DEVONIAN. 331 



and determined by Dr. A. Smith Woodward and Dr. Henry Woodward and others, that the 

 confusion that existed was evident to me, and the necessity of separating these two sets of strata 

 became apparent. This led to the separation of the Knoydart formations from their supposed 

 equivalents "the red rocks of Union." I have no hesitation in saying now that the Union and 

 Eiversdale formations, as they are developed at the type localities at the Union and Riversdale 

 in Colchester county in Nova Scotia, are Carboniferous in age, and are Meso-Carboniferous at 

 that. Further, it is also evident that the New Brunswick equivalents of these two formations, 

 namely, the Mispeck and the Lancaster formations (the latter sometimes designated as the 

 Little River group) , can not any longer be classified as Devonian, but as truly Meso-Carboniferous 

 formations, with an abundant flora found the world over, and in all countries other than Canada 

 referred to as the Middle Carboniferous. 



In view of the conclusion that the supposed Devonian of the original descrip- 

 tions is in part Carboniferous, it is difficult to determine what the Devonian rocks 

 of Pictou, Antigonish, and Colchester really are. A basal Devonian formation 

 is, however, distinguished by Ami ^^ as the Knoydart formation of Antigonish 

 County. A detailed section of the rocks by Fletcher ^^^ shows 684 feet of red sand- 

 stone and shale with greenish layers and thin flinty or calcareous or carbonaceous 

 layers, some of which consist of volcanic ash. The included fossils are ostraco- 

 derms, constituting a very primitive and early type of fishes and establishing a close 

 correlation with the lower Old Red sandstone of Great Britain. 



The Silurian and Devonian iron-bearing formations of Digby and Annapolis 

 counties, southwestern Nova Scotia, are thus described by J. W. Dawson: '^ 



In Nova Scotia the rocks older than the Carboniferous system have all undergone more or 

 less alteration and disturbance. This, with the imperfect preservation of their fossils and their 

 inland position, renders the working up of their details of structure very difficult. Large 

 tracts of country thus remain in a state of uncertainty, their rocks being manifestly older than 

 the Carboniferous, but yet otherwise of uncertain age. In the case of the Devonian, the only 

 place in which it has been clearly made out as distinct from the Silurian is the belt of hilly coun- 

 try extending along the south side of the Annapolis Valley. Here, in the section of the Nictaux 

 River, the first old rocks that are seen to emerge from beneath the New Red sandstone of the 

 low country are fine-grained slates, which I shall describe in the sequel as Upper Silurian. Their 

 strike is N. 30° to 60° E., and their dip to the southeast at an angle of 72°. Interstratified with 

 these are hard and coarse beds, some of them having a trappean aspect. In following these rocks 

 to the southeast, or in ascending order, they assume the aspect of the New Canaan beds; but I 

 could find no fossils except in loose pieces of coarse hmestone, and these have the aspect of the 

 Upper Arisaig series, or newest Silurian of the eastern part of Nova Scotia. In these and in some 

 specimens recently obtained by Mr. Hartt I observe Orthoceras elegantulum, Bucania trilohita, 

 Comulites jlexuosus, Spirifer rugsecosta% and apparently Chonetes novascotica, with a large 

 Orthoceras, and several other shells not as yet seen elsewhere — aU Upper Silurian. These 

 fossils appear to indicate that there is in this region a continuance of the upper Arisaig series 

 nearly to the base of the Devonian rocks next to be noticed. 



After a space of nearly a mile, which may represent a great thickness of unseen beds, we 

 reach a band of highly fossiliferous peroxide of iron, with dark-colored coarse slates, dipping 

 S. 30° E. at a very high angle. The iron ore is from 3 to 4^ feet in thickness. The fossils of 

 the ironstone and the accompanjdng beds, as far as they can be identified, are Spirifer arenosus, 

 Strophodonta magnifica, Atrypa unguiformis, Stropliomena depressa, and species of Avicula, 

 Bellerophon, Favosites, and Zaphrentis, etc. These, Professor Hall compares with the fauna 

 of the Oriskany sandstone; and they seem to give indubitable testimony that the Nictaux iron 

 ore is of Lower Devonian age. * * * 



