In June 2006, a 20.12 m shallow ice core was recovered from an elevation of 5,040 m in the northern branch firn basin of No. 12 Glacier, Great Snow Mountain, in the western part of Qilian Mountain, China. Isotopes (δ18O), major soluble ions, and radionuclide (β-activity) measurements from the ice core revealed a 46-year record (1960–2006). In this research, the method of sea-salt ion tracer, correlation analysis and trend analysis were used in this research to confirm the source of the chemical composition. The correlation analysis and HYSPLIT backward trajectory analysis suggests that atmospheric soluble dust species dominate the chemical signature.

The research focused on discussing the main chemical composition characteristic and the situational meaning of the ice core in the No. 12 Glacier of Qilian Mountain. From the above analysis, we draw the following conclusions. The main soluble ions in the ice core display characteristics of an obvious seasonal variation: The values in winter and spring are high; while summer values are low. The correlation analysis and backward trajectory model analysis show that the main soluble ions in the ice core originate mainly from the west wind circulation precipitation which is controlled by the west wind, and summer's plateau monsoon precipita-tion. The ion components of the No. 12 Glacier are mainly affected by the arid and semi arid sand-dust activity in Northwestern China. However, besides the input of terri-genous material, Na+, Cl− and SO42− also originates from salt particles weathering from the numerous salt lakes around the plateau glacier area.