

116 



SCOTLAND. 



Upper 

 Gallery. 



"Wall-case 45 



serpentine on the shores of the straits south of the Holy, 

 head road. Contained in metamorphic Cambrian rocks. 



The serpentinous rocks of Anglesea and Caernarvon- 

 shire are metamorphic, and not irruptive. They have 

 a layered (and almost a foliated) look, and are full of 

 numerous small twisted contortions, like the ordinary 

 foliated rocks of the country. The major part of Anglesea 

 consists of foliated rocks, which are probably the equiva- 

 lents of the purple and green Cambrian slates and grits of 

 Nant Francon and Llanberis. 



124. 



Metamorphic rocks from Scotland. 



125. — Greenish grey siliceous grit, altered, near 



Shandon, Gare-Loch, Dumbartonshire. 



126. — Grey siliceous grit, metamorphic, Shandon, 

 Gare-Loch, Dumbartonshire. 



This rock is much altered, and contains crystals of felspar 

 and numerous semi-crystalline granules of white and pale 

 blue quartz. The district is penetrated by felspathic dykes : 

 No. 127. 



127. — Felspathic trap, with small crystals of black 

 mica. Like some of the Cornish Elvans : (Case No. 6.) 

 Pierces No. 126. 



128. — Gneissic mica -schist, near Arrochar, Loch Lo- 



mond, Argyleshire. 



finely foliated lamince of quartz 



and mica, with a few quartz grains. 



129. — Gneissic mica-schist, Arrochar, near Loch Long 

 Head, Argyleshire. More strongly foliated contorted gra- 

 nular quartz and mica. 



130. — Ditto, wavy. 



131. — Gneiss, passing into granite, Strontian, Argyle- 

 shire. Felspar, quartz, and black mica faintly laminated, 

 very crystalline. 



132. — Junction of granite and mica slate, Stron* 

 tian, Argyleshire. Mica slate formed of black mica very 







f 



i 



f 



: 





i» 



Jli 



P 



151 



W 



1 



IJi 



12! 



HI 



■ 



