THE NORM IN IGNEOUS ROCKS 



ANALYSIS N. TENTATIVE 



Vesuvose (Leucite Basanite). Professional Paper 14, p. 306, No. 2 



Lava of 1872, Mount Vesuvius 



With leucite and nephelite there will be no quartz nor will there be 

 hypersthene. With leucite in the norm there will be no albite. 



ANALYSIS N 



Vesuvose (Leucite Basanite). Professional Paper 14, p. 306, No. 2 



Lava of 1872, Mount Vesuvius 



Analysis O is like N, where K^O goes partly to orthoclase and 

 partly to leucite, but here we make the minor inflexible molecules 



