NO. 12 CAMBRIAN FORMATIONS ROBSON PEAK DISTRICT 2>2)7 



CAMBRIAN SYSTEM 



UPPER CAMBRIAN 



LYNX LIMESTONES.— Thin-bedded bluish-gray limestone with inter- 

 bedded bands of light gray shale, and at the base a band of 

 about 200 feet in thickness of gray, greenish and reddish- 

 brown shale 2,100 



Fauna. — No fossils were found below the arbitrary line drawn at 

 the base of the shaly limestones containing the fauna from 

 Locality 6iq. 



MIDDLE CAMBRIAN 



TITKANA LIMESTONES.— Massive-bedded bluish-gray limestone in 

 thin layers interbeddcd with gray siliceous, buff-weathering 



limestone that occurs in bands 50 to 100 feet thick 2,200 



This formation is best seen in the west slopes of Titkana 

 Peak and lyatunga Mountain. Fossils were found at two 

 horizons that clearly correlate the lower part of the Titkana 

 formation with the Stephen formation of Mount Stephen. 

 Fauna. — At the upper horizon the following species occur 

 (Locality 6iv) i mile (1.6 km.) each of summit of Titkana 

 Peak in clifif above Hunga Glacier: 



Micromitra senobia Walcott 



Obolus mcconnelli Walcott 



Obolus septalis Walcott 



Acrotreta of. depressa Walcott 



Wimanella ? borcalis n. sp. 



Hyolithes carinatiis Matthew 



Selkerkia major Walcott 



Agnostus mantis Matthew 



Zacanthoides spiiiosits Walcott 



Kootania dawsoni Walcott 



Ptyclwparia n. sp. 



Of the above all but Wimanella ? borealis occur in the 

 Stephen formation. 



At an horizon estimated to be 1,000 feet lower, the fol- 

 lowing genera are represented in the collection from localities 

 61 1 and 6im, about 1.5 miles (2.4 km.) west-northwest of the 

 summit of Titkana Peak on slopes above Lake Adolphus : 

 Acrothele Glenoid es 



Acrotreta cf. sagiffalis Salter Zacanthoides 



Agnostus Ptychoparia 



MUMM LIMESTONES.— Massive-bedded, gray siliceous limestone 



weathering to gray and buff tints on cliffs 600 



Exposed at northwest base of Titkana Peak and north face 

 of Mumm Peak. 

 Fauna. — No fossils found. 



