Physical and chemical conditions of the formation and evolution of late pleistocene-holocene magmas of the Gorely and Mutnovsky volcanoes, southern Kamchatka

摘要

A detailed mineralogical and geochemical study of basic volcanic rocks from the modern edifices of the Gorely (Q_3~4-Q_4~4) and Mutnovsky (Q_3~2-Q_4) volcanoes, as well as the results of numerical modeling with the COMAGMAT program, made it possible to estimate the role of fractional crystallization, the fluid regime, and geodynamic conditions in the petrogenesis of the studied basaltoids. The specific features of the evolution of magmas of the two volcanoes give grounds to suggest that beginning from the Late Pleistocene (Q_3~4), all of the considered territory experienced a change in geodynamic regime, with an increasing role of extending strains in its evolution.