RED CHEEK QUAETZITE. 137 



flexure of the slope, are opposed to it, and the faults themselves, in a part 

 of their courses, change to flexures. In addition to the complications thus 

 mentioned, there are other minor flexures within the greater. All of these 

 complications will be spoken of further on. 



Within the district which I undertake to describe, another great flexure 

 must be mentioned. This has a north and south axis, and brings to view in 

 the region north of Aspen Mountain the Sulphur Creek Cretaceous. On 

 the flanks of this flexure we find the Salt Wells and Point of Rocks Creta- 

 ceous, and the Bitter Creek, Lower Green River, Upper Green River and- 

 Bridger Tertiaries, all of which groups took part in the movement which 

 made this flexure ; but there is no evidence that the Brown's Park Group or 

 the Bishop Mountain Conglomerate was involved in the movement. The 

 southern extremity of the flexure is well seen at the head of Red Creek, 

 where the rocks dipping south from the end of the Aspen flexure become 

 horizontal, and again are turned up by the great Uinta flexure, thus forming 

 a synclinal between the flank of the greater flexure and the end of the 

 lesser. The characteristics of this displacement also will be discussed here- 

 after. 



I now proceed to describe the geographic distribution of the groups or 

 formations in this district, and to give their general stratigraphic character- 

 istics, and also to note some interesting facts concerning their conformities 

 and unconformities. 



All of the groups of rocks tabulated in Chapter II are found within 

 this area except the Grand Canon Group and the Grand Canon Schists. 



EED CHEEK QUARTZITE. 



The only locality where this group has been found within the territory 

 embraced in the discussion is in the vicinity of Red Creek, a small tributary 

 of the Green River, emptying into the latter at the head or western end of 

 Brown's Park. Its geographic extension is well shown on the map, and 

 needs no farther description. 



Red Creek separates Quartz Mountain and Mount Wheeler by a tor- 

 tuous, flaring, craggy canon whose sides rise to an altitude of about "2,000 

 feet above the creek, and here the interior structure of the group is revealed. 



