J. F. Campbell Collection > Something from the gold diggings in Sutherland

Prospecting. 5
like blocks of lapis lazuli above the plateau of copper and silver.
This gorge of Shin clearly was one outlet from a great central sea
of ice. The river has quarried its own bed since the ice melted ;
but rocks and drift in the hollow prove the extinct glacier, mark its
course, and measure its depth. The whole plateau, which is seen
from Lairg, is dotted with great stones. These, and the heather
and peat amongst Avhich they stand, rest upon various kinds of
drift. It is seen by the roadsides, in gravel-pits, and in the sides
of burns. Every here and there a stream or a road-cutting has
cleared the drift and exposed the rock-surface. Where it appears
it invariably is worn or weathered ; and it cuts through folded
beds of crystalline metamorphic Silurian rock all the way to the
hills. It is a surface of glacial denudation, i:)artly destroyed by
subaerial denudation, but generally well preserved by glacial drift.
Prom the highest point between Shin and Strath Fleet, Avhich is
about 500 feet above the sea, the railway descends through a
groove, which is too short to catch rain enough to make a river.
It contains a small burn. It certainly did once contain a large
glacier, an oflfshoot from the central icy sea. At the top of this
groove the rock is Silurian with Granite, lower is Old Red Sand-
stone, at the end is Lias or Oolite. A carpenter who cuts a groove
against the grain with a gouge makes a rude model of this moun-
tain gorge ; the grain of the rock is clearly seen from the train :
rock-surfaces and sections of drift abound beside the line. All the
rock-forms indicate motion down hill eastwards, and a depth of ice
equal to the top of the highest hill. Drift left in the groove is
glacial drift, overlaid by washed drift in some parts, overgrown
with heather, and fern, and grass, where the hand of the railway
engineer has spared nature's summer garments, which it is his
delight to tear and spoil. A traveller in search of glacial marks
can best learn the general system by crossing Scotland in some
other place. By starting from Dingwall, a continuous system of
fine lines engraved upon the surface of newly-bared rocks, which