK COMBE DISTETCT. 431 



that is, towards the head of the Nettle- Crags Channel. The 

 boulders are chiefly of Eskdale Granite and Borrowdale rocks, 

 but there are also small boulders and pebbles of soft Triassic 

 sandstone and Skiddaw Slate. Another pit showed a similar 

 section, consisting to a great extent of big granite-boulders in 

 granite-sand. Many of the granites were quite rotten, and 

 crumbled beneath the fingers. 



(a) The Damkirk Channel. — At the time of the initiation 

 of this channel the ice-margin, after a very small advance over the 

 gravels, lay in an almost north-and-south line between the western 

 «ide of the Kinmont Channel (350 feet approximately), Bootle Bank 

 (350-386 feet), and the shoulder of Black Combe, holding up a 

 small lake north of Bootle Bank. The outflow was first cut 

 through drift, but was finally sunk into the rock-floor. The intake 

 faces west, but the channel turns quickly southwards after crossing 

 the junction between granite and andesite. 



At its head the Damkirk Beck enters by a post-Glacial course, 

 and traverses Damkirk Bottom as a stream hardlj' more than a foot 

 wide, and an obvious misfit. At this part of its course the 

 channel is a steep-sided flat-bottomed valley, about 45 yards 

 wide and fully 70 feet deep. A few yards north of the road 



Fig. 9. — The Nettle-Crags Channel, loohing northwards. (Seep 











At*** 



[The original steepness of the walls is obscured by screes.] 



over Damkirk Brow it receives Oldclose Gill, which enters from a 

 post-Glacial ravine, and throws an alluvial cone across the valley 

 floor, forming a marshy tract to the north of it, which Damkirk 

 Beck is powerless to drain thoroughly (fig. 8, p. 430). 



After crossing the road the main valley makes a bend to the 

 south-east, receiving Grassoms Beck which cascades into it at 

 Oibson's Spout. This is joined by Damkirk Beck, and the com- 

 bination, under the name of Crookley Beck, traverses the valley 

 (here cut along the junction between andesite and slate) and leaves 

 it, on its western side, at Cat Crags, by its re-excavated pre-Glacial 

 gorge. The Glacial channel then swings to the south, its marshy 

 floor being slightly above the present alluvium of Crookley Beck. 



