l{ELATIO^'S OF THE AJIBIK QUARTZITE. 297 



fragmental rocks. We have, then, an ap})an'nt traui.ition be, ween tlie 

 green schists and the clastic rocks just above, as we have an apparent 

 gradation between the ]\Iesnard quartzite and the granite-gneiss south of 

 Marquette. In both cases, however, the conglomerates along the contact, 

 in areas in which dynamic action was not so severe, reveal the true nature 

 of the relation, and show that the downward gradation is secondary, and 

 is not evidence of a single continuous series with downward progressing 

 metamorphism. 



The contacts east of Teal Lake may belong rather at the base of the 

 Me.snard quartzite than at the base of the Ajibik quartzite, as has l)een 

 explained above, but the connection between them and the contacts west 

 of Teal Lake is so close that their description was deferred to this place. 

 Whatever their correlative positi(m, all of the contacts along this belt of 

 conglomerate mark the advance of a shore-line, fi-om the east toward 

 the Avest. 



The intricate structural relations which (il)tain lietween the quartzite 

 and granite in sees. 30 and 31, T. 48 N., R. 2S W., and in sec. 25, T. 48 N., 

 R. 29 W. (Atlas Sheets XV and XVIII), have already been described. 

 Here, alonsr the irregular dividing line, the contacts between the two rocks 

 are found at numerous localities. In many cases the lowest horizon of the 

 quartzite is strongly conglomeratic, the pebbles of the conglomerate being 

 derived mainly from the immediately subjacent granite. These conglom- 

 erates at the contacts show conclusively that the granite is older than the 

 quartzite and was deeply denuded before the deposition of the latter forma- 

 tion. However, at many places so close has been the folding and so great 

 the movement along the contact plane that the ([uartzite has become a 

 quartz-schist, closely resembling the mashed granite. Further, the secondary 

 schistose structure in the granite and that in the quartzite are parallel, and 

 this structure is particularly prominent just at the contact of the two rocks. 

 Here again, if one considered only certain localities, the phenomena might 

 be regarded as an indication of the downward gradation b}' progressive 

 metamorphism of the quartzite into the granite, or the explanation might 

 be given that the granite is intrusive within the quartzite. However, if the 

 contact be followed throughout its various windings, and the phenomena 

 carefully studied, the only conclusion which can be reached is that the 



