356 THE AZOIC SYSTEM AND ITS SUBDIVISIONS. 



In 1875 Dr. Hunt remarked of the White Mountain or Montalban 

 series (Hastings series) : — 



" These ancient rocks are also largely represented in Hastings County, Ont., 

 where they occupy a position between the Laurentian and the fossiliferous 

 limestones of the Trenton group, and are the equivalents of similar limestones 

 and micaceous quartzites in Berkshire County, Mass., and elsewhere in New 

 England." (Proc. Bost. Nat. Hist., 1875, XVII. 509.) 



In 1878 Dr. Hunt referred the limestones of the Hastings series to 

 the Lower Taconic (Taconian). (Proc. Bost. Soc. Nat. Hist., 1878, XIX. 

 278 ; Preface to Second Edition of Chemical Essays, pp. xxii, xxvi.) In 

 the last quoted work the Hastings limestones and slates are said to lie 

 between the Huronian and Trenton. In 1879 the Norian was said 

 by Dr. Hunt to rest unconformably upon the gneisses and crystalline 

 limestones of the Laurentian, and held to be older than the Huronian. 

 The Huronian was also said to rest unconformably on the Laiirentian, 

 on the nortli shores of Lakes Huron and Superior, thus rejecting the 

 positive evidence given by Messrs. Logan and Bell of their conformable 

 relations (in one case underlying however) on the north side of Lake 

 Superior. 



The rocks of the Montalban series " are believed to be younger than 

 the Huronian, although some geologists have supposed them to be older." 

 (The Geologist's Travelling Hand-Book, pp. 10-13.) The Taconian in 

 the previous year was said to be found reposing alike on the Lauren- 

 tian, Huronian, and Montalban, and to be overlain, in apparent uncon- 

 formity, by the Upper Taconic, which was considered to be identical with 

 the Quebec group of Logan. (Nature, 1878, pp. xviii, 444.) 



In the Report of Progress for 1877-78, Mr. Selwyn made some re- 

 marks on the Quebec Group and the older Crystalline Rocks of Canada." 

 (A., pp. 1-15.) 



He separated the Quebec into three groups : — 



1. The Lower Silurian group. 



2. The Volcanic group, probably Lower Cambrian. 



3. The Crystalline Schist group. (Huronian ?) 



Mr. Selwyn further said : — 



" In any case, I think, there are very few who would agree with Dr. Hunt 

 in the general proposition that the diorites and serpentines of the Quebec 

 group are of sedimentary origin, and the amygdaloids altered argillites ; unless 

 all contemporaneously interbedded volcanic products are to be considered as of 

 sedimentary origin, the Quebec group might be said to present some of the most 



