Controlling factors of groundwater chemistry and statistical analysis of the samples related to ophiolite of Nourabad-Harsin, West of Iran.

Abstract

Recognizing controlling factors of groundwater chemistry in the ophiolite region of the southeastern area of Kermanshah is the aim of this study. The findings reveal that some samples' calcium, magnesium, and sodium absorption risk is higher than the standard range. Besides, statistical relationships of the data were investigated to recognize the key factors controlling water chemistry. Pearson's correlation was used to determine the elements with the same source. Saturation index (SI) and water-rock interaction helped us find the important minerals in reaction with water. Besides, the map of the spatial distribution of heavy elements was applied to prove the elements with a common source. According to these ties, the important factors controlling groundwater chemistry of the region are dissolution of gypsum as the common source of Ca, Sr, and S; dissolution and weathering of Cr-spinel mineral in peridotites as the common source of Si, Mg, and Cr; dissolution of existing Fe-Mg olivine and pyroxene in peridotite silicates as the common source of Mg and Ni, and dissolution of chalcedony, barite, and calcite as three minerals with the highest dissolution in water-rock interactionof groundwater samples.