JURA. QUARTZ ROCK. 



rock, as no distinct account of it is to be found among 

 systematical writers. This rock is found in various parts 

 of Scotland, forming considerable tracts of country, 

 and holding, in point of extent, the next rank among 

 the primary strata to micaceous schist. Independently 

 of the space which it occupies in the four associated 

 islands, Lunga, Scarba, Jura, and Isla, it is found in the 

 Slate isles in small quantity; forming there part of a 

 series that occupies a large part of Argyllshire and will 

 immediately come under review. In the northern parts of 

 the mainland it forms a considerable tract, being very 

 conspicuous in Ross-shire and Sutherland, where it rises 

 into mountains of considerable elevation. It also occurs 

 on this coast, further to the south, in several places, as 

 in Arisaik and in Appin ; but in limited quantities, the 

 predominant rocks of this division of Scotland being mica- 

 ceous schist and gneiss. A very extensive tract of it 

 is found reaching from the southern shore of Loch Leven, 

 and the boundaries of Glenco, to the foot of Ben Nevis, 

 where it seems to terminate ; alternating here, as in most 

 other places, with micaceous schist, and, like that, reposing 

 on granite. It is also to be f6und on the east side of 

 Sutherland, and as already noticed, in Sky. 



The next district in which it predominates, lies toward 

 the east side of Scotland ; where it may be traced from 

 Ben Gloe in different directions over a considerable space. 

 To the westward, it is seen stretching towards Rannoch, 

 where it alternates with, and passes into, micaceous schist 

 and schistose gneiss ; thence tending to the southward it 

 forms the highest ridge of Schihallien, and terminates at 

 length in Glen Lyon. Eastward, it extends far through 

 Mar toward the mountains of Forfarshire ; while, in a 

 northern direction, it is to be traced for a considerable 

 space on the eastern flank of the granite ridge of Cairn 

 Gorm towards Tomantoule. In several parts of this 

 extent it is found to alternate with clay slate and lime- 

 stone, as well as with micaceous schist ; and, like all 



