Sir PF. E, Logan on the Quebec Groujpy Sfc, 199 



however, every deduction which can be made, we must be pre- 

 pared to find that the facts thus brought to light in the valley of 

 the Somme will be held to furnish important collateral evidence 

 in support of the reasoning founded on other sciences, such as phi- 

 lology and ethnology, which has long demanded, for the develop- 

 ment of our race, a number of years far exceeding that which is 

 allowed by the chronology previously received. It is the beauti- 

 ful expression of Sir Thomas Browne, which I find quoted by Dr. 

 Mantell in a former paper on this subject, that " Time conferreth 

 a dignity upon the most trifling thing that resisteth his power; " 

 and it is impossible to look at these rude implements — perhaps 

 the earliest efforts of our race, in the simplest arts of life — without 

 being impressed with the high interest of the questions with which 

 they seem to be inseparably connected. 



ARTICLE XIV. — Considerations relating to the Quebec Group, 

 and the Upper Copper-bearing rocks of Lake Superior. By 

 Sir W. E. Logan, F.R.S., Director of the Geological Survey 

 of Canada. 



CEead before the Nat. Sist. Society.) 

 In a communication addressed by me to Mr. Barrande on the 

 fauna of the Quebec group of rocks, (Canadian Naturalist and 

 Geologist vol. v. p. 4Y2), after showing that the organic remains 

 discovered last year at Point Levi placed the group about the 

 horizon of the Calciferous formation, I stated that the apparent 

 conformable superposition of the group on the Hudson River for- 

 mation was probably due to an overturn anticlinal fold or overlap. 



Fig. 1. 



Montmorency N.Channei. Orleans island 



F I 



g, Laurentian gneiss. 

 bj Trenton limestone. 

 M^, Utlca shale. 

 M*, Hudson River shale. 



^, Quebec group. 



F. Fault. 



O, Overlap. 



S, Level of the Sea. 



Horizontal and vertical scale, 1 inch to 1 mile. 



The character of this overlap is exhibited in the accompanying 

 wood cut (fig 1) of a vertical section in the neighbourhood of 

 Quebec, extending from the Montmorency side of the St. Lawrence 

 across the north channel and the upper end of the Island of 



