176 SUBDIVISIONS OF THE CARBONIFEROUS SYSTEM 



Just where to place this Windsor formation in the column 

 of Palaeozoic formations has not yet been definitely ascertained. 

 Whether it is to be classed as one of the Eo-Carboniferous sedi- 

 ments, or whether it constitutes a factor or part ot what may be 

 termed, according to Prof. H. S. Williams'.s very appropriate 

 classfication, Meso-Carboniferous, is the question occupying our 

 mind at present. It is, nevertheless, to be remarked that the 

 fauna it contains is one in which so far not one of the Upper- 

 most Devonian fossils of the Gaspe and other regions of Eastern 

 Canada have been detected. 



The occurrence of this formation in certain basins of Nova 

 Scotia marks a cessation of the conditions existing in the areas 

 which these limestones cover, showing that the sea or Atlantic 

 waters in Carboniferous times extended over the Eo-carboniferous 

 deposits previously laid down, which had been subjected to 

 subsidence and erosion previous to their being overlaid, whilst 

 the vegetation and climate did not, probably, change very 

 materially in the high land during this period of submergence 

 and encroachment of the sea. A period of elevation evidently 

 must have followed the deposition of the limestones, marls, &c., 

 and sandstones and mudstones and shales were deposited, to be 

 followed later again by sandstones with shales and coal seams 

 peculiar to the "Coal Measures " and " Millstone Grit " formations. 



Such deposits are essentially terrigenous as to their origin 

 and the structure, as well as origin and mode of deposition of 

 the Coal Measures need not be described. The flora and fauna 

 they hold mark the estuarine conditions existing and prevailing 

 at the time, also the luxuriant growth of plants on land with 

 the contemporaneous animal life of the period both in the water 

 and on the land also. 



A brief summary of the succession of the sediments in the 

 Carboniferous of Nova Scotia in Pictou, Colchester and Cumber- 

 land counties in part, such as the writer has observed it in 

 numerous outcrops and localities, gives the following section in 

 ascending order : 



1. Riversdale and Union formations: Consisting of red 



