Chronology and provenance of aeolian sediments from Poyang Lake area in the middle reaches of the Yangtze River in China

Abstract

Aeolian deposits (including aeolian sands and loess deposits) are widely distributed in the Poyang Lake region located in the middle reaches of the Yangtze River. The chronology and provenance, and their environmental implications, of these aeolian sediments have been debated for decades. Based on the OSL chronology, sedimentology, grain size analysis, and elementary data, we conclude that: (1) The source materials for the aeolian sediments in the Poyang Lake region originated from the local flood plains of the Yangtze River and its tributary Ganjiang River, whose fine materials were transported by the strong northwestern winter monsoon wind. (2) Aeolian deposits occurred throughout Late Pleistocene. Loess has a timing interval of 160–25 ka, concentrating in 115–50 ka. Sand accumulated as early as 115 ka, actively occurred during 85–80 ka. (3) Compared with the channel of the Yangtze River of today, the channel was further to the north before 80–85 ka in the Last Interglaciation, and shifted southward afterward.