283 



Miomefres ^^ detachcd areas but the bulk of the Pre- 

 Cambrian is formed of granite and which is 

 intrusive into the limestone, etc. 



53-3 m. River Denys Station — Alt. 72 ft. (21-9 m.). 



85 • 7 km. From River Denys station the railway runs 

 southwestward up the valley of Big brook along 

 the foot of the slope of North Mountain. The 

 valley of Big brook is underlain by strata of the 

 Limestone series dipping at angles of 20° to 70° 

 to the west beneath a synclinal basin of Mill- 

 stone Grit and perhaps younger strata lying 

 about midway between the Pre-Cambrian areas 

 of North Mountain on the east and the Craignish 

 hills on the west. In the lower part of the 

 valley of Big brook, the Craignish hills, distant 6 

 to 8 miles (9 to 13 km.), are visible but as the 

 railway ascends the valley the view of these 

 hills is cut off by the intervening ridge of Mill- 

 stone Grit. Towards the head of Big brook 

 valley, the bounding ridge of younger Car- 

 boniferous strata on the west attains altitudes 

 comparable with those of North Mountain 

 along the foot of which the railway continues 

 to run. 



From the head of Big brook valley the railway 

 crosses a summit (altitude, 286 feet or 87-2 m.) 

 and enters a watershed draining southward to 

 the Strait of Canso. As the railway descends, 

 a view is afforded to the w^estward across the 

 wide low valley of River Inhabitants which 

 flows from the northwest. The valley of the 

 river and the lower slopes on both sides are 

 underlain by strata of the Limestone series and 

 perhaps older divisions of the Carboniferous 

 dipping in various directions and traversed by 

 a series of east-west and north-south faults. 

 The higher lands, on the western side of the 

 valley are occupied by measures that have been 

 mapped as Devonian but which are believed to 

 include at least some members that are the 

 equivalent of the Horton series (Lower Carbon- 

 iferous). The areas of so-called Devonian 

 encircle or partly surround still higher ridges of 

 Pre-Cambrian strata. 



