[BAILEY-MATTHEW] NEW BRUNSWICK GEOLOGY 111 



resemblance is certainly very marked, so far as superficial features are 

 concerned, but not more than to very similar deposits which, in 

 Charlotte county, around the shore of Passamaquoddy Bay, un- 

 questionably overlie, and in a nearly horizontal attitude, fossiliferous 

 strata of Silurian age. When therefore, the writer several years later 

 made a second and more detailed survey of the Tobique-Nepisquit 

 region, having previously become familiar with the aspects of the 

 Silurian as seen in Aroostock County, Maine, where precisely similar 

 relations are revealed, he naturally felt a doubt as to whether the 

 great antiquity which had been assigned to the region could be ac- 

 cepted as correct. It was not long before the suspicion aroused by 

 the general aspect of the rocks received definite confirmation, for at 

 one point, (on the slopes of Mt. Teneriffe or Bathurst Mt.) the felsites 

 exposed on the summits of the hills, and wrongly supposed, except in 

 some instances, to form their entire mass, were really underlaid by 

 or rested upon beds of conglomerate and sandstone, closely compar- 

 able with similar rocks which both about Ashland, Me., and again 

 upon the Beccaquimic, N.B., overlie fossiliferous Silurian strata. 

 Thus a part at least of the felsites and associated rhyolites which cover 

 so large an area on either side of the Tobique and Nepisiquit rivers 

 are clearly much more recent than they had previously been supposed 

 to be, and are to be regarded either as Silurian or Post-Silurian in 

 origin. Dr. Ells, to whom the early reference to the Pre-Cambrian 

 is due, after a visit to the spot, admitted the facts as stated, but 

 endeavored to explain the super-position of the felsites as due to an 

 overthrust; as however, the beds are conformable and lie, as around 

 Passamaquoddy Bay, in nearly horizontal attitude, such a supposition 

 cannot be entertained. It may be added that a typical series of rock 

 specimens collected from the volcanics of the region and associated 

 strata, and subsequently examined petrographically, gave entire 

 confirmation to the view here advanced. 



The problem then in connection with these rocks is to distinguish 

 the limits occupied respectively by the igneous and sedimentary 

 deposits, to ascertain whether any other rocks, older or newer, are 

 to be found in the large area concerned, and to map these accurately. 

 The solution of the problem will be a difficult one, for the region is re- 

 mote and comparatively difficult of access, thickly forest-clad and show- 

 ing, except on the streams, most of which cannot be ascended by 

 canoe, very few exposures; but whether thoroughly surveyed or not, 

 it is desirable that in the issuance of any new map of the region this 

 should no longer be represented as wholly Pre-Cambrian but as com- 

 posed largely of volcanic rocks of uncertain, but comparatively recent 

 age. In the lower part of the Nepisiquit River (below Partage 



