32 NOTES ON MT. ANNE AND THE \\T:LD RIVEK V.VLLEY. 



It now appears that during the Pleistocene times wo 

 have traces of three ice invasions. The earliest apparent 

 one was by far the most considerable, and was followed by 

 two later phases. The writer suggests that this would 

 correspond with the Mindel ice sheet of the Northern 

 hemisphere. The size and intensity of this have obscured, 

 if not obliterated, the traces of the Gunz in Tasmania, if 

 any ever existed. The succeeding ice invasions may corre- 

 spond with the Riss and Wiirm respectively. This theory is 

 not yet proved, but may be useful as a working hypothesis. 

 The finding of definite traces of interglacial periods between 

 the various morainal deposits is necessary for the proof of 

 the theory. 



In the Mt. Anne region, in the National Park, and in 

 Cradle Valley and elsewhere in Western Tasmania, there is 

 every reason to believe that the obvious moraines arc de- 

 posited en the top of a previously formed glacial topography. 

 The regularity with which lakes appear in pairs, one 

 superimposed on the othei with, occasionally, mountain tarns 

 at a greater altitude, the fact that this arrangement is never 

 exceeded, and the definite signs of an older and a newer 

 glaciation mentioned befoi-e, ai-e indications that the appar- 

 ently superimposed deposits are not merely a later phase in 

 a receding cycle of glaciation, but are due to separate 

 invasions. This contention, however, still remains to be 

 proved. 



If it will be borne out by future investigations the 

 history of the Pleistocene glaciation in Tasmania will be in 

 general this: The traces of the Gunz glaciation have been 

 obliterated. During perhaps Mindel times a tremendous 

 ice cap covered the western and south-western highlands and 

 the more elevated portion of the central plateau. In the 

 west the ice descended nearly to the sea. It covered, and so 

 protected, the higher mountains, but moved down the valleys 

 and out from the edges of the cap in great glaciers which, as 

 Sir Edgeworth David has informed the writer, have left 

 great outwash deposits in the vicinity of Strahan, and wei'e 

 responsible for the old glacial pavements of the Pieman, 

 and the big terminal moraine seen at llii miles from 

 Strahan on the railway track to Zeehan. Lake St. 

 Clair was possibly a cirque formed at the head 

 of a glacier growing from this ice sheet, which 

 then filled the Cuvier Valley and covered the surroundin« 

 hills. Farther east, as at Cradle Mt. and Mt. Field, the 

 ice cap covered the summits of the higher ranges but did not 



