386 EEPORT UNITED STATES GEOLOGICAL SURVEY. 



sandstone outcrops in a low ridge at an elevation of about 1,200 feet 

 above the river. 



8. A few hundred yards above the preceding bed, and perhaps one 

 and a quarter miles distant from the trail, a heavy deposit of gray, spar- 

 seamed, gritty limestone outcrops over a considerable belt in a rocky 

 point, accompanied by drab, indurated, calcareous shales, the ledges 

 dipping southwestward. 



9. Succeeding the last ledge is a space several hundred yards across, 

 in which frequent exposures of red arenaceous shales and red sandstones 

 appear, though imperfectly exposed. 



10. A thin bed of drab limestone. 



11. Space several hundred yards across, with exposures of red and 

 *chocolate-colored shales below, red shales above, immediately underly- 

 ing— 



12. Red sandstone, dipping southeastward at an angle of 30°, forms 

 crest of prominent point about two and a half miles from the saddle. 



13. A belt perhaps half a mile in width, in which no rock exposures 

 ■were observed, intervenes between the last exposure and the second 

 prominence north of Station XXVI. The latter point is some 200 feet 

 lower than the station, or 8,200 feet above sea-level. It is crowned by 

 a heavy deposit, consisting of alternations of drab-gray fragmentary 

 limestone and indurated shaly calcareous deposits; dip 30° to 50° 

 southward. The lithological characters of this horizon bear intimate 

 ^comparison with the bed described under No. 8. The limestone contains 

 i columns of Pentacrinus, and an imperfect shell probably referable to 

 .Aviculopecten. A rusty dark limestone, exposed in the south flank of 

 the same ridge, affords two forms of Lamellibranch shells, preserved as 

 casts, which may be compared with Pholodomya and Tancredia, species 

 -of which genera were described by Messrs. Meek and Hayden from lower 

 Jurassic horizons in the Black Hills region of Dakota. 



11. Thin-bedded sandstone and red arenaceous shales, passing up 

 into drab, nodular, indurated calcareous shales, and red shales above, 

 making a thickness of several hundred feet. The two latter beds, each 

 100 feet or more in thickness, are best seen in the northeast flank of Sta- 

 tion XX Y I ; also in the amphitheatre west of the first high point a mile 

 north of the station, where the whole series may be seen at a glance, 

 "but so cut up by deep ravines as to greatly enhance the difficulty of esti- 

 mating their thickness even approximately. 



15. Heavy ledge of cross-bedded, reddish-gray, chocolate-brown weath- 

 ered sandstone, with heavy-bedded conglomeritic layers. This rock 

 outcrops in the summit of the high point one mile north of XXVI, where 

 it sweeps down in the west flank, forming the coping of the walls of the 

 -amphitheatre which opens into the canon of Pyramid Creek. It also 

 occurs in the east flank at Station XXVI, where the remaining strati- 

 graphic elements of the section were observed. The dip of the ledge is 

 about the same at either locality, or 35° south. 



16. Eed arenaceous shales, 10 to 20 feet. 



17. Chocolate-red and grayish sandstones, cross-bedded and beauti- 

 fully laminated, forming a thick bed ; dip, locally, 25° south. 



18. Deep red arenaceous shales, above pink indurated calcareous 

 shales, exposed in slope 75 to 100 yards across. 



19. Dark and light drab, fine-grained, brittle limestone, heavy ledge 

 in summit at Station XXVI. Dip 35° south westward. Contains numer- 

 ous individuals of a small undetermined Gasteropod, Viviparus ? 



The upper beds of the foregoing section are clearly Jurassic, and it is 

 •scarcely less probable the " red beds " of the Trias hold their proper posi- 



