THE PRECAMBRIAN ROCKS OF THE CANTON QUADRANGLE 55 



boundary the foliation of the garnet gneiss, which at a distance of 

 a few feet makes an angle of about 30 degrees with it, is locally 

 dragged round into parallel position. The hypothesis suggested by 



Fig. 9 Diagrammatic sketch of west joint face of xenolith of figure 8. 

 (a) Amphibolite; (b) garnet gneiss. Formations show usual comformability. 

 Section about 6 feet high. 



Same locality as shown in figure 8. 



these phenomena is that we have here the tip end of a fragment of 

 included garnetiferous country rock, attenuated by later dynamic 

 stress, and that the sharp, straight contact is due to a later fracture 

 developed in the resistant amphibolite against which the more plab- 



FiG. 10 Diagrammatic sketch of southwest joint face of xenolith shown 

 in figure 8. Nonconformability of garnet gneiss against amphibolite shown 

 by dragged schistosity of former near contact. Indicates a probable igneous 

 origin for amphibolite. 



Same locality as shown in figure 8. 



tic garnet gneiss was deformed. The alternative view that the 

 whole apparently igneous phenomenon is merely a tectonic feature, 

 encounters the objection that garnet gneiss is not known anywhere 

 else in the quadrangle to have been fractured and to have allowed 



