Types and physical properties of igneous rocks of Popov Island in Peter the Great Bay of the Sea of Japan

This paper presents the results of geological and petrophysical research carried out on Popov Island by the Pacific Oceanological Institute of the Far East Branch of the Russian academy of Sciences during 2003–2009. As a result, 7 types of rocks were identified. Their density and magnetic susceptibility have been determined. It was established that the rock types are clearly differentiated with respect to their physical parameters. The identified relationship allows one to use these physical properties, first of all, for the geological interpretation of the gravity and hydromagnetic survey carried out in the surrounding water area of Peter the Great Bay and, secondly, as an additional indicator for igneous rock typification on other islands of the region. Such comprehensive and integrated research was carried out for the first time in this area. The results obtained are important for solving the problem of the structural, compositional, and genetic relationships between the terrestrial and marine structures at the junction zone between the Japanese Basin and the adjacent continent.     

Model of the formation of marginal seas in the western Pacific Ocean

A geodynamic model for the formation and movement of marginal seas in the Pacific Ocean during lateral interaction between the Eurasian and Pacific lithospheric plates is proposed. In a transition strike-slip megazone, the continental and oceanic plates disintegrate into blocks, which are involved in rotation, thus causing formation of mantle plumes and tectonospheric funnels (ascending and descending lithospheric vortexes). The implications of the model are formulated. Three scenarios of the evolution of the marginal sea basins depending on the direction of motion of the Pacific plate are discussed.     

Structure,Rheology, Petrology,and Geodynamics of the Tectonosphere of the Sea of Japan

Oceanology - The geological-structural, magmatic, seismic, and thermometric models of the Earth’s crust and upper mantle of the Sea of Japan region are considered in relation to...     

Formation mechanism of central-type structures in the West Pacific continent-ocean transition zone

The rotary formation mechanism of various central-type geological structures functioning in the strike-slip fault systems of the West Pacific continent-ocean transition zone is considered. This mechanism explains many tectonomagmatic processes and is confirmed by geological, geophysical, and geomorphological studies. At the same time, it is not the only possible mechanism. Examples of magmatogenic central-type ring and vortical structures in the Japan Sea segment of the West Pacific continent-ocean transition zone are given. In our opinion, the proposed geodynamic model is inscribed into the paradigm of tectonic delamination of the lithosphere developed by Yu.M. Pushcharovsky.