Fig. 2: Variation in Aluminium Saturation Index with SiO2. | Communications Earth & Environment

Fig. 2: Variation in Aluminium Saturation Index with SiO2.

From: Giant lithium-rich pegmatites in Archean cratons form by remelting refertilised roots of greenstone belts

Fig. 2

Variation in the Aluminium Saturation Index [ASI = Molecular ratio Al/(Ca + Na + K)] with SiO2 for leucogranites of the Yilgarn and Pilbara cratons. Note that the leucogranites form fields that follow the same trends as those of the tonalite-trondhjemite-granodiorite (TTG) series rocks which represent melts of mafic, igneous, lower crust32.

Back to article page