Marine stratigraphy since Late Pleistocene on Wenzhou coastal plain and its depositional environment

Coastal deposits are critical important for revealing sedimentary environmental changes and their mechanisms. The Hole QTZ1 is a borehole located in the coastal plain of the northern Oujiang estuary of the Wenzhou city. Lithostratigraphy and paleomagnetic stratigraphy of the cores suggest that the boundary of Q_h/Q_p³ is located at 34 m in depth, while the boundary of Q_p³/Q_p² at 91.5 m. The microfossil assemblages of dinoflagellates and cyclostriatum, and the grain size data of the sediments suggest that there are three marine stratigraphic units since late Pleistocene in the coastal plain of Wenzhou, with a continental deposit between the 2nd and 3rd marine layers, which recorded an evolutionary process from low energy(Q_p³) to medium low energy (Q_p³), medium high energy(Q_p³), low energy (Q_p³), high energy(Q_p³), high energy (Q_p³), medium low energy(Q_p³) and low energy (Q_h). With sea level changes, the Late Pleistocene deposits vary frequently by alternation of marine and continental transitional facies, continental facies and local neritic facies. The Holocene sediments are dominated by neritic facies, which gradually turn to coastal facies at the end of Holocene.