New insights into the magnetic variations of aeolian sands in the Tarim Basin and its paleoclimatic implications

The Tarim Basin, where aeolian activity is widespread, has been regarded as a major source for global dust production. Therefore, knowledge about variation of magnetic parameters in aeolian sands from the Tarim Basin has a global significance. Systematic rock magnetic studies of aeolian sands from this region are still scarce because of the vast area and poor accessibility of the basin. In this paper, multi-parameter rock magnetic investigations of a larger number of aeolian sand samples from a wide area in the Tarim Basin have been conducted. We find that magnetic properties of aeolian sands are controlled by changes in the concentration of larger pseudo-single domain and multidomain magnetite grains, which are produced by weathering and erosional processes in the surrounding mountain regions. In addition, aeolian sands, collected from different geographic regions of the Tarim Basin, exhibit different magnetic properties, suggesting that selective wind and river transport and low-temperature oxidation might play a critical role for the magnetic properties of aeolian sands in the Tarim Basin. Our study also provides a better understanding of the complex relationships between magnetic properties and source materials for Pliocene deposits in the basin.