2 THE ROYAL SOCIETY OF CANADA 



indentation of the Atlantic coast of North America; it is with the 

 portion of this complex in the immediate vicinity of Saint John that 

 we are most directly concerned. 



The core of this complex consists of pre-Cambrian rocks having 

 as a central mass, some old intrusive granitic rocks which have cut 

 and altered others that are associated with them, such as gneisses and 

 mica-schists; with these are found masses of limestones, argillites 

 and intrusive diorites. Outside of this core, one finds on each side 

 Cambrian slates and sandstones holding characteristic fossils ; there is 

 a considerable breadth of these Cambrian strata on each side of the 

 complex, on the Southern side there are three synclinal folds, and on 

 the North perhaps an equal number in the valley of the Kennebecasis 

 river, where, however, they are much broken up, and concealed by 

 the lake-like expansions of that stream. 



Resting upon these Cambrian rocks on each side of the complex 

 are strata of Silurian age, recognizable on the North side by marine 

 fossils of that time; but on the South holding so far as is known, only 

 remains of land plants, insectians and phyllopod crustaceans. Sir J. 

 W. Dawson considered these plants to be Devonian, while David 

 White and Mrs. Stopes thought them to be Carboniferous. 



There remains a still later series of beds on the southern slope 

 of this complex, but these beds have no counterpart on the Northern 

 slope in this vicinity (though they outcrop further West). 



The whole of this complex must have been subjected to severe 

 pressure from the seaward (Southeastern) side, as all its argillaceous 

 beds are characterized by a similar slaty cleavage, have a N.E.-S.W. 

 course, and a hade to the S.E. usually at a high angle; whereas the 

 overlying shales are devoid of cleavage, and the beds dip Northward 

 at a lower angle than do the strata of the complex, It is in these 

 overlying strata, however, that the indications of ice-action have 

 been found. 



It does not appear that the most pronounced indications of ice 

 action are to be found amongst the comparatively fine red shales and 

 sandstones which constitute the basal beds of this series as seen at the 

 "narrows" near the outlet of the St. John river and elsewhere along the 

 northern slope of the complex, but rather amongst the conglomerates 

 and other coarse beds which attain a thickness of many scores of feet 

 at the Boar's Head further up the river, and are easily distinguishable 

 from those of the older terrains by their high content of fragments of 

 limestones similar to the limestones found at the centre of the complex. 



These limestone fragments are found in the conglomerates on both 

 limbs of the complex, from which it would appear that they were 

 thrown off on both sides of a central elevated protaxis. 



