574 



APPENDIX. 



Generalized Section fok the Grand Canyon Region. 1 



Names of Formations. 



si 



EiQ 

 i g 



c3 



Tertiary. 



Thickness 

 in Feet. 



815 



Characteristics. 



Marls and shales, with sandstone and limestone. 

 Fresh- and brackish-water deposits. 



Cretaceous. 



3095 



Soft, more or less calcareous sandstones and 

 dark argillaceous and carbonaceous shales 

 containing extensive beds of coal; mainly 

 marine, in part non-marine. 



Jurassic. 

 Jura-Trias. 



960 

 3430 



3. Bright-red calcareous and gypsiferous 

 shales, with some sandstone; in part 

 marine. 



2. Massive white sandstone; probably marine. 



1 . Red and buff sandstones, with beds of shale 

 and gypsum; largely non-marine. 



>»S 



fl Upper Permianl 



— ~ U neon for mity^^- 

 Lower Permian. 



Unconformity ^v>^ 

 Upper Aubrey lime- 

 stone. 



710 



145 



805 



Gypsiferous and arenaceous shales and marls; 

 shaly limestone at the base; partly non- 



marine. 



Similar to the above, with more massive lime- 

 stone at the base; largely marine. 



Massive, cherty limestone with arenaceous 

 gypsiferous bed; calciferous sand rock below. 



Lower Aubrey sand- 

 stone. 



1485 



Friable, reddish sandstone, becoming more 

 compact and massive below; a little lime- 

 stone. 



Red Wall lime- 

 stone. 



Unconformity -~~~» 



Temple Butte lime- 

 stone. 



Unconformity ~~~->- 

 Tonto series. 



Unconformity 

 Chuar. 



962 



94 



1050 



5120 



Unkar. 



Great unconformity— 



Vishnu. 



[ Base not exposed. 



Arenaceous and cherty limestone above, with 

 massive limestone and chert below. 



Impure limestone and sandstone. 



Calcareous and arenaceous shales above, sand- 

 stone below. 



Shales, sandstones, and thin beds of limestone. 



Sandstones, shales, interbedaed lavas, and 

 some limestone. 



Schists, gneisses, etc., with dikes and veins of 

 granite. 



i Walcott, Jour, of Geol., Vol. Ill, pp. 317-324; Bull. Geol. Soc. Amer., Vol. I, p. 50; Amer. 

 Jour. Sci., 3d series. Vol. 20, 1880, p. 222. Dutton, Tertiary History of the Grand Canyon, pp. 35, 

 40. Vishnu is classed as Algonkian in some of the above. 



