126 THE ROYAL SOCIETY OF CANADA 



DiASTROPHISM 



It may well be supposed that in a region which, geologically, is 

 as complex as New Brunswick, evidences of physical movements 

 and disturbances, with consequent changes of level, changes of sedi- 

 mentation, and changes, it may be, of geography, climate and life, 

 should make themselves apparent. And this is actually the case. 

 All the formations, even including the coal measures, have been sub- 

 jected to orogenic changes and are broken by innumerable faults. 

 But while the greater number of these are slight, affecting only a 

 small thickness of strata or producing correspondingly slight upward or 

 downward movement, others were of much greater magnitude, and 

 led to far more important consequences. Thus if not actually deter- 

 mining, they are so intimately connected with geographic and life 

 evolution, as to help in the subdivisions of geological time and the 

 formation of a time-scale. It will therefore not be out of place to 

 emphasize a few of these here. 



1. Post Laurentian. The highly folded character of all the 

 sediments referred to this system, including the upper limestone- 

 quartzite series, abundantly prove the diastrophic influences to 

 which they have been subjected. Unconformity between the 

 limestones and underlying gneiss is clearly shown, as also with the 

 overlying Cambrian. An interval of extensive erosion and 

 weathering of land surfaces separated the Laurentian from the 

 Cambrian era. 



2. Post Huronian. The rocks which have been referred to 

 under the name of the Kingston Group are, for distances of 

 thirty or forty miles, bordered by profound faults, whose influ- 

 ence is readily recognized in the present physiographic features 

 of the region. But these same faults conceal the relations 

 of the Kingston rocks to the other groups in the region, and 

 except to say that they are Pre-Cambrian, highly crystalline, and 

 in attitude nearly vertical, but little can be predicated from them. 

 They are extensively invaded by volcanics. 



The relations of the so-called Coastal group are also involved in 

 much obscurity. It is certain, however, that they are unconformably 

 overlaid by the fossiliferous Cambrian, and have themselves been sub- 

 jected to extensive orogenic movements, as well as to the extrusion of 

 much igneous matter and of granite batholiths. 



Post Cambrian. The rocks of the St. John group, as seen in the 

 city of that name, show the position of more than one overturned and 

 compressed synclinal, but there is nothing to show at what time that 

 overturn took place, except that the Cambrian rocks are folded with 



