122 ART. 2. — B. KOTÔ : 



followed them for 10 hn as far as Ku-jin-nl^'' where prophyritic 

 masanite made its appearance. This carries the phenocrysts of 

 orthoclase and plagioclase in a microcrystalline groundmass. It 

 is a part of a large mass that stretches nortliwards to Ko-saii'^. 

 Red tnffite occurs abundantly as river-gravel coming from the 

 northeast, but its origin is unknown. Feld spar -conglomerate is 

 also found as blocks on the flat. Both bespeak the proximity 

 of the Upper Kyöng-sang formation. 



The road next turns southeastwards (PI. XXVIII. fig. 1) to 

 the ascent of the Chyöng-nai-chhi^^, 450 7?? high, on the eruptive 

 terrane of masanite, coarse tourmaline-pegmatite, limestone (?), 

 and sheared aplite with pseudocleavage oriented N. 60° E., dipping 

 S.E. The top is of the Chyong-jiju gneiss, pierced through by 

 muscovite-pegmatite. 



At Söi-dong^^ on the high plain (320 m), we again entered 

 the terrane of the spatulate area of the Mesozoic, the 

 rocks being represented by greenish flinty tnffite and black marl, 

 the latter containing pistachio -green epidote- concretions (2 cm 

 in diameter) with fimbriate fissure-border. This peculiar but 

 characteristic concretion or rather induration is met with in the 

 marl in contact with granite at Phißng-häi^^ on the east coast, 

 and also in the Mesozoic marl in contact with x^orphyrite in the 

 province of Nagato, Japan, where it goes by the name of " grape- 

 stone " {buclô'Seki). From analogy with other occurrences, I take 

 it as having resulted from a contact metamorphism either with 

 granite or diabase -porphyri te ; but I have not seen the actual 

 contact. Another contact hornfels of reddish tint from marl and 

 sandstone is in Mr. Yabe's collection. The third contact rock is 



1) A ^ M 2) ig m a 



