PEESIDENTIAL ADDEESS. 5 



clear, varied aud widely distriljuted. It is equally evident that amoug these Archteau 

 rocks, at least two great groups of sediments are to be distinguished, which, in a general 

 w^ay, bear many features of resemblance to those which in other parts of Canada are 

 known as the Laureutian and Hiironian systems. At the same time it is impossible for 

 any one familiar with the rocks of the iirst named of these great systems not to see that 

 between them and the supposed Laurentian rocks of St. John there are equally striking 

 differences. This is especially to be seen in the greater proportionate amount, in the 

 case of the district last mentioned, of distinctly stratified rocks, siK^h as slates and 

 quartzites, in the comparative absence of coarsely crystalline deposits, of crystalline 

 minerals and ore-beds, and in the much greater regularity and uniformity of the whole. 

 But too muih weight must not be given to differences of this kind, more especially as the 

 area in question is itself but very limited. A more satisfactory basis of comparison might 

 perhaps be found in the examination of the microscopic characters afforded by the 

 rocks of the two series, but neither in the case of the supposed Laurentian, nor in that 

 of the Huronian strata, has this yet been done. As regards the Huronian rocks, such 

 examination is especially to be desired, as the greater part of the rocks which make 

 up the bulk of the formation, and which have been referred to as felsites, claystones, 

 porphyries, petrosilex, etc., were described some years prior to the introduction of the 

 present methods of petrological research, and their names, in some instances at least, 

 are probably misapplied. 



Another desideratum in connection with these two ancient systems is a better under- 

 standing of their true relations to each other, for, though no doubt is entertained by the 

 author as to the fact that the felsitic and schistose rocks referred to the Huronian are 

 more recent than the granitoid and gneissic rocks and the great belts of crystalline lime- 

 stone which have been regarded as Laurentian, a contrary view has been taken by others ; 

 while neither has any satisfactory contact of the two formations been o))served, nor any 

 instance in which the conglomerates of the one are unquestionably niadf up of material 

 derived from the other. 



In addition to the areas above referred to as Archœan, several other tracts, of 

 more or less considerable extent, occur in the northern part of the Province, and have 

 also been represented as of Pre-Cambrian age, but the evidence as to these is of less satis- 

 factory character, no overlying Cambrian beds having been here observed, while both 

 their limits and relations are rendered difficult of detei'mination by the uncleared, rugged 

 and ahnost inaccessible character of the region in which they are found. Judged, how- 

 ever, by their lithological aspect, and the fact that they are bordered in places by rocks 

 which are at least as old as the so-called QueV)ec Group, a good degree of probability is 

 given to the belief that a belt of such rocks traverses the northern interior of the Province, 

 where it also constitutes its most elevated section, and forms the watershed from which 

 How manj^ of its most important streams. 



Of the formations succeeding the Archsean, to none does a greater interest attach than 

 to the Primordial or Cambrian, so assiduously and so successfully studied by our associate, 

 Mr. Matthew. As the important results of these studies have been given to the world 

 through the medium of our own Transactions, it will be unnecessary to speak of them here 

 at length ; but to convey some idea of the extent to which they have added to our know- 

 ledge of this ancient fauna, it may be sufficient to state that whereas, in the first publi- 



