NEW BRUNSWICK. 



369 



1870, placed this point beyond (pcstion, they having been then found by me to 

 occupy irregular troughs in the older Pre-Siluriau rocks, resting sometimes 

 upon one and sometimes upon another of the subdivisions of the latter, crossing 

 their strike obliquely, and having at their base coarse conglomerates made up 

 of the waste of the underlying formations. The latter being thus unquestion- 

 ably of Pre-Silurian age, it is equally obvious that in their vast thickness, in 

 the markedly different conditions under which their several divisions were 

 accumulated, and finally in the further unconformability indicated between 

 these divisions, they represent a vast interval of time, and are at least as old as 

 the Iluronian and portions of the Laurentian system, which in all their physi- 

 cal characters they sO nearly resemble. No more marked coorduiation of dis- 

 tant formations could be desired than is here furnished between the great mass 

 of coarse gneisses at the base of the series, associated with finer gneisses, quart- 

 zites, graphitic and serpentinous liuiestones and dolomites (the probable equiv- 

 alents of the Hastings' series of Mr. Vennor), and capped by the great volcanic 

 series of the Huronian, with its petrosilicious and felsitic strata, ash -rocks and 

 aggh)merates, the whole unconformably traversed by bands of the lowest Cam- 

 bro-Silurian, and the sinular succession observed about Lake Huron and else- 

 where It should be added in this connection that in the rocks here 



assigned to the Iluronian, there are as a whole two well-marked divisions, the 

 lower (or Coldbrook, group) consistiug almost entirely of fine grained felsitic 

 strata, with dioritcs, amygdaloids and porphyries, and the upper (or Coastal 

 group) of schistose rocks, often talcoid or nacreous, with conglomerates and 

 limestones and holding ores of copper, and that between the two there is not 

 unfre([uently evidence of at least a partial unconformability, but in general 

 the rehitions to each other are nmch more intimate than are their relations 

 either to the underlying Laurentian, or to the Primordial strata which overlie 

 them." (/. o.,pp. 416, 417.) 



In this paper the Kingston was separated by Prof. Bailey into two 

 groups : one of these was placed in the Iluronian, and the other in the 

 Lower Silurian. This author further states, that the Upper Silurian 



** age can now be definitely assigned to the very remarkable group of rocks sur- 

 rounding Passamaquoddy Bay, and which include the peculiar orthophyrcs or 

 felspar-porphyries of Eastport and Pembroke, Me., these latter having been 

 found to rest directly and almost horizontally upon a series of foasiliferous 

 sandstones, identical with tliose which at the last-named locality have been 

 long known to contain a rich Upper Siliu'ian fauna. Another instance of the 

 diiliculty of distinguishing the rocks of this most variable formation is to be 

 found in the occurrence, first observed by Mr. Matthew, of corals and other 

 Silurian organic remains on the Long Reach of the St. John Biver, in amygda- 

 loidal ash-rocks, "which are undistinguishable lithologically from those of the 

 Iluronian formation, and which, like those of Passamaquoddy Bay, had pre- 

 viously been referred to this horizon." (I. c, p. 421.) 



VOL. VII. — NO. 11.. 24 



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