231 



Triassic genus. Still later, it was determined that the 

 reptilian remains had been misidentified and that they 

 represented a lower Permian genus; consequently the 

 highest beds on Prince Edward Island are definitely con- 

 sidered to be of Permian age. 



During the flux of time as opinions changed regarding 

 the age of the highest members of this great group of strata, 

 various terms were applied to the lower divisions by Sir 

 W. J. Dawson and other observers, These terms were such 

 as Newer Coal formation [1], Upper Coal formation [2], 

 Permo-Carboniferous [4], Permian, etc. In all cases the 

 different terms were used with the definitely stated or 

 plainly implied meaning that the group of strata repres- 

 ented a thick series laid down uninterruptedly from late 

 Carboniferous on into Permian time. In certain districts as 

 for instance where the strata are exposed along the Joggins 

 shore, there is no appearance in the exposed sections of an 

 unconformity between the Carboniferous Coal Measures 

 and the overlying Permo-Carboniferous group. In other 

 districts, as in the neighbourhood of New Glasgow, the evi- 

 dence implies the existence of a profound stratigraphical 

 break above what is customarily considered to be the 

 horizon of the Productive Coal Measures but below the 

 summit of the Carboniferous. Presumably, sedimentation 

 ceased over the greater part if not over the whole region 

 in later Carboniferous time, and in places at least, the strata 

 were folded, faulted and eroded. In other places the strata 

 were scarcely deformed at all, perhaps but little eroded and, 

 it is possible that in some local areas the processes of 

 sedimentation may have operated continuously. At a 

 later date but still before the close of Carboniferous time, 

 the processes of sedimentation were renewed and con- 

 tinued in force during the closing epochs of Carboniferous 

 and the opening period of Permian time. 



The conclusion that the strata of the above mentioned 

 four areas are all portions of one great, unbroken group, 

 rests on evidence collected by Dawson and afterwards 

 substantiated by the detailed field studies prosecuted by 

 Fletcher. There does not seem to be any reasonable 

 grounds for doubting the truth of this general conclusion. 

 It is, however, as yet uncertain how high the strata range 

 in the four main areas though it has generally been thought 



