184 
BATHYMETRICAL SURVEY OF 
The Assynt district furnishes impressive evidence of denudation by 
the removal of a vast covering of Torridon Sandstone, by the persistent 
eastward recession of that escarpment, by the stripping off of the 
materials overlying the successive thrust-planes, and also by the 
development of the present drainage system. It is a remarkable fact 
that south of the mountainous region of Assynt the watershed lies to 
the east of Cul Mor, Cul Beag, and the Coigach mountains in the less 
elevated platform of the Moine schists. It is evident that the present 
drainage system originated at a remote geological period, when the 
eastern or Moine schists extended far to the west of their present 
limits, and were arranged in the form of a dome round the displaced 
masses which now form the mountainous region of Assynt. It is highly 
probable, also, that before the glacial period the land stood relatively 
higher than at present, and that the rivers on the west side 'of the 
watershed occupy consequent valleys which extended far to the west 
of the present coast-line. 
Everywhere throughout the Assynt district, and especially in the 
mountainous region extending from Glas Bheinn to the Coigach area 
and over the plateau of Archaean gneiss, there is conclusive evidence of 
intense glaciation. Perhaps the most striking feature of the glacial 
phenomena of Assynt is the evidence pointing to the conclusion that 
during the maximum glaciation the ice-shed did not coincide with the 
existing watershed. From an examination of the striae indicating the 
direction of the ice-flow, and from the distribution of boulders, it 
appears that the ice-parting lay to the east of the present watershed. 
Indeed, the ice must have accumulated to a great thickness on the less 
elevated plateau occupied by the Moine schists east of the Ben More 
Assynt range and east of the Coigach mountains. 
The general movement of the ice at great elevations in this district 
was in a westerly direction, sometimes to the north and sometimes 
south of that point. For example, on Glas Bheinn, on one of the 
exposures of Archaean gneiss, at a height exceeding 2000 feet, the 
striae point W. 5° N. Again, on Beallach an Uidhe, between Glas 
Bheinn and Beinn Uidhe, at an elevation of about 2000 feet, the 
direction is west-south-west. East of Inchnadamph, on the quartzite 
of Beinn an Fhurain, between the 2000- and 2250-feet contour-lines, 
the striae run north of west. In the lofty pass crossing the Ben More 
range, that leads into Corrie Mhadaidh, at a level of 2750 feet, the 
direction is W. 10° S. or W.S.W. In like manner, on the long ridge 
of Breabag that runs northward from the Beallach of Coniveall, the 
average height of which is over 2000 feet, splendidly striated surfaces 
have been recorded which indicate an ice-movement in a westerly 
direction. 
Passing westwards to the mountains north and south of Loch 
Assynt, we find similar evidence of a westerly movement during the 
