Abstract:

The deposition of Diexi ancient barrier lake in the upper reaches of Minjiang River was redated by AMS14C dating, and the result shows it started at 405 ka BP. The grainsize proxy index can reflect the precipitation and thus the climate drywet change. In addition, the obvious comparability between the mean grainsize curve of Diexi Section lacustrine deposits and the δ18O of Greenland ice core and Nanjing Hulu Cave stalagmites shows that the grainsize proxy index could respond to the global climate change, and reflect the chilling and warming. Thus the paleoclimate evolution in the studied area could be divided into three stages: 405334 ka BP, cold and dry; 334317 ka BP, warm and humid; 317311 ka BP, warm and humid, but not as much as the previous stage. The differences between these curves could be interpreted by the variation in location, insolation and monsoon.

Key words: Minjiang River; Diexihai Basin; barrier lake; grainsize; rapid climate change