68 ROYAL SOCIETY OF CANADA 



complex against which the later deposits were faulted and ridged upon 

 the south side. This ridge was about seven miles wide, and all along its 

 northern side after it had been hardened and compacted, there flowed 

 out great masses of feldspathic and hornblendie traps with various 

 schistose beds, that formed a belt of about five miles wide, running along 

 the borders of the older complex, and forming together with it a rigid 

 mass at the opening of Palaeozoic time. 



This period of the earth's history opened here with extensive vol- 

 canic effusions that built up two ranges of hills one on each side of the 

 Cambrian valley of St. John. Thus were formed three ridges of hard- 

 ened rock that played an important part in directing the movements of 

 the earth's crust in this district in early Palaeozoic Time, as in the inter- 

 vening valleys were deposited, first the sediments of the Cambro-Ordo- 

 vician Time, and later those of the terrane which forms the subject of 

 this communication. 



Only two basins of measures that can, without question, be referred 

 to the Little Eiver terrane are known; the first has for its centre the 

 outer Harbour of St. John, the second extends from Musquash Harbour 

 to Lepreau Harbour (see map), and lies to the west of the former basin; 

 both have an approximately S.W. to N.E. course, rudely parallel to the 

 Bay of Fuudy. For most of its course the Bloomsbury group, which 

 is the basal part of the plant-bearing series, rests on the Cambro- 

 Ordovician terrane which borders it to the north, without any very 

 obvious difference of dip or strike; but in the western end of the basin, 

 where the Cambro-Ordovician terrane is quite cut out tlie former rests 

 on the Pre-Cambrian limestones and gneisses; in the Musquash Basin, 

 however, the Little River group and Bloomsbury rest on Laurentian or 

 Pre-Cambrian rocks wherever the contact with an older terrane can be 

 Been. 



It is where the plant-bearing terrane rests on these older rocks that 

 the plant remains it contains are in the best state of preservation ; toward 

 the centres of the basins and on their south sides metamorphism renders 

 the plant remains increasingly obscure so that at length they are entirely 

 obliterated, and the clay slates and shales converted into sericic schists. 



Amount of Metamorphism. ' 



It will be seen that in the conditions of metamorphism and in 

 the dip and strike of the measures the plant beds are more nearly related 

 to the older palaeozoic sediments than to later terranes ; they march with 

 former and their carbonaceous contents are markedly debituminized and 

 even graphitized, and not merely converted to bituminous coal like the 

 plant remains of the Coal-measures and the Lower Carboniferous terrane 

 of this district. 



