Petrological evidences of degassing of magmatic melts in granite intrusions of the East Sikhote-Alin.

Abstract

The paper considers the influence of the water presence in granite melts on the rock structures and parageneses of the coexisting feldspars in the process of the granite crystallization from the early to closing stages. There is shown the dependence of the quartz quantity in granophyre and micropegmatite aggregates of the PH2O and distance to the contacts and roof in granophyre granites of Araratsky and granodiorites of Brinerovsky massifs (Dalnegorsky district, Primorye) that makes it possible to distinguish the facies, diffent in fluid saturation and depth of occurrence, in the monotonous at first sight granophyre rocks. The gradual increase in PH2O from contacts deep into the intrusion, which was “fixed” by changes in the composition of granophyres, indicates the diffusional character of the removal of water from the intrusion into host rocks.