24 



N. L. Bowen — Genetic Features of 



Fig. 3. 



Fig. 4. 



Figs. 3, 4, 5 and 6. — Projections of fields of stability in nephelite-diop- 

 side mixtures upon the CaO-MgO-Si0 2 plane. Same orientation as fig. 1. 

 Projected point for mixtures of nephelite with diopside, A; with monti- 

 cellite, B; with akermanite, C; with enstatite, D; with forsterite, E. 



Fig. 3, 20 per cent nephelite; Fig. 4, 40 per cent; Fig. 5, 55 per cent; 

 Fig. 6, deduced relations in magma. 



