JOURNEYS THIIOUGH KOREA. 167 



liave, however, once seen it at Un-hong ^^ which is located nearly 

 at the centre of the massive ; and further researches will probably 

 disclose many other occurrences outside the marginal belt. The 

 adamelhte has also the granitic and gneissoid phases accompanied 

 by cataclastic structures. 



It is corapoäad of microsliue, biotite, greenish hornblende and 

 granitic quartz, Avith the cliaracfceristic accessoiy of titanite besides 

 apatite. Microscopically it closely resembles the batliolitic granitoid, 

 being composed in graater part of microcline with the idiomorphic, 

 zonal oligoclase (the extinction Avitli p/m on (010) is +9 to -1-14), and 

 simple ortlioclase. The last is not easy to distinguish from the un- 

 twinned microcline nor from the brachypinacoidal section of oligoclase. 

 The brown biotite is abundant as compared with the greenish-blue 

 liornblende, the former fringing the latter as if it were a typomorphic 

 mineral from amphibole. The hornblende often encloses pegmatitically 

 round grains of ortlioclase and quartz of the same orientation, and the 

 microcline or ortlioclase, or both, contain globular quartz in a similar 

 manner. The latter may fitly be termed microclin.e (ortlioclase) 

 poikilite. Long experience leads me to regard poikilitic and myr- 

 mekitic structures as characteristic of tha deep-seated intrusives. 

 The richness of microline in the adamellite proves unequivocally the 

 close " consanguinity " of this rock to the granitoids. 



IV. c. Le ucoc rates. — Complementary to the preceding, the 

 products of the opposite pole of the magmatic differentiation are 

 the anorthosite and the tourmaline dyke-rock. The former 

 is strictly speaking the labradorite-rock, the latter the tourmaline- 

 microcline-perthite. The former represents a phase of an intru- 

 sive of considerable dimensions, the latter a typical dyke-rock. 

 Both are true intrusives pressed up as an after-effect before the 

 complete consolidation of the granitoids, just as the adamellite is 



1) See ante, page 81, footnote 1. 



