Evaluation of water source origin around Kerman tunnel, Iran: water transfer tunnel path using 2H, 3H, 18O, and 34S isotopes

Abstract

Safa Dam Tunnel to Golzar makes it possible to transfer water from Dam Safa to Kerman City. The tunnel, which is approximately 40 km long, is located in the Kerman Cenozoic magmatic arc as a part of the Dehaj-Sarduiyeh belt. The aim of this study was to investigate and identify the source of water resources around the tunnel path as well as the source of water entering the northern and southern parts of the tunnel. In this study, isotopes of oxygen, hydrogen (deuterium and tritium), and sulfur have been used. The values of these isotopes are first interpreted analytically on the reference graphs displayed in the next step. As a whole, 13 samples were taken for isotopic analysis from different parts of water resources around the tunnel path. In all samples, O18\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ {}{}^{18}O $$\\end{document} and H2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ {}{}^2H $$\\end{document} were measured, and in addition, in 5 samples of S34\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ {}{}^{34}S $$\\end{document} isotope and in seven samples H3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ {}{}^3H $$\\end{document} isotope values were measured as well. According to the isotopic composition, age of the samples, and hydrogeological conditions of the region, four types of water sources have been identified, which include the following: (1) meteoric waters (water samples of Chari and Dizin Mah Rivers, Mubarak Shah salt spring, Sarzeh and Ashkan, BH5 and artesian Shirink well), (2) hydrothermal waters (sample of Shirink hot spring water), (3) ancient waters (sample of water in the northern part of the tunnel), (4) ancient waters of snowmelt origin (southern part of the tunnel and BH4). The BH9 water sample is the result of mixing ancient water with ancient water from the source of snowmelt. Sulfur originates from water samples in the northern part of the tunnel and in the southern part of Thenardite sulfate (Na2SO4) mineral. In the source of sulfur, the samples of Shirink hot spring water and BH9, in addition to the extraction of Thenardite, also have some oxidation and reduction processes. The source of water sulfur of Ashkan spring was mainly fossil fuels and air currents. The results stated that the age of water samples shows a direct relationship with their depth.