4 B. Koto : 



We have as yet scarcely any information respecting the 

 alkaline rocks in China and the lands adjoining that part of the 

 continent. But so far as the writer's knowledge of them goes, the 

 granitic rocks on the southern border of the Mongolian plateau, 

 extending from In-shan to Manchuria (Jwidii-slian), are mainly of a 

 reddish, coarse-aplitic, microdine-YlGh variety^-. The same group 

 which is often mylonitized, forms the foundation of the Koreo- 

 Manchurian highland in contrast to the granodiorites which are 

 l^revalent in Japan. A nepheline-syenite is said to occur in 

 southern China' \ I have a specimen of riebeckite-granite from a 

 quarry near the city of Foo-cliou, in the province of Fokien. 



As to effusives, lack of knowledge is also deeply felt here. It 

 is well known since the explorations of R. Pumpelly"-* and the ]ate 

 VON RicHTiioFEN^^ that basalt is widely distributed over the southern 

 Mongolian plateau as the counterpoise of the vast basaltic mesa of 

 the east Koreo-Manchurian landmass. P. Vénukofï*^ gave a 

 description of Mongolian basalts^-* collected at several widely 

 separated localities by tlie celebrated travellers, M. Potanin, and 

 General PREjEVALSKy. They all proved to be plagioclase-basalts, 

 and no mention was made of aiiy feldspathoid variety. However, 

 in this connection it may be of special interest to cite from the 

 paper referred to, the occurrences of tachylite and limburgite, with 

 the chemical analyses made of them : 



t) The so-called gneiss that built np the core of the Tsin-liny Shan range, lying to the 

 south of the city Si -nan Fu {M^M), the well-known ancient capital, is found, on microscopic 

 exauaiuation, to be a sheared modification of this variety. 



1 ) R. Daly, loc. cit., p. 103. 



2) " Geological Researches in China, Mongolia, an I Japan." Sviithsonian Contribution 

 Publication, 1886. 



3) "China." 



4) " Les roches basaltiques de la Mongolie." Bulletin de la société BeUje de (jéoloyic de 

 ixdeontolO(jie et dliydroloaie, Bruxelles, tome II., 1888, p. 441. 



5) According to V. A. Obrutschew (" Central Asia," I.), there is a large basaltic field, 

 500 m thick near Kaigan. resting on a great thickness of loose conglomerates and sandstones 

 belonging to the Gobi series— the fresh-water Tertiary with Bhinoceros—-with. trachyte at its 

 base. There is another large basaltic area in Morgen in northern Manchuria. 



