XXXV.—On the High-Level Shelly Deposits, and their Bearing on the Question of Submergence, with Special Reference to the Recent [Third] Edition of Dr. James Geikie's “Great Ice Age.”

Abstract

Dr. Geikie had intimated that he no longer believed in a “great submergence” of about 1400 feet during the Glacial period, which had been inferred from such high-level shelly “drifts” as those of Moel Tryfaen, in Wales. These, he admitted, were most probably transported to their present position by an ice-sheet. He still, however, believed in a submergence of from 500 to 600 feet, the evidence for which rests on one or two instances of high-level shelly clay in the west and north of Scotland. Indeed, it may be said to rest on only one instance; for the Aberdeenshire “beds,” it was tolerably clear, could not be accepted as proofs of submergence; and another and, till lately, leading instance was in this edition “conspicuous by its absence.” Chapelhall, near Airdrie, which had figured so largely in connection with this subject for forty years, and on which great stress was formerly laid by Dr. Geikie, is now entirely omitted from the “Great Ice Age” without a word of explanation! It seemed unusual to allow one9s favourite facts thus to sink out of sight without some brief In Memoriam being inserted where they once figured so largely. But Chapelhall being thus summarily discarded, Clava, near Inverness, which had become known since the previous edition, might be said to be the single instance on which Dr. Geikie had to rest his proof of a submergence of about 500 feet. It was, so to speak, the “a9e button” which had to bear a great