202 Notice of Ancient Moraines in Argyleshire. 



These ancient moraines are in general of a slightly curved 

 form, with the concave side facing the upper part of the val- 

 ley, but some are straight, as that of Hussern. 



The mounds E, F, D are perhaps the work of the glacier of 

 Corusk valley, but they may have been formed by that of 

 Glenmessan before the mounds A B existed. At n, right in 

 front of the opening of Corusk valley, there is a vertical pre- 

 cipice, 100 feet high, facing that opening, and as smooth as a 

 w r all of dressed masonry, though cut across the planes of the 

 mica slate. Might w r e suppose that the glacier issuing from 

 Corusk valley abutted against the rock here, cut it down ver- 

 tically, and smoothed it ? 



The valley of Glen Eck, which unites with Glenmessan at 

 m, contains many traces of glacial action. Abraded and 

 rounded rocks are numerous on the east side of Loch Eck, and 

 there are fine examples of striae and groovings from the level 

 of the water up to an elevation of 100 feet. They may be 

 seen at various points within three miles from the foot of the 

 loch, sometimes on highly inclined surfaces, and always run- 

 ning horizontally, or nearly so, leaving no doubt that a glacier 

 many hundred feet in depth had moved along the valley. The 

 loch is shut in at the foot by a flat, uneven mound of earth 

 rising 25 feet above its surface, and through which the water 

 has cut a winding passage. This mound is in reality the 

 commencement of a plain that extends two miles southward, 

 but it has much the aspect of a terminal moraine ; and when 

 we consider its size, materials, and position, as a barrier of 

 clay and gravel shutting in a narrow cavity ten miles long, 

 and rising 360 feet above the bottom of that cavity (for such 

 is the depth of Loch Eck), we are tempted to think that it 

 may be what its appearance indicates. If it ever was a mo- 

 raine, the rude stratification seen on the banks of the stream 

 shows that the materials composing its upper part must have 

 been re-arranged, and of course under water. 



We have seen that blocks embedded in the old boulder clay 

 have their upper surfaces striated in situ. The question, then, 

 presents itself, Do these striated blocks (which in some cases 

 lie very compact, and, as it were, in one plane) only occur at 

 one level, namely, at the top of the old, and immediately below 



