Marker tephra layers in the late quaternary deposits of the Sea of Okhotsk as evidence of catastrophic eruptions in the Nemo caldera complex (Onekotan Island, Kuril Islands)

On the basis of complex studies of tephra layers (morphology of volcanic glass particles, chemical composition of glass particles and minerals, and REE distribution), marker tephra layers (K2, K3) were distinguished in the stratigraphic columns in the area of the Sea of Okhotsk. The areas of distribution of tephra layers and their age datings were determined. Tephra layers are shown to be similar in their chemical composition. They are correlated with strong explosive eruptions in the Nemo caldera complex on Onekotan Island (northern part of the Kuril Islands) in the Late Pleistocene.