Satellite Geological Indication of Morphostructural Elements of the Coasts and Bottom of Adjacent Water Areas (Peter the Great Bay, Sea of Japan)

The implementation of satellite geological investigations within the continent–Sea of Japan transition zone in Southern Primorye has made it possible to establish series, connected with faults, of rows (chains) of Miocene and Miocene–Pliocene volcanic structures and large fracture zones, which extended over the continental slope from the shelf to Central Basin of the Sea of Japan. They are structural markers, the steady strike of which calls into question tectonic formation models of the Sea of Japan Basin, based on large-scale horizontal movements of crustal blocks. The combination of linear systems of small monogenic volcanic structures and fissure eruptions of basalt lava reflects the multioutlet nature of Central Basin volcanism, which occurred due to the rather shallow location of asthenospheric highs or mantle diapirs. It is suggested that the formation and relatively rapid subsidence of this basin is related to active mantle defluidization, with large-scale basalt volcanism and injections of deep mafic and ultramafic material that replaced rocks of the continental crust.