Xbailey] the bay of FUNDY TROUGH 113 



it was to the continued subsidence of the Buy of Fundy trough, of which 

 Nova Scotia may have represented the axial line, that we are to ascribe 

 the vast number of igneous dykes by which, on both sides of the bay, its 

 sediments are intersected, as well, probably, as the origination of the 

 granite which, again on both sides of the bay, was the closing event of 

 the Devonian age. 



In the distribution, character, and fossils of the Lower Carboniferous 

 rocks in the Acadian region is afforded pretty satisfactory information 

 as to the condition of that region at this latter period. At its opening 

 the land on either side of the Bay of Fundy ti-ough undoubtedly stood 

 somewhat above its present level, the main difference between its contour 

 .at that time and the present being in the absence of the North Moun- 

 tains, which now mark its border; but as the age advanced, differential 

 movements, with increase of subsidence in the direction of the gulf, led 

 gradually to the expansion of its waters until these, in New Brunswick at 

 Jeast, spread over the highest hills of the southern coast, as they did also 

 -over much of the interior and over some of the ridges bounding the 

 Gaspe-Worcester trough. Annapolis and Minas basins, with the lower 

 portions of the valleys of the Avon and Shubenacadie, would then be con- 

 tinuous with the main trough, the southern border of which would be 

 marked by the South Mountains ; Nova Scotia would have been separated 

 from the mainland by the submergence of the peninsula now connecting 

 the two, and nearly midway in the strait thus found the Cobequids would 

 have stood as a long island, parallel with the axis of the trough. As in 

 •earlier periods, continued subsidence led to igneous extensions, but these, 

 instead of being, as heretofore, of granite, were now contined to more 

 limited areas and took the form of doleritic dykes and overflows, such as 

 everywhere cap the Lower Carboniferous rocks of southern New Bruns- 

 wick. 



In the case of the rocks of the Coal Measures, the principal facts to 

 be noticed ai-e the occurrence of them everywhere around the shores of 

 the Gulf of St. Lawrence, as well as upon Prince Edward Island, etc., 

 indicating their former continuity over the area now occupied by the 

 waters of the "-"If ; the extension of the latter over the central counties 

 of New Brunswick almost to its western border ; similar extension across 

 the Isthmus of Cbignecto, indicating similar conditions there; but, 

 tinally, with a most wonderful contrast in the thickness of the beds there 

 <ieposited, as compared with those laid down over the mainland of New 

 Brunswick, the one represented by a thickness of 14,000 ft. or more, 

 while the other probably does not exceed 400 or 500 ft. The attitude of 

 the beds in the interior is nearly horizontal ; that of the strata bordering 

 the bay shows everywhere evidence of profound disturbance. Thus, the 

 Bay of Fundy trough as a subsiding area is again strongly accentuated» 

 while the vast thickness of the strata about the head of the bay, as 



