XXIII.—The Glacial Deposits of Tullos and the Bay of Nigg, Aberdeen

Extract

A series of extensive temporary exposures in glacial deposits, partially filling an abandoned valley of the River Dee immediately south of Torry Hill, Aberdeen, has thrown some light on the late glacial history of the Aberdeenshire coastal strip. These deposits consist of rather more than twenty feet of fine, well-stratified sediments, similar to sediments recorded in other parts of the city of Aberdeen, and at a number of points along the coast almost as far as Peterhead.

These sediments, which were first mentioned by T. F. Jamieson (1858), were not differentiated by him from the red boulder clay found also in this area. A. Bremner (1915), the only worker to publish important communications on the glaciology of the area since Jamieson, has explained the sediments as deposits formed in glacial lakes when an ice-sheet filling the North Sea dammed the natural drainage. Bremner (1931) believed that three separate ice sheets had succeeded one another in North-East Scotland. The ice sheet responsible for damming up the waters in which the sediments under discussion were formed was the second of these. It moved in a northerly direction in this area, bringing with it erratics from the Old Red Sandstone of Strathmore. The third ice sheet was local. Movement was eastwards from the high ground towards the sea. According to Bremner, this ice failed to reach the coast at some points, as, for instance, immediately south of the Bay of Nigg. However, in the area of Aberdeen city this ice is supposed to have given rise to the morainic topography which backs the beach.