[matthew] CAMBRIAN FORMATION IN EASTERN CANADA 77 



The fine grained dark gray mud of which this subzone is com- 

 posed tells of smooth waters and show deposition in a sheltered 

 bay, and the fauna is one that would have flourished in such a place. 



DIVISION 2 (JOHANNIAN). 



These conditions were changed as time went on by the removal 

 of the barrier which has kept out the ocean surf and seams of sand 

 begin to alternate with the dark mud until in time the fauna of the 

 Paradoxides beds was banished and the typical conditions of Division 

 2 of the Cambrian succession was established, viz., alternations of 

 coarse gray slates and gray flags and sandstones. Ripple or wave 

 marks on these sandstones show that the open sea was to the south 

 of the St. John basin. In this portion of the Cambrian System in 

 eastern Canada, the remains of trilobites are exceedingly rare, hence 

 the means of close identification are wanting.* There are remains 

 of corneous Brachiopods, but these do not afford a basis for deter- 

 mination of the age of the several assises. Moreover, there is a great 

 variation in the bulk of the strata of this division in the several basins 

 where the Cambrian strata are found; it is only when we encounter 

 finer deposits, shales, coming in at the base of Division 3, that the 

 trilobites and calcareous Brachiopods reappear, and afford means of 

 comparison with the Cambrian strata of other lands. 



Although the strata of this division of the Cambrian system are 

 to all appearance arenaceous or argillaceous there must have been 

 considerable calcareous matter intermingled as numerous calcareous 

 as well as siliceous veins are found in the sandstones. 



DIVISION 3 (BRETONIAN). 



The oldest strata of this division recognizable by fossils are found 

 in the ledges which connect Navy island in the harbor of St. John with 

 the main land. At this point and along the shore in this upper part 

 of the harbor of St. John, one can trace the contact between the flags 

 and slates of Division 2, and the finer soft black shales of Division 3. 

 This division has a thickness of about 700 feet, the whole width of the 

 harbor at this point, but most of these soft rocks are concealed be- 

 neath its waters. Navy island which alone rises to the surface con- 

 tains characteristic fossils of three faunas, viz., Parabolina, Peltura 

 and Dictyonema. On the opposite (northern) side of the harbor 

 still higher shales are seen, which have yielded characteristic Arenig 



*In Cape Breton the remains of a Paradoxides have been found about two thirds 

 from the base of the flags and sandstones of this division. 



