Petrogeochemical features of Oligocene-Early Miocene volcaniclastic rocks of the Sea of Japan

Petrographic and geochemical studies showed that the Oligocene-Early Miocene volcaniclastic rocks from the southern part of the Sea of Japan are ascribed to the high-potassium aluminous rocks of the subalkaline volcanic series of active continental margins. A comparative analysis revealed the spatiotemporal relation of Oligocene-Early Miocene subaerial volcanism of the Sea of Japan with Late Cretaceous and Eocene-Early Miocene ignimbrite volcanism of the East Eurasian margin. This allows us to refer the volcaniclastic rocks of the Sea of Japan to a stage of ignimbrite volcanism that occurred during relative quiescence against a general extension in the continental margin setting.