78 THE LOWER SILURIAN. 



10. THE LOWER SILURIAN. 



In the second edition of Acadian Geology, following, though under 

 protest, the Murchisonian nomenclature, then current both in England 

 and America, and adopted by the Canadian Geological Survey, I 

 included under this head all the fossiliferous rocks older than the 

 Upper Silurian. If, however, we restrict the term Lower Silurian to 

 that geological group of which the great Trenton formation in America 

 and the Bala in England are the main and typical members, and which 

 contains what Barrande has called the " second fauna," then we have 

 as yet no certainly determined fossiliferous group of this age in 

 Acadia ; and there seems little doubt that the great Lower Silurian 

 fossiliferous limestones are absent, as they appear also to be in New- 

 foundland.* If, therefore, there are any representatives of the Lower 

 Silurian, we have to look for them in those rocks underlying the 

 Upper Silurian series, and which are largely of the nature of volcanic 

 or trap-ash deposits. 



In New Brunswick the band of old rocks lying on the north of the 

 crystalline belt extending south-west from Bathurst, and composed of 

 greenish felsites, quartzites, and slates of various kinds, is usually 

 referred to the Lower Silurian. The evidence of this is, first, its 

 appearance from under the Upper Silurian beds in the same manner 

 with the rocks of the Quebec group on the north ; and, secondly, the 

 occurrence of a few graptolites, found by Mr Robb, but as yet only 

 in loose stones. Lithologically these rocks may be regarded as cor- 

 responding somewhat closely with portions of the Quebec group, and 

 also with the contemporaneous Skiddaw and Borrowdale series in 

 England. According to Messrs Bailey and Matthew, similar rocks 

 occur also in several places in the south-west of New Brunswick, and 

 underlie the Upper Silurian of that region. If this view of their age 

 is correct, then it would follow that the mixed aqueous and volcanic 

 deposits so characteristic of the Huronian recurred in the Lower 

 Silurian, and again in the deposition of the Upper Silurian Mascarene 

 series. On the evidence of mine'ral character, as well as of relation to 

 the Upper Silurian series, there seems some reason to suppose that the 

 Kingston group of Messrs Bailey and Matthew, occupying the penin- 

 sula between Kennebecasis Bay and the St John River, and extending 

 south-westward to the coast, may also, as stated above, be of this age. 



Crossing over to Nova Scotia, we have in the Cubequid Mountains 

 a great series of slates, quartzites, and volcanic rocks, evidently under- 



* Murray's Geological Map, 1*77. 



