HYPOGEIC WOEK. 



363 



H., the Hurricane fault, about 1800 feet, 

 becoming 6000 at the Virgen River. And 

 some of the plateaus exceed 11,000 feet in 

 height. The long range of bluffs to the 

 eastward, commencing above the letter E., 

 is that of the Echo Cliffs ; and the upward 

 bend is attributed to a fault of 3000 feet 

 (Dutton). 



Ascending the plateaus facing the Grand 

 Canon region, the Carboniferous rocks are 

 left behind, and a rise made over outcrops 

 of Permian, Triassic, Jurassic, and Cretace- 

 ous rocks. At W. K., and to the westward, 

 the faulting is a downthrow of the block 

 next west, while east of it the displacement 

 is a downthrow of the block next east. 



These plateaus south of the Wasatch 

 Mountains take the place of the mountains, 

 being results of the same post-Cretaceous 

 disturbance. 



Mr. King, in his account of the Wasatch 

 IVIountains, recognizes the principle that Ar- 

 chaean forms of surface determined the po- 

 sitions of lines of disturbance or uplift in 

 mountain-making areas of later time, and 

 influenced also the kind and amount of dis- 

 turbance. He observes that the Archaean 

 ridge which makes the flank and partly the 

 crest of the Wasatch Range was the means 

 of locating there, by mechanical resistance, 

 the great flexures. In other parts of the . 

 same region, where there are no Archaean 

 elevations, the disturbance resulted only in 

 "high plateaus." He suggests that the 

 Uinta plateau may have been thus located, 

 although very little Archaean rock is now 

 in sight about it. 



To the eastward of Utah, through Col- 

 orado, along the Elk Mountains, the San 

 Juan Mountains, and the Park regions 

 farther east, there are other more or less 

 independent ranges of contemporaneous 

 origin, and they are continued interruptedly 

 into the northern part of Kew Mexico. The 

 eastern foot of the Front Range of Colorado, 



336. 



narrow upturned belt at the 

 described, from the beds near 



