of Nova Scotia. 143 



presenr the most probable arrangement, that represented in the 

 little section attached to the map. The coast series would thus 

 belong to an anticlinal, bringing up Lower Silurian rocks. On 

 these, in proceeding to the north-west, rest middle and upper 

 Silurian and perhaps Devonian beds in a metamorphosed condi- 

 tion, which along the northern margin of the metamorphic dis- 

 trict rise again with an opposite dip, at Arisaig, East River, New 

 Canaan, &c., forming a trough, the middle of which, in the east, 

 is divided by a secondary anticlinal and filled with carboniferous 

 rocks, but in the west is occupied with a great mass of granite 

 into which the beds appear to have sunk in the direction of their 

 dip. Beyond the northwestern edge of this trough, the Silurian 

 beds probably again dip to the northward, but are hidden by 

 carboniferous deposits, and reappear in another anticlinal with 

 east and west strike in the Cobequid Mountains. 



Rocks similar in character and relations to those above described 

 are extensively distributed in the Island of Cape Breton and also 

 in New Brunswick, but I have no detailed knowledge of their 

 distribution. The formations described in this paper, represent 

 in age, and resemble in their state of alteration, many portions of 

 the metamorphosed Silurian and Devonian rocks of New England 

 and Eastern Canada. In the latter, the relations of the intrusive 

 granite and the middle and upper Silurian rocks as described by 

 Sir William Logan, and as I have observed them in a few locali- 

 ties, strikingly resemble the phenomena observed in Nova Scotia. 



I have no doubt that a detailed survey of these rocks in Nova 

 Scotia and Cape Breton, would develop many curious and intri- 

 cate disturbances, and might also ascertain the presence of mem- 

 bers of the Silurian series, now supposed to be absent, but which 

 may be only obscured by denudation. In the mean time local 

 observers can do much to increase our knowledge of these rocks 

 by carefully collecting the few fossils that remain unobliterated in 

 the semi-metamorphic beds, and the above remarks may serve to 

 guide such explorations, and to enable geologists to speak with 

 more confidence than heretofore of the older palaeozoic rocks of 

 an important region of eastern America. 



