112 ROYAL SOCIETY OF CANADA 



If now we advance a step upward in the geological scale, we find that 

 the information to be obtained is still very scanty. No rocks of undoubted 

 Cambro-Silurian age have been identified in that part of Nova Scotia 

 which lies directly south of the present Bay of Fundy, and they occcur 

 very sparingly on its northern border. It is probable, however, that 

 extensive areas of such rocks have been removed by denudation, the 

 Dictyonema slates found at the mouth of the St. John river showing such 

 relations to the Cambrian rocks, on which they rest, as to indicate that 

 they at one time completely covered them. (Matthew.) It is probable 

 that they spread over much of Nova Scotia as well, but of this no definite 

 proof has yet been obtained. 



In the Upper Silurian the data are more ample. In New Brunswick 

 the rocks of this age are widely distributed, but between those of the- 

 northern and those of the southern part of the province a great contrast 

 exists. In the northern portion the rocks are calcareous slates and lime- 

 stones, and both by their character and fossils (which include many 

 corals), show deposition in clear waters, marking, in fact, the continuance 

 of the old G-aspe -Worcester trough. In southern New Brunswick, on the 

 other hand, the rocks are almost exclusively slates and fine sandstones, 

 almost without limestones and corals, but with much volcanic debris, show- 

 ing, unmistakably, both by their character and distribution, that they 

 were deposited in shallow bays and straits in and among the old Huroniaii 

 hills, these latter then existing as islands in the Silurian sea. 



There can be but little doubt that the source of these materials, so 

 far as New Brunswick is concerned, was still, as in the earlier Cambrian, 

 to be found in the waste of the old Archœan ridges near by, and remnants 

 of which, like islands, are seen projecting through them ; but while the 

 northern edge of the trough now occupied by the Bay of Fundy thus con-^ 

 tinues to be more or less clearly indicated, we are still wholly without 

 evidence as to its southern border. We do, indeed, find, all along the 

 southern side of the Annapolis valley, in the basins of Bear Eiver, 

 Clements, Nictau and Torbrook, a great body of rocks, which are abun- 

 dantly fossiliferous and contain extensive iron ore deposits, both indicative 

 of their marginal or shallow- water origin ; but through much of their 

 length the rocks with which- they come into contact are granites, which 

 at the same time show, by their penetration and alteration both of the 

 fossil beds and the ore beds along their line of contact, that they arc of 

 later origin. The fossil- bearing strata being clearly of Eo-Devonian age^ 

 and the granites as clearly of later Devonian origin, while to the south 

 no rocks more recent than those of the Cambrian are to be found, we 

 are again forced to the conclusion that, as in the earlier Pahipozoic, so 

 through the Silurian and Devonian eras, the Nova Scotia peninsula, in 

 its western part at least, still lay below the sea level, the old protaxis, if 

 any, lying outside of and to the eastward of its present limits ; also, that 



