Recurrence of Yuan Dynasty sluice from Zhidanyuan relics and paleostream evolution

摘要

The excavation of Shanghai Zhidanyun relics makes the recurrence of a splendid Yuan Dynasty sluice. It is a good example for the study of Shanghai history in the Wu-songjiang River irrigation, the ancient shipping and the town development. Based on the data of microfossil Pediastrum, Zygnema, Concentricystes, diatom, foraminifera and ostra-cods from the sediment section of the relics, the paleostream change after the construction of the sluice was guessed. The paleostream was influenced by the sea water due to the connection with the sea in the earlier stage. The upstream of the sea water was enhanced in the middle stage that was indicated by the increase of marine diatoms and foraminifera. The decrease of marine diatoms and foraminifera in abundance reflected that the connection of the paleostream with the sea was reduced, and the sea influence was decreased gradually in the later stage.