242 /. M. BELL 



veined and slashed with irregular and lensoid areas of more coarsely 

 crystallized ice which show no banding, and represent small crevasses 

 or irregular holes filled with water derived from the melting of the 

 banded ice, and subsequently frozen. What little has been done by 

 the writer seems, however, to prove the hypothesis. It is chiefly in 

 the hope that microscopic and chemical work will be undertaken on 

 this interesting problem, in a careful and systematic way, that these 

 suggestions are now made. 



If the theory which is here proposed with regard to the origin of 

 the granites is correct, the geological history of the Michipicoten and 

 Pucaswa areas may be briefly summed up as follows: First, were 

 laid down the series of acid and basic volcanics, with the sedimentary 

 phyllites and iron-bearing cherts, which compose the Lower Huro- 

 nian on some pre-existing floor, of whatever character that may 

 have been. These were gently folded, and in the consequent syn- 

 clines were deposited the conglomerates and slates of the Dore 

 Formation. Evidently volcanic activity continued during Upper 

 Huronian times, allowing the deposition of the Dore agglomerates 

 and tuffs. Succeeding the laying down of the Upper Huronian, 

 both Upper and Lower Huronian rocks were intensely corrugated. 

 During this corrugation, and in the main as the direct result of it, 

 came the regranitization of the Lower Huronian acid igneous rocks, 

 which must have existed in quantities largely predominating over 

 all other rocks, and the consequent intrusion of vast masses of granites 

 and allied rocks. 



