CLASSIFICATION OF THE PLUTONIC ROCKS 253 



end of the series the lime and magnesia ratios are nearly equal, 

 but the magnesia falls more rapidly than the lime. The ferrous 

 iron is parallel to and uniformly lower than the magnesia. The 

 alumina is fairly constant throughout the series. 



o 



g 



M 



g 

 M 

 P 



In In 



I 



M 



13 

 I 



M 



Q 



I 

 O 



CaO -18 



MgO -179 

 17 



A1 2 3 



TeO -106 



K £ ONa a -042 ; 



N 



in 

 o 



«3 



5 



Fig. 2.— Diagram of the Molecular Proportions of the Calc- Alkali Series. 



The Monzonite Series 

 Table of Analyses of Rock- types 



Si0 2 

 ALA 



FeA 

 FeO 



MgO 



CaO 



Na.0 



K 2 6 



H,0 



Ti0 2 



Other 



I. 



Biotite- 

 granite 



(Adamellite) 



71-53 

 i3 - 55 



T20 



o-88 

 1*45 



3'2I 

 2'6l 



3'95 

 i"75 



II. 



III. 



IV. 



Adamellite. Banatite. Monzonite. 



68-97 



14-80 



3'29 



1-15 

 3-82 

 2-46 



4 - 53 

 0*70 



64-30 

 1789 



475 

 not det d 



1*12 



3-98 

 3-84 

 3'37 

 i'6o 



54-90 



1 7 '44 



9-64 



3-26 



6-96 



3"5o 



3"5i 

 1-23 



constituents 



(PA, MnO, etc.) 



V. 



Kentallenite 

 (Olivine-mon- 

 zonite). 



5035 

 15-76 

 2-32 

 7'3o 

 7 '40 

 1012 



2'75 



3-89 



"45 



•30 



74 



100-13 



99-72 



100-84 



100-44 



101-38 



