72 A-Ï^T. 2 — B. KOTÔ : 



porphyry which has crystals but they are those of feldspar. 

 The quartz is present in one and absent in the other, and its 

 occurrence is not constant, as the quartz is often corroded and 

 resorbed in this class of porphyries during tlieir consolidation. 



On the left we met with a graphite -schist, now decomposed 

 into red earthy, thinly-split shingles, striking N. 45° E. with the 

 dip S.W. The phyllite, havmg the uplifted ridge on the northwest 

 side, runs in the direction of the strike forming a headland 

 beyond tlie inlet along whose eastern shore we were passing. A 

 microscopic slide reveals the fact that this phyllite is of the same 

 kind as that of Tong-pok ^\ and is probably of the same age 

 (the Metamorphlc Mesozoic). The slide shows a rounded quartz, 

 which has pronounced undulatory extinction, being enveloped 

 radially with phyllitic lamellae ; and the muscovitized crystals of 

 feldspar are still seen within the phyllitic membranes. In short, 

 it presents the appearance of an extremely deformed porphyritic 

 igneous rock. 



We next proceeded northeast from the forlorn eumnai of 

 Mu-cui '■', encircled as usual with a stone-wall built up of typical 

 specimens of the purplish claystone-porphyry and porphyritic 

 masanite. A denuded hilly flat (PI. X. fig. 2) was then passed, 

 and we plunged into an Alluvium tract of paddy fields (PI. X. 

 fig 3.) 4 km wide, draining from the northwest (Hmn-phybng) into 

 the Yöng-san-gang river. We then crossed the low Ul-chin-chhi 

 pass to Komang-gol '''\ The rocks of the pass are ^alternations of 

 red claystone-porphyry, greenish-brown variegated breccia with 

 corroded quartz, and grayish sandy tuflSte, having the strike N.N.W. 



1) See cinU'. pages 06 (iii) and 68. 



2) For a description of the route from Mu-an to Cliyöng-eup \ia Cliyang-söng, see the 

 beading " Spatulate Älesozoic area" in Chyöl-la-Do in Chapter III. "The Second Traverse." 



■•i) V-t ^ M 



