JOURNEYS THROUGH KOREA. 175 



eutectophyric variety of granite, wliicli I have named masa- 

 nite. It is not entirely without reason that Gottsche and Inouye, 

 as I have already stated, wholly exclude this formation from the 

 Mesozoic group ^^ ; but I have also already pointed out that the 

 porphyrite and the Mesozoic complex appear closely associated 

 in southern Korea. Mereover, if any one follows the profile of 

 the Mesozoic beds from the east coast of the Kyöng-sang province, 

 he can scarcely fail to see this green eruptive formation occupy- 

 ing the highest position in the series of the Mesozoic. 



The rocks composing this eruptive green formation are of 

 several types'^ though they all belong to the same magma. 



(a) The main sheet rock is dark-gray and aphanitic with 

 few flecks of feldspar which can only be recognized by reflected 

 light. Despite its fresh appearance, the rock under the micro- 

 scope is seen to be very much altered. The original, macro - 

 or micro-phenocrystic ferro-magnesian mineral, either diopside or 

 hornblende, is usually altered into chlorite and epidote. The 

 •structure is pilotaxitic ; the lath-shaped, twinned plagioclase 

 makes up the groundmass together with interstitial, amorphous 

 substances rich in chlorite. In it are imbedded the phenocrysts 

 of tabular plagioclase. Clumps of ilmenite are abundant altering 

 into leucoxene. The rock effervesces with acid. Besides the 

 common (diabasic) porphyrite, there are some which contain 

 corroded quartz, the former representing augite-andesite, the 

 latter dacite of a later period. Magnetite is observed as at 

 Fusan in the form of bedded veins accompanied with skarn (p. 

 14). 



{b) A greenish-blue, compact and flinty rock with conchoidal 



1) See arde, page 171. 2) See ante, page 12. 



