The Studying On Late Quaternary Seismic Stratigraphy And Neotectonic Movement Of The South Yellow Sea

The South Yellow Sea is a typical epicontinental sea, which is enclosed by Chinese Mainland and Korea Peninsula. Compared with other sea areas, the South Yellow sea is characterized by shallow water, gentle slope, abundant sediment source, complex oceanic dynamics environment and intensive tectonic movement, Which is an ideal area to study sedimentary characters, sea level fluctuation, sedimentary environment evolvement and neotectonic movement.The work of the thesis is based on the interpretation of high resolution seismic profiles , using the method of seismic stratigraphy. The Late Quaternary deposit can be divided into three sequences which named A, B and C. The sequence B and C can be divided into two sub-sequences respectively. There is an unconformity in two sequences and a regional downlap surface or an intensive reflecting surface in two sub-sequences. A sequence represent the deposit in a global sea level fluctuation cycle. Therefore, there are three transgressions and two regressions since Epileistocene in the South Yellow Sea. The sequences( sub-sequences ) which are divided by drills can be well matched with the seismic sequences( sub-sequences ). Tidal-ridges, paleo-channels, paleo-lakes, paleo-deltas, shallow gas, shallowfaults, erosive troughs, sea floor benches, relict sands and so on are identified from profiles. The space distribution shape and interdependence of the seismic facies indicate the depositional environment and dynamic factors.Some important and significative conclusions are gained from the interpretation of single-channel seismic profiles and the analysis of natural earthquakes, such as:1. The vertical up–and–down movement is intensive in Neotectonic Epoch in the South Yellow Sea. There are three bigger subsidence centers and one persistent uplift area. The stratum thickness is about 2000m in the two bigger subsidence centers. But in the east uplift area, it is only 50m. The transgression and regression are the combined responses of the global climate fluctuation and the Neotectonic movement.2. Most of the faults confining the sags are growth faults in the study area and the main strikes are NE–NEE and EW. The successive movement of the faults in Neotectonic Epoch controlled the formation and development of the structural units...