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but the whole seems to be a fairly homogeneous argillite, 

 now largely recrystallized by static metamorphism — a 

 metargillite. All phases are charged with sericite, devel- 

 oped parallel to the bedding planes, and occasionally one 

 finds thin beds glittering with coarser mica like a normal 

 muscovite schist. The colour is generally gray, of a dark 

 tint due to disseminated particles of carbon. 



The lllecillewaet quartzite is hard, gray, massive to fissile, 

 and relatively homogeneous except for thin intercalations 

 of metargillite. Unlike the basal quartzite, it is poor in 

 feldspathic material and evidently represents a more com- 

 pletely washed and assorted sediment. 



In the monoclinal section between Albert Canyon and 

 Ross Peak stations, the Laurie formation (named after the 

 mining camp at the railway) is of most remarkable thick- 

 ness. Measurement on the actual outcrops gave the fol- 

 lowing succession. 



Approximate 

 Thickness. 



Base of the Cougar formation. 



Gray, phyllitic metargillite 



Quartzite 



Black to dark gray metargillite 



Alternating beds of phyllite and quartzite 



Black to dark gray, carbonaceous, often pyr- 

 itous metargillite, with interbeds of blackish 

 limestone 



Gray quartzite 



Black to dark gray, strongly carbonaceous met- 

 argillite, with numerous interbeds of blackish 

 limestone 



Massive, light gray limestone 



Top of lllecillewaet quartzite. 



There is no sign of important duplication by strike- 

 faulting, though some thickening is represented in local 

 crumples. Admitting all possible duplication suggested 

 by the facts now in hand, this formation must be credited 

 with a thickness of more than 15,000 feet (4,572 m.). On 



