New Data on the Composition and Geodynamic Nature of Ultramafic Rocks of the Mt. Poputnaya Massif, Valagin Range, Eastern Kamchatka

摘要

The geodynamic typification of ultramafic rocks within the paleoisland terrains of eastern Kamchatka remains controversial. Ultramafic rocks often compose imbricated slices and blocks within the nappe structure and associate with island-arc volcanogenic rocks. We studied peridotites of Mt. Poputnaya that belong to the Late Cretaceous-Early Paleogene Achaivayam-Valagin volcanic arc, which is presently involved in the accretionary structure of eastern Kamchatka. Based on geological, geochemical, and min-eralogical data on materials collected during field investigations in 2003, we present a new perspective on their origin.