Suction IV., 1908. [ 113 ] Trans. R. S. C. 



A^I. — Notes on a proposed New Base for ilie Cambrian Rocks of Southern 



New Brunswick . 



By R. W. Ells, LL.D. 

 (Read May 27, 1908.) 



Many papers relative to the age and the several divisions of the 

 Cambrian rocks of southern New Brunswick have been printed in 

 various scientific journals during the last forty years. As a result 

 of more recent studies the range downward of the system has been 

 considerably extended, as compared with the original conception of 

 the structure and distribution of these rocks, since the classification 

 given in the report to the Geological Survey of Canada, 1870-1, by 

 Drs. L. W. Bailey and G. F. Matthew. 



To the latter much of the credit belongs for working out many 

 details regarding the general distribution of these sediments, and for 

 deciphering the abundant fauna which they contain, both in New 

 Brunswick and Nova Scotia, by means of which the whole series has 

 been divided into several distinct divisions. Within the last few 

 years, owing to the investigations of Dr. C. D. Walcott, the recent 

 Director of the United States Geological Survey, both in the rocks 

 about St. John city and in similar formations of eastern Nova Scotia 

 and in Newfoundland, a number of new features have been brought to 

 light which have tended to simplify the general structure of the Cam- 

 brian system as a whole, and have greatly modified the views formerly 

 held, by including in the Cambrian proper a considerable portion of 

 the underlying formations once regarded as the Coldbrook division 

 of the Huronian system. 



It is not proposed in this paper to review in detail the various 

 changes of opinion which have been held from time to time as to the 

 classification of the rocks of this system; but rather to direct attention 

 to certain points of structure, and to the occurrence of certain organ- 

 isms found at different localities, which hitherto do not appear to have 

 received the consideration which they deserve; in order, if possible, 

 to render the structure of the Cambrian rocks proper, and their rela- 

 tions to those which have been, for a long time, regarded as occupying 

 a much lower horizon, more intelligible. Recent study of the areas 

 about St. John city have shewn that these lower rocks are closely 

 .related to and may form, possibly, an integral portion of the Cambrian 

 system regarded as a whole. 



In the earlier classification of the rocks about St. John city, 

 1870-1, they were arranged under three heads or groups comprising 

 the Laurentian, the Huronian and the Cambrian systems. Of these 



Sec. IV., 1908. 8. 



