JOUENEYS THROUGH KOREA. 53 



upon the kernel of eye-gneiss of deep-seated igneous origin. 



On our way down to Chyang-heung, I saw for the first time 

 in Korea a true Alhivial terrace of o-ravel deposited on a "ranitic ^^^^vial 



Ö i O TERRACE 



base. Can the coast liave been shghtly rising in recent times ? 

 By the way, I should mention that it was not Diluvium. I have 

 never found the genuine Diluvium in Korea. Its absence as well 

 as tliat of clay soil must be counted as the two peculiarities of 

 Korean geology. 



We started down the depression w^hich opens eastwards. In 

 it is Inu'ied tlie eumnai of Chyang-heung out of whose poor south heung 

 gate we passed tln-ongh a narrow cutting made in a purpfish- 

 brown brecciated hornblende -andésite with northerly dips. The 

 microscope revealed that the volcanic is made up of a devitrified 

 glassy base with granules of sesquioxide of iron, in whicli corroded 

 grass-green liornblende is porphyritically imbedded. A little 

 colourless angite and much apatite are present as accessories. It 

 is an acid volcanic. 



On the north, the rugged crown-shaped Sul-ln-san, which 

 had already attracted our attention from Chycmg-noro-moh, was 

 seen raishig its head ; and from that direction a streamlet flowed 

 down laden with al)undant volcanic gravel, and pebbles of needle- 

 diorite. We were here evidently in a young volcanic region. 

 Similar, though decomposed, clay rock of this class is in my 

 possession from Keum-dang-do ^\ an islet at the entrance of Teimg- 

 nyang bay '\ not far from here. Its main mass consists of devi- 

 trified glass of flowage structure with axiolite. The porphyritic 

 crystals are plagioclase and orthoclase. It seems very striking 

 to find sporadic occurrences of young andesitic efiusives on the 



ii ^ ^ ê '-2) î^ m m 



