CAMBRIAN CORDILLERAX SECTIONS— WALCOTT I77 



ORR FORMATION (continued) : 



2a (continued) : . Feet 



Fauna (at base) : 



Lingulclla desiderata (Walcott) [1898, p. 399]. 

 Acrotrcta idahoensis Walcott [1902, p. 587]. 

 Crc[>ic-cphalus texanus (Shumard) [1861, p. 218]. 

 Bathyurisciis. 

 lUccnnrus ?? 



Fauna (275 feet above base) : 

 Agraulos. 



Crel'icephalus texanus (Shumard) [1861, p. 218]. 

 lllcenurus. 



2b. Gray limestone and dark gray chert in alternating layers, one- 

 half to 2 inches thick. The irregular cherty layers weather 

 in relief as dark brown bands and the limestone as lead- 

 colored bands, which give a very characteristic banded ap- 

 pearance to the cliff 170 



2c. Gray, arenaceous limestone in massive beds that usually break 

 up, on weathering, into irregular layers one-fourth to 4 

 inches thick. The upper 20 feet form a more massive, solid 

 bed than the layers below 165 



Fauna: 



Traces of trilobites and brachicpods. 



Total of Orr formation 1,825 



Total Upper Cambrian 3,3I5 



CUDDLE CAMBRIAN 



WEEKS FORMATION: 



The Weeks formation [Walcott, 1908a, p. 10] is exposed at Weeks Canyon 

 (see pi. 13) from beneath the massive limestone on the south side of the 

 canyon to the top of the cliffs on the south side of Marjum Pass. Average 

 dip, 12°; strike, north 20° east (magnetic). 



Feet 

 la. Thin-bedded limestones in layers I to 4 inches thick. The lime- 

 stone is mainly fine-grained, dark gray, weathering lead- 

 colored, except on bedding planes, where it is usually more 

 or less pinkish colored 245 



Fauna : 



Fragments of trilobites and brachiopods of the fauna in 

 shaly limestone in ib. 



lb. Shaly limestone, usually dark gray, with pinkish tinge in some 

 la3-ers and on the surfaces ; sometimes buff yellow on weath- 

 ering. The shales vary from one-eighth to i inch thick. 

 This is a marked band in some sections and is arbitrarily 

 separated from the shaly beds below 285 



