342 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 75 



UPPER CAMBRIAN 

 Sabine Formation ' 



Feet Meters 



icr. Calcareous shale, with thin, irregular layers of com- 

 pact, dark, bluish-gray limestone, and interbedded, 

 thicker layers of a hard, semicrystalline limestone 

 from an inch (2.54 cm.) up to 6 feet (1.8 m.) in 

 thickness. Many of the layers are almost made up of 

 flattened nodules and fragments of limestone of an 



intraf ormational conglomerate aspect 320 97.5 



Fauna. — The fauna of la is limited, as far as known, to 

 a thin layer of gray limestone 15 feet (4.5 m.) from 

 the base (64n) : 



Obolns cf. leda Walcott 

 Briscoia splendens Walcott 

 lb. Calcareo-argillaceous shale, with oolitic and gray lime- 

 stone layers 3 inches (7.6 cm.) to 2 feet (.6 m.) 

 thick rather abundantly interspersed at irregular 



intervals 185 56.4 



Fauna. — 'A layer of limestone 50 feet (15.2 m.) from the 

 base contains (64f ) : 



Cystid (fragment) 

 Eoorthis sp. undt. 

 Huenella sp. undt. 

 Scenclla ? 



Ptychaspis eurydice Walcott 

 Briscoia sp. 

 This fauna, although small and fragmentary, is 

 typical of the Sabine formation. 



In a block of limestone that fell from a cliff above 

 the Mons glacier, on the south side of the canyon, a 

 few fossils were found that appear to belong to the 

 Sabine fauna (66w) : 



Eoorthis cf . ivichitacnsis Walcott 

 Syntrophia isis Walcott 

 Agnostus sp. 

 Saratogia ? sp. 



Total Sabine formation 505 153.9 



Lyell Formation ^ 



I a. Dark and medium-gray rough-weathering limestone in 

 massive layers, with magnesian bands extending down 

 490 feet (149.4 rn-) to where there is a band about 

 50 feet (15.2 m.) thick of a thinner-bedded, bluish- 

 gray limestone. 



* It is somewhat doubtful whether this is a true representative of the Sabine 

 formation. — C. E. R. 



^ The faunas of this formation are not typically Lyell, the little knowledge 

 we have pointing rather to a post-Sabine age. — C. E. R. 



