[bailey] presidential ADDRESS . 3 



Pre-Cambrian 



Unquestionably the oldest land to be found in New Brunswick 

 is that which now constitutes the Southern Highlands, being a series 

 of ridges of no great elevation which cross the St. John river at and 

 above its mouth, and which, on either side of the latter, bound for 

 the most part the present Bay of Fundy on its northern or northwestern 

 side. Apart from certain overlying beds of much later origin, they 

 consist of rocks which upon good grounds (mainly the fact that they 

 are unconformably covered by f ossiferous Cambrian strata) were, 

 as early as 1871, referred to the Laurentian and Huronian systems 

 as then understood. The former embraces two principal members, 

 of which the lower or Laurentian proper consists mainly of gneisses, 

 with granitic and syenitic batholiths, while the upper includes heavy 

 deposits of quartzites, limestones and dolomites. The supposed 

 Huronian on the other hand also embraces two terranes of which the 

 lower is represented by clastic rocks (argillites, magnesian schists and 

 grits) and the upper largely by volcanic eruptives. Whether or not 

 these formations are the exact equivalents of the resembling beds in 

 Ontario which have been termed the Animikie and Hastings groups, 

 their Pre-Cambrian origin cannot be successfully questioned, and 

 from them some reasonable deductions may be drawn as to the geo- 

 graphic and climatic conditions which then characterized this part 

 of America. 



The lower division of the Laurentian rocks; owing to their highly 

 disturbed and altered condition, afïord but little satisfactory evidence, 

 and the granites and other similar rocks which accompany them may 

 be of much later origin. Even the gneissic structure of many of the 

 beds may be no indication of ordinary sedimentation. But the 

 strata which succeed, viz., quartzites, slates and limestones, are 

 evidently sedimentary, and point unmistakably to the fact that the 

 areas which they now occupy were in Pre-Cambrian times covered 

 by the sea. The frequent changes in the character of the deposits, 

 from arenaceous to argillaceous or to calcareous beds, give equal 

 evidence of oscillations in the sea floor and variations in the depth of 

 water, but no evidence exists which can be safely regarded as indicative 

 of dry land. If such there was, it must have been destitute of any 

 ordinary vegetation, though bacteria may already have been present 

 and played some part in the disintegration of exposed surfaces. If 

 the Archœozoon of Matthew, found in the limestone series, is really 

 of organic origin, as believed by him, it is a probable inference that 

 the seas in which reefs of the latter were growing were at least warm 

 temperate. 



