210 



ICE-ACTION IN THE EOCENE PERIOD. 



[Ch. X. 



E sclier von der Linth, Studer, Hiitimej^er, and Bacliiiiann are 

 clearly of opinion that they have been washed out of the 

 coarse conglomerate. The flysch of Bolgen, near Sonthofen, 

 also contains foreign blocks of considerable size, but neither 

 on them nor on any others have any glacial striae been as yet 



have to account not only for the wonderful 



varying 



from 



which they have travelled 



observed. We have to 



size of the granitic bio- 



diameter, but for the c 



which seems to be implied by our inability to refer them to 



any known source. They are distinguishable by their mineral 



character from all granitic erratics of the true or modern 



lacial period, such as are strewed over the surface of those 



districts of Switzerland where there is no outcrop of flysch 

 conglomerate. It has been alw r ays objected to the hypothesis 

 that these huge masses were transported to their present sites 

 by glaciers or floating ice, that the Eocene strata of nummu- 

 litic age in Switzerland, as well as in other parts of Europe, 

 contain genera of fossil plants and animals characteristic of 

 a w T arm climate. It has been particularly remarked 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 decidedly tropical aspect. The entire absence of 

 shells, or of organic remains generally, may perhaps bethought 

 to favour a glacial origin for the flysch, but this negative cha- 

 racter is too common in strata of every age to be of much 

 value, except in connection with other proofs of intense cold. 

 Nor must we disguise from ourselves the fact, that in the seas 

 of polar regions where icebergs abound at present there is by 



On the other hand, the 

 regular stratification and even fine lamination of portions of 

 the flysch cannot be said to be inconsistent with a glacial 

 origin, for on the Norfolk coast we see thinly laminated clays 

 devoid of organic remains forming an integral part of un- 

 questioned glacial drift. 



The great thickness of the flysch and the fucoids preserved 



means 



in a few beds of it, leads to the conclusion that it was of 



marine 



origin. 



To imagine icebergs carrying such huge 

 fragments of stone in so southern a latitude, and at a period 

 immediately preceded and folio-wed by the signs of a warm 





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