A STUDY ON THE GEOLOGICAL CHARACTERISTICS AND GEODYNAMIC ORIGIN OF DONGYING MOVEMENT, BOHAI BAY BASIN

Dongying movement in Bohai Bay Basin is an intensely regional tectonic movement occurred during late Paleogene. According to the geological features of Dongying Movement in Bohai Bay Basin and the research results of the former, this paper analyzed the potential geodynamic origins of Dongying movement. One is the effect of quick stretching of lithosphere, upwelling and temperature raising of upper mantle, the other is result of the flexibility discrepancy among upper, lower crust and lithosphere under crust during the lithosphere cooling. Furthermore, this paper illustrated the reason of transition of basin evolution style, i.e. from rifting and extension to uplifting and whole subsidence during Dongying movement of Bohai Bay Basin. Based on isostasy principle, this paper made out a correction method for the calculation of disconformity erosion amount. The possible influences of Dongying movement on the formation and accumulation of petroleum reservoir in Bohai Bay Basin were mentioned.