YANGTZE DELTA, EASTERN CHINA .2. LATE QUATERNARY SUBSIDENCE AND DEFORMATION

Late Quaternary deposits, examined on high-resolution seismic profiles, provide evidence of Recent subsidence of the outer Yangtze delta in the East China Sea. Deformed late Pleistocene strata and mud diapirs, tilted bedding, and gas-deformed structures in Holocene sequences record remobilization of underconsolidated sediment within and adjacent to the Yangtze depocenter. Deformation types and their specific position relative to the depocenter record displacement of sediment as a result of Quaternary overburden and probable compaction and deep-seated tectonic motion. The configuration of depositional sequences demonstrates that subsidence in the outer Yangtze delta has continued from the late Pleistocene to the present.