NO. 5 PRE-DEVONIAN PALEOZOIC FORMATIONS ' 279 



Feet Meters 



lb. Finely arenaceous limestone in thick, alternating bands 



of a light gray and dark lead-gray color. The lower 



20 feet (6.1 m.) is a light gray, finely arenaceous, 



laminated limestone, the lamellae showing finely on the 



weathered surface 270 82..1 



Fauna. — Traces of annelid borings occur abundantly within 

 the layers and on their surfaces. The Ross Lake shale 

 member of the Ptarmigan formation was not seen, 

 but if present would probably occur about 100 feet 

 (30.5 m.) down in this section. 



If. Massive-bedded, bluish-gray and light gray, more or less 

 finely arenaceous limestone, with many dark layers of 

 oolitic limestone, the oolites varying from 5 to 25 inm. 

 in diameter no 33.5 



Fauna. — A few minute fragments of trilobite tests were 

 seen. 



Total of Ptarmigan formation 426 129.8 



LOWER CAMBRIAN 

 Mount Whyte Formation 



la. Thin-bedded, dark, bluish-gray limestone that may or 



may not be included in the cliff 28 8.5 



Fauna. — (63d) : 



L'lngulcUa sp. undt. 

 IVimancUa ? 



" Ptychoparia " cillcs Walcott 

 Crepicephaliis chares Walcott 

 lb. Finely laminated and shaly bluish-gray limestone, with 



a few intercalated thin, hard layers 62 18.9 



This band of almost fissile limestone and shale is a 

 marked feature in the section. It is crossed diagonally 

 by joint planes that cause it to weather into projecting 

 points, giving the effect of the irregular surface of 

 dogtooth spar. This may be seen on the face of the 

 cliffs of Ptarmigan Peak for a long distance; also on 

 Redoubt Mountain on the southeast side of the Pass. 

 ic. Dark gray, oolitic limestones in bands from i to 8 

 inches (2.5 to 20.3 cm.) thick, alternating with hard, 

 thin-bedded and shaly sandstones. At the top a band 

 of finely oolitic limestone occurs beneath the cliff- 

 forming limestone of ib 135 41. i 



Fauna: — In the upper band of oolitic limestone (63a) : 



Nisusia (Jamesella) lozvi Walcott 

 Wimanella catulus Walcott 

 Hyolithes billmgsi Walcott 

 Ptychoparia cercops Walcott 

 Crcpicephalus cccinna Walcott 



