CAMBRIAN CORDILLERAN SECTION'S — WALCOTT 179 



MARJUM FORMATION: 



The Marjum formation [Walcott, 1908a, p. 10] is exposed in the cliffs 

 southeast of Marjum Pass and in the ridge east of Wheeler Amphitheater. 



Feet 

 la. Graj', more or less thin-bedded limestone that weathers to a 

 dark lead-gray color and breaks down into angular frag- 

 ments one-half to 2 inches thick. 

 Flattened cherty nodules and thin, irregular cherty layers occur 



at intervals 305 



Fauna (in upper 100 feet) : 



Obolus mcconnelli pclias (Walcott) [1905, p. 330]. 

 Oholus (Fordinia) gilberti Walcott [1908^, p. 65]. 

 Obolus {Fordinia) perf edits Walcott [1908^, p. 65]. 

 Acrotreta bellatula Walcott [igoScf, p. 93]. 

 Acrotreta marjumensis Walcott [igo8d, p. 94]. 

 Acrotreta cf. sagittalis Salter [1866, p. 285]. 

 Agnostus (4 species). 



Fanina (central portion) : 

 Micromitra sculptilis Meek [1S73, p. 479]. 

 Lingulella argiita (Walcott) [1898, p. 396]. 

 Dicellomus proliftcus Walcott [1908c?, p. jj'l. 

 Acrotreta attenuata Meek [1873, p. 463]. 

 Acrotreta bellatula Walcott [i9o8flf, p. 93]. 

 Agnostus. 

 Ptychoparia. 

 Anomocare. 



Fauna (near base) : 



Micromitra (Iphidella) pannula opiiirensis (Walcott) 



[1905, p. 306]. 

 Obolus mcconnelli pelias (Walcott) [1905, p. 330]. 

 Obolus rotundatus (Walcott) [1898, p. 4x5]. 

 . Hyolithes. 

 Ptychoparia. 

 Anomocare. 



lb. Alternating bands of dark, bhie-gray, compact limestone in 

 massive layers that break up into thin irregular layers; and 

 gray arenaceous limestone in layers i to 8 inches thick. 



Feet 



1. Gray limestone 35 



2. Blue-gray limestone 7 



3. Gray arenaceous limestone 95 



4. Blue-gray limestone 12 



5. Gray arenaceous limestone 90 



6. Blue-gray limestone 8 



247 



Fauna: 



Ptychoparia, sp. undt. 



ic. Dark and light-gray, thin-l)eddod limestone, more or less 



arenaceous 250 



