ORIGIN OF AUGITE ANDESITE 



409 



TABLE I 



Average Analyses — Basalts and Allied Rocks 



SiO^ 



TiOj 



AI2O3 



Fe^Oj 



FeO 



MnO 



MgO 



CaO 



NaaO 



K2O 



H2O below iio°C 

 HjO above 1 10° C 

 P.O. 



AU 

 Basalt 



No. of analyses . . 



48.78 

 1-39 



15-85 

 5-37 

 6.34 

 0.29 

 6.03 

 8.91 

 3.18 

 1.63 



0-73 

 1.03 



0.47 



161 



Hawaiian. 

 Basalt 



48.36 

 0.66 



15.40 

 6.48 



10.07 

 0.80 

 4.19 

 8.69 

 3-34 



^ 1.30 



jo -43 

 0.28 



Olivine 

 Diabase 



50.10 



1-25 



14-43 

 5.06 

 6.31 

 0.25 

 7-32 

 9-53 

 2-75 

 0-73 



0.27 



17 



Dolerite 



49-5° 

 1 .42 



14-37 

 6-55 

 5-84 

 0.17 



7-75 

 9.96 

 2.50 

 0.84 

 (0.29 



(0-37 

 0.44 



Melaphyre 



50.60 



0.68 



17.40 



4-57 

 6.29 

 0.46 

 4.89 

 8.09 



1.76 

 1.83 



Olivine 

 Gabbro 



46.49 

 1. 17 



17-73 

 3-66 

 6.17 

 0.17 

 8.86 



11.48 

 2.16 

 0.78 

 0.18 

 0.86 

 0.29 



17 



7 



First 



General 



Average 



49.06 

 1 .36 



15-70 

 5-38 



6-37 

 0.31 

 6.17 

 8.95 

 3-" 

 1-52 



1 .62 



0.45 



Sum, 100.00 in each case. 

 Sum, 100.00 in all analyses. 



TABLE II 



Average Augite Andesite, Olivine Basalt, Peridotite, Limburgite and 



PiCRITE 



Second Gene- 

 ral Average 

 Olivine Basalt 



9 



Augite 

 Andesite 



Peridotite 



Limburgite 



Picrite 



SiO^.. 

 TiO,. . 

 AUO3. 

 Fe^Oj. 

 FeO... 

 MnO., 

 MgO.. 

 CaO.. 

 NajO. 

 K,0.. 

 H^O.. 

 P.O5.. 



48.84 



1-35 

 15-90 

 5-23 

 6.30 

 .29 

 6.38 

 9-15 

 3-05 

 1 .46 

 1 .60 

 0.45 



57-50 

 0.79 



17-33 

 3-78 

 3.62 



5-83 

 3-53 

 2.36 

 1.88 

 0.30 



44-39 

 0.88 



5-14 

 3-88 

 6.70 

 0.19 

 29.17 

 6.31 

 0.64 

 0.76 

 1.80 

 0.14 



41.69 



0.67 



14.80 



15-04 



8.64 

 11.98 

 3-52 

 1. 17 

 2.36 

 0.13 



No. of analyses. 



215 



i?, 



49 



Sum, 100.00 in each case. 



All of these averages were made after the method of Washington 

 and Clarke in their latest determinations of the average rock-analysis 

 for the world. Thus, the average for each oxide is based only on the 



