The Sedimentary Geochemical Partitioning For Changjiang Estuary And Its Adjacent Sea Area During First-stage Storage Of San Xia Project

After the first-stage storage of San Xia Proiect, a research group conducts comprehensive survey at Changjiang Estuary and its adjacent sea area in good time. The paper studies the abundance of 31 elements (or oxides) in 29 surface sediments from Changjiang Estuary and its adjacent sea area. After analyzing variance coefficients and features of surface distribution for all elements,it finds that the abundance distribution of all major elements and rare earth elements from Changjiang Estuary and its adjacent sea area are more mean than others. there are at large six different distribution characteristics for all elements.By conducting Q-type cluster analysis for all samples and combining sedimentary environment with distribution characteristic of sediment, it then divides study area into five sedimentary geochemical subareas, subsequently gave a account of the distribution characteristic of abundance for each subarea. Laterly the research conducted correlation analysis between elemental abundance and grain size of sediment, between elemental abundance and environmental factors of bottom water, and R-type factor analysis for all elements, consequently it lists the controlling factors of elemental distribution as the sedimentation of terrigenous debris, grain size effect, flocculating in Changjiang Estuary, autogenous process, reduction and oxidation process and biogenous sedimentation et al. For each subarea, it list its controlling factors as follows. The autogenous process account for high Ba value in subarea A located at the inner of Changjiang Estuary. The distributions of many elements in subarea B are controlled...