[bllsI interesting problems in new BRUNSWICK geology 31 



Quite recently an attempt has been made to revise this classification 

 of the Devonian rocks near St. John city. It is assumed by certain 

 palœobotanists that the determination of the fossil plants by Sir William 

 was incorrect, and that the later determination of these, based on a cor- 

 relation with plant remains obtained from strata of supposed Car- 

 honiferous horizons in the United States, must place these rocks in New 

 Brunswick ahout the horizon of the middle or even upper Carboniferous. 

 This assumption is made purely on plant evidence and without regard 

 to the stratigraphical sequence of the sediments in question. The 

 history of this controversy is interesting. 



The Devonian beds of St. John were in 1884 correlated with cer- 

 tain sediments which occur in Nova Scotia, and which there form an 

 extensive belt, continuing across the northern portion of the province 

 from the head of the Bay of Fundy, past the town of Truro, and as far 

 east as the Strait of Canso. In this province the succession and actual 

 horizon of these rocks had been carefully worked out by Mr. H. Fletcher 

 as the result of several years close study over a large area. They were 

 found to agree precisely with the Devonian shales and sandstones near 

 St. John, not only in their lithological characters and their contained 

 fossils, but in their stratigraphical relations to the lower Carboniferous 

 •as well, in being nnconformably beneath the limestones of that forma- 

 tion. In Nova Scotia, east of Truro, the rocks of the series are known 

 locally as Eiversdale and Union, and have been correctly mapped as a 

 part of the Devonian series. 



A few years prior to this correlation, Sir William Dawson had 

 obtained a few plant remains, which were admittedly imperfect, from 

 the rocks of this series near Eiversdale. Upon examination, he decided 

 that these fossil plants belonged to the horizon of the Millstone grit. 

 The strata from which these plants were obtained have, however, been 

 shown to be an integral part of the great series which has been proved, 

 both in New Brunswick and Nova Scotia, to nnconformably underlie 

 the lowest known lower Carboniferous rocks, including the lower Car- 

 boniferous limestone. The position of this formation is definitely 

 fixed in the geological scale on the evidence of marine fossils, as also 

 by its being stratigraphical ly beneath the Millstone-grit and productive 

 coal-measures; so that to accept the recent determinations of the 

 palaeobotanists would necessarily remove the lower Carboniferous, with 

 the other members of the Carboniferous system, altogether above their 

 true position in the geological scale. Areas of these lower Carboniferous 

 limestones are found at a number of points capping or overlying the so- 

 called Devonian shales and sandstones of the Eiversdale series. 



