SEDIMENTARY CHARACTERISTICS OF GY07-02 COLUMN AND ENVIRONMENTAL CHANGES OF GAOYOU LAKE

The work is based on a continuous column GY07-02 taken from the Gaoyou Lake in North Jiangsu Province. Detailed evidence of particle size, water content, organic carbon content and total carbonate content is collected, combining with ¹⁴C dating and calibration. The history of environment variations of the Gaoyou Lake since 1100a is reconstructed. During 920-980AD, the study area was a marsh;During 980-1240AD, the lake area was expanded with water level rising;and since 1240AD, the Huanghe River shifted to the south and the Yellow sea invaded the area through the Huanghe River estuary that resulted in the increase in sediments. The changes in lake environment were not only related to the natural environment changes, but also human activities, such as the shifting of Huanghe (Yellow) River channel, construction of dams around the lake, land reclamation and water eutrophication.