114 



METAMORPHIC ROCKS OF MALVERN, 



Upper 



GA-LLERY. 



Wall-case 45 



110. — Syenite, hornblende, felspar, and blue transit 

 cent quartz or siderite. A little north of the Wych, near 

 Malvern. Map 55 S.E. This rock is associated with 

 gneissic rocks, as above. 



111. — Quartz and felspar coated with serpentinous 



matter. 



112. — Ditto. This specimen, when a fresh fracture of 

 the interior is obtained, shows a kind of rude gneissic folia- 

 tion, 111 and 112 are from rocks close to the eastern 

 boundary fault of the Malvern hills. The ground seems 

 much broken, and the fragments are coated with soft serpen- 

 tinous matter, marked by " slickenside" polish. (See also 



of Great Britain," 



"Memoirs of the 



Geological Survey 



Phillips, vol. ii., p. 44.) 



113. — Gneiss, very crystalline, exhibiting strong foliations 

 of felspar and quartz, interlaminated with mica. North 

 Hilly Great Malvern, Worcestershire. Map 55 S.E. 



114. — Syenite, very felspathic. Felspar, quartz, and 

 hornblende. North Hilly as above. 



This rock shows a feebly foliated structure, and may pos- 

 sibly be the last stage before the gneiss passes fairly into 

 granite, of which the Malvern Hills is partly composed. 

 In these hills, such passages are so frequent, that it is often 

 impossible to draw any absolute line between the meta- 

 morphic and igneous rocks. 



■ 



Metamorphic rocks of Caernarvonshire. 



115. Gneissic rock, foliated. Aberdaron, Caernarvon- 

 shire. Map 76 S. Composed of foliations of quartz, sil- 

 very mica, and calcspar. 



116. — Ditto, without mica, and with a little hornblende. 

 Same locality. 



117. — Red ribboned jaspar. Forth Dinlleyn Head, 

 Caernarvonshire. « The rock of Porth Dinlleyn Point is a 

 kind of coarse serpentine, with nests of red jaspar appa- 



$ 

 I 



\i 



t 



¥ 



J 



lft 



p 







I 



t 



htl 



