84 ART 2. — B. KOTÛ: 



some specimens. The cataclastic structure, so universally observed 

 in the rocks of tlio present region, is not present owing perhaps to 

 the relieving of tlie strain in consequence of the development of 

 twinning, just as marble behaves under similar circumstances. 

 It was not possible for me to decide in my rapid journey whe- 

 ther the leucocrate occurs in the form of a dyke, or whether it 

 represents a magmatic diflerentiation of a granitic rock, though 

 the latter view seems to be tlie more plausible explanation. It 

 is not labradorfels nor anorthosite as there are no such rocks as 

 gabbros nor norites with which it could have been brought into 

 connection. At present I simply call it plagioclasiïe. The schis- 

 tose direction is already N. 20^^ E. Its eluvial soil is grayish-blue 

 and clayey, and the debris ash-colored. 



San-cuhyöng After covering five kilometers of l)a<l rocky road on the 



plagioclasite, we reached San-chhyöiKj (80 m) '\ located on an 

 erosion-hill (PL XVI. fig. 2) of ortho-hornblende-gneiss '"'\ 



Turning aside from the course of the rapid Nam-gang, we 

 climbed eastwards up a talus slope of dark hornblende -gneiss 

 to tlie pass of ChJiyöng-niöri-chhl'^^ (oGO m) which is already on 

 the light-colored normal orthogneiss. The sudden change of the 

 hornblendic to the biotite rock forces mu to believe that the 

 former is intrusive in the latter ; but it is remarkable for the 



The Eastern pcrsistcnco of tlic liomblendc rock which makes a distinct belt 



BELT 



all along the eastern or inner margin of the Chiri-san sphenoid 

 from here through Tan-song", and the Knang-ial-chhi''^ as far as the 

 south coast, west of Kon-gaiig. It is an open lickl for investiga- 

 tion by future observers. 



1) Ui '^ Scenic situation on the east bank of the Nam-gang. 2) See footnote 5, page 35. 

 3) R B lll'le ^) See footnote 5, page 35. 5) Sec footnote 3, jîage 38, 



