356 



THE AZOIC SYSTEM AND ITS SUBDIVISIONS. 



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

 scries (Hastings series) : 



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

 wliere they occupy a position between the Laurentian and the fossiliferoua 

 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. NTat. Hist., 1875, XVII. 509.) 



In 1878 Dr. Hunt referred the hmcstoncs of the Hastings scries 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 lluronian and Trenton. In 1870 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 lluronian. 

 The lluronian was also said to rest unconformably on the Laurentian, 

 on the north 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 Hiu-onian, although some geologists have supposed them to be older." 

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

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

 tian, Haronian, 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 Beport of Progress for 1877-78, Mr. Selwyn made some re- 

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



(A., pp. 1-15.) 



He separated the Quebec into three groups.: 



F 



1. The Lower Silurian group. 



2. The Volcanic group, i)robahly Lower Candjrian. 



3. The Crystalline Schist group', (lluronian ?) 



Mr. Selwyn farther said : 



" In any case, I think, there are ^ .jj ?gw who would agree with Dr. Hunt 

 in the general proposition that the di(jriLes and serpentines of the Quel)ec 

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

 all contemporaneously interhedded v(dcanic products are to be considered as of 

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



