DALY. 



COMPOSITIONS OF IGNEOUS-ROCK TYPES. 



219 



TABLE II. 



Showing the Average Compositions calculated for the Principal 

 Igneous-rock Types. 



GROUP I. 



No. of 

 Analyses. 



Plutonics. 



.-a m 



3*> 



figS 



47 



Oo 



S c 



Xi _ 



114 



1- 71 ~ 



SI'S 



.-Ph S 

 S-dO 



184 



Ph^ 



236 



Effusives. 



Sn 

 a 



64 



ssO 



'§•5 

 as 



3* 



24 



13 

 c q 



4> m 



!3 O 



40 



& 

 o . 



A.— - 



" a 

 IS o 



50 



Si0 3 



Ti0 3 



A1 2 3 



Fe 2 3 



FeO 



MnO 



MgO 



CaO 



Na 2 



K 2 



H 2 



P,0< 



71.06 



.48 



14.10 



1.46 



1.63 



.18 



.59 



1.97 



3.24 



4.50 



.69 



.10 



69.81 



.54 



13.76 



2.17 



1.87 



.26 



.84 



2.20 



3.17 



4.38 



.74 



.26 



69.73 



.34 



14.98 



1.62 



1.66 



.11 



1.08 



2.20 2 



3.28 



3.95 



.78 



.27 



69.92 



.39 



14.78 



1.62 



1.67 



.13 



.97 



2.15 



3.28 



4.07 



.78 



.24 



72.60 



.30 



13.88 



1.43 



.82 



.12 



.38 



1.32 



3.54 



4.03 



1.52 



.06 



72.90 



.48 



14.18 



1.65 



.31 



.13 



.40 



1.13 



3.54 



3.94 



1.33 



.01 



72.62 



.25 



13.77 



1.29 



.90 



.12 



.38 



1.43 



3.55 



4.09 



1.53 



.07 



72.36 



.33 



14.17 



1.55 



1.01 



.09 



.52 



1.38 



2.85 



4.56 



1.09 



.09 



Calculated as Water-free. 



73.16 



.33 



14.33 



1.57 



1.02 



.09 



.53 



1.39 



2.88 



4.61 



.09 



Each sum = 100.00. 



Includes .08% BaO and .01% SrO. 

 Includes .06% BaO and .02% SrO. 

 Includes .06% BaO and .02% SrO. 



