Geochemistry of Sabkhas in Abu Ghraib, Western Baghdad, Iraq

Abstract

The study aims to detail the chemistry of Sabkha located in Abu-Graib, western Baghdad to know the content of the rare elements distributed. Sabkhas are found in dry areas with significant evaporation rates. The quantity of dissolved salts rises as water evaporates from the shallow basins, eventually causing salt to crystallize. The creation of the distinctive salt pans and crusts on the top is greatly influenced by this process. The trace elements (Ti, V, Cr, Mn, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Y, Zr, Nb, Mo, Sn, Ba, Ta, Tl, Pb, Th, U, I, and Br) beside the major oxides were analyzed using XRF technique. There are no clear significant differences in the distribution of the elements between the two Sabkhas in the village of Kadim Alaa’ab and the village of Haj Shiaa. Sabkhas are characterized by limited oxygen supplies in the brine, high temperatures, and precipitation of evaporite minerals including chlorides, sulfates, and sulfides. Halite predominates in the Sabkha sediments due to the association of chloride with Na2O. The CaO is distributed forming calcite, dolomite and gypsum as well as a small amount of clay minerals. The association of trace elements, especially Ni, Rb, Ta, Tl and Br, is mainly concentrated with clay minerals, followed by their concentration in silica, especially Y, Zr and Th. As for halite, it is not associated with trace elements.