Investigating Role of Yarlung Zangbo River Valley as a Dust Source over the Tibetan Plateau, China

Aeolian sediments are widely distributed across the broad valley of the Yarlung Zangbo River on the Tibetan Plateau in China and within its valley, which is enclosed by high mountains that act as natural barriers to incoming dust transport. Whether the Tibetan Plateau is a dust sources or a transitional region for dust emission from the Taklimakan Desert to downwind regions had been disputed. Sixteen land surface aeolian sediments were collected from field in the valley of the Yarlung Zangbo River and Nd and Sr isotopic composition were analyzed in the laboratory. By comparing the Nd and Sr isotopic composition of aeolian sediment in the Yarlung Zangbo River Valley with those from adjacent glacier aeolian sediments, China’s main deserts and Loess Plateau, we found that the river’s upper reaches were the dust source for these areas. This indicates that only part of the river valley serves as a dust source, possibly due to the barrier to transport created by the mountains. Our results therefore suggest that dust from high elevations, such as the sites in our study, is easily transported over long distances. Therefore, previous study overestimated the dust sources on the Tibetan Plateau.