15 



INTRUSIVES. 



Jurassic to Lower Cretaceous. . . .Coast Range batholithic 



rocks. 

 Post-Lower Cretaceous Granodiorite stocks, east 



of Coast range. 



Skeena Formation. The rocks of this formation 

 occupy isolated basins folded in with those of the Hazelton 

 formation, and resting apparently conformably or nearly 

 so on them. The exact relationship has not been worked 

 out. The varieties commonly present are felspathic 

 sandstones, conglomerates, hardened clays, shales usually 

 more or less carbonaceous, and occasional seams of coal. 

 The beds are less indurated than those of the underlying 

 Hazelton formation, are seldom fractured, and usually 

 undulate in open folds. 



The shales are plant bearing in places. A small 

 collection made by W. W. Leach and reported on by Dr. 

 Penhallow contained the following species: — 



Sequoia Rigida, Heer. 



Thuya Cretacea, (Heer) Newberry. 



Thyrsopteris sp. 



These species indicate an age equivalent to the Koote- 

 nay or lowest Cretaceous. 



Hazelton Group. The beds of this formation over- 

 lie the semi-crystalline Kitsalas formation at Mile Post 123. 

 on the railway, and they are the principal rocks exposed 

 along the Skeena and the Bulkley rivers up to Telkwa, the 

 terminal point of the excursion. 



The Hazelton rocks are mostly tufaceous in origin, 

 but, unlike those of the Kitsalas, they are well bedded 

 and banded, and are seldom much altered except in the 

 immediate vicinity of intrusive masses. The predominat- 

 ing variety is a heavily banded, bluish grey, rather even 

 grained rock, made up of minute rock fragments usually 

 andesitic in character, with some broken feldspar crystals 

 and occasional angular grains of quartz. Dark argillace- 

 ous beds and bands alternate with the tuffs and tufaceous 

 sandstones. These are usually more or less carbonaceous, 

 and in places, carry thin streaks of coal. Conglomerates. 



