Evolution Features And Tectonic Migration Trends Of The Mesozoic And Cenozoic Basins In Eastern China

The paper bases on the application of the balanced section techniques in analyzing theBohai Bay Basin, the North Yellow Sea Basin, the South Yellow Sea Basin and the EastChina Sea Basin, analysising the single well subsidence history and other relatedinformation of the relevant period of prototype basin, comparison of different basins intectonic evolution, and the discussion in the plate dynamics background.The analysis results show that the Bohai Bay Basin stayed in the stage of the erosionbefore the late Cretaceous, and its rifting stage was from the Dongying period in thePalaeocene, to the Sha1period in the Eocene. Dongying period in the late Oligocene wasits depression period, while the subsidence stage was the Guantao period in the Miocene,when the fault activity weakened.The tendency in the Bohai Bay Basin shows that themovement of the structure is from the edge to the middle, from the continent to the sea,from the west to the east, and from the south to the north.The structure in the North Yellow Sea and South Yellow Sea Basin evolution isrelatively similar.As to the North Yellow Sea Basin, it became the rifted basin in the lateJurassic, and the depression basin in the early Cretaceous.The North Yellow Sea Basinenters into the uplift stage in the late Cretaceous, while it got into the rifting stage again inthe Eocene.From the late Oligocene to the early Miocene, the layer was squeezed andrising, followed by the depression period.As to the South Yellow Sea Basin,it experiencedthe rifting period in the late Cretaceous,the erosion period after the Eocene,the stablesedimentary period after the Miocene. The Yellow Sea Basin generally has a movementcharacteristic of the north part moving toward the northeast and the south part movingtoward the southeast.The East Sea Basin is mainly composed of the East China Sea Shelf Basin.Its WestDepression entered the rifting period in the Paleocene and got into the depression stage inthe Eocene.At the end of the Paleocene the East Sea Basin was corroded till it began tostep into the stable sediment stage.Its Easr Depression became the rifting basin in theEocene, then entered the depression stage in the Oligocene till the Pliocene it smoothlysubsided.The principle of the movement in the East Sea Basin is about from north to the south,from the west to the east.The migration characteristics of the accumulation elements of the oil and gas tend thatearly in the east and late in the west.The comparison and analysis of the above basinsshows that from the tectonic aspect, they have a common characteristic of zoning from eastto west and blocking from south to north, and the EW trending faults controlling thedepression and the NE-SW trending faults controlling the basin.Take the Yellow Sea Basinas the structure center, from the Mesozoic to the Cenozoic, the basins in their turns to rifttowards the south and north.According to the discussion of the tectonic background of the migration, the evolutiontrend and formation mechanism of the Cenozoic basins in the eastern China is affected bythe movement of the boundary between the Pacific plate and Eurasia plate, the internalEurasia plate adjustment and the deep geological dynamics change of the Pacific-Eurasiaplates.