"24 THE CANADIAN NATURALIST. [Yol. ix. 



tain highly crystalline rocks : diorites, dolerites, amygdaloids 

 and volcanic agglomerates, with bands of white, grey and mottled 

 dolomites and calcites which have much more the appearance of 

 great lenticular, vein-like, calcareous masses than of beds belonging 

 to the stratification. No traces of ors-anic forms have been found in 

 them, and yet many of them are scarcely more crystalline than 

 certain Devonian and Carboniferous limestones in which fossils 

 are abundant. The Acton mines, and the numerous openings that 

 have been made in searching for copper ore in that vicinity and 

 in the neighbouring townships of lloxton, Milton, Wickham and 

 "VYendover, may be cited as instances of this second class. And it 

 certainly appears as if the copper ore in these upper divisions 

 were in some way connected with the intrusion or segregation of 

 the crystalline rocks which everywhere accompany it. In any 

 case, I think, there are very few who would agree with Dr. Hunt 

 in the general proposition that the diorites and serpentines of the 

 Quebec group are of sedimentary origin, and the amygdaloids 

 altered argillites ; and, unless all contemporaneously interbedded 

 volcanic products are to be considered as of sedimentary origin, 

 the Quebec group might be said to present some of the most 

 marvellous instances on record of '■^selective met amor phism.'^ 

 But whether this is so or not, there seem to be no sood grounds 

 for assigning either an age or an origin to the cupriferous diorites, 

 dolerites, and amygdaloids of the Eastern Townships different 

 from that of the almost identical rocks of Lake Superior, which 

 Dr. Hunt * states have been shewn to overlie unconformahly the 

 Huronian and Moutalban series, but which at Keeweenaw Point 

 are stated by Professor Pumpellyj- to rest conformably on the 

 Huronian; and Prof. Pumpelly justly remarks that '' the question 

 would still seem to be an open one, whether the cupriferous series 

 is not more nearly related to the Huronian than to the Silurian." 

 The same may certainly be said of the cupriferous rocks of the 

 Eastern Townships. Brooks does not, in his paper | quoted by 

 Dr. Hunt, give any very conclusive reasons for his change of 

 views since 1872, and writes altogether as if the question of the 

 unconformable superposition of the copper- bearing rocks on the 

 Huronian were still undecided ; and so late as 1877, Professor 



* 2 G. S. of Penn., Special Keport on Azoic Rocks and Trap Dj-lces, 

 §458. 



t Geo. Survey of Michigan, Vol. I, 1873. 

 X Am. J. of Sc, Vol. XI, 1876, pp. 206-207. 



