BROWN ON THE GEOLOGY OF CAPE BRETON. 



211 



An extensive tract of millstone grit, with red shales and some 

 thin limestones, commencing at Soldier's Cove, on the lake shore, 

 seven miles to the eastward of St. Peter's, continues to the Gut of 

 Canso ; but I have not had an opportunity of tracing the northern 

 boundary of these, except at the head of the West Bay, where 

 limestone and gypsum show themselves. A few thin seams of 

 coal, of no practical value, have been found in this tract ; viz. at 

 St. Peter's ; at the mouth of the River " Inhabitants ; " and at 

 Carabacoo Cove, near Bear Island. It has not been ascertained 

 how far the millstone grit extends up the valley of the River 

 " Inhabitants ; " but workable seams of coal are said to occur 

 twelve miles above its mouth. A mass of trap protrudes through 

 the grits and shales on the narrow isthmus which separates St. 

 Peter's Bay from the lake, and there forms a conical hill, called 

 Mount Granville, 600 feet in height. On its eastern declivity, beds 

 of a coarse limestone are seen nearly on edge, but quite destitute 

 of fossils. This trap is soft and crumbling, of a mixed green and 

 white colour, and it resembles in every respect the mass of the 

 same rock which bursts through the New Red Sandstone of Truro, 

 in Nova Scotia. 



On the western shore of Cape Breton, the millstone grit com- 

 mences at the northern end of the Gut of Canso, and it underlies 

 the coal measures which extend in a narrow belt from Port Hood 

 to Chimney Corner, near Margarie. I have not visited this part 

 of the island ; but am credibly informed that valuable seams of 

 coal exist at both extremities of this coal field. 



One of the most characteristic features of the Cape Breton, as 

 well as of the Nova Scotia coal field, is the constant association 

 of extensive beds of gypsum and marls with the carboniferous 

 limestone. These gypsiferous strata are nowhere more fully de- 

 veloped than in the Bras d'Or Lakes, where, most fortunately, the 

 numerous creeks and inlets which ramify in all directions expose 

 sections on their shores ; and from these, at a future time, I trust 

 I shall be able to collect a body of facts, that will clear up any 

 doubts that may yet remain concerning the relative age and posi- 

 tion of the gypsum and coal measures. In the vicinity of Sydney, 

 gypsum appears at the head of the East Bay, and again, crossing 

 the Boulardrie Island, following the course of the fault, as is shewn 

 in the above section. Beyond this fault, the limestones, with the 

 overlying sandstones, stretch out horizontally to the head of Bou- 

 lardrie Island, the gypsum showing itself only at two places, viz. 

 at Island Point and Big Harbour. The following is a section 

 from Island Point to Baddeck : — 



W. Salt Springs. Baddeck Harbour. 



Red Head. 



Ship Entrance. Boulardrie Island 



4. Millstone grit. 



3. Limestone and shales.] 



2. Gypsum and marls. 



1. Coarse red conglomerate. 



p 2 



