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GRANITIC PORPHYRIES. 



235 



89— Granitic porphyry, from the central parts of a 

 dyke, and composed of quartz, a small proportion of mica 



felspar and jcAor/, some in crystals. 



Qua 

 Cornwall. 



Map 31. 



Penhale Cliffs (South side), 



*i. 90 *T P f r ' ° f a GEANITE DYKE > apparently cutting 

 through the schistose rocks of the district, and is probably 



the continuation eastward of JSos. 89. 



Map 31. 



It is 



quarried for building stone and road material.— St.' Cubert 



Cornwall. 



91— Felspathic porphyry, composed of disseminated 

 crystals of schorl, in a fine-grained felspathic base. It forms 

 part of an el van dyke traversing granite. Map 31.— Pen- 

 struthal Mine, Cornwall. 



92.—GRANITIC porphyry, composed of a roseate fel- 



No 



) 



hitefelsp 

 Map 30. 



f flesh-coloured felspar 



Map 30. 



and plates of brown mica. (See 

 Tremore, near Bodmin, Cornwall. 



93— Granitic rock. Crystals __ „ w , 



and ^arte in a felspathic and hornblendic base. Ma „ w 

 It forms part of the granitic rock noticed No. 80, and is 



employed for roads— Hill on the South side of Endcllyon 

 Cornwall. J * 



94— Granitic porphyry, composed of crystals of quartz 



and specks of mica in a greyish-white quartzo-felspathic 

 base. Map 30. L 



It forms part of the same granitic dyke noticed Nos. 71 

 and 78. ^ It 1S used for roads and buildings, for both of 

 winch it is a good material— Near Camelford, Corn: 



< Granitic dyke ; the northern portion, as far as is 



visible above the level of the sea, of the dyke noticed 97. 



wall. 

 95. 



Map 



felspar, and mica. 



^v liA x 6 uunenm unaer tiie name of ' 



•H atergate Bay, Cornwall. 



96— Granitic rock, felspathic base containing disse- 



ifelspa 



■ 



UrPER 

 Gallery. 



Wall-cases 

 6 and 7. 



