PHYSIOGRAPHY OF BISHOP CONGLOMERATE 629 



Comparison of other observations hearing on the problems pre- 

 sented in this paper. — Both King' and PowelP described the high- 

 level gravels of this region — King, under the name of Wyoming 

 Conglomerate, and Powell under that of Bishop Mountain Con- 

 glomerate. Powell recognized the true nature of the gravels as 

 well as the peneplained surface on which they lie. He writes: 



The Bishop Mountain Conglomerate is found at different places to lie 

 unconformably upon every group of the table which is represented in the Uinta 

 Mountains and adjacent country. Its plane of demarkation represents a 

 cessation of the movements of displacement in the region over which it is 

 found, and that the same region was planed down to a base-level of erosion, 

 which base-level was continued during the accumulation of these beds, for it 

 is believed to be a subaerial conglomerate; but should further evidence prove 

 it to be a subaqueous accumulation the plane of separation would then repre- 

 sent an epoch of change from a period of erosion to a period of deposition. ^ 



As to the mode of accumulation he has this to say : 



I think that many geologists would ascribe this conglomerate to the action 

 of ice, but throughout all that portion of the Rocky Mountain region which I 

 have studied, I have so frequently found gravels and conglomerates of sub- 

 aerial origin, and have in so many cases found reason to change my opinion 

 concerning them, often having attributed a driftlike deposit to glacial action, 

 and afterward, on further study, abandoned the theory, being able to demon- 

 strate its subaerial origiit, and witnessing on every hand the accumulation of 

 such gravels in valleys and over plains where mountains rise to higher altitudes 

 on either side, and having in so many cases actually seen the cliffs breaking 

 down and the gravels rolling out on the floods of a storm, I am not willing to 

 disregard explanations so obvious and so certain for an extraordinary and more 

 violent hypothesis.'^ 



Hay den in connection with his "Survey of the Territories "^ 

 reports high-level gravel-deposits similar to those of Miller Moun- 

 tain as occurring on Table Mountain, an isolated butte southeast 

 of the Wind River range ; in the valley of South Pass ; and along the 



I Clarence King, Explorations of the 40th Parallel. 



^ J. W. Powell, Geology of the Uinta Mountains, U.S. Geol. and Geog. Survey, 

 Division II. 



3 J. W. Powell, Geology of the Uinta Mountains, 62. 



4 Ibid., 170. 



5 Hayden, U.S. Geol. and Geog. Survey of the Territories of Idaho and Wyoming, 

 1S77, 133- 



