376 



DEPARTMENT OF THE INTERIOR 



2 GEORGE V, A. 1912 



Correlation. — Combining facts and probabilities, the following table of the 

 formations occurring in the Rossland mountains has been prepared. The 

 formations are named in groups which are not to be considered as strictly 

 contemporaneous but are to be interpreted in the light of the foregoing 

 statements. The table carries a heavy burden of hypothesis and every 

 chronological table for this district must carry the burden until the sedi- 

 mentary formations are more closely dated. The general sequence of the 

 formations is more certain than their correlation with the recognized geological 

 systems. The table is to be read and used only in the light of the many doubts 

 expressed or implied in the foregoing pages. On that basis the table is offered 

 as embodying the stronger probabilities; so understood it may perhaps be of 

 service in suggesting future observations on these difficult terranes. 



Uncrushed. , 



Deformed and 

 locally crushed' 



( Biotite-granite porphyry dikes ! 



Biotite-augite syenite porphyry dikes and chonolith. . . . 



Syenite-aplite dikes ' 



Camptonite dikes 



Missourite dike 



Coryell syenite batholith . 



Porphyritic olivine syenite masses 



Some of the mica-lam prophy res (?) 



Sheppard granite stocks and dikes 



Beaver Mountain group 



Conglomerate of Sophie mountain, Lake mountain, etc. 



I Trail granodiorite batholith 



Granite stock east of Cascade 



Rossland monzonite ; shonkinitic rocks ; hornblendite at 



Columbia ri ver 



Latites of Rossland volcanic group .... 



Dunites ; harzburgite (effusive?); Fife and Baker gab- 



bros and peridotite 



Much andesite and basalt of Rossland volcanic group, 



with argilhtic interbeds 



Plant-bearing argillite at Little Sheep creek 



Tertiary (Miocene ? to 

 Eocene). 



>Mesozoic. 



Unconformity. 



Mashed and 

 metamor- 

 phosed, 



[Greenstones and older andesitic rocks of area mapped as"j 



underlain by Rossland volcanic group ; fossiliferous I Paleozoic (Garhoni- 

 ■l limestone, chert and quartzite of Little Sheep credk > ferous at least in 



valtay ; phyllite, quartzite, limestone, etc., of Pend part). 

 \ D'Oreille group ; Sutherland schist complex J 



