title: Estimation of deepwater temperature and hydrogeochemistry of springs in the Takab geothermal field, West Azerbaijan, Iran.
abstract: Chemical analyses of water samples from 19 hot and cold springs are used to characterize Takab geothermal field, west of Iran. The springs are divided into two main groups based on temperature, host rock, total dissolved solids (TDS), and major and minor elements. TDS, electrical conductivity (EC), Cl(-), and SO4 (2-) concentrations of hot springs are all higher than in cold springs. Higher TDS in hot springs probably reflect longer circulation and residence time. The high Si, B, and Sr contents in thermal waters are probably the result of extended water-rock interaction and reflect flow paths and residence time. Binary, ternary, and Giggenbach diagrams were used to understand the deeper mixing conditions and locations of springs in the model system. It is believed that the springs are heated either by mixing of deep geothermal fluid with cold groundwater or low conductive heat flow. Mixing ratios are evaluated using Cl, Na, and B concentrations and a mass balance approach. Calculated quartz and chalcedony geothermometer give lower reservoir temperatures than cation geothermometers. The silica-enthalpy mixing model predicts a subsurface reservoir temperature between 62 and 90 °C. The δ(18)O and δD (δ(2)H) are used to trace and determine the origin and movement of water. Both hot and cold waters plot close to the local meteoric line, indicating local meteoric origin.
authors.affiliation: Department of Earth Sciences, Faculty of Sciences, Shiraz University, Shiraz, Iran. rezasharifi@shirazu.ac.ir.
authors.forename: Reza
authors.initials: R
authors.lastname: Sharifi
authors.affiliation: Department of Earth Sciences, Faculty of Sciences, Shiraz University, Shiraz, Iran. moore@susc.ac.ir.
authors.forename: Farid
authors.initials: F
authors.lastname: Moore
authors.affiliation: Department of Earth Sciences, Faculty of Sciences, Shiraz University, Shiraz, Iran. zmohammadi@shirazu.ac.ir.
authors.forename: Zargham
authors.initials: Z
authors.lastname: Mohammadi
authors.affiliation: Department of Earth Sciences, Faculty of Sciences, Shiraz University, Shiraz, Iran. bkeshavarzi@shirazu.ac.ir.
authors.forename: Behnam
authors.initials: B
authors.lastname: Keshavarzi
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D060587:Groundwater / Q000737:chemistry*; D045482:Hot Springs / Q000737:chemistry*; D006358:Hot Temperature; D062070:Hydrology; D007492:Iran; D008962:Models, Theoretical; D013696:Temperature
keywords: Geothermometry; Hydrogeochemistry; Isotope; Takab geothermal field