1865.] MATTHEW — SOUTHEKN' NEW BRUNSWICK. 427 



The Primordial forms of no. 1 have been met with at a number 

 of localities within the area covered by this formation, but always 

 near its base ; and they show that this portion of the formation is 

 equivalent to the Potsdam of New York, the Olenellus- shales of 

 Vermont, and those schistose beds which at Braintree (Massachu- 

 setts) hold Paradoxides Harlani, and in Newfoundland contain 

 P. Bennettii and a Conocephcdites ; while the cotemporary deposits 

 in Europe would be the Lingula-flags of Britain, the alum-schists of 

 Scandinavia, and " Etage C " of Barrande in Bohemia. 



While there is therefore no longer doubt regarding the age of the 

 fundamental part of this Lower Silurian series, a degree of uncer- 

 tainty still hangs around those slates and flags which form its prin- 

 cipal mass. 



That a portion of it is equivalent to the Calciferous (with perhaps the 

 Chazy) formation of the west seems highly probable. But the series 

 differs both from it and the Quebec group in lithological characters, 

 approaching more nearly the cotemporaneous deposits of Europe. 



The old coast-line of the Huronian period in this quarter left 

 its impression upon that which succeeded. Eor, while deposits of 

 great thickness are found at St. John and a few miles to the east- 

 ward, the series is much attenuated west of that city. In the east- 

 erly exposures of the formation it also decreases in bulk, and the 

 sediments become finer. 



In appearance they present a marked contrast with those of the 

 formation on which they rest. Coarse fragmental beds and volcanic 

 products are common in the latter ; but among the former no con- 

 glomerate nor even a grit has been detected, or any evidence of syn- 

 chronic igneous action. 



Two wide belts of slate, admitted by all observers to be of great 

 antiquity, traverse the central portion of the province, and represent 

 a mining region of some importance. They were denominated 

 " Cambrian " both by Dr. Gesner and Dr. Robb. But as this term 

 is now by some restricted to a series of deposits, which Sir E,. I. Mur- 

 chison and others consider equal to the Huronian of Canada, if we 

 limit the base of the Silurian by the Potsdam formation, it will not 

 be sufficiently accurate, provided they prove (as we suppose they 

 wiU) to be of the latter age. They do not assimilate in appearance 

 to the known Acadian representative of the Cambrian or Huronian, 

 namely, the Coldbrook formation ; but they do resemble the St. John 

 or Lower Silurian. 



The more southerly of the two slate districts in question extends 

 through the counties of York and Charlotte into the State of Maine, 

 coming out upon the Atlantic at Columbia (Hitchcock). A pro- 

 vincial collection in the University Museum of the rocks in this 

 quarter closely resembles those of the Lower Silurian slates of St. 

 John, and differs essentially from the Upper Silurian and Devonian 

 deposits which have been recognized in this region*; and since the 



* The greater width of these slates is no objection to their being equivalent -with 

 those of St. John, since Professor Hitchcock states that they are folded on fine 

 synclinal and anticlinal axes along the St. Croix river. 



