248 .THE DEVONIAN AND CARBONIFEROUS. [bull. 80. 



culties in regard to the relation of the members of the Productive Coal 

 Measures in various parts of the Sydney field. Accordingly a section 

 extending from the supposed limit of the Lower Carboniferous forma- 

 tion at Point Edward and Sydney to its base is indicated. The rocks 

 consist of red and gray shales, with marls containiu g nodules of lime- 

 stone and iron ore. The limestones often hold marine fossils of Lower 

 Carboniferous types, also plant remains, fish scales, teeth, spines, and 

 coprolites. The estimated thickness is about 4,637 feet. On the shore 

 opposite Point Edward the rocks are of .the Millstone grit formation. 

 These rocks rest upon massive beds of conglomerate and sandstone, 

 which are prominent in Cape Breton coal fields. In constructing sec- 

 tions of a minute character the author finds that the difficulties are 

 caused by faulting. The rocks at Great Bras d'Or entrance appear to 

 be analogous to the Millstone grit of the English coal fields, consist- 

 ing of sandstones highly colored by oxide of iron, and occasionally a 

 bluish gray, shaly, and bedded limestone. 



In Mr. Brown's section, on the northwest of Sydney Harbor, the coal 

 seams appear to run into the Millstone grit. 



Mr. Scott Barlow, 1 in 1874, reported that the rocks of the Spring Hill 

 coal field of Nova Scotia consist mainly of alternate beds of sandstones, 

 blue argillaceous shales, fire clays, and coal seams. On the west slope 

 of the Spring Hill Mining Company a section was run having a total 

 thickness of 516 feet, about 12 feet of which are coal seams. A section 

 is also given to the north of Spring Hill Mining Company's west slope, 

 which has a total thickness of 918 feet 11 inches, of which 25 feet are 

 coal deposits. The characters of the rocks are similar to those of the 

 former section. In the Old Pit, belonging to the same association, the 

 same physical characters already mentioned are maintained, the total 

 thickness found at this point being 624 feet GJ inches, 36 feet of which 

 are coal seams. 



Mr. Walter McOuat, 2 in 1874, reported on the coal fields of Cumber- 

 land County. The section specially examined by the author extends 

 from the Chiegnecto and St. George Mines to the post-road from Am- 

 herst to Truro. As a result of his observations the following classifi- 

 cation was arrived at, exclusive of the Lower Carboniferous rocks, as 

 seen at Black River, given in descending order : 



Feet. 



1. Millstone grit, red shale, flaggy sandstone (gray and greenish) 1,800 



2. Conglomerate, coarse sandstone, reddish and brownish shales 1,500 



3. Middle coal formation, gray sandstone and shale, probably the same as at 



the Joggins 4, 500 



4. Upper Coal Measures, gray sandstone with false bedding 1,000 



5. Red shale, greenish sandstone, conglomerate, and arenaceous gray lime- 



stone 5,000 



Total 13,000 



1 Barlow, Scott : Report on the exploration and survey of the Spring Hill coal field, Cumherland 

 County, Nova Scotia. Geol. Survey Canada: Report of progress for 1873-74, 1874, pp. 147-160. Map. 



2 McOuat, Walter: Report on a portion of the coal field of Cumherland County, Nova Scotia. Geol. 

 Survey Canada: Report of progress for 1873-74, 1874, pp. 161-170. Map. 



