102 GEOLOGICAL SURVEY OF THE TERRITORIES. 



a slight synclinal fold between c and <?, which is more marked farther 

 w^est, as shown in Fig. 2, which Is a section across the Gunnison just 

 before it leaves the canon, on the line G H. The Ibllowing is the sec- 

 tion represented in Fig. 3, the figures corresponding with section L. 



SECTION. 



1. Granite reaching to edge of the river. 



2. Eed sandstone (TriassiefJ. 



3. Greenish and gray shales and sandstones (Jurassic f). 



4. Shaly sandstones. ) Dakota arouv ^ 



5. Massive sandstones. | J i- j 



6. Laminated sandstones and black shales. | 



7. Black shales. J> Cretaceous, 



8. Dark yellow shales. 



9. Light yellow and gray beds. 



10. Terrace with light-colored shales. 3 

 At a in Fig. 2, Plate VIII, the strata are seen to be curved abruptly, 



the river occupying the axis of an anticlinal fold. This is at the point 

 where it leaves the canon. The fold, however, is not simply a north 

 and south fold, for, as we see in Fig. 1, Plate VIII, there is folding 

 east and west. This is the main fold.^ or rather the termination of the 

 anticlinal fold, the axis of which the Gunnison follows in the caiion 

 above Smith's Fork. 



Fig. 1 represents a section on the line I K, almost at right angles 

 to the sections in Figs. 2 and 3. 



The following are the beds represented in Fig. 2 (Section K) : 



1. Shaly sandstones. \ t)„7,„/„ „^„,,„ ^^t^ -.n 7 



2. Massive sandstones. | -^'"'''^''- '^'^^''^' (^^- "^^ | ; 



3. Shales and sandstones. J> Cretaceous. 



4. Black shales. | 



5. Yellow and gray shales. 3 



In Fig. 1, the following is the section (Section I) : 



1. Sandstones of No. 1, Cretaceous. 



2. Yellowish and black shales. 



3. Fine hard brownish shales. 



K* > Shales forming terraces. 



As we go south along the west side of the caiion of the Gunnison, 

 we see that the dip, at first, is to the northwest, gradually coming 

 around to the west. The connection between the Dakota group and the 

 overlying shales seems to be broken. Opposite station 80, the Eed 

 Beds (Tiiassic) are seen resting on the schists. A little farther south 

 the Dakota group is wasbed off, and there are simply remnants of the 

 red sandstones left. I did not have time to visit this from the west 

 side, and until this is done, all opinions must, to a certain extent, be 

 conjectural. As we go farther south we find the granite plateau, before 

 referred to, shown in Fig. 2, Plate VII, / to g, standing between the 

 Gunnison and the valley of the Uncompahgre. Abutting against this 

 plateau, at the head of Cedar Creek, and on the branches of Cebolla 

 Creek, as we have already seen, the Cretaceous shales are horizontal. 

 Whether the fold noticed at the northern end of the canon becomes a 



