REPORT OF THE DIRECTOR AND STATE GEOLOGIST 1900 r87 



green rock is as gneissoid as the black, and the scarcity of augen 

 renders its appearance quite different from that of the rock at the 

 village. The major portion of the rock has been wholly recrystal- 

 lized, but in many cases the feldspar augen are seen to be sur- 

 rounded by a rim of granular feldspar which has plainly origi- 

 nated by simple granulation of the edges of the augen. 



Some f of a mile east of the depot the rock as a whole becomes 

 gradually more acid (no. 8), and here presents characters not seen 

 elsewhere. It is very thoroughly foliated, almost schistose, in 

 grayish green and black colors, with numerous augen of red 

 feldspar. These differ from the ordinary augen in being, them- 

 selves, thoroughly crushed and granular, and being much 

 squeezed and stretched, so that they are usually broadly 

 lenticular, the larger ones being about J inch thick and 

 from 2 to 3 inches in diameter. Except that they are 

 wholly inclosed in the rock, thinning out in all directions 

 from their center, they would be taken for injections of fine 

 grained granite parallel to the foliation. There is some 

 resemblance to a stretched conglomerate, but such an origin 

 seems negatived by the fact that the augen are all alike 

 and all of feldspar. If it is simply a phase of the syenite, as 

 it seems to be, it is difficult to see why the augen should be so 

 much more completely granulated here than elsewhere. An 

 apparent intermediate stage is found, however, at the extreme 

 east end of the exposures, a mile away (no. 11). Here a quite 

 similar rock appears, a green and black gneiss with augen of red 

 feldspar. The rock is not so w^ell foliated, and the augen are not 

 so large, but otherwise there is little difference. While some of 

 the augen are entirely granulated, others have a core of uncrushed 

 feldspar, surrounded by a zone of red feldspar grains, whose 

 source is plainly shown, since the usual feldspar of the rock is 

 green, only the augen being red. The wholly crushed augen are 

 not so much stretched as in the previous rock, but a comparison 

 of the two seems to make it quite clear that we have here the 

 same rock, though showing different degrees of metamorphism. 



