70 ROYAL SOCIETY OF CANADA 



In other respects, as well as in the de-bituminization of the plant 

 remains, the Little Eiver terrane agrees with the Lower Palaeozoic and 

 not with the Upper. For instance, the sandstones have the grains of 

 sand of which they are composed strongly cemented together with second- 

 ary silica, and though the massive condition is not so marked as in the 

 sandstones toward the base of the Cambro-Ordovician terrane, the se- 

 condary silica is sufficient to make a tough and resistant rock, far more 

 coherent than the sandstones of the Upper Palaeozoic in this district. 



Another feature which associates the Plant beds with the older 

 Palaeozoic terrane and separates them from the younger Palaeozoic is the 

 free development of slaty cleavage in the argillaceous layers of the ter- 

 rane, and the compacting of these layers. No such condition is found 

 in the Upper Devonian or Carboniferous shaly beds, which, where they 

 are not held together by a calcareous cement, are soft and rubbly ; the 

 lateral pressure which has been active in producing cleavage planes in 

 the mud beds of the Little Eiver teri'ane has had no effect on these more' 

 recent rocks. 



The time in geological history at which this change in the condition 

 of the earlier sediments of this district took place is perhaps not settled 

 With entire exactness, but there are considerations which point to the 

 Middle Devonian as the time when the metamorphism occurred. 



Lying upon the Little River terrane is a set of red beds chiefly 

 slates with some sandstones and with a conglomerate or breccia at the 

 base; these indicate a change from the slow and quiet accumulation 

 which had gone on for so long a time during the accumulation of the 

 Little River terrane, to one of more violent change with the deposit of 

 thoroughly oxidized muds, accompanied with some volcanic disturbances 

 of local import. A few plant remains are found in this, the Mispec 

 terrane, but they are obscure ; perhaps they are fragments of Psilophyton. 



On the south side of the Bay of Fundy in the province of Nova 

 Scotia about fifty miles from this terrane are similar red beds with re- 

 mains of Psilophyton, the age of which is determined by the presence iu 

 some of the layers of marine shells showing that they were formed at the 

 commencement of Devonian Time. These are the hematite, and magne- 

 tite-bearing rocks of Nictau and Bear River, and like the Mispec beds 

 they exhibit slaty cleavage, and more or less metamorphism from the 

 influence of granitic m.asses to the south. Their aspect and condition of 

 metamorphism is therefore similar to that of Mispec terrane on the north 

 side of the bay. 



Above this terrane, both in New Brunswick and Nova Scotia, we 

 lose the condition of metamorphism which marks this and the two sub- 

 jacent Palaeozoic terranes, and here we think is to be drawn the line 



