1862.] HARKNESS SKIDDAW SLATE SERIES. 131 



however, on the east side of the high road, a small quarry in which a 

 felstone occurs, intermediate in character between a syenite and the 

 greenish rocks ; and a similar rock is also seen south-west from Wast- 

 dale Crag in the direction of Long Sleddale, where it is known under 

 the name of " flint." It is probably a mass of plutonic rock having 

 the same origin as the Wastdale Crag syenite, but possessing a less 

 crystalline nature in consequence of more rapid cooling from having 

 been in immediate contact with the greenish-grey rocks. 



§ 6. The Skiddaw Slates of Black Comb. 



The most southerly position occupied by the Skiddaw slates in 

 Cumberland or in Westmoreland is Black Comb, a mountain rising 

 abruptly to the height of 1919 feet, in the south-west of Cumber- 

 land ; it is surrounded on all sides, except the west, by the greenish- 

 grey rocks which succeed the Skiddaw slate series in the north of 

 England. On the west side, Black Comb is margined by a compa- 

 ratively low and flat tract of country, composed of the Trias sand- 

 stones extending southward from St. Bee's Head, and flanking on the 

 west side the Silurian rocks and their accompanying granites and 

 syenites. 



To the south of Black Comb there is a flat tract of country which 

 separates this mountain from the greenish-grey craggy rocks of Mil- 

 lom, and in which no rocks are seen, the area being covered with till 

 and soil. Still further south, greenish -grey rocks occur, exhibiting 

 their usual broken outline, and presenting bold escarpments towards 

 the north — a feature generally accompanying their line of outcrop, 

 while on their dip they present commonly a less rugged aspect. To 

 the S.S.E., at Millom, these greenish-grey rocks pass under the 

 Coniston limestone and Coniston flags, which also dip S.S.E. 



Fig. 6. — Section across Black Comb (5 miles). 



N. Whicham. S. 



, Stoneside-fell. Black Comb. (Till and soil.) Millom. 



a a Fault. a b 



a. Skiddaw Slate, b. Green slate, porphyries, &c. 



On the north side of the Whicham valley (the flat interspace just 

 alluded to, where the southern flanks of Black Comb exhibit the 

 Skiddaw slates) the beds dip N.N.W. 



Portions of the southern escarpments of this mountain have been 

 wrought for slate ; and among the debris of the quarries Graptolites 

 may be found, though from the Black Comb beds I have obtained 

 only one species, namely, Gh~aptolites Sagittarius. The position of the 

 strata here shows that they are very low down in the Skiddaw slate 

 series. 



k 2 



