44 ART. 2, — . KOTO : 



overhung the river without impcdiug our way. These volcauics 

 w^ere of the formation that I have frequently mentioned as oc- 

 curring near Maxan-pho, and which will reappear on our way 

 farther on. (See page 18. et seq.) 



Proceeding from Ilan-su-nai via Peulx-clihi-nai ^^ to the cumnai 

 of Ku-nßi for a distance of 8 km we descended the flat west- 

 wards, seeing before us a meridional ridge of paragneiss ; at the 

 foot of which was our destination (PI. IV. fig. 1). Behind it, 

 still another parallel ridge was seen, through wliich the upper 

 Söm-jin-ijang according to the map makes its way obliquely. 

 Towards the north for a distance of 8-12 km extends a plain 

 bounded on tlie east by the Chu'ôl-Ja-Do portion of tlie Chlri-san, 

 on which stands the monastery of Hoa-am-sa'\ Farther north 

 we saw the equatorial ridge of the Pam-chhi'^^ pass, which 

 separated us from the plain of Nam-uön. We saw the same 

 ridge again from the north in our second traverse. 



Ku-RYöi From Ku-i'i/oi, we took a southerly course to the coast as far 



as Sun-chj'ôn ^\ advancing first across rice fields, over gravel beds, 

 then on paragneiss (the schistose axis N. — 8.) until we came down 

 to Chan-su ^^ at the outcurve of the Söm-jin-gang where we again 

 met with the volcanics of the Upper Kyong-sang formation (see page 

 43) composed of the sheet of greenish porphyrite, red tuff and green 

 breccia ^\ The augite-porphyrite had the pilotaxitic structure. The 



1) At^)\\ 2) mm^ 3) m (If 4) M % 5) m * 



6) This is a quartz-bearing fusion-tuff, or in a more strict sense Lacroix's brèches de fric- 

 tion, and not a normal aqueous or aeolian tuff. It flowed from a certain volcanic -vent with 

 solid fragments floating on it, and partially fused during its flow. It makes massive beds, but 

 sometimes cleaves into the pot -sherd-like flakes, characteristic of tufaceous rocks. ]\Iacroscopical- 

 ly, it has small angular fragments (1 cm) of black and sometimes greenish colour, imbedded in 

 the greenish matrix. Microscopically, the greenish splinter is seen to be of jjoriihyrite of fine 

 pilotaxitic structure with i^henocrysts of plagioclase, sometimes epidotized, and of a chloritized 

 ferromagnesian mineral. The black splinter is the same volcanic in which magnetite-crystals are 



