256 ON THE GEOLOGY OF ST. JOHN. 



genera Megaphyton (?), Sigillaria, Calamites, Cordaites, Astero- 

 phyllites, Sphenopteris, Neuropteris, are represented. 



JSfew-Red-Sandstone. — Bright red sandstones with some pebble 

 beds, skirt the sea shore for a few miles near Gardner's Creek, 

 and may be seen both on the east and the west side to rest upon the 

 upturned edges of the carboniferous beds just referred to. They 

 dip to the northwest, and hold fragments of coniferous wood. 



MetamorpMsm. — In comparing the appearance of the beds 

 of the Portland series to that of the Laurentian formation 

 in Canada, Dr. Dawson indicates the apparent antiquity of the 

 former and the extreme metamorphism which the older strata 

 have undergone. In the upper part of the series, however, the 

 change is not so complete, and small fragments of plants may still 

 be detected in the shaly layers. In the St. John slates metamor- 

 phism has not proceeded so far, and the two highest Devonian 

 groups present still less alteration in their shales, though the 

 coarser sediments are often strongly cemented, the vegetable re- 

 mains of the sandstones converted into anthracite, and the lustre 

 of graphite given to the forns, &c, which the finer beds contain. 



As soon as we pass to the Lower Carboniferous deposits a wide 

 distinction is this respect is at once apparent. The vegetable re- 

 mains which they contain have the appearance of plants from un- 

 altered coal-measures. The conglomerates also differ largely from 

 those of the Devonian series in their incoherence, and many of 

 the shales are scarcely harder than the dried mud of a pond. 



Beside the regional metamorphism which characterizes all the 

 Devonian and subjacent deposits, some of the beds have under- 

 gone a local change, which is most prominent in the volcanic se- 

 diments. By an alteration of this kind the stratification of the 

 lower beds of the Coldbrook group has been almost obliterated. 



In the Bloomsbury group it is very marked, because the depo- 

 sits above and beneath have undergone much less change. Sev- 

 eral of the finer beds of this group have been converted into quart- 

 zites and micaceous slate. 



I have already alluded to a group of metamorphic strata at 

 Black river and vicinity, which have been considered to be much 

 older than the fossiliferous deposits in the vicinity of St. John. 

 That they form a part of the Upper Devonian series seems clear, 

 bacause, — 



