ON THE SO-CALLED CRYSTALLINE SCHISTS OF CHICHIBU. 103 



These felspar-spots seem to have been arranged parallel in accord- 

 ance with the stratification ; and the spots themselves have fine, 

 curved, approximately parallel fissures in the direction of the 

 breadth, prt^bably due to a strain normal to the axis of mountain- 

 flexures, and these minute fissures have been sometimes filled up by 

 calcium carbonate. The felspars already referred to are mainly non- 

 striped, and occasioniilly a few lines parallel to the basal cleavage are 

 to be seen ; still it is not easy to prove optically the nature of the 

 felspar. The extinction-direction with reference to the trace of 

 cleavage is about 12°-19°, and it may prol)ably belong to albite.^) 

 In saying so, the presence of orthoclase is by no means excluded. 



The felspars contain also grains of the same mineral species 

 whose presence is proved by different optical orientations. There 

 seems, however, to be no crystallonomic relation between those grains 

 within, and the enclosing mineral; the latter serves, as it were, as a 

 cementing material ; the former may be considered as a product of 

 dynamo-metamorphism. 



The spots of felspar are rich in other interpositions of light- 

 yellow epidote-crystals and crystalloids, with a few actinolite-needles, 

 and tourmaline-prisms, arranged in a most confused manner especially 

 in the central part, as viewed in a slide made parallel to the plane of 

 schistosity of the rock. Spots in the transverse section of the rock 

 have a special arrangement of their interpositions, minute needles and 

 crystalloids being disposed more or less after the fashion of streams. 

 These diminutive bodies are not decomposition-products in the ordinary 

 sense of the term ; still they might have derived their materials in part 

 from the felspar-substance during a dynamo-metamorphic process. 



1) If I riglitly remember, Herr Dr. Dalmer made a chemical analysis of a pure 

 felspar from the chlorite-amphibolite of Saxony, which, as has already been pointed out, has 

 a, close resemblance to our rock, and he found it to be albite. 



