222 



ANNALS NEW YORK AVADEMY OF" SCIENCES 



Norms 



1 :? 



Orthoclase 7.2S% 27.24% 



Albite i-k'i^^'. 16.77 28.30 



Anorthite . 27.80 22.52 



Nephelite 2.27 1.14 



Diopside 22.32 7.55 



Olivine 13.08 12.36 



Magnetite 3.25 



Ilmenite 7.08 1.54 



No. 1. Hornblende schist from south shore of Croton Lake. Magmatic sym- 

 bol, III, 4.4.3. Auvergnose. 



No. 2. Epidote schist or epidosite from above locality. 



No. 3. Granodiorite gneiss. Greenwich, Connecticut. Symbol II, 5.3.3. Sho- 

 shonose. 



In the following table, analyses of massive igneous rocks very similar in 

 chemical composition to the hornblende schist and granodiorite gneiss are 

 given for comparison : 



