390 



CHAPTER XIX. 



THE CARBONIFEEOUS ^YSTE^i— Continued. 



CARBONIFEROUS DISTRICT OF RICHMOND AND SOUTHERN INVERNESS 



USEFUL MINERALS DISTRICT OF NORTHERN INVERNESS AND VICTORIA 



USEFUL MINERALS DISTRICT OF CAPE BRETON COUNTY USEFUL 



MINERALS. 



Carboniferous District of Richmond and Southern Inver?iess. 



This district is separated from those of Sydney and Guysboro' only 

 by the Strait of Canseau, a narroAV transverse valley excavated by the 

 currents of the drift period. The Lower Carboniferous conglomerates 

 and limestones are seen on both sides of the strait, and the lowest 

 members of the system are seen at Plaister Cove and its vicinity, and 

 are succeeded to the southward and eastward by the Coal formation. 

 As this district presents some curious and interesting features, I shall 

 notice some parts of it in detail. 



The coast section in the vicinity of Plaister Cove is remarkable for 

 the highly perfect manner in which it displays the gypsiferous rocks, 

 and the information which it consequently affords as to their structure 

 and origin. 



The following summary of the beds seen in this section is from a 

 paper contributed by the writer to the Geological Society in 1849 

 (see Fig. 154) : — 



" (1.) At M'Millan's Point, about three-quarters of a mile north of 

 the Cove, are thick beds of gray conglomerate, in a vertical position. 

 These beds form the base of the Carboniferous system in this district ; 

 and, at a short distance inland, they have been invaded by trap and 

 other igneous rocks, belonging to a great line of igneous disturbance 

 extending to the north-eastward. The conglomerates near M'Millan's 

 Point have been thrown up along an anticlinal line connecting the 

 igneous range last mentioned with that of Cape Porcupine, on whose 

 flanks the same conglomerates appear. The valley now occupied by 

 the strait is in great part due to the want of continuity of the igneous 

 masses at this point, though the distribution of the surface detritus 



