[MATTHEW] GEOLOGICAL CYCLES IN MARITIME PROVINCES 137 



In ISTova Scotia rocks of a similar age occur at Torbrook and Nictau, 

 where the iron ore beds are rich in brachiopods and other forms of 

 Lower Devonian age. Here the terrane passed through a wider range 

 of conditions than in New Brunswick, for it has quite a body of fine dark 

 slates at the top, but these are not so fossiliferous as are the beds below. 

 Going east from Nictau, certain fine slates and calcareous beds come in 

 which contain a Silurian fauna, and to which these beds of Nictau are 

 probably superjacent, as are certain red beds at Arisaig, which overlie 

 the Silurian terrane there. These beds at Arisaig contain Lower De- 

 vonian fish remains, and, therefore, would seem to be of the same terrane 

 as the red strata of Nictau and Mispec. 



In New Brunswick, north of the inmiediate shore of the Bay of 

 Fundy, no strata of this terrane have been found, and no fauna of the 

 Middle Devonian is knov/n in all Acadia and in Maine. These facts 

 seem to favour the presumption that all this area was above the sea in 

 Middle and most of it in Ijower Devonian time. If we couple this 

 with the fact tliat extensive extrusions of granite occurred in the two 

 Canadian provinces and in Maine with great folding and crushing of 

 all the older sediments, it will be seen that Early and Middle Devonian 

 time, was a critical period in the geology of Acadia. 



In New Brunswick the pebbles of the conglomerates jn the Lower 

 Devonian are derived from rocks immediately north of them, and though 

 the accompanying slates contain only poorly preserved plant remains, 

 the corresponding strata in Nova Scotia have yielded P silo phy ton and 

 other fossils of types peculiar to the Devonian age. But nothing has 

 been found which recalls the peculiarly rich and varied earlier flora of tho 

 St. John plantbeds. It would appear that the conditions which had 

 encouraged the growth of that vegetation had been removed. Chief 

 fimong these, no doubt, was the change from an insular to a continental 

 climate, the barriers which shut off the cold and dry north winds were 

 removed, and the flora which had had its home in Gaspé invaded the 

 continental and insular parts of Acadia. 



The Upper Devonian Cycle. 



This consists ;of beds which, for a long time, have been classed in 

 New Brunswick as Lower Carboniferous. It is true that in the first 

 geological survey of New Brunswick Dr. Abraham Gesner placed them 

 as " Old Eed Sandstones," but as he classed the Lower Carboniferous 

 limestone as Lias Limestone, it is evident that his determinations of 

 the sandstones and shales were based on lithological data, as was the 

 custom in the early days of the last century. The later reference of these 



