364 



THE AZOIC SYSTEM AND ITS SUBDIVISIONS. 



Lower Devo:nian". Possibly some portion of tlie Kingston group. 



r Mispeck group. 



Upper Devonian. < Little River group. 



(_ Bloomsbury group. 



In a paper presented to the American Association for tlie Advance- 

 ment of Science (1869, XVIII. 179-195) by Messrs. Bailey and Mat- 

 thew, it is remarked that *' several hills of crystalline felspar rock, 

 associated with hypersthene," were, on the authority of Dr. Hunt, re- 

 ferred to the Labrador or Upper Laurontian series. (1. c, p, 181.) The 

 Kingston series the authors were inclined to regard as Upper Silurian 

 and Devonian. The overlying formations below the Carboniferous, ex- 

 cepting in their subdivisions, and being classed as Siluro-Devonian, re- 

 mained about as in 1865. This paper was revised up to April, 1870. 



In a joint report by Messrs. L. W. Bailey and G. F. Matthew (Geol- 

 ogy of Canada, Report of Progress, 1870-71, pp. 13-240) numerous 

 changes were made in the supposed sequence of the formations, Dr. 

 Hunt having worked in the field with them. Lithological evidence had 

 been thouglit suficient authority for enlarging the amount of Lauren- 

 tian rocks ; and the finding of a few pebbles in some of the granitoid 

 masses was regarded as proof that they were altered conglomonites. 



The rocks referred, on lithological evidence, to the Iluronian, were 

 divided into three groups : the Coldbrook, Coastal, and Kingston. - The 

 former was found in some places to overlie the Primordial or St. John 

 group, and to conformably underlie roeks of Devonian age, to which 

 age these rocks (the Bloomsbury group) had formerly been referred. 

 However, lithological characters being then regarded as more weighty 

 than stratigraphical ones, this difficulty, together with some others, was 

 surmounted in the following manner. 



*' Prior to tlie work of the present survey, the river St. John, at tl-e Suspen- 

 sion bridge, was considered as marking the extreme western limit oi ihe Iluro- 

 nian rocks of St. John County, the only sediments noticed to the westward of 

 this point, which bore much rescmhlaTice to them, being' supposed, on strati- 

 graphical grounds, to be more recent Recent observationy, however, 



have led us to the conclusion that a part of these supposed more recent sedi- 

 ments are in reality the Iluronian strata hrougbt up by a fold, and by an over- 



turn of the whole series made to rest upon newer strata The diorites 



and schists of Bloomsbury Mountain, although apparently resting upon the 

 slates of the St. John group, and overlaid by Devonian sandstones, which con- 

 form to them in dip and strike, are now also regarded as Huronian strata. 

 . . On both sides of Musquash Harbor a series of hard green epidotic sub- 

 crystalline schists, sometimes with dark green serpentine, may be seen resting 



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