234 N. L. BOWEN 



Kolderup's Representation of Differentiation in the Ekersund- 

 sogndal anorthosite area 



Bronzite granite 



I 

 Adamellite 



I . 

 Banatite 



I 



Monzonite 



Quartz-norite 

 Gabbro-norite— Norite — Anorthosite-norite — Anorthosite 



B ronzitite — Norite-bronzitite 



I 

 Ilmenite-norite 



I 



Ilmenitite 



Kolderup's anorthosites become more basic and schistose toward 

 their borders and their contact relations are obscure. One cannot 

 be sure from his text whether there are small dikes of anorthosite 

 in the surrounding rocks or not, but apparently there are not. 1 



Apophyses consisting of 95 per cent basic labradorite and 5 per 

 cent augite cut the Sooke gabbro of Vancouver Island described 

 by Clapp. 2 The anorthosite veins and the gabbro are consanguine- 

 ous, however, and the former with, say, 20 per cent liquid might 

 have been squeezed into the not completely crystallized gabbro 

 mass, the process involved being then rather different from that 

 occurring in the injection of anorthosite into cold country rock. 



Dikes of anorthosite are described as cutting the older rocks in 

 the Rainy Lake region, but one cannot be sure from the description 

 whether the dikes are strictly anorthosite or rather the related 

 anorthosite-gabbro. 3 And so it is with many descriptions. It is 

 profitless, therefore, to pursue the discussion of various anorthosite 

 occurrences further since they were not examined with the questions 



1 "Die Labradorfelse des westlichen Norwegens," Bergens Museums Aarbog, No.V 

 (1896), p. 14. 



2 C. H. Clapp, "Southern Vancouver Island," Geol. Survey Canada Mem. No. 13, 

 1012, p. 116. 



3 Since the above was written Professor Coleman has informed me that in so far 

 as he can recall there are no dikes of typical anorthosite. 



