Section IV., 1905. [ 21 ] Trans. R. S. C 



II. — Some Interesting Prohlems in New Brunswicl; Geology. 

 By E. W. Ells, LL.D. 



(Read May 25, 1905.) 



The geology of the southern part of the province of New Bruns- 

 wick, from the Maine boundary on the west to the Petitcodiac river on 

 the east, presents some of the most interesting problems for investiga- 

 tion to be found in Canadian field-work. 



The rock formations extend from the base of the Archaean upward 

 into the Triassic. The intermediate formations are often intricately 

 folded and faulted, while over large areas metamorphism has proceeded 

 to such an extent that comparatively new rocks present the aspect of 

 the old crystalline schists. In the comparative absence of organisms 

 in many places great difficulty has been experienced in working out 

 the structure satisfactorily. 



The oldest series, usually stjded pre-Cambrian, consists for the 

 most part of crystalline rocks. In places these are intimately associated 

 with comparatively recent formations. The lowest portion, comprising 

 limestone, gneiss, granite and quartzite, was originally styled the Port- 

 land group, which was regarded as belonging to the Laurentian system. 

 It is now considered as the equivalent of the Grenville and Hastings 

 series of Ontario and Quebec. The upper portion was divided into 

 three groups, known respectively as Coldbrook, Coastal and Kingston, 

 and these were regarded as probably representing the Huronian of 

 Ontario. The position of all these rocks was determined by the occur- 

 rence of fossiliferous Primordial or Cambrian sediments, usually known 

 under the name St. John group, at various places in an overlying 

 attitude, so that very little doubt could exist as to the horizon of most 

 <:f these crystalline rocks. 



Of the newer formations, after passing over the Cambrian slates, 

 which are readily identified by their contained fossils, large areas of 

 slates and associated rocks are found, which were regarded as in past 

 Cambro-Silurian, Silurian or even Devonian in age, though many of 

 these were so much altered by local intrusions or by regional meta- 

 morphism as to resemble very closely in physical character much of the 

 pre-Cambrian. In the working out of the problems presented, there- 

 fore, very careful attention was necessary, in order to interpret correctly 

 the stratigraphical sequence, which was often complicated not only by 

 the presence of faults and overturns, but by an absence of fossil remains 

 over large areas. 



