Magnetic characteristics and source analysis of modern snow dust from the Tianshan Mountains

Abstract

Dust deposited in high-altitude snow is often exceptionally well-preserved, making high-altitude snow deposits an excellent medium for studying dust fluxes. We investigated the magnetic characteristics of snow dust at high altitudes in the Tianshan Mountains and then determined its potential source areas. Our results indicated the following: 1) The magnetic mineralogy of snow dust at high altitudes in the Tianshan Mountains is mainly magnetite with a minor amount of hematite. 2) There is a significant pollution contribution to the high-altitude snow in the Tianshan Mountains, as well as a natural contribution from surface sediments in the Yili Basin. 3) Composite fingerprint factor analysis showed that the relative contribution of anthropogenic pollution to snow dust in the Tianshan Mountains is about 6–42 %. Our results also indicate that the dust release capacity of sedimentary environments in the Yili Basin can be ordered as: desert > fluvial sediments > loess > alluvial fan.