Stable carbon and oxygen isotopic composition of carbonate in fugitive dust in the Chinese Loess Plateau

Stable C–O isotopic composition of loess samples for TSP, PM10, PM2.5, and PM1 at five sites (Yulin, Yanchi, Huanxian, Luochuan, and Xi'an) in Chinese Loess Plateau are examined. The average δ13C and δ18O abundances were −6.00‰ and −8.30‰ in TSP, −6.05‰ and −8.22‰ in PM10, −6.07‰ and −8.33‰ in PM2.5, and −6.00‰ and −8.28‰ in PM1, respectively. Little differences were found for δ13C and δ18O abundances in four size fractions. The differences of δ13C between the averages of fugitive dust and bulk soil were smaller than 2‰ at five locations, which implied that the isotopic composition of bulk soil (surface soil) can be used as substitute of fugitive dust carbonate in dust source apportion study. The distribution of CO3–C, δ13C and δ18O in fugitive dust shows that only δ13C is a powerful tracer of source regions. A database about the δ13C distribution in soil carbonate in major source regions of Asian dust was summarized for source apportion study of atmospheric dust.