The Cenozoic formations in the Peter the Great Gulf, Japan Sea and on its shores: Indicators of a polygenic continent–ocean transition zone

Abstract

The Cenozoic formations in the Peter the Great Gulf in the Japan Sea and on its shores are part of the activated cover (Triassic to Neogene) of a young platform. They reflect the Cenozoic destruction of continental crust accompanied by active basaltoid magmatism and by transformation of this crust into marginal-sea crust in the near-continental part of the polygenic (Late Cambrian to Cenozoic) Japan-Sea transition zone from continent to ocean. The Cenozoic formations notably include an industrial coal-bearing and a potentially hydrocarbon-bearing group of Paleogene and Early to Middle Miocene formations, as well as a potentially diamond-bearing Late Miocene to Pliocene formation. The existence of these formations shows that continent–ocean transition zones have potential for these mineral resources. The accumulation of industrial coal-bearing Cenozoic formations seems to have occurred in a connected extensive sedimentation basin that was overlain by Paleozoic tectonic blankets, while the evolution of potentially diamond-bearing pipes that are akin to kimberlites occurred during a powerful phase of tectonomagmatic activation.