[MATTHEW] GEOLOGICAL CYCLES IN MARITIME PROVINCES 139 



ditions ; and around the Basin of Mines in Nova Scotia there are abun- 

 dant indications of marsh and lagoon deposits in the middle of this 

 cycle. The whole cycle may have been epicontinental. 



The Lower Carboniferous Sub-cycle. 



The geologists who have studied the Lower Carboniferous rocks 

 in New Brunswick and Nova Scotia agree that this cycle is distinctly 

 marked off from the preceding by an uncomformity. This is clearly 

 set forth in the report of Messrs. Bailey and Ells on the Albert shales ;^ 

 and of the corresponding beds in Antigonish county Mr. Fletcher says, 

 " it rests unconf ormably upon all the formations from the pre-Cambrian 

 to the Carboniferous conglomerate" {i.e., Upper Devonian conglo- 

 merate) . 



The cycle opened, therefore, with the submergence of an extensive 

 tract in southern New Brunswick, northern Nova Scotia, and Cape 

 Breton, below the sea. There is no means of judging its widtih, as 

 Carboniferous and later terranes cover the areas to the north, but in 

 the neighbourhood of the bands of territory which in Silurian time had 

 supported a littoral fauna, this marine Lower Carboniferous fauna 

 spread itself. 



There was, however, almost immediately a return to re-elevation 

 by slow degrees, for above the limestones containing marine invertebrates 

 are marls with beds of gypsum and saliferous clays, and other indica- 

 tions of a gradual desiccation of the surface of the land. The prevalence 

 of red clays and sands in this terrane also tend to show a dry climate 

 and long exposure to oxidation. 



Going westward in New Brunswick the limestones become thinner 

 and tihe mass of the deposit less, hence it seems probable that the sea 

 in Lower Carboniferous time invaded this area from the eastward, but 

 was soon excluded. 



The Carboniferous Cycle. 



That the epoch of the Millstone grit was the beginning of a new 

 order of things in the Maritime Provinces of Canada is evident from the 

 change in the nature of the sediment and in discordance in dip which, 

 may be observed almost everywhere at the contact of this with the pre- 

 oeeding terrane. 



The red colour of the sediments and the proofs of drying up of 

 ponds and flats, which are so prominent a feature of the Lower Car- 



• Rep. Geol. Surv., 1886, p. 79P, par 3. 



