A study of differentiation pattern and rare earth elements migration in geochemical and hydrogeochemical environments of Airekan and Cheshmeh Shotori areas (Central Iran)

The Airekan and Cheshmeh Shotori areas are located about 60 km northeast of Khour, in Isfahan province from Central Iran. Research on characteristics and rare earth elements (REE) pattern in hydrogeochemical environments of these areas suggests the same origin for the elements dissolved in groundwater in these areas. Investigation of migration pattern of REE in hydrogeochemical environments shows that the migration and transportation of REE has occurred through chloride complexes. REEs, leached by water/rock interaction from the Airekan granite, are transported by groundwater and then precipitated in the Cheshmeh Shotori area. Study of the Cheshmeh Shotori sediments shows the presence of a sequence of red oxidized and dark layers. Geochemical characteristics of these sediments reveal that their REE characteristics are mainly inherited from the Airekan granite. Changes in the REE pattern of these sediments with depth show that changes in oxidation and reduction process have not played a significant role in controlling their behavior. It is crucial to note that adsorption of REEs dissolved in water by hydrosilicate increases these elements in depth. The REE behavior shows water/rock interaction between the granitic rocks and groundwater as the main factor of solution, migration and precipitation of REEs in the Cheshmeh Shotori area.