Quebec Group of Logan. 13*7 



borne in mind here, that the sediments which were de- 

 posited and the animals which lived in the comparatively 

 cold and deep waters of the Atlantic basin, were alwaj^s 

 different from those which existed on the submerged por- 

 tions of the continental plateaus, and that while in some 

 cases, as in the Siluro-Canibrian and Silurian, we know both 

 kinds of deposit and life, in others, as in the lower and 

 middle Cambrian, we know only the oceanic forms, and in 

 others again, as the Devonian and Carboniferous, we are as 

 yet entirely ignorant of these latter conditions. I have not 

 space here to illustrate this significant fact, but may refer 

 to my British Association Address of 1886. 



It has been further objected to the name Quebec Group, 

 that it has been used to designate other rocks, both older 

 and newer than those included in it by Logan. As to 

 newer rocks, I can testify that neither Logan nor Billings 

 ever knowingly included any rocks or fossils newer than 

 Chazy in this group ; and in the case of certain beds at 

 Quebec, to which reference has been made, they knew of 

 the existence of these, but supposed them to be there 

 faulted against the Quebec series, or as Hunt has suggested, 

 i*estiug unconformably on it, a view which I have my- 

 self been inclined to adopt. 



With respect to Cambrian and other rocks, said to be in- 

 cluded in the Quebec Group, I can state from my own ob- 

 servations, that fossils older than the Quebec Group are 

 imbedded in large boulders iu the lime conglomerates, in 

 such a manner, that unless where the exposures are very 

 good it is difficult 'to separate them. I have seen such 

 travelled slabs, as much as nine feet in length, full of fossils, 

 and lying flat in the conglomerate. In point of fact, the 

 Quebec Group is in part, as I have on many occasions 

 affirmed, a great palaeozoic boulder formation, and iu this 

 respect as well as others, very distinct from its equivalents 

 further to the west. 



Again, in districts so disturbed as many of those in 

 Eastern Canada, it is inevitable that rocks of different ages 

 must be folded up together, and may be difficult to separate. 



