^8 Walk from Aberdeen 



granite, some of these several hundred feet thick. From these 

 beds of granite, veins of the same rock shoot out on both sides 

 into the bounding slaty strata. In other parts, distinct veins of 

 granite were observed waving through the hornblende-slate. We 

 also examined particularly the effects of the granite-rock on the 

 substance of the slaty strata, and their different positions, as 

 connected with the intrusion of the granite. It is worthy of re- 

 mark, that, in some veins, one part of the rock was quartz-rock, 

 like that of the Lion's-Head, while other parts were composed 

 of red or grey gi-anite. The micaceous hornblende-slate is used 

 as a roofing material, clay or roofing slate not occurring in this 

 district *. 



Having reached the mouth of the glen, we continued our 

 examination along the course of the Clunie water, and the hills 

 that bound it, to the Castleton. The stratified rocks in this 

 direction we found to be mica-slate, quartz-rock, gneiss, and 

 hornblende rock and slate. Among these, in the form of veins, 

 or in apparent beds, that is, in branches of veins, and varying 

 in size from a few feet to many yards in breadth, and many fa- 

 thoms in extent, we noticed granite, felspar-porphyry, granite- 

 porphyry, and hornstone-porphyry. The slaty rocks exhibit 

 many interesting varieties of structure, which our limits will not 

 allow us to describe. In some places the gneiss was disposed 

 as represented by this figure. 



• Shell-marl is met with in the glen in small quantity on the side of Loch 

 Callader, consequently at a very considerable height above the sea, although 

 not so high as the shell-marl on the mountain of Ben-i-gloe in Glen Tilt. 

 Sir T. D. Lauder mentions shell-marl, in which, as is often the case, lacus- 

 trine and land helices, f:c. are intermixed, at a great height, in the farm of 

 Inchrory, in Glen Aven. 



