hto 



GLACIERS : MORAINES OF NORTH WALES. 



tie 



ex. 



about 



2 a th er i 



ing 



a 



°M the 



i-anitc, or 

 olish of 



^^rvious 

 5 of lime. 



striated, 

 low, thi 



is 



•m 



of the 



Dniena 



of 



eous un- 



L 



The 



ugheneil 



remain 8 



tcre anJ 



itli tbos e 



A 



k 



of ** 



the ^ 



ass*"* 



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fro" 1 



P 



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ire 



17 



of ice ; and thus it happens that on the very summit of some Vtvek 

 tower-like crag, the sides of which have been rent by the GA fff_ ET » 

 frosts of untold winters, the student of glacial phenomena inS^Ji 

 sometimes finds yet intact the writing of the glacier ; while 

 below on its sides all trace of the ice-flood has long since dis* 

 appeared. These things may seem almost incredible to those 

 who are unaccustomed to read the records of many terres- 

 trial revolutions in the rocks ; but, nevertheless, of these 

 extinct glaciers it is true that just as a skilful antiquary, 

 from the wreck of some castle or abbey of the middle ages, 

 can, in his mind's eye, conjure up the true semblance of 

 what it was when entire, so the geologist, from the signs 

 before him, can truthfully restore whole systems of glaciers 

 that once filled the valleys of the Vosges, the Highlands, or 



In other 

 d glacier 

 ill retain 



ings, and of Wales.* 



they had 



exposure, 



I general 

 >s rough- 



2 present 



3 deeper 

 but even 

 yoft after 



Specimens illustrative of the ancient glaciers of North Wales, 

 and of the glacial drift (Newer Pliocene or Pleistocene). 



60. — Moraine mud in its native state, from a well-marked 



moraine at the upper end of Cwm-ydlan, south of the peak 

 of Snowdon. This mud, and that in the other trays con- 

 taining Welsh moraine matter, bears the closest resemblance 

 to the moraine mud of the Swiss glaciers in some of the 

 trays between Nos. 1 and 20. 



61.— Moraine mud, as above, containing small angular 

 stones in native proportion ; Ctvm-y-llan, Snowdon. 



62 and 63. — Moraine mud of two descriptions, partly 

 separated from larger material, with small angular and 

 scratched stones ; Cwm-y-Uan, Snotvdon. 



* The part of Wales chiefly referred to in the preceding notice 



and in the following list of specimens is contained in Maps 75 and 

 78. 





