西安凹陷热储流体环境同位素研究

为了了解西安凹陷地下热水的补给循环及其赋存环境特征，对西安凹陷地下热水D、^18O、^13C、^14C、^34S分布特征进行了测定与分析。研究表明：西安城区地下热水中环境同位素δ（^180）、δ（^13C）、δ（^34S）的分布规律与其所在的关中盆地存在相反趋势，指示西安城区地下深部存在欠压实作用，表明西安是一个年轻的快速沉积盆地或其深部存在开启性断裂。通过水化学分析表明西安地区主要水化学类型为SO4-Na型，咸阳主要为Cl—Na型，指示咸阳地区的地质环境更为封闭。根据补给高程计算，西安、咸阳城区地下热水补给来源分别为秦岭和北山末次冰期高山雪水补给。

The Environmental isotope in geothermal water in Xi'an depression

In order to understand the supply and circulation and the host environment of the geothermal water in Xi＇an depression . The research on the isotopes of D, ^18O, ^13C, ^14C ,^34S in geothermal water in Xi＇ an depression show that the char- acteristic distributing of environmental isotope like δ（^18O） , δ（^13C） , δ（^34S） in the geothermal water in Xi＇ an city have the opposite trend to the whole scale of Guanzhong basin. Iindicate that there exist Undercompaction in the deeper ground of xi＇ an city. which is a Fast young sedimentary basin or have a open fracture . hydroehemical analysis indicate that the main hydrochemical type is SO4 - Na in Xi＇ an while Cl - Na in Xianyang. It show that the geologic environment is more closed in Xian- yang. According to recharge height , geothermal water of Xi＇ an and Xianyang maybe come from the snow water of Qinling anti Beishan.