ADDITIONAI. COMMKNTS ON THE GF.OI.OGV OF THF, JIAN FERNANDF.Z ISLANDS 55 



X 





\» 



r 



Fig. 12. Lumps of magnesite the so-called Glockenstein . Nat. size. Eahia del Padre, Masatierra. 

 Reproduced from P. Quensel, 12, p. 269. 



Fig. 13. Scoriaceous lava with newtonite and bole. Nat. size. B.'hia del Padre, Masatierra. 

 Reproduced from P. Quensel, 12, p. 269 



will in this connection only .summarize the facts. The s in question are very 



fine-grained and of a greenish colour. The abundant ck age plains are coated 

 with epidote and calcite. Pyrite is finely dispersed tht^- ■ out the rock. Under 

 the microscope one can see that original phenocrysts of ,th olivine and augite 

 are more or less completely changed to serpentine and c orite. The matrix con- 

 sists of olivine, augite, plagioclase, magnetite and ilmenite — i.e., the usual 

 mineral assemblage of the basaltic lavas. The greater part of the silicates are, 



