1862.] BIGSBY CAMBRIAN AND HURONIAN. 51 



and both granular and compact. For details the Society is referred 

 to the admirable descriptions of Durocher ; for general information, 

 necessarily limited, the column in the Synoptical Table III., under 

 the head " Norway," may be consulted. 



My reasons for believing the Norwegian Second Azoic Group to 

 be Huronian are as follows ; and it is believed that they are not 

 without great force : — 



1. Its place — lying on the Fundamental Gneiss, and covered by 

 Silurian. 



2. The discordance of the palaeozoic rocks above in regard to it. 



3. Its resolving, as in Canada, into several distinct and important 

 parts, not altogether dissimilar to those of Canada. 



4. The schistose rocks, the same in kind and proportion in both 

 countries. 



5. The immense prevalence in this formation of diorite or green- 

 stone, and of hornstone, both in Norway and Canada. 



6. The peculiar, greenish-grey, talcose quartzite, and quartzite- 

 conglomerates,with aphanite and red jasper pebbles, in these countries. 



7. The dark-coloured slaty conglomerates, with boulders of gneiss, 

 granite, and greenstone, in both. 



8. The limestones in the two regions, similar in kind, and much 

 so in quantity, but few in comparison with the other members, though 

 large in comparison with the Cambrian limestones. Here they are 

 dark, perhaps from graphite. 



9. The total absence of life in both regions. 



10. The presence in both countries of certain ores of copper and 

 iron. I shall content myself, for the sake of brevity, with referring to 

 Table III. for information regarding the probable Huronian of France. 



IV. Relations of the Cambrian and the Huronian. — Having now 

 sketched the leading features of the Huronian series, while those of 

 the Cambrian have been treated of in Part I. of this paper, I am 

 at length enabled to exhibit such of their geological differences as 

 point to a difference of epoch, and they are as follows : — 



1. The Huronian is unconformable to the Silurian both in 

 America and Europe : — ncft so the Cambrian. 



2. The Huronian in Norway is conformable to the Fundamental 

 Gneiss formation ; and confidently believed to be so in America : — 

 not so the Cambrian. 



3. Its mass is principally conglomeratic, such conglomerate being 

 of a special and typical kind: — not so the Cambrian. 



4. It contains large and prolonged beds of marble : — not so the 

 Cambrian, which is nearly destitute of limestone. 



5. Its plutonic invasions and disturbances are quite different in 

 quantity and intensity from those of the Cambrian period, being of 

 five distinct epochs *. 



6. The Huronian is more highly metamorphosed than the Cambrian 

 (containing gneiss, <fcc, Foster and Whitney) ; notwithstanding that 

 in Anglesea the latter formation has been completely changed into 

 gneiss. 



* A. Murray, Canada Geol. Report for 1849, p. 14. 



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