ADDITIONAL COMMENTS ON THE GEOLOGY OF THE JUAN FERNANDEZ ISLANDS 83 



Table I. 

 Analyses of the rocks from the Juan Fernandez Islands. 



SiOa . . . 

 TiOj ... 

 Al,03 . . . 

 Fe^O, .. 

 FeO ... 

 MnO . . . 

 CaO . . . 

 BaO.... 

 MgO . . . 

 Na^O . . . 

 K^O . . . . 

 P.O. ... 

 Cr,03 . . . 



F 



CI 



S 



I. Olivine basalt (dolerite). Masatierra, Bahia Cumberland. Raoult anal. 

 II. Olivine basalt. Masatierra, Bahia Cumberland. Raoult anal. 



III. Olivine basalt. Masatierra, Bahia Cumberland. Raoult anal. 



IV. Aphyric basalt. Masatierra, Bahia Cumberland. Raoult anal. 



V. Feldspar phyric basalt. Elevation i 420 m. Masafuera. A.-M. Bystrom anal. 

 VI. Picrite basalt (Masafuerite, Oceanite) dike rock. Masafuera. N. Sahlbom anal. 

 VII. Iddingsite-basalt. Elevation i 000 m. Masafuera. N. Sahlbom anal. 

 VIII. Soda trachyte. Elevation i 200 m. Masafuera. N. Sahlbom anal. 



Analyses I — IV have been made for A. Lacroix from specimens collected at Bahia Cumberland 

 by members of Dumont d'Urville's expedition in 1854, These analyses were first published in 

 Lacroix' paper: Constitution lithologique des lies volcaniques de la Polyne'sie Australe in 1927. 



Analysis No. V is new, representing a sample of the abundant light grey feldspar basalts at 

 higher elevations on Masafuera. 



Analyses VI — VlII are produced from my earlier paper on the geology of the Juan Fernandez 

 Islands (No. 12). 



