Palaeoclimatic and palaeoenvironmental implications of late-Pleistocene aeolian sand in the Jin-Shaan Gorges of the Yellow River valley revealed by luminescence chronology

River valleys are critical water-gas-rock interactions zone, where close interaction between fluvial and aeolian deposition are a pronounced feature in arid, semi-arid, and semi-humid environments. Pedo-sedimentological investigations were carried out in the Jin-Shaan Gorges of the Yellow River valley. Two late-Pleistocene and Holocene aeolian sand-loess profiles were identified within the cliff riverbank. The aim of this study is to reveal the palaeoclimatic conditions and driving factors for the formation of palaeo-aeolian sand in the Jin-Shaan Gorges of the Yellow River valley. Five samples were taken from the aeolian sand-loess profiles for optically stimulated luminescence (OSL) dating. The OSL ages are in stratigraphic order and range from 12.8 ± 0.7 ka to 11.8 ± 1.0 ka. By combining OSL ages with additional stratigraphic correlations, the deposition period of the palaeo-aeolian sand is dated to 12.5–11.8 ka, which would place it at the Younger Dryas (YD) time interval that punctuated the last glacial-Holocene transition period. The formation of palaeo-aeolian sand in the region was due to sufficient sediment supply from the riverbed sand of the Yellow River, strong East Asian winter monsoon, and strong wind erosion. These results give insights into the palaeoclimatic and palaeoenvironmental conditions for the formation of aeolian sand associated with the river valleys in semi-arid and sub-humid regions.