广西贺州热泉水文地球化学特征、热储温度与循环深度估算

Hydrogeochemistry,temperatures and circulation depth of geothermal springs from Hezhou,Guangxi

广西贺州地热资源分布于3个异常带中，热储层主要为花岗岩及石英砂岩。分析了贺州热泉的水文地球化学特征，对其热储温度及循环深度进行了估算，结果表明：热泉水为中低温偏碱性水，水化学类型为HCO3-Na和HCO3-Ca型。区内硅酸盐矿物的水解作用控制着热泉水化学组分，Na-K-Mg平衡图显示热泉的水岩相互作用仍处于初级阶段。玉髓温标估算热储温度为42．3～119．5℃，循环深度为786～3597m。较高的温度促进了氟化物的溶解，使得地热水中氟离子含量较高。

The geothermal resources in Hezhou are distributed in three anomaly belts and the geothermal reser-voirs are mainly comprised by granite and quartz sandstone.In order to understand the circulation depths and reservoir temperatures of geothermal water,hydrogeochemical investigations are conducted on geothermal springs from Hezhou.The results indicate that the geothermal water contains weakly alkaline,and mainly HCO3 -Na and HCO3 -Ca.Hydrolysis of the silicate minerals is responsible for the hydrochemistry of geothermal water in the study area.The Na -K -Mg diagram shows that geothermal springs are at the early stage of water-rock in-teractions.Quartz thermometric scale suggests that the reservoir temperatures of the geothermal springs vary be-tween 42.3 ℃ and 119.5 ℃,and the circulation depths range from 786 m to 3 597 m.The detected high con-centration of fluoride ions in geothermal waters can attribute to the high reservoir temperatures of the geothermal springs.