CAMBRIAN CORDILI.ERAN SECTIONS — WALCOTT I75 



NOTCH PEAK FORMATION (continued): 



la (continued) : Feet 



Fauna: 



Lingulella isse (Walcott) [1905, p. 330]. 

 Dicellocephalus ? sp. ? 



A drift boulder found 2.5 miles from the peak, and on its east- 

 ern drainage slope, and similar in its lithological appearance 

 to the gray, arenaceous limestone of this horizon, contained 

 the following fossils : 



Eoorthis coloradoensis (Meek) [1870, p. 425]. 



Schizambon typicalis Walcott [1884, p. 70]. 



Agraulos. 



Solenopleura. 



Illcmurus. 



Another drift boulder was found near this with slightly diflfer- 

 ent fauna. 

 Crepicephalus, 

 Ptychoparia. 



lb. Shaly, dark gray to bluish gray, arenaceous limestone, with 



small dark concretions in some layers 90> 



No fossils observed. 



ic. Gray, siliceous limestone in layers of varying thickness, 4 inches 

 to 2 feet, banded with dark cherty layers and purer arena- 

 ceous limestone. The chert takes the form of flattened 

 nodules and very thin irregular layers 340 



id. Shaly and thin-bedded, bluish gray, arenaceous limestone 65- 



le. Gray, siliceous limestone in layers 2 inches to 2 feet thick. In 

 the lower part of this limestone, where it is not metamor- 

 phosed, it is dove-colored and in layers 6 inches to 3 feet 

 thick. There are occasional occurrences of gray, cherty mat- 

 ter, as flattened nodules, and thin layers that weather a 

 dark brown 355- 



Faima (about 120 to 150 feet from the base) : 

 Obolus tetonensis leda Walcott [1908c?, p. 62,]. 

 Fragments of the free cheek of a trilobite. 



Total of Notch Peak formation 1,490 



ORR FORMATION: 



The section is carried along the strike of the exposed strata two miles east 

 to the west side of Orr Ridge, where the rocks of the Orr formation [Walcott, 

 1908a, p. 10] are unmetamorphosed and present the following characters : 



Feet 

 10. Bluish gray to gray, compact limestone in layers i inch to 2 feet 

 thick. On weathering the thicker layers break down into 

 thin, irregular layers, which form a talus of angular frag- 

 ments 375, 



