4 THE ROYAL SOCIETY OF CANADA 



In the Huronian era again we find no certain evidence of dry land 

 over any portion of Acadia, the clastic portions of the system indicating 

 a marine origin, while the eruptives, which constitute so marked a 

 feature in its composition, were probably, in part at least, also sub- 

 marine. 



While, however, we have not, as stated, any satisfactory evidence 

 of dry land during the eras under discussion, the nature of the sedi- 

 ments indicates that some such source of derivation could not have 

 been far distant, while the structural relations of the Huronian to the 

 Laurentian rocks render it probable that great physical disturbances 

 occupied the interval betw^een the two, and that as a result of such 

 disturbance elevations of considerable extent and height may have 

 been brought into view before the opening of the Cambrian Era. It 

 is to the Cambrian strata that we must look for the first clear evidences 

 of early Acadian geography. 



Cambrian 



The Cambrian rocks have been so long and so carefully studied 

 by our colleague, Dr. Matthew, that it would be out of place to do 

 anything more here than to indicate their bearing upon the geogra- 

 phical conditions existing at that time. They have already been 

 alluded to as affording in southern New Brunswick indisputable 

 proof of the age of the Pre-Cambrian rocks upon which they rest. 

 Their distribution and characters also indicate that they were laid 

 down in narrow troughs, four or five in number, and parallel to the 

 Bay of Fundy, which were traversed by oceanic currents. The 

 basal (Etcheminian) beds are coarse conglomerates, so coarse and 

 holding such large boulders, derived from the subjacent beds, as to 

 suggest bold shores and the undermining action of ice, but the higher 

 beds are finer, chiefly grey and dark slates and quartzites, indicative 

 of quieter waters, but these also from the occurrence of such physical 

 markings as rill-marks, furrows, worm burrows, etc., clearly indicate a 

 littoral origin. They are also in certain beds abundantly fossiliferous, 

 the fossils (Trilobites, Brachiopods, Pteropods, etc.), being such as 

 would naturally tenant muddy shores. From these facts we may 

 infer that, whatever was the case during the greater part of Pre- 

 Cambrian time, the close of the latter, or rather the opening of the 

 Cambrian Era, found the region of the southern Highlands of New 

 Brunswick represented by a massif of hard crystalline rocks, and that 

 these stood above the sea-level, forming a series of island ridges 

 between which flowed the currents of the Cambrian sea, the abode 

 of the rich and somewhat varied fauna so fully described by Matthew. 



