| 摘 要： | Rock weathering by carbonic acid is one of the important atmosphere CO2 sequestration. Actually, it depends on whether carbonic acid or other acids as weathering agents, which is important to understand the model of global carbon cycle. For example, sulfuric acid derived from oxidation of pyrite takes part in the rock weathering, which might counteract one part of CO2 drawdown by silicate weathering. In this study, chemicals and carbon isotopic composition of waters were determined in the Beipan River, Guizhou. The δ^13C values of dissolved inorganic carbon in the province, Southwest China. The values of the samples range from -13.1‰ to -2.4‰, which show a good negative correlation with the equivalent ratio of HCO3]/（Ca^2＋＋Mg^2＋]） and a good positive correlation with the equivalent ratio of SO4^2-]/（Ca^2＋＋Mg^2＋]） and SO4^2-]/HCO3^-]. The relationships suggest that sulfuric acid took part in carbonate weathering. Acid rain is thus a significant source of sulfuric acid to the karstic rivers of Guizhou Province.
|
