Vol. 65.] IN THE NEIGHBOURHOOD OF ESKDALE. 75 



north of Allen Crag (B.M. 2185.4), is a grey andesite. The 

 ground-mass is principally felspar and chlorite, and the phenocrysts 

 are chiefly of andesine. There are also large pseudomorphs in 

 calcite and chlorite after pyroxene, and smaller ones after biotite. 



The Dykes of Group 3. (Figs. 5 & 6, pp. 72 & 76.) 

 (Nos. 236 & 249 to 256.) 



There are numerous dykes connected with the intrusions at 

 Bursting Knotts and Peers Gill, and extending north-westwards on 

 the one hand to Kirkfell Crags, and south-eastwards on the other 

 to the neighbourhood of Angle Tarn, by way of Little Narrow Cove. 

 Descriptions of several varieties of rocks from this series follow. 



Specimen 236. — A. pink felsitic rock, much streaked with 

 dark-green matter. The ground-mass is cryptocrystalline, and 

 there are many porphyritic crystals of andesine, also pseudomorphs 

 in epidote after an amphibole or a pyroxene. Numerous veins of 

 epidote and chlorite traverse the rock, imparting to it the streaked 

 appearance noted in the hand-specimen. Evidently, the rock 

 is an altered andesite. The dykes in Little Narrow Cove show 

 some slight variation in character, but, on the whole, are of 

 andesitic type. 



Specimen 250 a is a fine-grained rock of granitic texture, 

 and consists of quartz, white felspar, and streaks of dark-green 

 matter. Microscopic examination reveals orthoclase and plagio- 

 clase, with large quantities of chlorite after biotite and of epidote. 



Specimen 250b is greenish in colour, and shows marked 

 porphyritic structure, felspar and dark-green pseudomorphs being 

 conspicuous. The ground-mass is felsitic, and there are large 

 phenocrysts of andesine, with a smaller quantity of orthoclase 

 and a few crystals of quartz which are corroded. Chlorite and 

 epidote, apparently after biotite, are also present in considerable 

 quantity. The rock moreover contains numerous small needles of 

 apatite. 



Specimens 251 to 256 are similar as regards their general 

 characters to No. 250 b, although they are somewhat finer in 

 texture. 



Specimen 249, at the foot of Skilling Crag, is distinctly 

 andesitic in character. It contains much epidote, with oligoclase 

 and andesine. There is no quartz, and the ground-mass is crypto- 

 crystalline. 



V. General Relations oe the Intrusive Rocks. 



The dykes on Kirkfell Crags consist of two sets (fig. 6, p. 76) — 

 one with a north-west to south-east trend, and the other running 

 in a north-east to south-west direction. 



Of these, the former consists of a group of two main dykes, 

 which, though cut and displaced by several faults, can be traced 

 by Kirk Fell and 111 Gill to Gable Beck, where they form the two 



