Abstract:

The cadmium anomalies are spreading along almost the whole Yangtze River basinThis is the major ecological environmental issue discovered by the Multipurpose Geochemical Investigation that is being carried out in ChinaBy taking the Anhui section of the Yangtze River basin as its object, a systematical study on methodology of the source tracking and quantitative estimation of the Cd anomalies has been made in the paperBy determining contents of elements in suspended matters in the Anhui section of the trunk stream and main tributaries of the Yangtze River, it is shown that the suspended matters are the main carriers of heavy metals for long distance migrations; the concentration of Cd in the suspended matters is much higher than those of other heavy metals, this may be the main reason for forming the Cd anomalies spreading along the whole Yangtze River basin; and the tributaries of the Yangtze River have significant influences on the variations of heavy metal contents in the suspended matters in its trunk streamThe quantitative computation of output flow of heavy metals for the trunk stream and main tributaries for the Anhui section of the Yangtze River shows that the largest output flow of heavy metals is from the Qiupu River, with roughly 445 t of Cd deposited in soils along either bank of the Anhui section of the Yangtze RiverResults of source tracking of Cd anomalies along the Shunan River by detailed survey of suspended matters, soil survey on a scale of 1∶50 000 and rock survey indicate that endogenetic mineral deposits, especially PbZn deposits, are the largest suppliers of Cd in the suspended mattersWith techniques of layer sampling of sediments on alluvial beds and isotopic agedetermination, we have primarily reconstructed the geochemical history of sedimentation of Cd and other heavy metals and of their pollutions, and have made the prediction and early warning of evolution of anomalies of Cd and other heavy metals

Key words:

Key words: Yangtze River basin; source tracking of Cd anomaly; quantitative estimation; suspended matter; sediments on alluvial bed