EOCENE PERIOD.
Switzerland.—In a coarse conglomerate belonging to the “flysch” of Switzerland, an Eocene formation, there are found certain immense blocks, some of which consist of a variety of granite which is not known to occur in situ in any part of the Alps. Some of the blocks are 10 feet and upwards in length, and one at Halekeren, at the Lake of Thun, is 105 feet in length, 90 feet in breadth, and 45 feet in height. Similar blocks are found in the Apennines. These unmistakably indicate the presence of glaciers or floating ice. This conclusion is further borne out by the fact that the “flysch” is destitute of organic remains. But the hypothesis that these huge masses were transported to their present sites by glaciers or floating ice has been always objected to, says Sir Charles Lyell, “on the ground that the Eocene strata of Nummulitic age in Switzerland, as well as in other parts of Europe, contain genera of fossil plants and animals characteristic of a warm climate. And it has been particularly remarked,” he continues, “by M. Desor that the strata most nearly associated with the ‘flysch’ in the Alps are rich in echinoderms of the Spatangus family which have a decided tropical aspect.”[190]
But according to the theory of Secular Changes of Climate, the very fact that the “flysch” is immediately associated with beds indicating a warm or even tropical condition of climate, is one of the strongest proofs which could be adduced in favour of its glacial character, for the more severe a cold period of a glacial epoch is, the warmer will be the periods which immediately precede and succeed. These crocodiles, tortoises, and tropical flora probably belong to a warm Eocene inter-glacial period.