Tour Scotland
Home Page

 


 



It is said that the death of a MacDonald of Clanranald is foretold by the appearance of a monster in the waters of Loch Morar. If the Morar monster has knowledge of the mysteries of life and death, perhaps it knows also about the origins of the deep that it normally inhabits. The monster has been dubbed Morag by locals.

This is a mystery indeed, because Loch Morar reaches the astonishing depth of 1017ft. It is the deepest lake or loch in Britain, deeper even than the neighbouring Atlantic, until the floor of that ocean pitches down the continental shelf over one hundred and thirty miles to the west. The 81,000 million cubic feet of fresh water contained in Loch Morar are separated from the ocean waters by a fast flowing river only nine hundred feet long. This river, the River Morar, is surely one of the shortest rivers in Scotland. It used to leap most of its descent of thirty feet in a fine waterfall, which is now tamed by a hydro-electric installation.

We know the fjords of Norway as long, narrow, rock-bound inlets of the sea, similar to most of the sea lochs of the west coast of Scotland. One of the characteristics of fjords is that they are shallower towards their seaward ends. Usually this threshold, which separates the rock basin of the fjord from the deeper water of the sea beyond, is not seen at the surface. At Loch Etive it is so near the surface, off Connel, that it creates a marine waterfall: the waters of the loch spill over the Falls of Lora towards the sea at the ebb and, at the flood, the flow is reversed. At Loch Morar, as with others such as Loch Maree and Loch Lomond, the threshold is exposed as dry land and the waters of the loch drain seawards by means of a short river. After the last Ice Age, when the sea level stood higher in relation to the land, these lochs would have been fjords.

During the period of maximum glaciation, when the erosive power of ice was at its greatest, the ice-shed, like the present watershed, lay towards the west of Scotland. Westward-moving ice flowing from the mainland moved more or less radially, overwhelming the Inner and Outer Hebrides and the Flannans but stopping short of St Kilda, which developed its own ice cap. As ice moved over the country any structural weakness in the rock, such as a line of fault, was exploited, resulting in rapid erosion.

Loch Maree and Loch Linnhe are obvious examples of such structurally controlled erosion. However, no such weakness has been proved at Loch Morar, which is excavated in hardened, largely sandy rocks belonging to the Morar Division of the Moine Group, originally deposited some 1000 million years ago. The east-west orientation of the Loch cuts across the rock structures, but is parallel to the direction of movement of the westward-flowing ice stream originating from the high country of the Ben Nevis region. The ice gouging through the Loch Morar trench must have been at least 4000ft thick. When this was channelled between the mountainous walls of the western part of the valley in which the loch is now situated, downcutting of the glacial basin was intense. However, as the ice moved westwards, it was able to spread out, as the westerly widening of the present loch demonstrates, and immediately its erosive power was reduced. As it reduced, so the valley bottom rose to form the threshold described above.

 

Return To Lochs and Rivers



Tour Scotland
Tour Edinburgh
Tour Island Of Skye

Rent A Self Catering Hoilday Cottage In Scotland

Share This Tour Scotland Web Page

Top Destinations
Tour Europe