MINERAL CHARACTERISTICS OF DUST-STORM DUST IN SHANGHAI AREA AND THEIR PROVENAN CE SIGNIFICANCE

摘要

In this study, airborne dusts generated during a dust storm event in the Shanghai area and cities along the dust transportation pathways were used as the main objects of study. In addition, the methods of X-ray diffraction (XRD) and scanning electronic microscopy and energy dispersive spectroscopy (SEM+EDS) analysis were used to characterize the mineralogical characteristics of the dust samples to explore the provenance of the dust-storm dust in Shanghai. The results illustrate that more mineral species were observed in the airborne dust from the Shanghai area during the fall and winter seasons and the spring dust-storm period compared to the summer season and the spring non-dust-storm period. The mineral compositions of the storm dust in Shanghai were similar to the dust from caities along the dust transportation route and the loess, thereby indicating a provenance relation between the dust storm dust in Shanghai with the dust along the dust transportation route and the loess. The airborne dust mainly exhibited irregular-shaped particle polymers, regular mineral particles, and artificial aerosols, which indicate that the Shanghai area airborne dust originated from a mixed source of crustal material and artificial source pollution. These conclusions may have important significance for the provenance constraint of eolian deposit in Yangtze River delta.