AND QUARTZ DEPOSITS OF ASSYNT. 361 
northern parts of Sutherland is found overlaying its quartz 
rock ; and “this relation of quartz rock of undoubted mechani- 
eal origin to highly crystalline gneiss is a fact,’ remarks 
Professor James Nicol, in his “ Guide to the Geology of Scot- 
land,” “of considerable importance, though merely what might 
have been anticipated on the metamorphic theory.” I visited, 
two years ago, the district near Whiton Head, in which the 
sections occur that are said most thoroughly to demonstrate 
this superiority of the gneiss to the quartz rock, but was pre- 
vented from examining them by a tract of wet and very 
boisterous weather. There seems, however, to be a link want- 
ing in the evidence, in its bearing on the matter specially in 
hand,—the position of the Assynt deposits. The gneiss of the 
Moin,—a dreary waste, that stretches between Loch Eriboll 
and the Kyle of Tongue,— does seem to overlie the quartz 
rock of Whiton Head, just as in many other localities genuine 
gneiss holds, on the small scale, a superior position to genuine 
quartz rock; but it has, perhaps, still to be shown that the 
quartz rock here is at all of the same age, or occupies rela- 
tively the same place, as that which in Assynt overlies the 
calcareous flagstones, and forms the summit of Ben More. 
The nearest Red Sandstone to the gneiss and underlying 
quartz rock of Whiton Head is that. of Craig na Vrechan, at 
Tongue ; and ?¢ very decidedly overlies the gneiss. But this 
special point I do not profess to have examined. 
In conelusion let me remark, that while, from the reasons 
adduced, I have been led to conclude that the sandstone 
deposit of the west of Sutherland, with its associated quartz 
rock and limestone beds, represents the Lower Old Red Sand- 
stone of the eastern coast, I do not regard the conclusion as 
founded on other than merely a strong probability. In specu- 
lating on the true place of a deposit in which fossils do not 
occur, and whose stratigraphical relations to the well-known 
31 
