Geochemical Characteristics of the Pelite Component of Bottom Sediments Near the Mouths of Modern Major Rivers: How Stable Are They Upstream?

Several geochemical characteristics ((La/Yb)N, Eu/Eu*, and Th content) of gray silts of the Volga River, suspended particulate matter of the Lena River, and silt–pelite fraction of bottom sediments in the Yangtze River are analyzed. It has been established that the above parameters of the chondrite-normalized lanthanide spectra and the Th content turn out in almost all cases to be comparable with their values determined for the specially prepared (removal of nonterrigenous carriers of rare earth elements (carbonate minerals, Fe–Mn oxyhydroxides, and organic components) pelite fractions of bottom sediments deposited near the mouths of named major rivers, and are retained over thousands of kilometers upstream from their deltas/mouths. The regulation of the Volga and Yangtze flows does not have a significant impact on parameters of the suspended particulate matter and bottom sediments under consideration.