Section IV, 1889. [ 135 ] Trans. Eoy. Soc. Canada. 



XII. — On Cambrian Organisms in Acadia. [Plates V to IX.] 

 By G-. F. Matthew, M.A. 



(Read May 30, 1889.) 



A. — Remarks on the Stratigraphy and Correlation of the Basal Series. 



The writer's previous contributions to the knowledge of the Cambrian rocks in 

 Acadia, as published in the Proceedings of this Society, have referred to the Fauna of the 

 St. John group, and chiefly the Paradoxides beds, but as he has found evidence of an 

 older fauna than that with Paradoxides, he has in this paper given a brief outline of 

 the relations of the group of beds containing the older fauna and descriptions of the 

 organisms which compose it. 



It seems better to regard these rocks as a lower series of the Cambrian system, for in 

 Wales the corresponding slates and sandstones have long been called Cambrian, whether 

 we take the authority of Sedgwick, Murchison or Hicks ; and, although no physical 

 break between the Paradoxides beds and these older Cambrian rocks has been established 

 in Europe, there is such a break at the base of the St. John group in Acadia, and if 

 we accept as correct the observations of Mr. A. Murray, a similar discordance exists in 

 Newfoundland. 



In the section given in my first paper on the Paradoxides fauna, ' this part of the 

 Cambrian has but an insignificant thickness ; and further west, along the north side of 

 the Cambrian basin of St. John, this thickness is further reduced, and the St. John group 

 may be seen to rest directly upon the Laurentiau limestones. But in tracing the red 

 rocks of the section cited eastward, they are found to exhibit a much greater thickness 

 and, at the furthermost Cambrian exposiires in St. John county, have an apparent thickness 

 of about 1,200 feet. 



The importance of these older Cambrian rocks is better understood by a study of their 

 relations in these eastern exposures than about St. John, as they are not only thicker 

 there, but they contain a fauna which, though not extensive, is distinct and important. 



In the report on the geology of Southern New Brunswick, 1865 (p. 24), this mass of 

 sediment was spoken of as the upper member of the Coldbrook group, and thus distinct 

 from the St. John group ; later" it was joined to the latter formation, because the want of 

 conformity between the two could not then be established. But it is now found that 

 this red series is unconformable, not 'only to the St. John group, but also, as had already 

 been discovered, to the underlying Coldbrook group. 



In the Kennebeckasis River valley, which is the next important valley containing 



'See Trans. R'ly. Soc. Can. vol. i. sec. iv. p.l88. 



-' Beport of Progress.Geol. Survey Can. 1870-1, p. 59. 



