PRECAMBRIAN TECTONIC PROVINCES 





TURTLE 

 LAKE 

 QUAD. 



MAGNESITE 

 BELT 



METALINE 

 QUAD. 



LITTLE 

 SALMO 



PURCELL RANGE CRANBROOK GALTON 



WESTERN DIVIDE RANGE 



WATERTON 



MIDDLE CAMBRIAN 



PEND OREILLE 

 METALINE LS. GR. 



LARDEAU SER 



LOWER CAMBRIAN:::: :•■••••■. •.••.•; •.••.;••.■:•.• 



; •.AppYQUARTZITE'-.':- 



MAITLANO PHYLLITE LAIB GR 

 •QUARTZ IT E R 



"UPPER PURCELL s M F PPARD--KJNJ' L_A 

 ^PURCELL LAVA 



10,000 



■ 20,000 



130,000 

 VERTICAL SCALE 

 IN FEET 



Fig. 4.6. Suggested correlation of Precambrian formations of southern British Columbia and northeastern 

 Washington, after Reesor (1957) and Weiss (1959), restored to Middle Cambrian time. 



the top of the Belt series, and the Beltian orogeny occurred soon after its 

 deposition, so the date is about as good for the time of deposition as for 

 the metamorphism, if any, or orogeny. 



In conflict with the illite date we note that samples of uraninite in a 

 vein system in the Coeur d'Alene district of Idaho that cuts folded meta- 

 sedimentary rocks of the St. Regis formation of the Belt series have 

 yielded a date of approximately 1190 m.y. (Eckelmann and Kulp, 1957). 



Although different laboratories have confirmed this date, Wehrenberg 

 (personal communication) thinks there is still justification to question its 

 validity in dating the age of the strata and their folding. The St. Regis 

 is about three-quarters of the way up from the lowermost beds of the 

 Belt exposed. From samples of galena in the same mine Farquhar and 

 Cummings (1954) give the age as 1030 =*= 290 m.y. 



It is clear from Fig. 4.3 that the Belt sediments and correlatives lie in 



