CAMBRIAN CORDILI^ERAN SECTIONS — WAtCOTT I99 



LANGSTON FORMATION (continued): Feet 



Orthotheca. 

 Stenotheca. 

 Platyceras. 

 Agnostus. 

 Microdiscus. 

 Solenopleura. 

 Ptychoparia (2 species). 

 Oryctocephalus. 

 Dorypyge (2 species). 

 Neolenus (2 species). 

 Asaphiscus. 

 Ogygopsis? 

 2. Massive bedded, dark, arenaceous limestone, passing at about 

 150 feet down into a calcareous sandstone, and then a gray 

 sandstone 390 



Total of Langston formation 498 



BRIGHAM FORMATION [Walcott, 1908a, p. 8] : 



la. Quartzitic sandstone, gray, greenish, gray brownish, dirty gray, 

 all weathering reddish dirty brown in layers 3 inches to 3 



feet in thickness 28 



lb. Greenish, hard, sandy shale ". 4 



Fauna: 

 Annelid trails. 

 Trilobite tracks. 

 ic. Same as la (estimated) 1,200+ 



Total of Brigham formation 1,232 



Total of Middle Cambrian * 5,420+ 



RfiSUMfi, BLACKSMITH FORK SECTION 



UPPER CAMBRIAN: 



ST, CHARLES FORMATION: Feet Feet 



1. Fossiliferous limestone 190 



2. Arenaceous limestone yyy 



3. Fossiliferous limestone 94 



4. Shaly and thin-bedded sandstones 166 



1,227 



MIDDLE CAMBRIAN: 

 NOUNAN FORMATION: 



I. Arenaceous limestone 1,041 



BLOOMINGTON FORMATION: 



1. Limestone and shales 220 



2. Thin-bedded limestone 1,100 



1,320 



^ The line of separation between the Middle and Lower Cambrian occurs 

 somewhere in the Brigham formation, and this thickness (5,420 feet) likely 

 includes several hundred feet of Lower Cambrian beds. 



