82 ART 2.— B. KOTO: 



sometimes changing into eye-gneiss. It is worth wliile to re- 

 mark here that all the dykes run, and also are sheared N. 80" E. 

 in the Pam-clthl direction. 



ham-yanqI) We passed by tlie eumnäi (PI. XVT. fig. 1) of Ham-ycmg^^ 



and followed a torrential stream down to Sa-keun'\ on the fine 

 white eye-gneiss terrane, where it is joined by a tributary from 

 the north. The eumnäi of An-eui''^ is only 11 km from here, and 

 I shall touch the place in my next traverse. When at Pi-dj'ôn 

 (March 11th, 1901) on the high plain (370 m) amid the snow- 

 covered peaks of tlie Chiri-scm, I met with frost and frozen streams ; 

 but at Sa-keun we found the warm spring mists. The contrast 

 in climate between Kyöng-scmg-Do and Chybl-la-Do is very mark- 

 ed. Sa-keun is at the divide of tlio roads from Cfiin-jyu to 

 Nam-u'on on tlie one liand, and from (^Jiifôn-jyu via the Yuk-sim- 

 nyong pass on the other. From liere we followed Yabk's route as 

 far as San-chhyöng, whence he went directly soutli to Clnn-jyu *\ 



The first rock met with is a brownish, fine-grained two- 

 mica orthogneiss which under the microscope is seen to consist 

 mainly of xenomorphic microcline and cataclastic quartz. The 

 brownish colour is due to the slight decomposition of plagioclase 

 which contains poikilitic grains of quartz. The schistose strike 

 runs N. 60°E. The rock is replaced just before Neul-hot-jynng''^ 

 by a compact aplitic rock whicli is intruded by melanocrate 

 dykes of a dioritic composition. 



The aplitic leucocrate is a granitic-granular aggregate of 

 plagioclase and quartz. A little orthoclase is also present. The 

 micropegmatitic structure is wanting. Tlie melanocrate is fine- 



1) £5; ^ 2) '^ Jr 3) ^ ^ 4) See footnote 5, page 35. 5) f^ ^[^ ij,- 



