Paleoenvironmental reconstruction is fundamental to understand the modern environmental changes and to predict future environment,which is especially critical to understand the evolution of land and sea during geological periods.However,the basic geological research on China’s muddy coastal zone is not enough to provide Paleoenvironmental reconstruction is fundamental to understand the modern environmental changes and to predict future environment, which is particularly critical to understand the evolution of land and sea during geological periods.However, the basic geological research on China’s muddy coastal zone is not enough to provide