The environmental implications for dust in high-alpine snow and ice cores in Asian mountains

Dust in ice cores is an excellent proxy for atmospheric dust and can reveal long-term dust history, but the relative contribution from high mountains close to Asian deserts, such as the Tibetan Plateau, remains uncertain. Here we show that dust from high-alpine snow collected from Eastern Tien Shan (Tian Shan), Eastern Pamirs (Muztagata), and Qilian Shan displays a different geochemical composition (e.g. rare earth elements, REEs) to adjacent moraines and neighboring surface soils, but is similar in composition to the upwind remote arid regions. For high-alpine snow dust, the local contribution from moraines and surface soils is minor, with the major source being the Asian deserts. The results have revealed that the snow dust is representative of mid- and upper troposphere dust from Asian deserts, and demonstrates a weak event-based discrepancy but a strong concentration-independent uniformity in composition in the long-term, and confirm the regional environmental implication for the paleo-climatic records from ice cores. •We compare element composition of snow dust and cryoconite of Asian alpine glaciers to local moraine and surface soil.•Snow dust shows an event-based composition variation, but the long-term uniformity is dominant.•REE composition of snow dust differs from the local moraine and surface soil, but resembles that of cryoconite.•We prove that dust in Asia ice cores are majorly derived from upwind remote deserts, but not from local materials.