26 rOEMATION AND FILLING UP 



miles. The northern ridge consists of trap, resting upon 

 a red sandstone, and forms the southern boundary of the 

 Bay of Fundy. The southern ridge, called the South 

 Mountains, consists of granite and of, more or less, meta- 

 morphic (Silurian and Cambrian) slates. The surface of 

 the former has been crumbled by the action of the weather 

 sufficiently to form over the greater part of the North 

 Mountains a considerable depth of soil, which, like that 

 of so many other trap rocks, is said by Dr Gesner to be 

 rich and fertile. The granites and slates of the South 

 Mountains have in general been slowly acted upon by 

 the weather, and have unwillingly produced poor and 

 scanty soils. 



Between these ridges runs a long valley, widening 

 towards the Bay of Minas, and affording at that extre- 

 mity a larger expansion for the fertile alluvials of Corn- 

 wallis and Horton. In this valley lies, or formerly lay, 

 a red sandstone deposit — that which still dips beneath the 

 trap of the North Mountains — resting probably on some 

 of the softer slates of the Silurian age. 



In the drift period, when the whole of this country was 

 submerged, the northern current, of which we have so 

 many traces in these countries, rushing between the two 

 lofty ridges of hard rock, scooped out the softer and less 

 coherent red sandstones and marls and softer slates, and 

 produced the existing valley, which, like the Bay of Fundy 

 — a wider and longer excavation — has a north-east and 

 south-westerly course. 



And now, when the land was elevated to the existing 

 level, the tides began to act as at present upon the Bay 

 of Fundy, and to run round either end of the North 

 Mountains, which, from Cape Blomedon to the Digby 

 Gut, formed a long narrow island, having the Bay of 

 Fundy on one side and the Strait of Annapolis on the 

 other. 



But the natural entrance of the tide into the strait 



