proceedings: geological society 297 



GEOLOGICAL SOCIETY OF WASHINGTON 



The 252d meeting was held in the Cosmos Club, February 14, 1912, 

 and the following papers were given: 



A continually rising base level and its results: Sidney Paige. 



Color photography in petrographic work. Illustrated. F. E. Wright. 



Undescribed glaciers of Mt. Rainier. Illustrated. F. E. Matthes. 



In his classic report on "The Glaciers of Mount Rainier," the late 

 I. C. Russell described only six of the eleven principal ice streams of 

 that mountain. The other five, situated on its west and southwest 

 flanks, he did not have an opportunity to visit; and, as no one else has 

 thus far given any description of them, they have virtually remained 

 unknown. Last summer (1911), happily, these glaciers were mapped 

 in the course of the topographic survey of the Mount Rainier National 

 Park, and some data regarding them are consequently now at hand. 



The interest that attaches to these glaciers arises chiefly from the 

 fact that they are associated with the two subsidiary summits of the 

 mountain, Peak Success and Liberty Cap. These are the two largest 

 remnants of the rim of the main crater, and so extensive are their slopes 

 that several large ice streams originate upon them. Indeed, of the 

 five glaciers in question, only two, the Kautz and Tahoma glaciers, 

 come from the summit neves of the mountain and are therefore true 

 "primary" glaciers in the sense in which Russell used that term. The 

 other three, the Wilson, Puyallup, and Edmunds glaciers, head in cirques 

 situated at a level some 4000 feet lower than the summit. They are 

 strictly speaking "secondary" or "interglaciers," to follow out Russell's 

 classification to its logical end ; but such is their size that they may easily 

 be considered as ranking with the "primary" glaciers, and the term 

 "secondary" scarcely seems appropriate to them. Should it be found 

 desirable, however, to retain the distinction between primary and sec- 

 ondary glaciers as suggested by Russell, then it will become necessary 

 to reclassify two of the glaciers described by him and classified by him 

 as "primary," namely, the Carbon and Willis glaciers. Both of these 

 ice streams originate in cirques on the sides of the Liberty Cap massif 

 and belong to the same type as the Wilson, Payallup, and Edmunds 

 glaciers. Of especial interest is the case of the Carbon Glacier which 

 is perhaps the second largest ice stream on Mount Rainier. Russell 

 sought to explain the evolution of its huge cirque as the result of the 

 eroding action of a primary glacier cascading from the summit regions. 

 All primary glaciers, according to him, normally tend to produce such 

 cirques, only Carbon Glacier, owing to especially favorable circumstances, 

 has been able to develop its cirque in advance pi the other glaciers and 

 to give it a maturely rounded form. Indeed, so far has the recession 

 of the headwall already progressed that but little now remains of the 

 upper neve area that formerly alimented the glacier from above. As 

 a consequence, Russell thought, the glacier "is now destroying the very 

 conditions on which its existence depends," and with the diminishing 

 of the snow supply from above, will gradually decrease in size. 



