ox THE SO-CALLED CRYSTALLTXE SCHISTS OP CHICHIBU. 109 



Somewhat large, pleochroic pistacite-grains are found in isolated 

 patches, but they deserve no special mention. Some specimens are 

 rich in calcite ; its occurrence is, however, not constant. 



As we have already pointed out, the more we ascend to the hio-her 

 horizon, the more papery the rock becomes, and finally this cpidote- 

 sericite-gneiss acquires such a structure as to be easily cleaved into 

 thin laminated slabs. The microscopic habitus differs in no way from 

 that of the foregoing variety. 



A very characteristic feature of the rocks of the Upper Samba- 

 gawan is their papery structure, and also their richness in sericite- 

 scales. Thus the weathered exposures of the rock in any road-cuttino* 

 present a more or less advanced stage of disintegration, and finally 

 become resolved into tough, slippery, silver-white splinters — a peculiar 

 aspect of road which, if once seen, cannot be easily forgotten. 



