298 proceedings: geological society 



This interpretation, in the light of recent studies on cirque develop- 

 ment, seems scarcely admissible. Cirque glaciers do not require tribu- 

 tary upper neves for their alimentation, but are capable of developing, 

 and ordinarily do develop, independently from such nev6s. The wind 

 is their chief alimenter, and the prime reason that cirques are capable 

 of collecting such large quantities ol snow is that they are the most capa- 

 cious windschatten in the relief. All the cirque glaciers on Mount Rainier 

 are to be conceived as having been initiated primarily by the accumula- 

 tion of windblown snow in depressions already existing in the mountain's 

 flanks. These depressions they have progressively enlarged into cirques 

 through the eroding effect chiefly of their own mass movements. The 

 enormous size and the mature character of the Carbon Glacier cirque 

 are due, first, to the great capacity of the original depression which 

 gave it birth, and second, to the superior eroding power of the huge 

 ice masses it has from the beginning contained. . The part played by 

 snow descending from the summit regions has never been more than a 

 subordinate one. The cirque, to begin with, does not head in the summit 

 neves, but in the rocky platform surrounding Liberty Cap. What 

 neve bodies gather on the platform are quite limited in extent, and can 

 at no time have supplied, in the form of avalanches, more than a frac- 

 tion of the total bulk of ice filling the cirque. 



The Carbon Glacier, like the other glaciers mentioned, is a true cirque 

 glacier and not a "primary" glacier in a senescent stage. Its cirque, 

 instead of a sequential feature that is threatening to extinguish the 

 glacier's source of alimentation on the summit, is to be regarded, rather, 

 as the evergrowing generator of the ice mass. 



The 253d meeting was held in the Cosmos Club February 28, 1912, 

 and the following papers were presented : 



Age of the Worcester (Massachusetts) phyllite: David White. See 

 this Journal, 2: 115. 1912. 



The Chattanooga shale and its equivalent in the Ohio section: E. O. 

 Ulrich. 



The Chattanooga shale problems in the Southern Allegheny region: 

 E. M. Kindle. 



Ralph W. Richards, Secretary. 



