204 STRUCTURAL GEOLOGY. 



DEGKADATION. 



The amount of degradation in the region of the Yampa Plateau though 

 less than in the Uinta region as denned above, is still great. The maximum 

 degradation is found at the few points where deep canons cut the cliffs of 

 the Yampa fault, and Uinta Sandstone is found in the floor. In these places 

 there has been more than 15,000 feet carried away since the close of 

 Mesozoic time ; the mean degradation over the entire area has been 8,000 

 feet, or a little more than one and a half miles, and the total more .than 



1,200 cubic miles. 



SEDIMENTATION. 



A part of the rock material taken from this region was doubtless 

 deposited in the Tertiary lake region to the south, another portion probably 

 into the BroAvn's Park Lake, and still another and very considerable portion 

 has been carried away by the Colorado River to the distant sea. 



JUNCTION MOUNTAIN. 



This district was studied in the earlier years of the exploration of the 

 region, and since that time it has not been carefully reviewed. In my notes 

 I make mention of a fault running in a north and south direction to the east 

 of the axis of upheaval, with a throw to the westward, but the magnitude 

 and general characteristics of the fault are not given. The sections given 

 in Chapter I of this volume, figures 1 and 2, represent the idea of its structure 

 obtained at the time it was studied, but subsequent years of observation in 

 other regions lead me to place no great value on the observations made 

 and conclusions reached at that time. 



DIAMOND PEAK. 



To the north of 0-wi-yu-kuts Plateau is Diamond Peak. The principal 

 mass of the mountain is on the north side of the great Uinta fault, but the 

 foot of the mountain stretches across from the thrown to the upheaved side 

 of the fault. 



For a long time this mountain was an enigma. From its position it 



