THE GREAT EllUPTlON OF 8AKU11A-.JIMA IN 1914. 



181 



Norms '^ 



Quartz 16.81 



Oi-tlioclase 9.95 



Mhite 24.16 



Anoi-thite 30.63 



8od. sulphate . . . . 0.41 



Water 0.59 



H^^perstheue . . . . 14.33 



Diopskle 0.28 



Apatite 0.12 



^Magnetite 1.79 



Ilmenite 1.35 



Q 16.81 

 F 64.74, 



Sal 81.55 



Fern 17.87 



Sal 



81.55 



Fern 17.87 

 16.81 



F 



64.74 



K,0' + Na,0' 



CaO' 



KM' 179 



= 4.57<-^>- 

 1 3 



^ 1 

 : 0.26< — > — 

 5 7 



669 . 

 1132 



3 1 



5 7 



NaM' 



= 0.36<— >i 

 490 5 7 



Class n. 



Order 4. 



Ransc 4. 



Subrane; 4, Bandose 



c) Submarine Laya-flows (PL XIX. Figs. 6, 7 ; PI. XX. Figs. 2, 

 3 and 4).^The submarine lavas of the loestern field were taken 

 out by a diver under the writer's supervision at three spots from 

 depths of 10 to 40 fathoms at a distance of 20 to 80 m. from 

 the edge of the seaward encroaching lava- flows. The writer 

 therefore believes, that his specimens are not fragments wliich slid 

 fi'om the advancing front of subaërial lava. Contrary to our 

 expectation of finding pillow-lavas,'^ they form an arched-up 

 (1 o m e - s h a p e d solid sheet of lava, externally fractured and 



1) Calculated by Ogura and Matsumoto. 



2) Pillow-lavas are believed to be only formed from feraic magmas. H. S. Washington, « The 

 Submarine Eruptions of 1831 and 1891 near Pantellaria.' Am. Jour. Si'i, XXVII. Feb., 1909. 



