Astronomical forcing on loess deposition in the Junggar Basin since the late Pliocene
Deciphering dust outbreak frequency in inland Asia during the late Cenozoic is important for predicting the future hydroclimate in the arid parts of China. Here, we present an eolian sedimentary sequence in the southern Junggar Basin over the past 3.5 Ma, Northwestern China. Our data provide a minimum age of 3.5 Ma for the Gurbantunggut Desert of the Junggar Basin. Rb/Sr ratios exhibit prominent 405 kyr eccentricity cycles throughout our record with a weak expression 41 kyr cycles. We interpret this cyclicity as resulting from a strong impact of the global carbon cycle on western China hydroclimate. By contrast, GR data displays significant 100- and 41-kyr cycles after 2.8 Ma, suggesting important dust input variations controlled by westerlies strength. Our results demonstrate that humidity and Westerlies’ strength variations in inland Asia follow different cyclicity during the Quaternary, indicating that moisture supply by westerlies is not directly impacted by wind strength.
- 2023-02-13 first online, published, posted
Qinghai Institute of Salt Lakes, Chinese Academy of Sciences