Problems of geodynamics of the central type tectonic structures of the islands in Peter the Great Bay (the Sea of Japan)

Abstract

The article presents large-scale cosmogeological maps of a new generation of the Russky, Popov, Reyneke and Rikord Islands located in Peter the Great Bay in the Sea of Japan. The basis for compiling the maps was the original data on the study by the authors of the geological structure of the islands using modern methods – the interpretation of cosmic photographs with a high resolution. As a result, numerous structures of the central type were established within the islands, manifested in the relief in consequence of the breakup of lithospheric vortexes that arose in the process of strike-slip formation during the long-term development of a powerful left-hand strike-slip zone. Tectonic activity in this zone began in the Late Permian, but became most active in the Mesozoic, when the East Asian strike-slip zone and the West Pacific margin- al seas were formed. Lithospheric vortexes reflect deep lithocyclones and lithoanticyclones – “upward” and “downward” structures. The former contribute to mantle upwelling, the latter to the injection of crustal matter and its transportation to the lower layers of the lithosphere. This is confirmed by mechanical and mathematical modeling of the mechanism of vertical movements of the crust-mantle substance – in the “dome” mode and in the “trough” mode.