Yamasaki — Glaciation of Japan Mountains. 135 



have not as yet altered the forms greatly, and they are 

 still fresh and well preserved. Where many cirqnes lie 

 close together, as in Knrotake and Yakushidake, charac- 

 teristic comb-ridges are formed between them. 



The most important and peculiar feature of these cirques 

 is that their floors are all of about the same height above 

 sea-level, as shown in the following table : 



Meters. 



Goro 2550 



Mitsu 2G00 



Harinoki 2500 



Nakanomata 2550 



Kurotake 2500-2600 



Yakushi 2600 



Renge 2500 



Tateyama 2500-2600 



In short, the cirque floors range from 2,500 to 2,600 

 meters in elevation, and average 2,550 meters. What is 

 the significance of this regularity? Perhaps there is no 

 better explanation than a former lower altitude of the 

 snow-line. Above this level the lofty ridges of the Japan- 

 ese Alps were once covered with permanent snow, and 

 just below there were hanging glaciers here and there 

 along the flanks of the ranges. Of course these glaciers 

 were not so large or extensive as those which existed in 

 the European Alps during the last ice age. We have not 

 yet found any morainal landscape at the foot of the moun- 

 tains. There are neither terminal moraines nor glacial 

 lakes at the lower extremities of the mountain valleys. The 

 glaciers must have terminated at a little higher elevation. 

 Perhaps certain exceedingly deep incisions in the upper 

 parts of the valleys are due to glacial erosion. Other 

 indications of glaciation that have been noted are the 

 striations on the rock blocks of Shirouma and the 

 moraines in several places, especially the peculiar moraine 

 mounds in a high valley basin of Kamikochi near the 

 famous peaks of Yarigatake and Hodakayama, which 

 were recently discovered by the late Professor Ozeki. 



There is no question at present as to the glacial origin 

 of the peculiar features of our lofty mountains, and it 

 remains only to discuss when this glaciation took place. 

 We have not come to any satisfactory conclusions on this 



