330 INDEX TO THE STRATIGKAPHY OF NORTH AMERICA. 



The main argument advanced by those that held that these four Middle Carboniferous 

 formations were "Devonian" was based on the supposition that the Lower Carboniferous 

 limestones rested unconformably on these same or equivalent formations. 



In two of the crucial localities in Nova Scotia visited by the writer some time ago, where 

 Carboniferous shale rested unconformably on shales, etc., it has been ascertained beyond a 

 doubt that in one instance (at West Bay, near Partridge Island and Parrsboro, in Cumberland 

 County, Nova Scotia) the Carboniferous limestones proved, on examination of the organic 

 remains entombed in them, to be of true and undoubted Upper Carboniferous age and not Lower 

 Carboniferous, while in the other instance (in the MacArras Brook region of Nova Scotia, where 

 the "Lower Carboniferous" strata rested unconformably on the so-called "rocks of Union," 

 or Union formation) the writer finds that the subjacent strata are in no sense equivalent to the 

 rocks of the Union formation at all (as they are developed at the type locahty near Union sta- 

 tion, on the Intercolonial Railway, just below Riversdale). The Lower Carboniferous strata 

 at MacArras Brook rest unconformably on the upturned edges of the lowest Devonian of that 

 region, as the fossil evidence obtained very clearly showed. The Knoydart formation, of Eo- 

 Devonian age, as seen and developed at MacArras Brook, contains a fauna, which is so nearly 

 allied and identical with that of the lower "Old Red sandstone" strata of Scotland and Great 

 Britain generally that the two can very well be classed as homotaxial and belonging to the same 

 period in the history of the earth's crust — a horizon or formation which had not been previously 

 recorded iu America and which, nevertheless, occupies a definite position, not at the summit of 

 the Devonian, as some geologists would have us beheve, but indeed at the ver" bottom of the 

 system or division of the time scale. 



The error of correlating the rocks of MacArras Brook with those of the Union has led to 

 confusion, and the paleontological evidence, which has been obtained by the writer in both 

 series of strata has conclusively shown that the one (Knoydart formation) indicates a typical 

 "Old Red sandstone" fauna that is lowermost Devonian in age, while the other formation is 

 distinctly referable to the Middle Carboniferous, being associated with and intimately related 

 to the "rocks of Riversdale," containing a typical Meso-Carboniferous flora and fauna, which 

 opinion Messrs. R. Kidston, Prof. David White, Dr. Wheelton Hind, Prof. Charles Brongniart, 

 and Dr. Henry Woodward and others have shared with the writer. The fact that these "rocks 

 of Union" and the "rocks of Riversdale" had for so many years been referred to the Devonian 

 by Canadian geologists led the writer to seek diligently for Devonian types and forms in those 

 strata, and it must be distinctly stated here that I utterly failed to obtain any horizon markers 

 of Devonian aspect ia the true rocks of Union and Riversdale. All tjrpes found were of decidedly 

 Carboniferous f acies and well up in that system. The fossil plants, the fossil fishes, the Crustacea, 

 the insects, etc., all pointed to a horizor of Meso-Carboniferous age, and there we are con- 

 strained to place them. 



I desire here to correct an error made by myself in following and accepting without veri- 

 fication the statement made by stratigraphical geologists that the "rocks of Union" and the 

 "rocks of Riversdale" were always found overlain by the marine limestones of the "Lower Car- 

 boniferous" and were therefore older. On the contrary, I find that the so-called "rocks of 

 Union" as they are developed at MacArras Brook, are the only strata that can in any sense be 

 referred to the Devonian; in which instance it so happens that these so-called "rocks of Union" 

 are not at all the same as those of the Union formation proper. This error on my part in taking 

 for granted that all the strata were one and the same formation, and which had been referred 

 to the "rocks of the Union" and the "rocks of the Riversdale" as unconformably below the 

 limestones of the Lower Carboniferous, as the stratigraphical geologists had said, led me to 

 make the ftirther statement that the "rocks of Union" and the "rocks of Riversdale" were 

 Eo-Carboniferous in age. In referring these strata to the Carboniferous, I was guided by the 

 fossil remains entombed in them, whereas I wes misled by the succession as given by the strati- 

 graphical geologists without any qualifications. It was only when the faunas of the Knoydart 

 formation, from the so-called "rocks of Union" in the MacArras Brook region, were obtained 



