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Carbonates in loess-red clay sequences consist mainly of calcite and dolomite. The EDTA analysis of carbonates in different size fractions and magnetic susceptibility reveal that calcite is a sensitive index of summer monsoon. The chemical analysis of carbonates and calcite from an 8.1 Ma loess-red clay sequence at Chaona on the Chinese central Loess Plateau shows that the evolution of the Asian summer monsoon experienced four stages, namely 8.1―5.5 Ma, 5.5―2.8 Ma, 2.8―1.5 Ma and 1.5―0 Ma, with increasing intensification and fluctuation, suggesting a possible combining impacts of uplift of the Tibetan Plateau and global changes on the Asian summer monsoon.
The EDTA analysis of carbonates in different size fractions and magnetic susceptibility reveals that calcite is a sensitive index of summer monsoon. The chemical analysis of carbonates and calcite from an 8.1 Ma loess- red clay sequence at Chaona on the Chinese central Loess Plateau that that the evolution of the Asian summer monsoon experienced four stages, namely 8.1-5.5 Ma, 5.5-2.8 Ma, 2.8-1.5 Ma and 1.5-0 Ma, with increasing intensification and fluctuation , suggesting a possible combining impacts of uplift of the Tibetan Plateau and global changes on the Asian summer monsoon.