Transformation of Chemical Forms and Migration Characteristics of Cadmium and Selenium During Soil Formation in Black Rock Series

[Objective] Black rock series contain high amounts of cadmium (Cd) and selenium (Se). During weathering and soil formation on the rocks, the chemical form transformation and release of Cd and Se from the rocks can have an impact on the surrounding ecological environment. [Methods] In this study, a black rock series distribution area of Hetang formation of the Lower Cambrian was selected in northwest Zhejiang. By collecting horizonal soil samples from soil profiles along different parts of the terrain (hill upslope, hill middle slope, hill downslope, inter hill valley bottom and valley terrace), the quantity and chemical form transformation patterns of Cd and Se during the process of weathering soil formation and weathering material migration of the black rock series were discussed. [Results] The results showed that total Cd and total Se in the soil decreased from parent rock to soil. The loss of Cd and Se in the weathered matter of black rock series increased with the increasing of transportation distance alo