no 



WHITMAN CROSS 



(19, p. 215) it would appear that the exact horizon of the Shinarump 

 conglomerate of Powell could be recognized on the Little Colorado 

 near the main crossing of the early route of travel. Dutton reports 

 it at the base of the Echo Cliffs. The only detailed investigation 

 of the Shinarump beds of this valley thus far made has, however, 

 produced results so different from those generally accepted, and 

 especially at variance with Walcott's section as to require some dis- 

 cussion. 



In connection with an examination of the "petrified forests" 

 of northeastern Arizona in 1899 and 1901, Lester F. Ward made a 

 study of the formations either side of the Little Colorado from the 

 Aubrey (Carboniferous) to the Cretaceous. In a paper on the 

 "Geology of the Little Colorado Valley" (26) Ward assigns all 

 beds of this section to the Triassic, the Jurassic being entirely absent, 

 in his opinion. This supposed Triassic system embraces 3,500 feet 

 of strata divided by Ward into three parts, according to the following 

 generalized columnar section. 



SECTION IN LITTLE COLORADO VALLEY. WARD 



FEET 

 100 



15. White sandstones . . . . . . 



14. Brown sandstones ....... 200 



Painted Des- ) ^3- Variegated sandstones, regularly stratified, and bril- 



ert beds \ liantly colored; the well-known Painted Cliffs . . 800 



2. Red-orange sandstones ...... 100 



1,200 



o 



o 



S 

 =3 



Leroux 

 beds 



Shinarump 

 conglom- 

 erate 



II. Calcareous marls, sometimes worn into buttes . 

 10. Mortar beds, flint stones .... 



9. Limestone ledge, definitely stratified 



8. Sandstone ledge ...... 



7. Variegated marls, argillaceous and calcareous 

 with bones of belodonts, labyrinthodonts, and 

 dinosaurs . . ... 



200 

 80 

 20 



100 



400 



6. Conglomerate and coarse cross -bedded sand- 

 stones with clay lenses interstratified with gray 

 argillaceous shales and variegated marls . . 800 



1,600 



