368 



THE AZOIC SYSTEM AND ITS SUBDIYISIONS. 



vonian conglomerates contain pebbles from the Huronian could only 

 be accepted after a careful examination of the rocks in question by a 

 competent lithologist. 



Mr. 1{. W. Ells, in the same volume, describes some Huronian and 

 Laurentian rocks, claiming that they are unconformable, and that 

 " in many places a gradual transition can be traced from the green 

 slates through schists, felsites and gneisses to the syenites." (/. c, p. 4 



DD.) No evidence is advanced to prove either statement ; and in re- 

 gard to the latter one it is to be wished that some of the places where 

 these phenomena can be seen might be pointed out, so that the actual 

 existence of such a transition might be demonstrated. The rocks de- 

 scribed by Mr. Ells as Laurentian and Huronian were in 18G5 assigned 

 to the Devonian, but in 1871, under the divisions of Coldbrook, Coastal, 

 and Kingston, were included in the Hui'onian by Messrs. Bailey and 

 Matthew. 



In the Eeport on the Geology of Canada for 1878-70 is a contribu- 

 tion by Messrs. Bailey, Matthew, and Ells. In this the Laurentian or 

 Portland rocks are divided into two groups, one of which is regarded as 

 being more recent than the other, but no proof of this is given. The 

 Coldbrook, Coastal, and Kingston groups were placed in the Huronian. 

 No instance was observed of the Coldbrook resting upon the Laurentian ; 

 but as the Coastal lies upon the Coldbrook and the Laurentian, there 

 was thought to be no reasonable doubt as to the true succession. The 

 Coastal was also said to contain fragments of the Coldbrook in it. The 

 Kingston was replaced in the Huronian, because beds containing Upper 

 Silurian fossils were found to abut against those rocks, instead of forming 

 a continuous series. The St. John group was placed in the Cambrian, 

 while in the Cambro-Silurian were included rocks which in 1871 were 

 described as Laurentian, etc. 



In a paper read before the American Association the Advance- 



ment of Science, August, 1880, Prof. Bailey remarked : — 



"Beginning with the older formations, we have found no reason to depart 

 from the view fir&;t advanced by ub, that, beneath the fossilifcKnis rocks of tlic 

 St. John or Acadian Group, there exist two, if n(jt three divStinct formations, 

 e(}uivalent in part, at least, to tlie so-called Laurentian and Huroiiiaii j'ornia- 

 tions in other parts of Canada. It has been objected that this reference has 

 been based upon the wholly valueless ground of litliological characteriytics, and 

 that tlie strata in rpiestion, being destitute of fossils, may even, be Silurian; 

 but such objection entirely ignores the fact that, accompanyhig such diilcrences 

 of lithological character, there is, at the same time, the most marked evidence 

 of unconforniabilily. A study of the Primordial rocks east of St, John, in 



