Correlation of the Acoustic Parameters and the Age of the Basal Horizons of the Cenozoic Sedimentary Cover, the Sea of Japan

The velocity sections and acoustic parameters of the sedimentary cover in the Central (Japan), Yamato (Honshu), and Tsushima basins, and the Kita-Yamato Trough of the Sea of Japan, as well as the rocks of the basement and the Cenozoic cover of the submarine Yamato Rise were studied. A comparative analysis of similar parameters of the Cenozoic basins in the South China and East China marginal seas was performed. The relationship between the acoustic properties (P-wave velocity, V-p) of the basal horizons and the age of the Cenozoic cover in the above basins was analyzed. The values of V-p = 3.0-3.6 km/s have been validated as the acoustic parameter of Paleocene-Eocene sedimentary strata. According to the studies we performed, the basal layers in the supposed depocenters of the Japan basins (Central, Yamato, and Tsushima) have V-p = 3.0-3.3 km/s, which indicates the Paleocene-Eocene age of the onset of their formation.