Here we discussed the results of the first geochemical investigation of the fluids (groundwater and the associated gases) emerging in the southwest of Yazd Province. We carried out two surveys, one in July 2019 and the second in September 2019s, in the region of the Gariz aquifer (central Iran). We focused our attention to 1) the chemistry of the water (major and minor constituents coupled to the stable isotopes of oxygen and hydrogen), 2) the chemical composition of dissolved gases in water together with 3) the isotopic composition of Helium (³He/⁴He) and 4) the dissolved carbon in water (δ¹³C_TDIC). Hydrogen and oxygen isotope values of groundwater display a fairly narrow range and indicate that the waters are of meteoric origin. On the base of the major ions chemistry, the bulk of the water samples are classified as Ca-HCO₃, CaCl and NaCl types. The groundwater chemistry is mainly influenced by the interaction with CO₂-rich fluids, leakage of chlorinated saline water into the alluvial aquifer, and silicate dissolution. High dissolved carbon contents, mainly as bicarbonate ion, reflect the noticeable interaction of the groundwater with CO₂-rich fluids. CO₂ is the dominant gaseous component in most samples and its amount is always greater with respect to a water in equilibrium with the atmosphere (Air Saturated Water, ASW). Such excess of CO₂ contents (more than 730 cc/l STP) dissolved in groundwater also supports the presence of a deep source of CO₂-rich gas. The computed δ¹³C_(CO2) in equilibrium with the groundwater highlight a mixing in different proportion between an inorganic deep sourced CO₂ (¹³C-enriched) and organic CO₂ (¹³C-depleted). We also used the helium isotopes as a tools to figure out the origin of helium in the aquifer (air vs. mantle, and crust). The collected samples show a contribution of mantle-derived He in the Gariz aquifer up to (~45%) and the crust suggesting that at regional scale the tectonic discontinuities had a connection with the mantle or magmatic intrusions migrated through the crust transporting mantle volatiles to shallow crustal layers. However, we cannot infer the timing of this possible magmatism at depth in the complex tectonic evolution of the area.

在这里，我们讨论了对亚兹德省西南部出现的流体（地下水和伴生气）进行的第一次地球化学调查的结果。我们在 Gariz 含水层地区（伊朗中部）进行了两次调查，一次在 2019 年 7 月，第二次在 2019 年 9 月。我们将注意力集中在 1) 水的化学（主要和次要成分与氧和氢的稳定同位素耦合），2) 水中溶解气体的化学成分以及 3) 氦 ( ³ He ) 的同位素成分/ ⁴ He) 和 4) 水中的溶解碳 (δ ¹³ C _TDIC）。地下水的氢和氧同位素值显示出相当窄的范围，表明这些水是大气源。根据主要离子化学性质，大部分水样分为 Ca-HCO ₃、Ca Cl 和 Na Cl 类型。地下水化学主要受与富含CO _{2 的}流体的相互作用、氯化盐水渗漏到冲积含水层中以及硅酸盐溶解的影响。高溶解碳含量，主要是碳酸氢根离子，反映了地下水与富含CO _{2 的}流体之间显着的相互作用。CO ₂是大多数样品中的主要气态成分，其含量总是大于与大气平衡的水（空气饱和水，ASW）。溶解在地下水中的这种过量的 CO ₂含量（超过 730 cc/l STP）也支持了富含CO ₂的深层气体源的存在。计算出的与地下水平衡的δ ¹³ C _(CO2)突出显示了无机深源 CO ₂ ( ¹³ C 富集) 和有机 CO ₂ ( ¹³C-耗尽）。我们还使用氦同位素作为工具来确定含水层中氦的来源（空气与地幔和地壳）。收集到的样本显示，Gariz 含水层中地幔衍生的 He 的贡献高达 (~45%) 和地壳，表明在区域尺度上，构造不连续性与地幔或岩浆侵入体有联系，迁移穿过地壳，将地幔挥发物输送到浅地壳层。然而，在该地区复杂的构造演化过程中，我们无法推断这种可能发生在深处的岩浆活动的时间。