180 
Proceedings of the Royal Society 
the gravel deposits which form so marked a feature on the south 
shores of the Moray Firth. 
III. — THE LIVER-COLOURED CONGLOMERATE. 
On the east shore of Loch Ness, opposite this granite, extending 
from Loch Ashie to a little south of the Fall of Foyers, stretches a 
high ridge formed of Old Eed conglomerate, of which also the great 
mass of Mealfourvounie on the opposite shores of Loch Ness wholly 
consists, up to its very summit (3060 feet), which is the highest 
point attained by this basal deposit of the Old Red of Scotland. 
This conglomerate, on the east side of the loch, is best seen on the 
Stratherrick road from Inverness, where it runs above Loch Duntel- 
chaig, south of its junction with the roadtoDores, and along the side 
of Loch Kecklish (Ceo-glash), which lies between Loch Duntelchaig 
and Bochrubin. Here it forms a series of very striking precipices, 
vertical, bare, and cracked, overhanging the road and loch, and 
having a remarkable appearance, arising from their form and com- 
position. This conglomerate happens to contain in great abundance, 
imbedded in its matrix, a certain dark-purplish or liver-coloured 
quartzite, in pieces of considerable size. This quartzite is so marked 
and peculiar that it can be easily distinguished in any boulders in 
which it occurs, and it seems, so far as I have seen (and I have 
examined the most of the country minutely), to be peculiar to the 
conglomerate on this part of Loch Ness ; so that its existence in any 
conglomerate block is a very sure evidence of its parent site. A 
very good place to see it in situ is an abrupt little hill close by the 
junction of the Stratherrick and Dores roads, crowned by an ancient 
hill fort, called Caisteal-an-Duin-Riabhaich, or the Castle of the 
Grey Hillock, with rough enclosing walls, easily noted from the high- 
way. The fort is also worth visiting, on its own account, and for 
the fine view obtained from its summit ; and there this liver-coloured 
quartzite may be well seen embedded in the conglomerate which 
forms the mass of the hill. 
This special conglomerate is scattered to the N.E. of this 
point, in very numerous masses, onwards beyond Elgin. One 
peculiarity of this rock is that it is found so frequently in large 
blocks, often of immense size, — so large that they have attracted the 
attention of the old inhabitants and have received local names ; and 
