H. A. Nicliohon — On the Lake District. 107 



again. The trap can be traced along the strike for some two or 

 three hundred yards, hut no trace of it appears on the side of 

 Swinside, a little to the west of Eosetrees. These phenomena are 

 caused by the existence of an enormous E.N.E., and W.S.W. fault, 

 whereby almost the whole — if not the whole — of the Skiddaw Slates 

 are repeated to the south of this point. The existence of this fault was 

 determined by me in November, 1868, and I made out at that time 

 that the ujDper boundary of the Skiddaw Slates, instead of running, 

 as formerly supposed, up the vale of Newlands to the foot of 

 Buttermere, was really to be found some three miles to the south of 

 this line, passing by Lowdore, High Lowdore, Grange, and the 

 Hollows, in a south-west direction towards the head of Buttermere. 

 These facts will be rendered easily intelligible by the accompanying- 

 section.^ 



Fault. 



Fig. 1. Section from Portingscale, along tlie west side of Derwentwater, to Castle Crag in 

 Borrowdale. Length of section five miles. 

 a. Skiddaw Slates. 



6. Felspathic trap, forming the base of the Green Slate Series. 

 c. Cleaved Breccias and felspathic ashes (Green Slates). 



Proceeding now to the east side of Derwentwater, the Skiddaw 

 Slates are seen at various points between Lowdore and Grange. 

 They form the lower portion of the ledge over which Watendlath 

 Beck falls to form the celebrated cascade of Lowdore, the upper 

 portion of the ledge being formed by the felspathic trap, which 

 constitutes the base of the Green Slates. They are well exhibited, 

 also, in a field about half way between High Lowdore and the 

 village of Grange. They possess here all their usual character, and 

 dip E.S.E. at GO'^. They form a number of ice-worn bosses on both 

 sides of the road, and they are immediately succeeded by a fels- 

 pathic trap of a dark-green colour, compact, and fine-grained, which 

 forms the northern end of Grange Fell. The dip of this trap could 

 not be accurately determined, but its apparent inclination is small. 

 Crossing to the western side of the valley of Borrowdale, the junction 

 between the Skiddaw Slates and the Green Slate Series is very well seen 

 near a farmhouse called the Hollows, about three-quarters of a mile 



1 The further continuation of the Newland's Valley fault to the east is stopped 

 by a north and south fault which must occupy the line of Borrowdale and Derwent- 

 water. "Westwards it appears to be cut off by the great mass of intrusive felstone- 

 porphyry which forms the group of mountains between Buttermere and Eunerdale, 

 and of which Eed Pike, High Stile, and High Crag, are amongst the more striking 

 elevations. 



