14 THE ROYAL SOCIETY OF CANADA 



Post-Carboniferous 



Though the purpose of this Address is to consider the geographi- 

 cal conditions of Acadia in the Palaeozoic ages only, a few references 

 to those of later times may help to give completeness to the subject. 



Before the close of the Carboniferous age the land had already 

 again subsided, the Gulf region was again under water, and sediments 

 of marine origin were formed in what is now Prince Edward Island 

 and the opposing shores of Westmoreland county, while the probable 

 submergence of the Isthmus of Chignecto would connect the waters 

 of the Gulf with those of the Bay of Fundy, leaving Nova Scotia as an 

 island. 



In the Trias- Jura period similar conditions prevailed, but during 

 and at the close of the latter, remarkable changes took place through 

 the extravasation of vast quantities of volcanic material in the Bay of 

 Fundy trough. Such extravasation did not take place from separate 

 localized vents or craters, but, as in the case of the Palisades of the 

 Hudson, along extended cracks or lines, thus giving origin to long and 

 well-defined ridges, though of no great elevation. Of these the most 

 conspicuous is that which forms the North mountains of Nova 

 Scotia, and which by its production determined for the first time the 

 present south side of the Bay of Fundy trough. The island of Grand 

 Mailan, made up to a large extent of similar trappean and basaltic 

 rocks, is of like origin, as is also Isle Haute and some of the hills about 

 Parrsboro, while the occurrence of equivalent strata on the New 

 Brunswick shores, though only of limited extent, and the existence 

 of parallel ridges along the centre of the trough, as indicated by 

 soundings, show that this was throughout an area of intense vulcanism. 

 The extremely coarse character of some of the conglomerates of this 

 age on the New Brunswick coast, especially about St. Martin's, show 

 that the Bay was at that time swept by very powerful currents. 



The events of the Cretaceous and Tertiary Periods are in New 

 Brunswick without recognizable records. In Nova Scotia a very 

 small area on the south shore of the Bay of Fundy and overlying the 

 Triassic traps has been regarded as of probably Jurassic or Cretaceous 

 age, but with this exception no rocks of Mesozoic or Tertiary age are 

 to be found in any part of Acadia. Throughout the long period repre- 

 sented by these ages the land in this part of Acadia stood at higher 

 level than at present, with higher ranges, and the coast lay consider- 

 ably to the eastward along an area now submerged. It was a period 

 of extensive peneplanation, though not effectually effacing the more 

 dominant geographic features of the region, but any accumulations 



