I 



SOUTHERN TERMINATION— MIDGET'S CREST 



181 



superposed masses of volcanic beds resting upon the great conglomerate. 

 Here the faulted wall of the range swings around to the southwestward and 

 rapidly dies out. (See stereogram.) 



The lofty crest at the southern end of the Tushar has been named 

 Midget's Crest, and it presents to the southeast three bold saHents, standing 

 about 5,600 feet above Circle Valley, which Hes at the base of its great 

 spurs east-northeast. Its absolute altitude is about 11,600 feet. It is a 

 volcanic mass, built by the accumulation of andesitic, trachytic, and basaltic 

 sheets. The three salients are from 1,400 to 1,600 feet higher than the 

 summit of the conglomerate cliff to the north of them and their superior 

 eminence is due to this accumulation of lavas. The conglomerate passes 

 beneath them though its outcrop is masked by the talus. 



The sheets which compose Midget's Crest belong to a later period than 

 those which occupy the central part of the Tushar range, and which were 

 broken down to form the great conglomerate. Coulees of the same period 

 are found north of this crest, upon the summit of the tabular part of the 

 Tushar, where they are mainly trachytic. Upon the extreme summit of the 

 southern crest lies a true basalt, highly vesicular upon its surface, and the 

 first impression is that it is a comparatively recent eruption — Post-Pliocene 

 or Quaternary — the rocks on which it rests being certainly very much older. 

 It is of small expanse and thickness and is abruptly cut off at the crest-line 

 of the ridge. Its origin cannot easily be conjectured. There are no indi- 

 cations of a vent in the vicinity and, notwithstanding the freshness of its 

 appearance, it may be as old as early Pliocene. But the beds on which it 

 lies are less doubtful. They face southeastwardly, forming the salients 

 already mentioned, and have been wasted greatly by the general degrada- 

 tion. When the period of dislocation and uplifting set, in they extended 

 as far to southeast as the principal fault which runs around this angle of the 

 plateau with a throw of about 3,500 to 4,000 feet, and the entire mass 

 between the crest-line and the fault has been denuded to a corresponding 

 depth. The origin of the lavas I believe to have been to the southeast 

 and east of the ridge in the vicinity of the faults, where evidences of great 

 contortion and considerable chaos are still visible, and where rocks appar- 

 ently identical with those upon the summit of the table and near the 



