Major and trace element geochemistry of bulk composition of recent sediments from upper and middle Amur River (Eastern Siberia, Russia): description of sorting and transporting processes of river sediments

The Amur River is one of the largest rivers in Asia and the world. The initial data on major, trace geochemistry of the bulk composition of recent sediments from upper, and middle Amur River suggests that concentrations of most major and trace elements in the Amur sediments correspond to the upper continental crust. However, there are significant differences in the bulk composition of recent sediments in different river parts, e.g. ƩREE, (La/Yb)_n, Eu/Eu*. Besides, from “Upper Amur” down the river to “Amur–Zeya valley” the values of indices CIA, CIW, PIA, V increase, whereas STI and R values decrease. Farther down the river to “Khingan canyon” the opposing process occurs. That may be explained by the changes of river reaches, namely from mountain to valley and contrariwise. The statistical analysis results show a significant positive correlation of ƩREE with indices PIA, CIA, CIW, and a significant negative correlation with STI and R indices. Eu/Eu* values have a positive correlation with WIP. The correlations may be explained by the peculiarities of sorting and transporting river sediments, not chemical weathering.