DESCRIPTION OF THE KWA-GUNT SECTION. 



53 



The throw of the Tertiary fault (a, a'), in section 1, is about 500 feet, and 

 in section 3, taken one mile south, over 1,000 feet. One of the pre-Carabrian 

 faults (section 3) has here disappeared ; the other, probably b, or it may be 

 b and c of section 1 united, has displaced a fragment of the Grand Canon 

 group more than 3,000 feet in relation to the Chuar group (see fig. 3). 



In the next cross-section (fig. 4), taken on the divide between Nun-ko- 

 weap and Kwa-gunt valleys, all the faults of sections 1, 2 and 3 are united, 

 the pre-Cambrian and Tertiary movement having taken place on the same 

 line of displacement. The upturning of the strata towards the fault is 

 greatly increased, even to the reversing of the dip of the massive Red Wall 

 limestone to 30° W. ; and the throw of the fault to the eastward by the Ter- 

 tiary movement is doubled. Owing to the upward curvature of the strata 

 in the immediate vicinity of the fault, the displacement on the line of fault 

 is not more than 500 feet ; but measured a short distance back, where the 

 actual displacement is shown by the position of the horizontal beds, the 

 throw is from 2,000 to 2,200 feet. To this must be added the curvature of 

 the monoclinal fold that occurred prior to the actual faulting. This, on the 

 line of Kwa-gunt and Chuar valleys, varies from 500 to 700 feet, giving a 

 total displacement between the strata on the east side of the Colorado river 

 and on the summit of the Kaibab Plateau, of fully 2,700 feet, on a line 

 crossing the strike of the East Kaibab displacement. This condition of the 



West. 



R/W. 



C (a) U. T. 



Figure 5. — Section on the Divide South of the Kwa-gunt Valley. 



The section includes the west side of the Butte and also a portion of the divide on the ridge on 

 the north side of Chuar valley. The lettering and scale are the same as in section 4. 



