118 THE ROYAL SOCIETY OF CANADA 



of the beds containing them, and we thus learn that for much of 

 Silurian time the ocean had free access to the greater part of Northern 

 New Brunswick, this being in fact a portion of a great sea-filled strait 

 or basin extending from the Gulf of St. Lawrence about Anticosti 

 to western New England, the waters, though shallow, being sufficiently 

 clear and deep to permit of the growth of corals {Favosites, etc.). 

 In southern New Brunswick also the sediments, as found in Kings 

 and Charlotte county, are marine, but they are argillaceous and 

 arenaceous rather than calcareous, contain few if any corals, and are 

 evidently made up mainly of what were originally sand and mud beds 

 of littoral origin. Their disposition with regard to the rocks on which 

 they rest seem to indicate that southern New Brunswick, in contrast 

 with its northern portion, was in the condition of an archipelago, 

 among whose islands, such as the Pre-Cambrian hills of Kingston 

 and the Long Reach, together with certain portions of Charlotte Co., 

 the deposits were laid down by shallow shifting currents, suited 

 mainly to the life of brachiopodan and lamellibranch shells. 



(b) From the presence of corals it may be inferred thaf the 

 temperature of the Silurian seas was at least warm temperate. That 

 of the land may be judged from considerations to be presently dis- 

 cussed. 



(c) The source of the material, so far as ordinary sedimentary 

 deposits are concerned, but excluding limestones and igneous rocks, 

 was evidently that of the erosion of the pre-existing beds, Archaean 

 and Cambrian, on which they now rest. In northern Kings, and 

 about the Long Reach, they still lie, in nearly horizontal beds, at the 

 foot of high and nearly perpendicular hills, such as Blue Mt. and 

 Brokeneck, of Huronian age, as though laid down by currents sweep- 

 ing around and wearing down the latter. 



(d) On the other hand, the evidences of igneous activity during 

 this age in New Brunswick are most remarkable. 



Reference has already been made to the fact that in the Northern 

 Highlands very large areas, formerly looked upon as Pre-Cambrian, 

 are now believed to be occupied by igneous and pyroclastic rocks, 

 either Silurian or Post-Silurian in age. They consist very largely 

 of rhyolites and felspar porphyries occurring both as dykes and beds, 

 together with ash rocks, and which are unconformably underlaid by 

 conglomerates and sandstones of the Silurian. In southern New 

 Brunswick again, beds which most closely resemble these are found 

 around Passamaquoddy Bay resting upon fossiliferous strata, as seen 

 especially on the Mascarene shore and about the town of Eastport. 

 Their distribution and thickness as found in this region, where they 

 form prominent eminences such as Chamcook M t., indicate that the 



