提东大地热田是关中盆地地热资源较为丰富的地区之一，阐述其成因模式对于可持续开发利用热水资源具有一定的指导意义。应用同位素水文地球化学方法，结合区域内地质构造条件，对地热田成因机制进行了系统研究，结果表明该地热田属于中低温对流型地热系统。补给来源于西南部秦岭山区大气降水，深层热水的补给高程下限为1320 m。地下热水经深循环在较大的大地热流背景值下被围岩加热，深层热储最高温度为110℃，热水最大循环深度为3120 m，循环周期约为14461 a。区域内地质构造复杂，处于多条不同方向活动断裂的交汇地带，为热水提供了良好的运移通道。热水在上涌的过程中会混有更多的当地冷水，由于上覆较厚第四系松散堆积物盖层，区域内形成地热异常。%Dongda is located in the south of Xi’an City, Shaanxi Province. The region is of alluvial-pluvial plain and rich in geothermal resources. For the purpose of further exploration and sustainable use of geothermal resources, researchers should elaborate genetical mechanism of the geothermal field through the application of hydrogeochemical methods and analyzing regional geological conditions. The results obtained by the authors show that the geothermal field belongs to the low-medium temperature geothermal system of convective type. The regional heat flow is 74.5 mW/m2 without special additional heat source. The recharge area is located to the southwest of the geothermal field and geothermal water originates from precipitation of the Qinling Mountain with a recharge elevation of more than 1320 m. The temperature of the deepest reservoir is estimated to be 110℃, with a deep water cycling of 3120 m. The geothermal water age is about 14461 a. A number of different directions of active faults exist in the region. Under the effect of thermal convection, geothermal water flows upward along the faults and is mixed with more cold water. Because of the overlying Quaternary loose deposits, geothermal water is stored in the shallow reservoir, forming the Dongda geothermal field.
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