180 ART. 3. — B. KOTO : 



composition, with the only difference that in the lavas prior to 

 1779 olivine is wanting. 



J>) Chemical Characters.— An analysis was made of a very slaggy 

 land lava of the Nabé-yama area by Mr. S. Tanaka, of our 

 Geological Survey, with the result given in I., besides an in- 

 complete analysis of an upper crust of the lava sheet in the 

 western field in II. ♦ , 



100.48 



The Nabe-yania land-lava. Fusing point coriesponds to No. 2 Segel 

 cone =3 ±1, 170^0. Specific gravity at 15°C. is 2.64. 

 The present olivine-bearing liypersthene-andesite contains large 

 amounts of GoO, 3IgO, Na.,0, TiO., and MnO, especially the fii'st, 

 but less of /S'iOj, ^vhen compared with a typical liypersthene- 

 andesite. 



