250 THE DEVONIAN AND CARBONIFEROUS. [bull. 80. 



No definite division line is drawn between the Coal Measures (III) 

 and the Millstone grit. The limit of the Coal Measures in the south, 

 however, " is indicated by the occurrence of angular blocks of coarse 

 sandstone scattered over the surface. The rocks consist of argillaceous 

 shales containing numerous fossil plants, and even large tree trunks; red 

 and green marls containing a few plant impressions and Naiadites; sand- 

 stones, probably derived from the underlying Millstone grit, containing 

 casts of Catamites, Cordaites, Sigillaria, etc., aud forming the most per- 

 sistent member of the series; and lastly, underclays charged with Stig- 

 maria ficoides, and limestones full of organic remains, of which there are 

 some sixteen layers, with thickness varying from one-half inch to 2 feet." 



The fossils of the limestones are similar to those of the Joggins sec- 

 tion, 1 and are of the genera Naiadites, Cythere, and Spirorbis. 



The total thickness of the coal seams in the different subordinate coal 



basins is as follows : 2 



Ft. iu. 



Cow Bay coal basin 27 5 



Glac6 Bay basin 39 6 



Luigan tract 47 



Sydney mines 30 5 



Boulardrie 28 9 



Cape Dauphin 15 5 



In 1877, Mr. Hugh Fletcher 3 reported on explorations made by him 

 in Cape Breton. 

 The Carboniferous rocks referred to in his report are divided as follows: 



1. Carboniferous conglomerates. 



2. Carboniferous limestone. 



3. Millstone grit. 



The " Carboniferous conglomerate," which the author considers as 

 corresponding to the " Bonaventure formation M of Gaspe, is the "Basal 

 conglomerate" of New Brunswick and Newfoundland, rests upon the 

 Lower Silurian slates and sandstones, and has near the Coxheath Hills 

 a vertical thickness of 1,890 feet 11 inches, while from Watson Creek 

 to the above hills it attains a "thickness of 2,525 feet, maintains its gen- 

 eral character of brick-red color, and is somewhat friable. It consists 

 of reddish, micaceous, friable, and argillaceous sandstone, with bands of 

 marl intermixed, reddish friable conglomerate with interstratified fine- 

 grained pebbly sandstone. 



No distinct line can be drawn between the conglomerate and the lime 

 stone. The latter occupies a narrow strip along Sydney Eiver, widens 

 toward Point Edward, extending into the valleys of Ball and Leitch 

 Brooks. A section of this formation from the banks of the Sydney 

 River is given. The maximum thickness is 1,011 feet, 6 inches. 



1 See Acadian Geology, pp. 173-181. 



2 Robb, Charles: Report on explorations and surveys in Cape Breton, Nova Scotia. Qeol. Survey 

 of Canada: Report of progress for 1874-75, 1876, pp. 166-2G6, map. 



3 Fletcher, Hugh : Report of explorations and surveys in Cape Breton. Geol. Survey Canada: Re- 

 port of progress, 1875—76, 1877, pp. 369-418, map. 



