SEVIER FAULT. 31 



thrown side and remain horizontal on the other. The beds, five miles from 

 the fault on the thrown side, come back to horizontality at about the same 

 levels which they occupy on the other side of the fault, Fig. 3. The trend 

 of the fault at first is northeast. Ten miles from Pipe Spring it is a simple 

 fault. Farther on, in Long Valley, it is "stepped" with two branches. 

 Passing on to the base of the Paunsc^gunt at Upper Kanab the beds on the 

 thrown side are flexed upward, while on the lifted side (east) they are hori- 

 zontal. This form continues northward from Upper Kanab for about 13 

 miles, when branch faults appear on the thrown side and the fault is 

 stepped and here and there somewhat comminuted, but with one predomi- 

 nant shear, forming the western wall of the Paunsdgunt Plateau. These 

 modifications disappear about 6 miles farther on, and the fault becomes 

 simple with a diminished throw; the displacement opposite the village 

 of Hillsdale not exceeding 800 feet. Beyond Hillsdale the throw is nearly 

 uniform for about 10 miles and then increases again. The increase is 

 slow but steady for the next 60 miles. Along the east side of Panquitch 

 Valley it is very difficult to study, because it cuts the volcanic rocks, 

 which are much confused, and here is one of the great eruptive cen- 

 ters. It is probably somewhat complicated, though the principal dis- 

 placement is distinctly revealed in the great plateau wall on the east, and 

 in the great ravines and chasms which cut across it and open into the valley 

 below. Opposite Circle Valley the fault splits off" a large piece from the 

 Sevier Plateau by means of a branch which leaves the main displacement 

 and then reunites with it. At East Fork Canon the thrown beds, consisting 

 of volcanic conglomerate, are turned up monoclinally, but are sundered by 

 the fault at the summit, with a shear of 3,000 feet. A little north of this 

 canon a branch diverges from the main displacement, running off into the 

 Sevier Valley, where it rapidly dies out. The maximum displacement is 

 apparently attained a few miles south of the Mormon village Monroe, and 

 from that point northward it rather rapidly diminishes. Between Glenwood 

 and Salina the apparent shear has become zero. But the circumstances are 

 remarkable. The fault from Monroe northward is a secondary displacement 

 superposed upon an older one. The zero point of the fault is quickly suc- 

 ceeded in the same line by a resumption of the shear, but in the opposite 



