CHINA, MONGOLIA, AND JAPAN. IQl 



The relative ages of the metamorphic and intrusive rocks of this region appear 

 to be as follows, reading from younger to older: — 



1. Greenstone of Nichinbe ; dyke in syenitic granite. 



2. Syenitic granite. 



3. Aphanitic rock. 



4. Metamorphic conglomerate and granulite of Oouta. 



5. Amygdaloid. 



September 1st. Continuing the journey by boat we reached Kudo — the syenitic 

 granite forming high hills along the sea as far as Ouenkoto, near Kudo. 



At Kudo other metamorphic strata were observed, consisting of black and rose- 

 colored quartz-schist, clay slate in thin beds, and a dark brown, micro-crystalline 

 rock, apparently felspar and hornblende. These strata are folded and refolded, 

 and the stratification being well preserved, they presented the finest example of 

 plication I had ever seen. The general trend of the folding seemed to be about E., 

 but there was too much irregularity in this respect to make sure of the direction ; 

 further south the trend appeared more regularly N. W. and the dip N. E. 



The beds are traversed by a dyke of a porphyritic rock containing crystals of 

 green and greenish-white triclinic felspar and of hornblende, in a grayish purple 

 base. 



A cold spring of chalybeate and carbonated water rises on the beach from the 

 quartzite. 



September 2d. Riding along the sea-shore, a few miles, we reached the penal 

 establishment of Ousubetz, at the mouth of a creek of the same name. 



Ascending this stream, which is a wild mountain torrent contained, near the sea, 

 between cliffs of the volcanic conglomerate, we came upon an amygdaloidal rock, 

 and beyond this a chloritic granite containing, besides quartz and chlorite, white 

 orthoclase and a light green triclinic felspar. In this granite there is a broad belt, 

 apparently a dyke, of a claystone-porphyry, a yellowish rock with a rough, earthy 

 base free from visible quartz, and from which the crystals of felspar have dis- 

 appeared, leaving only their cavities. From this porphyry issue several springs, 

 which showed in different instances temperatures of 55°, 58°, and 58|° C. 



These springs have formed deposits, of carbonate of lime and brown oxide of iron, 

 Avhich are more or less cavernous, and are the abode of a great number -of snakes, 

 which, attracted by the perpetual warmth, and being respected by the natives as the 

 deities of the place, live unharmed. The cast-off skins of these reptiles flutter, like 

 streamers, from every hole and neighboring bush. 



Beyond the chloritic granite we found again the amygdaloid which, under various 

 forms, extended as far inland as our excursion continued, about one mile beyond 

 the chloritic granite. 



In one of the side ravines a bluish-white, highly silicious rock, with conchoidal 

 fracture and impregnated with minute cubes of iron pyrites, was observed in con- 

 tact with the amygdaloidal rock. 



This amygdaloid is very variable in character, in places brecciated, in others 

 massive — the base being generally dark reddish-brown, and containing nodules of 

 calcite and a green, soft clayey mineral, with here and there one of quartz. Frag- 



