170 



F. N. Guild — Eruptive Rocks in Mexico. 



Analysis of Basalt from El Salto de San Anton. 



Si0 2 . 



ai 2 o 3 



Fe 2 3 



FeO . 



MgO. 



CaO . 



Na 2 



K 2 0. 



H 2 0. 



H 2 0. 



Ti0 2 . 



PA- 



Cr 2 3 

 MnO. 

 SrO . 

 BaO . 



Above 110 

 Below 110 



Li„0 Trace 



51- 



56^ 



15 



24 



2 



73 



5 



99 



8 



30 



7 



67 



3 



74 



1 



25 





16 





15 



1 



81 





47 





005 





15 





05 



•07 



Trace 



99-945 



Normative Mineralogical Composition and Classification. 



Orthoclase, K 2 O.Al 2 0,.6Si0 2 ___ 11-12# 



Albite, Na 2 O.Al 2 3 .6Si0 2 31-44 



Anorthite, CaO.A1 9 0,.2SiO a ... 19-18 



Diopside 



Hypersthene 



Olivine 



( CaO.Si0 2 

 \ MgO.Si0 2 

 / FeO.SiO, 



MgO.Si0 2 

 FeO.Si0 2 

 MnO.Si0 2 



2MgO.SiO, 

 2FeO.Si(X 



3 8 

 60 

 19 



10 



45 

 26 



70 



45 



12-17 



6-81 



10-15 



Magnetite, FeO.Fe 2 3 3-94 



Ilmenite, FeO.Ti0 2 __ 3 34 



Apatite 1*24 



Rest -43 



99-82 



