PETROLOGICAL ABSTRACTS AND REVIEWS 781 



Kozu, S. "Penological Notes on the Igneous Rocks of the Oki 



Islands," Science Repts. Tokoku Imp. Univ., Sendai, Japan. 



Second Series, Vol. I (1913), No. 3, 25-56, pis. 4, figs. 5. 



The Oki Islands lie about 65 kilometers off the coast of Honshu, 



on the Korean side. They consist mainly of volcanic rocks extruded 



between the middle "of the Tertiary and the beginning of the Pleistocene, 



and lie upon or were intruded into the Tertiary beds which form the base 



of the islands. The succession of the igneous rocks cannot be exactly 



determined in all cases but it appears to be as follows, beginning with 



the most recent: 



10. Holocene sediment, a river deposit of limited extent in valleys 

 9. Trachydolerites and basalts 

 8. Pleistocene ( ?) deposits 

 7. Trachytic rocks 

 6. Trachydolerites 

 5. Banded alkalic rhyolites 

 4. Alkalic rhyolites 



3. Quartz-syenites and schistose granitic rocks 

 2. Andesites 

 1. Tertiary deposits 



The various rock-types are described in detail, chemical analyses 

 are given for most of them, and the names in the C.I.P.W. system are 

 determined. 



