walcott] SUMMARY NEW BRUNSWICK. 263 



ing the latter, Mr. G. F. Matthew has compiled a summary of the infor- 

 mation relating to the St. John terrane. He says: 1 



The strata of the St. Johu group fill a number of narrow, trough-like basins, lying 

 between the Bay of Fuudy and the central carboniferous area of New Brunswick. 

 Of these basins, that on which the city of St. John is situated is the most important, 

 and it is here also that the life of the period can be studied to the best advantage. 

 The St. John basin lies diagonally across the ridges of Huronian rock that are found 

 in the eastern part of St. John County and touches the ridge of Laurentian rooks 

 that divides this county from King's. As might naturally be expected, the coarser 

 sediments found at the base of the St. John group are largely derived from those 

 older rocks, chiefly the Huronian ; and the line of division between it (the St. Johu 

 group) and the Huronian formation is marked by conglomerates of mechanical origin 

 which show no trace of the hardening process by which the Huronian conglomerates 

 and breccias have been so firmly cemented. 



'The Conglomerates of the St. John group are most fully developed in the eastern 

 part of the St. John Basin, under the lee of the high ranges of Huronian hills which 

 exist in that direction. In Portland and the city of St. John, at the western end of 

 the basin, the following section represents the succession of members in this group 

 in ascending order : 



Feet. 

 Division 0: 



(a) Red Conglomerate — wanting at that part of the basin where this sec- 

 tion was made 



(6) Red and green sandy slates 150 



Division 1 : 



(a) Coarse'gray sandstone or quartzite 50 



(b) Coarse gray sandy slate (Linguloid shells) 50 



(c) Fine gray and dark gray slaty shales (Trilobites, etc.) 25 



(d) Fine black carbonaceous slaty shales (Trilobites, etc. ) 75 



Division 2: 



(a) Dark gray slates with thin seams of gray sandstone 220 



(&) Coarse gray slates and gray flagstones * .. 200 



(c) Gray sandstones and coarse slates (Linguloid shells) 130 



Division 3: 



(a) Dark gray finely laminated slates 450 



(&) Black carbonaceous and dark gray slates, less fissile than the last 300 



Division 4 : 



Slates and flags, resembling 2a and 2& (Linguloid shells) 800 



Division 5 : 



Black carbonaceous slate like, 3& (Orthids, Trilobites, etc. ) 450 



2,900 



Beyond Division 5 the beds are supposed to be repeated by an overturn, and have a 

 width across nearly vertical measures of 3,000 feet. Owing to this folding of the 

 measures there is some uncertainty as to where the summit of the formation is, and 

 the section given may not include the whole series of deposits. The fauna? of Divi- 

 sions 2 and 5 are very imperfectly known, but there are much larger species of Lingu- 

 loid shells in these divisions than in Division 1, and the orthids of Division 5 are 

 different from Orihis bilJingsi of Division 1. 



The Conglomerate at the base of the St. John group marks the time when the sea of 

 the Acadian epoch invaded the valleys of the Huronian formation near St. John. No 

 trace of life has yet been found in these coarse sediments, nor in the red and green 



1 Illustrations of ttie fauna of the St. John group. Royal Soc. Canada, Proo. and Trans., vol.1, sec- 

 tion 4, 1883, pp. 87-108. Supplementary section, pp. 271-279. 



