126 A.RT. '2. — B. KOTO: 



other to the Yellow Sea. Our road cut through a hill-neck of 

 coarse-lamellar biotite-orthogneiss which is at first undulating, 

 but finalh' dips to the northeast with the strike N. 20"' AV. The 

 little flat of 3fuI-kö-si'P^ was next reached, and there unexpected- 

 ly we met with a hornblende-porphyrite in a broad dj'ke carrying- 

 on its east shoulder a gray zigzag-lamellar mica-schist with white 

 spots (the strike N. 20^ W., the dip 80" N.E.), being overlaid on 

 the east by a sheared reddish orthogneiss with pseudo-cleavage 

 N. 40 W., the dip N.E. It is traversed by a coarse microcline- 

 pegmatite with muscovite and large tourmaline crystals. The dyke 

 trends N.E.-S.W., making hills for a considerable distance south- 

 wards. The contact-metamorphosed mica-schist is of a sedimen- 

 tary origin, being built up of psammitic quartz-grains alternat- 

 ing with coarse zigzag bands of brown biotite and white brittle 

 muscovite, with helicitic structure. This coming together of the 

 porphyrite, contact schist, and reddish gneissoid granite is to me 

 paradoxical. It is possible that we here have to do with a 

 pinched relic of thrust-blocks (PI. XXXIV. FG, ph). 



The way up to the Pha-lvgai (490 in) is built of pressed 

 orthogneiss witli injected veinlets, metagneiss, and crushed pegma- 

 tite with microcline and perthite ; the pegmatite being therefore 

 of the alkaline variet}^ The descent to Song-dam (350 m) is also 

 a sheared granite with a distinct pseudo- cleavage dipping south- 

 Avards. The FJia-Jxogä.i, just passed over, is an important topo- 

 graphic element. It is a sharp ridge which, coming northwards 

 from the Pi-Jwaiig-chJii''^, passes here northwards to the Chliyu- 

 jihung-nyöng pass (p. 125), where it joins with other converging 

 ridges. Separated from it by a méridional valley of the " Eed 



1) m g ?f 



2) See (iMe, pp. 7ft-7iJ. 



