RARE-EARTH ELEMENT DISTRIBUTION IN THE EVOLUTIONARY VOLCANIC ROCK SERIES OF THE GAMCHEN STRUCTURE, EASTERN KAMCHATKA

Abstract

The rocks produced in the Quaternary cycle of volcanism in the GVTS (Gamchen Volcanotectonic Structure) can be subdivided into three phases, each representing a volcanic regeneration phase in the region: early Pleistocene (Q1), middle Pleisotocene (Q2) and late Pleisotcene-Holocene (Q3-Q4). The chemical composition of volcanic rocks of the GVTS indicates that they are typically calcalkalic. The mafic and intermediate rocks, formed in individual phase of its evolution, include magnesian and high-alumina varieties, erupted simultaneously from specific volcanic centers. Based on experimental evidence, it is found that