Quebec Group of Logan. 141 



this group, in various relations, along its range from the 

 United States frontier to Gaspe"; but the complexities in 

 connection with these various points of contact, and the 

 doubts attending the ages of the several formations, have 

 never yet been fully solved in their details. 5. The identi- 

 fication of the members of the Quebec group and associated 

 formations with their geological equivalents in districts 

 where these had assumed different mineral conditions, either 

 from the association of contemporaneous igneous beds and 

 masses, or from subsequent alteration, or both. It is with 

 reference to the results under this head the most difficult 

 of all, that the greater part of the objections to Sir Wil- 

 liam's views, taken by Hunt, Selwyn and others, have ari- 

 sen, and that recent discussions and observations have 

 somewhat modified his conclusions." 



Into the question of the age or ages of the crystalline 

 rocks identified by Logan with those of the Quebec group, 

 I do not now propose to enter. Facts in my possession 

 with reference to the fossils contained in some of these 

 rocks, cause me to hesitate as to the more pronounced views 

 on the subject. This question is, however, independent of 

 those relating to the position and character of the unaltered 

 fossiliferous sediments, though very interesting in itself. 1 



' I had intended to refer here to what can scarcely be 

 characterized as other than a very injudicious attempt of a 

 recent writer in the " American Geologist," to revive 

 Desor's name " Laurencian " for the Pleistocene beds of 

 the St. Lawrence valley, to the exclusion of Logan's 

 name Laurentian for the rocks of the old Laurentide hills. 

 This attempt has, however, been so ably and temperately 

 rebuked by Professor Hitchcock, in the last number of the 

 same journal, that any further argument is quite unneces- 

 sary, especially in Canada, where it is probable that no one 

 would countenance such a heresy. Hitchcock says: 



" It does not concern us now whether it was judicious for 



1 See a paper by Dr. Sterry Hunt, American Geologist, April, 

 1890, p. 212. 



