Geochemical, isotopic characteristics and heavy metal content of Ankara Stream (Ankara) bed sediments

In this study, Geochemical and isotopic characteristics of the river bed sediments of Ankara Stream were studied and It demonstrated the heavy metal content of the sediments. Ankara Stream bed sediments are geochemically classified as lithic arenites. Average chemical index of alteration (KAİ), plagioclase index of alteration (PAİ) and index of compositional variability (BDİ) values are measured for studied samples as 57.6, 57.3 and 1.67, respectively and there is no correlation between KAİ and δ18O isotope values. Studied deposits were exposed to the simple sedimentary cycling history, which indicates that geochemical compositions of the sediments were dominated by the composition of source materials. δ18O, 143Nd/144Nd isotope and negative ƐNd(0) values of analyzed samples are similar to upper continental crust whereas 87Sr/86Sr isotope values are depleted to upper continental crust. This is because of the widespread carbonate rocks can be observed in the river basin. Heavy metal, such as Ni, As, Pb, Cu, Zn, Co, Hg, Sb, Cd and Bi, contents of river bed sediments are enrichment. It is understood that these heavy metals polluted studied sediments are industrial origin. When the data obtained reviewed likely low-to-moderate degNTE s of chemical weathering of these sediments indicate increased tectonic activity, increased erosion and semiarid to arid conditions in the studied area from a few hundred years to present. Ankara Stream bed deposits are derived from particle to intermedia – felsic sources and the sediments are chemically immature. Thus, these sediments are exposed to contamination from industrial sources day by day.