JOURNEYS THROUGH KOREA. 31 



by W. throngh paddy fields, and after 2 km came to the Neul- 

 eum-chhi '^ pass (100 m). Here good exposures of red and green 

 marls were seen striking E. 20" N. with the dip 5^ S. E. We then 

 went down to the chyumak of Kui-nai "\ To the north-west 1 saw 

 two isolated mountains of greenish augite-porphyrite, whose 

 southern neck (180 m) we passed over on our way to a flat gravelly 

 valley with a streamlet, on the north side of wliicli is located 

 Chliiju-chhon''^, a large village of 200 houses. 



We were still in the " red formation." The surrounding naked ^^""^ J^'^""^'*" 

 hills have suffered deep disintegration presenting a variety Of 

 strangely artificial colors, purple-red, carmine-red, and even orpi- 

 ment-yellow. The topography is like that of the " bad lands " of 

 Dakota. The benches of red and green marls dipping regularly 

 with low angles to the east, were best seen on Hu-nam-san ^\ We 

 then entered a sandy fiat, and crossed the river Yoiig-gang '^ by a 

 boat. Near the ferry an alternation of wet-gray marl and thick 

 sandstone appeared with a slow inclination to the east underlying 

 the red formation. What causes the red color has long remained 

 a mystery. It is a pure chemical process. Lately Hoenung has . 

 paid a great deal of attention to this phenomenon. According to 

 him, highly concentrated saline brine, produced by the evaporation 

 of sea-water under certain physiogeographical conditions, is able 

 to bring about a profound change in rocks. A characteristic fea- 

 ture of this halurgomefamorphosis is the intense action of oxida- 

 tion and the precipitation of red (anhydrous) oxide of iron (by the 

 presence of NaCl), which effectuate the concentration of heavy 

 metals in brine from diabase and the like '\ Probably this is the 



1) *^ # m 2) :^ ft 3) ts H 4) ^ m uj 



5) îê Ü1 This iiart of the river is popularly spoken of us the Nam-gang (^ tO. 

 G) F. Hornung : " Formen, Alter und Ursprung des Kupfer-schiefererzes.— Zur Beurteilung 

 der Mineralbildungen in Salzformation." Z. d. D. Geol. Ges., Berlin, Bd. 54, 1904, S. 209. 



