438 PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jufle 23, 



line the porphyry rises into the lofty chain of hills which separates 

 Buttermere from Ennerdale, comprising Ling Comb, Red Pike, High 

 Stile (2643 feet), and High Crag. Prom Scarf Gap the S.E. and S. 

 boundaries of the syenitic mass are continued across the valley of the 

 Liza (about 1| miles above Gillerthwaite), and thence to the south 

 of Ennerdale Lake by Ling Mell, Iron Crag, and the Side, to the 

 Revelin, all these hills being composed of the intrusive rock. All 

 along these boundaries the syeuite is overlain by the traps which 

 form the base of the green slate series, the latter appearing to suffer 

 no alteration near the Kne of junction. 



As regards the mineral characters of this great intrusive mass, 

 they are somewhat different in different localities. In the neigh- 

 bourhood of Buttermere, and indeed throughout the greater part of 

 its extent, it is merely a quartziferous porphyry, composed of a base 

 of reddish felspar containing numerous crystals of white felspar, 

 with specks of hornblende and grains of quartz disseminated through 

 it. In other localities, however, as at the head of Ennerdale, quartz 

 is present in considerable abundance ; and the rock then assumes the 

 characters of a true syenite. 



III. The Felstone-jporphyry of Carroclc Fell. 



This rock forms the summit and the northern spur of Carrock 

 Pell, near Hesket-new-market, where its occurrence has been de- 

 scribed by Prof. Harkness (Quart. Journ. Geol. Soc. vol. xix. p. 124). 

 The area which it occupies is not of any very grea.t extent, being 

 about If mile from E. to "W., and about a mile from JS". to S. 

 Throughout the greater part of its extent it is surrounded by trap- 

 pean rocks, which belong to the series of the green slates and por- 

 phyries, and which do not appear to have undergone any alteration 

 near the line of contact with the intrusive rock. Its eastern bound- 

 ary extends from a farm called Stone Ends, near Mosedale, north- 

 wards as far as Carrock Beck. Its northern boundary runs up 

 Carrock Beck, and is formed by the trajDS of West Pell and High 

 Pike, though the junction is nowhere visible. On the south it is 

 bounded by a singular crystalline rock which is seen near Mosedale, 

 and forms a mass of great thickness. At its south-western corner, 

 however, it becomes continuous with a mass of fine-grained granite, 

 which is seen in Grainsgill Beck (Brandy Gill), close to the junction 

 of this stream with the river Caldew. This fine-grained granite is 

 surrounded by metamorphosed, gneissic Skiddaw Slates, which are 

 seen almost in direct contact with it. It is, doubtless, as believed 

 by Prof. Harkness, in turn continuous with the coarse granite which 

 occurs higher up the valley of the Caldew, and which Prof. Sedgwick 

 described under the name of " the Granite of Skiddaw Porest." 



Admitting, as seems almost certain, that these three igneous 

 masses are directly connected with one another, and pass into 

 one another without a break, two facts are noticeable : — Pirst, 

 the strike of the igneous masses conforms to that of the stratified 

 rocks amongst which they are situated. Thus the strike of the 



