484 CROSS AND HOWE — RED BEDS OP SOUTHWESTERN COLORADO 



tained respecting the Paleozoic section and certain structural features 

 have been published. Of special Interest to the present discussion are 

 the discovery of Permian fossils and of an unconformity between the 

 Permian and the Triassic beds. In his published section of the Paleozoic 

 formations Walcott (39) refers to the Permian some 855 feet of reddish 

 brown, chocolate, lavender or drab, gypsiferous and arenaceous shales 

 and marls, with impure fossiliferous limestone. There are two divisions 

 with erosional unconformities above and below each one. The uncon- 

 formity above the Permian is the most important and has been specially 

 described (40). While this unconformity is not everywhere visible, the 

 Shinarump conglomerate was found abutting against a cliff of Permian 

 beds on the east side of the Kaibab fold near Paria, Utah. To the west 

 the shales above the conglomerate overlap the latter and come in appar- 

 ent conformable relations with the Permian strata. 



The sections of Mesozoic formations made by Walcott in Kanab valley 

 have never been published, but through his courtesy I am permitted to 

 give a typical one of the Jurassic and Triassic beds. 



Section of Jurassic and Triassic formations in the Kanab valley, Utah 



Made by C. D. Walcott in 1879 

 Top Feet 



Cretaceous strata occur above this section. 



1. White friable sandstone, stained yellow locally 75 



2. Cream-colored arenaceous, friable rock, somewhat gypsiferous 275 



3. Red arenaceous shales 150 



4. Conglomerate of quartz pebbles and fragments of sandstone and lime- 



stone with calcareous cement. 50 



5. White massive beds of gypsum with irregular partings of white marl. . 30 



6. Eed marl and conglomerate, the latter very variable in thickness 115 



7. Red arenaceous and gypsiferous shale and marl 50 



8. Cream-colored magnesian limestone, with many small cavities in upper 



portion and fossil-bearing at 6 feet below top 25 



Fossils: Myalina sp. ? Camptonectes bellastriatus, C. extenuatus,? C. 



stigius, Pecten n. sp., Myophoria ambilineata, Astartef sp. ? Trigonia? 



sp. ? Ostrea strigilicula, Solarium? sp.? 



9. Sandy shale with few indurated layers ; contains many fossils. . . 75 



10. Limestone 10 



11. Sandy shales 65 



12. Buff and cream colored, fine-grained magnesian limestone in layers 



from i inch to 2 feet thick 40 



13. White Cliff sandstone, massive, cross-bedded, light-gray, broken into 



five principal belts by horizontal lines of bedding 585 



14. Vermilion sandstone; cross-bedded, friable, readily disintegrating, form- 



ing the foothills and slope to the more compact sandstones at the 

 northern end of Vermilion Cliff canyon 650 



15. Gray and reddish-brown, cross-bedded sandstone. Horizontal beds of 



varying thickness divide the mass into bands of from 25 to 100 feet in 

 thickness 300 



