GLACIATION IN THE BIGHORN MOUNTAINS.' 



In Vol. IX of this Journal a brief outline of the results of 

 the work done on the glacial formations of the western moun- 

 tains in igoi was given. These studies were continued during 

 the past summer. One of the parties, under the immediate 

 charge of the junior author of this note, spent several weeks in 

 the Bighorn mountains of Wyoming. He was assisted by 

 Messrs. W. H. Emmons and F. W. DeWolf, while the senior 

 writer was with the party for about a week at the beginning of the 

 work. 



In 1900 Mr. Matthes^ gave a discriminating description of the 

 cirques and other topographic features in the Bighorn moun- 

 tains, due to glacial erosion. In the same year Professor W. C. 

 Knight made mention of the former existence of glaciers in the 

 same range. 3 When the party went into the field in 1902, Pro- 

 fessor Knight furnished it with some general notes on the geol- 

 ogy of the range, and in these notes there was a much fuller 

 statement of the general facts concerning the distribution of 

 glacial drift in these mountains than had hitherto been published 

 by him. These data had been gathered by Professor Knight in 

 the prosecution of his other work. 



So far as known to the writers, no detailed study of the drift 

 of these mountains had been attempted previous to their work 

 in 1902, and up to that time the existence of more than one 

 series of glacial formations had not been recognized. The stud- 

 ies of last summer revealed the existence of two series of glacial 

 formations, separated from each other by a relatively long inter- 

 val of time. A third series of deposits was found, much older 

 than the older of the preceding, which may prove to be of gla- 

 cial origin, though the evidence now in hand on this point is not 

 regarded as conclusive. 



'Published by permission of the director of the U. S. Geological Survey. 



= Twenty-first Annual Report U. S. Geol. Surv., Part II, pp. 173-90. 



3/4 Preliminary Report on the Artesian Basins of Wyoming. Bull. 45, Wyoming 

 Experiment Station, p. 174. 



216 



