MAGNETOSTRATIGRAPHY AND ITS IMPLICATIONS OF CORE DY03 IN THE YANGTZE RIVER DELTA

A large amount of sediment has been deposited in the Yangtze River delta area since the late Cenozoic,which has important implications for long-term research of sedimentary environmental evolution and changes of the Yangtze River.With methods of paleomagnetism,magnetic susceptibility and lithological analysis,a reliable chronostratigraphic framework of core DY03 in the Yangtze River delta was established.It is found that there are several short term magnetic excursion events which have global significance recorded in the sedimentary sequences,and are useful for the further application to the magnetostratigraphic dating in this area.It is indicated by the analyzed results that hard-clay layers which developed universally in the Cenozoic strata in this area play an important role in the stratigraphic correlation,not only in the late Quaternary but also in the whole late Cenozoic.The sedimentary evolution of the Yangtze River delta,which was controlled by tectonic activities in the early period of formation,has been mainly affected by sea-level fluctuations and climate changes in the followed period.