The effects of colemanite deposits on the arsenic concentrations of soil and groundwater in Igdekoy-Emet, Kutahya, Turkey

The hydrochemical study of the area surrounding the Hisarcik (Emet-Kutahya) colemanite mine shows extremely high arsenic contamination in ground water between 0.07 to 7.754 mg L-1. This contamination in and around the Igdekoy village of Emet was caused by naturally occurring arsenic dissolution from a borate bearing clay zone due to the leaching of arsenic bearing minerals. The arsenic concentration in the ground water varies locally from spring to spring and is related to the mineralogical and geochemical compositions and lithofacies of the contaminant aquifer. The Neogene borate-bearing clay unit, which contains some arsenic minerals such as realgar (AsS) and orpiment (As2S3) observed in colemanite (Ca2B6O11.5H(2)O) nodules, is responsible for the arsenic contamination in ground waters in the study area. Soil geochemical analyses show unremarkable concentrations, varying from <0.01 to 7.11 mg kg(-1).