Stable Carbon And Oxygen Isotopic Composition Of Carbonate In Fugitive Dust In The Chinese Loess Plateau

摘要

Stable C-O isotopic composition of loess samples for TSP, PM_(10), PM_(2.5), and PM_1 at five sites (Yulin, Yanchi, Huanxian, Luochuan, and Xi'an) in Chinese Loess Plateau are examined. The average δ~(13)C and δ~(18)O abundances were -6.00‰ and -8.30‰ in TSP, -6.05‰ and -8.22‰ in PM_(10), -6.07‰ and -8.33‰ in PM_(2.5), and -6.00‰ and -8.28‰ in PM_1, respectively. Little differences were found for δ~(13)C and δ~(18)O abundances in four size fractions. The differences of δ~(13)C 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 CO_3-C, δ`(13)C and δ~(18)O in fugitive dust shows that only δ~(13)C is a powerful tracer of source regions. A database about the δ~(13)C distribution in soil carbonate in major source regions of Asian dust was summarized for source apportion study of atmospheric dust.