On the Geochemistry of the Danube River Sediments (Serbian Sector)

To determine the nature and origin of the unconsolidated bottom sediments, as well as to demonstrate and quantify the presence of Presumably Contaminating Elements (PCE) in the Serbian Danube River, as a novelty, the mass fractions on nine major elements as oxides—SiO2, TiO2, Al2O3, FeO, MnO, MgO, CaO, Na2O, and K2O, as well as Sc, V, Cr, Co, Ni, Cu, Zn, As, Rb, Sr, Zr, Sb, Cs, Ba, La, Hf, Ta, W, Th, and U were determined by Instrumental Neutron Activation Analysis (INAA) in 13 sediment samples collected between Belgrade and Iron Gate 2 dam. INAA was chosen for its ability to perform elemental analysis without any preliminary sample treatment that could introduce systematic errors. The distribution of major elements was relatively uniform, with the sampling locations having less influence. Concerning the trace elements, excepting the PCE Cr, Ni, Cu, Zn, As, and Sb, their distributions presented the same remarkable similarity to the Upper Continental Crust (UCC), North American Shale Composite (NASC), Average Bottom Load (ABL), and Average Dobrogea Loess (AVL), and were in good concordance with the location of the Serbian Danube River in the Pannonian Plain. In the case of considered PCE, both Enrichment Factor and Pollution Load Index showed values higher than the pollution threshold, which pointed towards a significant anthropogenic contamination, and rising concern to what extent the water quality and biota could be affected

On the Geochemistry of Major and Trace Elements Distribution in Sediments and Soils of Zarafshon River Valley, Western Tajikistan

To assess the geochemical features of sedimentary material of Zarafshon river, (Western Tajikistan) catchment basin, the mass fractions of 38 major and trace elements were determined by Instrumental Neutron Activation Analysis (INAA) in 2 × 116 paired samples of sediments and soils collected along the Zarafshon River and its main tributaries from the sources to Tajik—Uzbek border. At each collecting location, the distance between sediments and soils’ sampling was no greater than 10 m allowing the studying of the interrelation between sediments and soils. This evidenced a significant similarity between paired soils and sediments’ samples, including the potentially contaminating elements As, Sb and Hg, whose mass fractions in some places were significantly higher than for the Upper Continental Crust (UCC) and North American Shale Composite (NASC), suggesting a common provenience. At the same time, the distribution of major, as well as of incompatible trace elements, Sc, Zr, REE, Th, and U, in spite of geological diversity of the Zarafshon river catchment basin, suggest a possible felsic origin of investigated material