14 O ROYAL SOCIETY OF CANADA 



boniferous shales, give place prevailingly to sandstones of a gray colour, 

 and the oncroachment of these sands on the red marls and limestones of 

 the anterior time. 



Still it would appear that the region was not much depressed, for 

 the coal measures are beds which would have been deposited chiefly in. 

 the lagoons and marshes of a widely extended flat and low country. 



The geographical outlines of the coal measures as they are now 

 spread out in Acadia was more or less the outlines of that great plain 

 over which the coal measures accumulated and are now exposed, their 

 material being supplied by the rivers that flowed down from the adjoin- 

 ing highlands to the south and, perhaps, to the northwest. The Car- 

 boniferous plain was an. extended triangular basin facing the Gulf of 

 St. T^awrence, having its apex at Oromocto lake in New Brunswick, 

 and the sides spread out to the east in Nova Scotia and northeast in 

 New Brunswick. 



Of this cycle the Millstone grit is essentially a part of the coal 

 measures, but by the greater prevalence of red sandstones and shales, 

 shows a relation in its climate and conditions to the underlying Lower 

 Carboniferous series. 



Sir Wm. Dawson well describes the conditions that may have pre- 

 vailed here in Carboniferous Time in his account of the Joggins section 

 in Cumberland county. He says, " The whole series of events in the 

 preceding historical sketch has depended on the following conditions : — 

 Gradual and long continued subsidence, with occasional elevatory move- 

 ments, going on in an extensive alluvial tract, teeming with vegetable 



life and receiving large supplies of fine detrital matter For 



a very long period these opposing ^forces (of subsidence and re-elevation) 

 were alternately victorious, without effecting any very decided or per- 

 manent conquest."' " It is impossible to contemplate this vast series 

 of deposits (of the Joggins section of coal measures, 13,000 feet) with- 

 out being forcibly impressed with the great lapse of time and the variety 



of change which it indicates It is to be borne in mind also 



that this section represents the structure of the whole plain of Cumber- 

 land, and in a less precise manner that of the whole Carboniferous areas 

 in Nova Scotia and New Brunswick." 



It will be noted that all the forms of animal life described by Sir 

 W. J. Dawson as inhabiting this great Carboniferous plain are those 

 of the land, or of ponds and lagoons, the sea margin may have been 

 far away to the northeast at the present deeper waters of the Gulf of 

 St. La^vrencc, outside of the Magdalen Islands and the northern shores 

 of Cape Breton. 



