© A.G. Rodnikov1, L.P. Zabarinskaya1, V.B. Piip2, V.A. Rashidov3,
N.A. Sergeyeva1, N.I. Filatova4

1 Geophysical Center, RAS, Moscow, 11999, Russi; e-mail: rodnikov@wdcb.ru
2 Moscow State University named after M.V. Lomonosov, Moscow, 119899, Russia;
3 Institute of Volcanology and Seismology, FED RAS, Petropavlovsk-Kamchatsky, 683006, Piip Blvd, 9, Russia;
4 Geological Institute RAS, Moscow , 109117, Russia.

The deep structure of the transition zone from the Asian continent to the Pacific Ocean was investigated under the Geotraverse International Project along the deep section of the tectonosphere, including the lithosphere and the asthenosphere. The profile of the geotraverse crosses the Mesozoic structures of the Sikhote-Alin, the rift of the Tatar Strait, the Cenozoic formations of Sakhalin I., the Kuril Basin of the Okhotsk Sea, the volcanic structures of the Kuril Island Arc, the Kuril Trench, and the Mesozoic plate of the Northwest Pacific Basin. The length of this profile is 2000 km with a depth of 100 km. A distinctive feature of the transitional zone is the presence of an asthenospheric layer in the upper mantle and the rising of the diapirs of a hot anomalous mantle material, which controlled the formation of the geological structures of region. There is an obvious correlation among the geological features, tectonomagmatic activity, and the structure of the upper mantle. The tectonically active regions, such as the island arcs and the rifts of the marginal seas, correlate with a thick, clearly expressed magma-generating asthenosphere.