HURRICANE FAULT IN SOUTHWESTERN UTAH 



6l 



reaches the Colorado river in much the greater part by the 

 Grand Wash, and only in small part by the Hurricane. It is to 

 this great uplift, limited on the west by the Grand Wash and 

 Hurricane faults, that we owe the inception of the canyon 

 cycle of erosion and the cutting of the Grand Canyon of the 

 Colorado. 



Fig. 9. — The Hurricane escarpment just north of Toquerville, as seen from the 

 northwest. The Aubrey escarpment, 2,000 feet high on the left, diminishes as it passes 

 into the torn flexure, which is shown in Toquer hill, the black lava-covered hill in 

 the middle distance. Beyond this are the Shinarump capped mesas of Verkin shales 

 that lie east of Gould's ranch. 



THE POST-FAULT OR CANYON CYCLE OF EROSION. 



During and since the later uplift there has been a cutting of 

 canyons in the hard strata, and a general stripping of unprotected 

 soft strata. In the Plateau region erosion has gone just far 

 enough to emphasize very successfully the topographic value of 

 hard and soft strata. Thus, along the fifty miles of the Hurri- 

 cane south of where most of the new displacement turned west- 

 ward, the rapid wearing away of weak Verkin shales on the 

 western side of the old fault line has left the hard Aubrey lime- 

 stone on the eastern side as an erosion escarpment so strong that 

 Button took the whole of it for an actual fault scarp of recent 



