NO. 12 CAMBRIAN FORMATIONS ROBSON PEAK DISTRICT 339 



At Locality 6ik, 2.5 miles (4 km.) west of 6it beneath the 

 north face of IMumm Peak and just above Mural Glacier, the 

 following 12 species were found in a band of dark siliceous 

 shale : 



PlanoHtes (Annelid trail.) 

 Cystid ? sp. undt. 

 ^ingulella cliupo Walcott 

 Lingidella hitka Walcott 

 ObolcUa liota Walcott 

 Obolclla cf. chroiiiatica Billings 

 HyoUthes sp. undt. 

 Callavia cucharis Walcott 

 Callazna pcrfccta Walcott 

 Wanneria occidens Walcott 

 Olencllus trueiiiani Walcott 

 Hyuicnocaris sp. undt. 

 Agraitlos sp. 



MAHTO SANDSTONES.— Massive-bedded quartzitic sandstones with 

 thin-bedded hard sandstones and dirty grayish-brown shale in 



thin bands i ,Soo 



This series extends down the northeast face of Mahto Moun- 

 tain and the slope of Tab Mountain nearly 800 feet (241 m). 

 Fauna. — No fossils found. 



TAH FORMATION.— Hard, green and purple siliceous shales with 

 irregular massive beds of gray and purple, compact limestone 



interbedded in central portion Soo 



Fauna. — No fossils found. 



McNAUGHTON SANDSTONES.— Light gray, massive-bedded quartz- 

 itic sandstone S00+ 



Fauna. — No fossils found. 



At ]\Ioose Pass there are only a few layers of this forma- 

 tion exposed, but to the southwest toward Yellowhead Pass the 

 sandstones have a thickness estimated at 500 feet (151 m.) . 

 This, however, is very uncertain as it is difficult to determine 

 the line of demarcation between the sandstone of Cambrian 

 and pre-Cambrian (Belt) age. 



