Mechanism of deep-seated magmatic activity below island-arc volcanoes and similar structures

Publisher Website
Google Scholar
Abstract
We have analyzed geophysical data on deep-seated magmatic activity below Eastern Kamchatka and the mechanism of uprise of magmas and have investigated phenomena associated with the uprise of magmas through hydrostatic forces. Ultrabasic magmatic columns must rise from a local layer at depths of 100–250 km. Above it in the asthenosphere, a regular series of major magmatic columns develops with a spacing of about 30 km, which provides separate individual volcanic centers. The optimal radius of the columns is 350–1000 m and the velocity of their uprise is about 1 m/yr. Magma is moved in them by an order more rapidly than in the asthenoliths. Excess magmatic pressure in the columns contributes to the formation of accumulations of ultrabasic and basic magmas near the base, the crust and the transitional layer between the crust and the mantle, and also to the development of peripheral andesitic magmatic foci on the boundary between the crystalline basement and the sediments. We present a probable scheme for deep-seated magmatic activity below the volcanic belt of Eastern Kamchatka, the island arcs and similar structures. —Author.

This publication has 2 references indexed in Scilit: