392 
THE TERTIARY VOLCANOES 
BOOK VIII 
for it lies in Glen Sligaehan immediately to the south of the mouth of 
Harta Cony. The rounded eminence of Meall Dearg, which rises to the 
south of the two Black Lochs, belongs to the granophyre, while the rugged 
ground to the west of it lies in the gabbro. The actual contact between the 
two rocks can be followed from the side of Harta Cony over the ridge and 
down into Strath 11a Creitheach, whence it sweeps northward between the 
red cone of Kuadh Stac and the black rugged declivities of Garbh Beinn. 
There is no more singular scene in Skye than the lonely tract on the south 
side of Meall Dearg. The ground for some way is nearly level, and strewn with 
red shingle from the decomposing granophyre underneath. It reminds 
one of some parts of the desert “ Bad lands ” of Western America. Grim 
dark crags of gabbro, with veins from the granophyre, rise along its 
western border, beyond which tower the black precipices of the Cuillins, 
while the flaming reddish-yellow cones of Glen Sligaehan stand out against 
the northern sky. 
Having recently described in some detail the relations of the boss of 
granophyre at this interesting locality, I will only here offer a brief summary 
of the chief features . 1 The granophyre of Meall Dearg forms a marginal 
portion of the great mass of the Eecl Hills. It has broken across the 
banded gabbros, and also cuts an isolated boss of agglomerate in the ridge of 
Druim an Eidhne. Its line of junction is nearly vertical, but along part of 
its course the wall of gabbro rises higher than that of the more decompos- 
able granophyre. Hence the origin of the black crags that crown the red 
slopes of granophyre debris. Seen from a distance the basic rock seems to 
rest as a great bed upon the acid mass. 
The younger date and intrusive nature of the granophyre are well 
shown by the change in the texture of the mass as it approaches the rocks 
against which it has cooled. The ordinary granopliyric characters rapidly pass 
into a fine-grained felsitic texture, and this change is accompanied with the 
development of a remarkably well-defined flow-structure and of rows of 
spherulites which run parallel to the boundary wall. In a ravine on the 
west side of Meall Dearg, the lines of flow-structure and rows of large 
spherulites are seen to be arranged vertically against the face of gabbro. 
Further proof of the later date of the protrusion of the granophyre is 
supplied by abundant felsitic dykes and veins which traverse the gabbro, and 
some of which can be seen to proceed from the main body of granophyre. 
These intrusions will be described in the next chapter, in connection with 
the dykes and veins of the acid rocks. 
Additional evidence as to the posteriority of the granophyre to 
the gabbro has recently been obtained by Mr. Harker from a study 
of the internal structure and composition of the masses of these rocks 
which have been intruded into the agglomerate above Loch Kilehrist 
in Strath. He has found that the granophyre has there caught up 
from some subterranean depth portions of gabbro, and has partially 
dissolved them, thereby undergoing a modification of its own composition. 
1 See Quart. Journ. Geol. Soc. vol. 1. (1894) p. 212. 
