IV.—On Changes of Climate during the Glacial Epoch

If one were asked to put into a few words the general results which have been arrived at from a study of the Glacial deposits, he would probably say that these deposits gave evidence of a severe Arctic condition of things having obtained in this country,—that the gradual approach of this Arctic clim...

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Bibliographic Details
Published in:Geological Magazine
Main Author: Geikie, James
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1871
Subjects:
Online Access:http://dx.doi.org/10.1017/s0016756800193331
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756800193331
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Summary:If one were asked to put into a few words the general results which have been arrived at from a study of the Glacial deposits, he would probably say that these deposits gave evidence of a severe Arctic condition of things having obtained in this country,—that the gradual approach of this Arctic climate caused the disappearance from our area of the fauna and flora which had previously characterized it,—that during the continuance of the cold in Britain several speciesof mammalia appear to have died out in the more southern regions of Europe, whither they had migrated,—and that it was not until after our climate had become greatly ameliorated that these islands were visited by what are termed the “Post-glacial mammalia,” several species of which, however, had been denizens. of Britain and northern Europe inPre-glacial times. In short, our island, throughout the Glacial period proper, is commonly supposed to have remained a barren waste of snow and ice. But the evidence which has been accumulating during recent years will compel us, I believe, to modify materially these general inferences. So far from the Glacial epoch having been one long continuous age of ice, it would appear to have been broken up by many intervening periods of less Arctic, and even temperate conditions, during whichthe snow and ice disappeared from our low grounds, and the glaciers shrunk back into our mountain valleys. I speak, of course, of that portion of the Glacial epoch which was antecedent to the general submergence, and is represented by the Till or Boulder-clay of Scotland. la this short paper I propose to give an outline of the facts upon which these conclusions are based. But before doing so it may be well to point out the order of succession of the Scottish drift deposits, which is now no longer a matter of dispute. Beginning with the lower beds, we have the following sequence