Investigation of hydrogeochemical properties of spring water associated with travertines in Maku Area and determination of the source of water springs based on geochemistry and mineralogy of sediments and their surrounding deposits

In the aquifers of hard rock, spring water is a good indicator for evaluating the interaction of rock water and water level changes. Maku area is located in West Azarbaijan province in northwestern Iran. Supplying part of the water needed for agriculture in the region through travertine-maker springs, the role of these springs in the travertine deposition process and the effect of the chemical composition of the waters on the travertine discoloration has made the study of hydrogeochemical properties of springs in the study area important. Thus, in this research, the assessment of hydrogeochemical characteristics, chemical composition and the water origin of springs were evaluated by water sampling, sediment deposits and rock units around the springs. The results of hydrogeochemical diagrams, ionic ratios and saturation index showed that the reservoir of the aquifer is impure limestone and the water of springs is saturated to supersaturated with respect to carbonate minerals and undersaturated for sulfate minerals and chemical type mainly is Ca- HCO3. The high pressure of carbon dioxide and its removal from the water composition of the springs has caused the limestone springs of the region to have a high deposition ability and formation of Fissure-ridge and vein-type travertine with relatively high height and expansion. The results of geochemical analysis of the elements in the composition of sediments around the springs show that the correlation between CaO and Al2O3, SiO2, TiO2, Fe2O3 is negative, also the correlation between CaO and Ba and Sr is positive and also the correlation between SiO2 and Fe2O3 and Al2O3, is positive, therefore, the water source of the spring can be considered mostly thermogenic.