Figure 5. a)-Normative Feldspathoid Silica-Saturation Index (FSSI) versus molecular Alkalinity Index (AI); b)- Fe-Index versus SiO2 after [38] and [39]. FSSI= Q-[Lc-2(Ne+Kp)]/100. (AI after [40]). Designations follow Figure 3.

From

Petrology and Geochemistry of the Granitic Rocks from the Itremo Domain, Central Madagascar

Désiré Alphonse Rakotondravaly, Roger Randrianja

Journal of Geosciences and Geomatics. 2022, 10(1), 31-44 doi:10.12691/jgg-10-1-3