Geochemistry of Major and Trace Elements in Recent Balakian River Sediments, Northern Iraq: Evidence for Provenance and Source Rocks

Abstract

The chemical characterization study of the river sediment contributes to understanding the weathering and transportation trend and their impacts on the nature of the source rocks in the catchment region. Accordingly, sixteen samples of recent stream sediment were collected from the Balakian River, northern Iraq. The significant correlation coefficients for the major oxids (CaO, MgO, K2O, Na2O) with the majority of the trace elements indicate that the abundance of carbonate and clay minerals significantly influenced the concentrations of these elements during the weathering and transport of BR sediments. The average values of the Chemical Index of Weathering (CIW = 57.77%) and Chemical Index of Alteration (CIA = 60.70%) reflect moderately intense weathering in the basin. The Upper Continental Crust and Post-Archean Australian Shale normalized ratios, as well as a comparison between the sediment chemistry and the composition of the source rocks, would suggest that these elements were lost from source rocks during weathering, with Na2O experiencing a significant degree of loss. Moreover, the Fe2O3, MgO, and CaO normalized ratios show that these elements were derived from the closest supplied outcrops of source rocks, which are represented by the Late Campanian carbonate and clastic rocks (Tanjero and Shiranish) formations and the Pliocene (Red Bed Series) in the catchment areas. Available Upper Continental Crust and Post-Archean Australian Shale normalized ratios for trace elements showed high enrichment values of most trace elements and slightly enriched values of Sr. This means that Sr is effectively more solubilized and more mobile than other metals. Thus, this demonstrates how distinct rock sources from different geological formations contributed to an enrichment in the concentration of certain elements in the river sediments.