The Great Ice-Age and its relation to the Antiquity of Man

Abstract

II.

WE must next turn to beds which furnish conclusive proof of a return of cold conditions, the well-known shell-bearing clays found here and there along the coast of Scotland. The fossils and the physical condition of these beds both concur in telling the same tale, that an Arctic climate again prevailed in Britain. These deposits are marine, and have not been met with at a greater height above the sea than 360 feet, and they were therefore formed towards the termination of the period during which the land was emerging from the sea. Evidence of a similar change of climate is, however, found in the interior of the country. In the Highland glens and the high valleys of the Southern Uplands morainic deposits, distinguishable from those of the earlier ice period, are of common occurrence, sometimes scattered loosely over the mountain slopes, sometimes arranged in ridges or lines of mounds across the valleys after the fashion of terminal moraines. The climate, therefore, must have become again severe enough to allow of the accumulation of ice; but, since the second set of glaciers is shown by the moraines which they have left behind them to have been confined to the high ground, and each restricted to its own valley, the cold, must have been far less intense than during the period of the first glaciation.

The Great Ice-Age and its relation to the Antiquity of Man.

By James Geikie. (W. Isbister and Co. 1874.)