江西武功山西部高氟地热水水文地球化学特征及成因机制  

Hydrochemical characteristic and genetic mechanism of fluoride-enriched geothermal water in western area of Wugong Mountains,Jiangxi Province

作　　者：邓岳飞[1] 张寿川 刘凯 张垚垚[2] 贾伍慧 王路瑶 余廷溪 DENG Yuefei;ZHANG Shouchuan;LIU Kai;ZHANG Yaoyao;JIA Wuhui;WANG Luyao;YU Tingxi(China Institute of Geotechnical Investigation and Surveying Limited,Beijing,100007;Chinese Academy of Geological Sciences,Beijing,100037;China University of Geosciences(Beijing),Beijing,100083)

机构地区：[1]建设综合勘察研究设计院有限公司,北京100007 [2]中国地质科学院,北京100037 [3]中国地质大学(北京),北京100083

出　　处：《地质论评》2025年第2期524-536,共13页Geological Review

基　　金：中国地质调查项目(编号:DD20221677-2);中国地质科学院基本科研业务费专项(编号:JKY202406,JKYQN202307)的成果。

摘　　要：江西省武功山地区地热资源较为丰富,但西部地区地热水中氟浓度较高,制约了区域地热资源的开发和利用。本次研究在武功山西部地区共采集22组水样,基于地热水物化参数和氢氧同位素数据,识别地热水补给来源,估算补给高程、循环深度、热储温度和冷热水混合比例,揭示地热水成因机制;运用Piper三线图、Gibbs图、氯碱指数图和离子比例关系图等方法,基于氟富集的水化学条件及水文地球化学作用两方面探究高氟地热水成因机制。结果表明:研究区地表水、地下水和地热水以Ca^(2+)、Na^(+)和HCO_(3)^(-)为主,水体呈碱性,高氟水主要存在HCO_(3)^(-)-Na^(+)型地热水中,氟浓度超过国家标准3~13倍,地表水和浅层冷水样品氟浓度均未超出国家标准;地热水起源于大气降水,补给高程为1011~1422 m,循环深度为470~1893 m、热储温度为64.9~113.1℃,地热水中冷水混入比例为0.68~0.93;地热水化学组分受地质因素和水文地球化学作用影响,富氟矿物风化、溶解是高氟地热水中氟的主要来源,阳离子交换作用和碱性地热水环境影响地热水中氟富集。Objectives:The geothermal resources are abundant in the Wugong Mountain area.However,the fluorideenriched geothermal groundwater in the western region restricts the development and utilization of geothermal resources.Methods:In this paper,a total of 22 samples were collected in the western part of the Wugongshan area.Based on the physical parameters and isotopic data,the recharge source of geothermal groundwater is identified,and the recharge elevation,circulation depth,heat storage temperature and mixing ratio are estimated for revealing the genetic mechanism of geothermal water.Based on the several hydrochemical analysis method,the genetic mechanism of high fluoride geothermal groundwater is analyzed by the environment and process of hydrochemistry.Results:The results indicate that:Ca^(2+),Na^(+)and HCO_(3)^(-) are the main ions in the surface water,shallow groundwater and geothermal groundwater.The hydrochemical characteristic of high fluoride geothermal groundwater is HCO_(3)^(-)-Na^(+).The fluoride concentration in geothermal groundwater is 3~13 times greater than the upper limited value,while these in the surface water and shallow groundwater are within the permittable threshold range.Geothermal groundwater is originated from meteoric precipitation.The recharge elevation is 1011~1422 m,circulation depth is 470~1893 m,heat storage temperature is 64.9~113.1℃,the proportion of cold water mixed in geothermal water is 0.68~0.93.Conclusions:The hydrochemical characteristic of geothermal groundwater is controlled by the geological setting and hydrogeochemical process.The fluoride in geothermal groundwater is originated from the rock weathering and mineral dissolution.Cation exchange and alkaline condition are the main influence factors for fluorine enrichment.

关 键 词：氟 地热水 水文地球化学 成因机制 武功山 

分 类 号：P31[天文地球—固体地球物理学]