Nd-Sr Isotopy and Geodynamics of the Albian-Quaternary Magmatism in the South Kuril Islands

摘要

Numerous Sm-Nd investigations carried out in recent decades for volcanic rocks from Late Cenozoic island arcs have demonstrated the present-day isotopic state of suprasubduction zones, which bear certain characteristics of depleted (ensimatic arc) or unde- pleted (ensialic arc) mantle. However, the isotopic evo- lution of magmatism at convergent boundaries (e.g., long-term island-arc evolution) has been poorly studied. Therefore, we conducted an isotopic study of Cre-taceous-Paleocene magmatism in the South Kuril Rise, which represents the southern ensialic segment of the present-day Kuril Belt. Quaternary volcanic rocks from the Kuril Belt were studied in [1, 2].