KAIBAB AND THOUSAND LAKE FAULTS. 33 



of the Aquarius Plateau it is joined by an important fault coming from the 

 southsouthwest. This is the Paunsagunt fault, which lies near the eastern 

 base of that plateau. As its throw is in the opposite direction to that of the 

 Kaibab fault, the two are apparently distinct, though they really are 

 branches of one displacement. The displacement now continues north 

 along' the western front of the Aquarius Plateau, and presents complication 

 with subordinate faults. Still northward it has the Awapa Plateau for its 

 uplifted and Grass Valley for its thrown side, the minor faults gradually 

 merging with the principal one. 



Near the north end of Grass Valley it rapidly passes into a sharply- 

 flexed monoclinal, forming the northwest shoulder of Fish Lake Plateau, and 

 the monoclinal so formed gradually expands into a broader flexure, with an 

 increasing displacement, and becomes the great monoclinal of the Wasatch 

 Plateau, one of the grandest flexures of the Plateau Country. This flexure 

 forms the southeast side of San Pete Valley for about 50 miles. It has not yet 

 been traced beyond the northern end of this valley, but from the topography 

 it is supposed to extend far beyond it, being in full force where it has been 

 last observed. Its total length, reckoning as one displacement the Wasatch, 

 Grass Valley, Table Cliff, and Eastern Kaibab portions, cannot fall much 

 short of 300 miles, and may considerably exceed that after the termini have 

 been discovered. It presents many phases or modifications, but the domi- 

 nant feature is the monoclinal form. The maximum displacement is at the 

 Wasatch Plateau, and reaches nearly 7,000 feet. 



The easternmost fault {Thousand Lake fault) of this system begins upon 

 the southern slopes of the Aquarius Plateau, trending due north. It crosses 

 that plateau with a dislocation of 500-600 feet, and splits into two faults, 

 which reunite upon the northern base. Crossing the lower end of Rabbit 

 Valley, it passes along the western base of Thousand Lake Mountain, and 

 then swings to the northeast The throw is to the west, and in passing 

 from the foot of the Aquarius to the base of Thousand Lake Mountain the 

 displacement rapidly increases to about 3,500 feet, and then as rapidly 

 diminishes, again becoming zero about 20 miles northnortheast of the mount- 

 ain. But it immediately recommences with a 'throw in the opposite direc- 

 tion (east), repeating the phenomenon presented by the Sevier fault a little 

 3 H p 



