The Diachronous Formation of the Enmyvaam and Amguema-Kanchalan Volcanic Fields in the Okhotsk-Chukotka Volcanic Belt (NE Russia): Evidence from Isotopic Data

摘要

The Okhotsk-Chukotka volcanic belt (OCHVB) located at the transition between two tectonic domains is characterized by complex lithotectonic patterns, which partly explain the ambiguous interpretations of its spatial and chronological boundaries. Some researchers believe that the belt formed during the middle Albian to the Santonian or, probably, to the early Campanian, i.e., in a period lasting approximately 25 myr. Many others consider this period to be substantially longer based on extensive phytostratigraphic and radioisotopic data.