The stone age in Scotland / [Armand Donald Lacaille].

  • Lacaille, A. D. (Armand Donald)
Date:
1954
Catalogue details

Licence: In copyright

Credit: The stone age in Scotland / [Armand Donald Lacaille]. Source: Wellcome Collection.

    83/404 (page 51)
    7. THE EMERGENCE OF THE SEA-FLOORS Our acceptance of the Yoldia Sea as the equivalent of the Late-Glacial sea outside leads to the obvious inference that the uplift responsible for the extinction of that water body in the Baltic trough, and the formation therein of the Ancylus Lake, is equatable with the process of land recovery initiated during the retreat of the remnant ice in the British Isles (pp. 39-45). The whole movement, therefore, was far-reaching. It continued until the land away from the ice-centres had risen above its present height relative to the surrounding seas. As a result, the earlier outlines of north-western Europe were partially restored, and Britain was once more united to the Continent at several points. Owing to the later submergence associated with the development of the Litorina and Tapes Seas, to marine erosion, tidal scour, and the creation of sandbanks, the exact gain of the land is not certainly known. It is probable, however, that the 20-fathom line gives a fair indication of the amount of the uplift (map, Fig. 20). The territory then reclaimed from the sea included the Dogger Bank. This became a low-lying island on the northern edge of the great alluvial plain traversed by the extended lower courses of the rivers which now flow into the North Sea. The Strait of Dover was again raised, and at least partial connexion between south-east England and the Continent renewed. To the west the Channel was probably reduced to an arm of the sea which received the lengthened English and French rivers. Among the islands on the British south coast, the Isle of Wight became tied to the mainland and the Scillies were joined together. On the Atlantic side the uplift had marked effects on the maritime tracts and sea-floors. The shores of the Bristol Channel lay farther out than now, and the elongated Severn coursed between them and emptied into the outer sea. Northward, beyond the capes of Wales and Wexford, the waste of the Pleistocene drifts was exposed on the upraised floor of the Irish Sea, just as it would be on the contemporary North Sea plain. Much of Cardigan Bay became dry land. Anglesey was connected with North Wales and stretched farther westward. To the north, the Isle of Man stood above the elevated sea-bed which enlarged the north-western mainland of England. The Irish Sea, however, was not wholly converted into dryland, although