99 



CHAPTER VII. 



THE TRIAS OR NEW RED SANDSTONE— Con/wMcoT. 



TRURO TO CAFE d'oR GENERAL REMARKS MINERALS OF THE NEW 



RED SANDSTONE AND TRAP. 



3. North Side of Cohequid Bay and Minas Basin and Channel. 



Recommencing at Truro, we may now consider the stripe of New Red 

 Sandstone, with occasional masses of trap, which extends with several 

 interruptions as far as Cape d'Or. Northward of Truro, the red sand- 

 stone meets and overlies unconformably the Carboniferous grits, shales, 

 limestone, and gypsum of the North River and Onslow Mountain. Its 

 boundary in this direction is about three miles distant from the bay, 

 and it occupies the low country ; the Carboniferous rocks rising from 

 under its edges into hills of considerable elevation. From the North 

 River it extends in a band about three miles in width to De Bert River, 

 where an apparently insulated patch of Lower Carboniferous rocks 

 projects through it. These last appear at the bridge, and consist of 

 limestone, with fossil shells characteristic of the Lower Carboniferous 

 period, gypsum, and hard brownish sandstone. They dip at a high 

 angle to the north-east, while the New Red Sandstone, Avhich laps 

 around them, dips at a small angle to the south-west. This lime- 

 stone and gypsum, as Avell as other rocks of the same age, were long 

 believed to belong to the Triassic period, and it was only 

 after their true age had been ascertained by careful comparison of a 

 number of sections, and the identification of the fossil remains with 

 those of the Carboniferous period in other countries, that their true 

 geological position was appreciated. This very locality at the De 

 Bert River, owing to the similarity of the Lower Carboniferous sand- 

 stones to those of the New Red, and to the circumstance that the former 

 have been ground doAvn and their debris mixed up with the latter, is 

 at first sight one of the most deceptive in the province, and might 

 readily lead a geologist imacquainted with other more distinct 

 sections into an error on this subject. 



As the section at this place is remarkably obscure, I copy from my 



