Allivalites as indicators of fractional crystallization of the island-arc calc-alkaline low-K series

Allivalites are particularly distinguished by their composition and morphology among the wide spectrum of inclusions in the volcanic rocks of the Kurile-Kamchatka island arc. This work reports new chemical and mineral data of a comparative study of the allivalites and host rocks using modern analytical facilities. On the one hand, it was confirmed that allivalites are genetically related with host volcanics. On the other hand, it was established for the first time that allivalites were formed in several stages: from the deepest stage of their origination at the generation depth of primary melts to the crustal and subsurface conditions of the formation of magmatic chamber. Hence, allivalites (olivine-anorthite inclusions) bear valuable information on the evolution of deep island-arc magmatism.