442 THE FRESH-WATER LOCHS OF SCOTLAND 
have been driven westwards for miles. In other words, the rocks in 
that region behaved hke brittle, rigid bodies which snapped across, 
were piled up, and thrust westwards in successive slices. 
These great displacements were accompanied by differential 
movement of some of the rocks, which resulted in the development of 
new structures. These features are especially developed at or near 
the Moine thrust-plane, which is the most easterly of the powerful 
lines of disruption. There we find that the Lewisian Gneiss, Torrid on 
Sandstone, and Cambrian quartzite are sheared and rolled out, 
presenting new divisional planes parallel to that of the Moine 
thrust. 
Regarding the age of these post-Cambrian movements, it is 
obvious that they must be later than the Cambrian dolomites and 
limestones, and older than the Old Red Sandstone ; for the basal con- 
glomerates of the latter rest unconformably on the Eastern Schists, and 
contain pebbles of quartzite, dolomite, and limestone derived from 
the Cambrian rocks of the North-West Highlands. 
METAMORPHIC KOCKS EAST OF THE MOINE THRUST-PLAXE 
East of the Moine thrust-plane, whose outcrop runs from the 
eastern shore of Loch Eireboll S.S.E. to Loch Alsh, we enter the wide 
domain of the metamorphic rocks of the Highlands, which extend to 
the Highland border. Two prominent types of crystalline schists 
(Moine Series of the Geological Survey) have been traced over wide 
areas in the counties of Sutherland, Ross, Inverness, and across the 
Great Glen to the Grampians. These consist of granulitic quartzose 
schists and muscovite biotite schists which appear to be of sedimentary 
origin. They are associated with recognisable masses of Lewisian 
Gneiss, which present many of the structures so characteristic of the 
fundamental rocks along the western seaboard of Sutherland and Ross. 
From the relations which these rock-groups bear to each other in the 
field, the inference has been drawn that the Moine schists represent a 
sedimentary series resting unconformably on the Lewisian Gneiss, the 
latter being brought to the surface along inverted folds and exposed 
by denudation. In the east of Sutherland, foliated and massive 
granites appear which are intrusive in the Moine schists and produce 
contact metamorphism. 
In the Eastern Highland belt, ranging from the counties of Banff" 
and Aberdeen through Perthshire to Argyll, the Moine series is 
replaced by metamorphic rocks, undoubtedly of sedimentary origin, 
which have been termed the Dalradian series by Sir A. Geikie. These 
have been divided into certain lithological groups which have been 
traced more or less continuously from Banff' and Aberdeen to Kintyre. 
There seems to be an apparent order of superposition in these sub- 
