104 NEW YORK STATE MUSEUM 



corner of the Lowville area) is thus at a large angle to the direction 

 of the forces which acted to crush the gneisses, and the latter can 

 thus have had little or nothing to do directly with the foliation. 



6 The foliation may be slightly accentuated by the crushing. 



7 In the crushed gneisses, those minerals wh : ch are most mashed 

 are the ones which normally crystallize out first in quantity from a 

 magma; and vice versa, the last minerals to crystallize out are the 

 least crashed. Thus in the case of the protoclastic gneisses, feldspar, 

 hornblende and augite are the most crushed, whereas quartz is 

 wholly uncrushed. Again, in the cataclastic-protoclastic gneiss, the 

 feldspar and ferromagnesian minerals are pulverized and the quartz 

 is only granulated. In some of the gneiss two generations of mag- 

 netite are present. In this case that occurring as inclusions in other 

 minerals and representing an early stage of crystallization is crushed, 

 whereas that associated with the quartz of a late pneumatolytic 

 stage is massive. In the hyperite dikes the augite may be partially 

 granulated and the feldspars unaffected. 



8 In the cataclastic gneisses the degree of crushing of the quartz 

 is roughly proportional to the degree of mashing of the other minerals, 

 the quartz varying from 2 to 5 times as coarse as the comminuted 

 feldspar. 



9 The primary foliation of the gneiss with a massive texture 

 forming the southeast zone is due to nrneral segregation, dimensional 

 orientation of minerals by crystallization under stress, and to flowage 

 in the magma. There is no crushing of the minerals and only here 

 and there do strain shadows appear in the quartz. The occurrence 

 of inclusions with a foliation at an angle to that of the inclosing rock, 

 the occasional presence of flowage lines swirling around a host of 

 separated small inclusions of Grenville gneiss, a texture and succes- 

 sion of crystallization normal to igneous rocks, occasional euhedral 

 character of the crystals, the frequent segregation of apatite, zircon 

 and magnetite with the ferromagnesian minerals in streaks, and the 

 presence of practxally massive hyperite dikes of an age older than 

 the foliation of the country rock, militate against an explanation of 

 this foliation by recrystallization. 



10 The protoclastic origin of the foliation of the central zone is 

 evidenced by the following data: the granulated character of the 

 feldspars and ferromagnesian minerals and the normally uncrushed 

 character of the quartz; the parallehsm of foliation and banding 

 irrespective of the widely divergent orientations of the latter, a 

 phenomenon best explained as the result of crushing in a semifluid 



