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GRANITE. 



227 



42. 



flesh-coloured and white) 



£ felsp 



two varieties (black and 



white), quartz, and schorl, the latter in small quantity. 

 Map 33.- 



•Near Penzance, Cornwall. 

 43. — Granite, composed of quartz, ivhite 



felsp 



This granite forms a 



mass which rises through a system of slate beds, having an 

 east and west strike, and seen to be fossilliferous, near New 

 Quay. The slates are much altered around this granite, 

 which is schorlaceous along its northern boundary. This 

 rock might be advantageously employed for purposes in 

 which granite is used ; large blocks of it are scattered over 

 the northern flank of Belovely Beacon. Passes into No. 63. 

 Map 30 — Belovely Beacon, near Roche, Cornwall 



44. — Fjne-grained granite, composed of quartz, schorl, 

 and much silvery mica. Map 25. — Dartmoor, Devonshire. 



45. — Granite, a base of quartz and felspar, containing 

 large crystals of felspar (in a decomposing state), and semi- 

 crystallized quartz, with schorl, a green steatitic mineral, and 

 a little mica. (See "Report on Cornwall/' p. 162.) Map 

 31. — West side of St. Agnes Beacon, Cornwall. 



46. — Large-grained granite, composed of highly crys- 



- 



crystals), 

 Trink 



k felspar, with white felsp 

 schorl, quartz, and a little black mica. Map 

 Hill, near St. Ives, Cornwall 



47. — Porpiiyritic schorlaceous granite, composed of 



large well-defined 



flesh-coloured felsp 



semi- crystalline quartz, in a base of felspar and quartz, with 



a few specks of schorl. ( S 



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Map 31 — West side of St. Agnes Beacon, Cornwall. 



p. 162.) 



48, — Schorlaceous granite, composed of a small- 

 grained mixture of felspar and quartz, with disseminated 

 portions of schorl, and a little mica. 



This rock cuts the great mass of the granite in the 

 manner of an elvan dyke, and holds a north-western 

 course towards the west of Chapel Carn Brea. Map 33. 

 Mayon or Mean, near the Land's End, Cornwall. 



h 2 



Upper 

 Gallery. 



Wall-cases 

 6 and 7. 



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