基于氢氧稀有气体同位素的咸宁地热流体特征浅析  

Study on Geothermal Fluid Characteristics in Xianning Area Based on Hydrogen,Oxygen and Rare Gas Isotopes

作　　者：江越潇 范威 王辛 牛俊强 江南 党慧慧 刘茜 易春瑶 Jiang Yuexiao;Fan Wei;Wang Xin;Niu Junqiang;Jiang Nan;Dang Huihui;Liu Xi;Yi Chunyao(Hubei Key Laboratory of Resources and Eco-environmental Geology,Wuhan,Hubei 430034;Geological Environmental Center of Hubei Province,Wuhan,Hubei 430034;Hydrogeology and Engineering Geology Institute of Hubei Geological Bureau,Jingzhou,Hubei 434020)

机构地区：[1]资源与生态环境地质湖北省重点实验室,湖北武汉430034 [2]湖北省地质环境总站,湖北武汉430034 [3]湖北省地质局水文地质工程地质大队,湖北荆州434020

出　　处：《资源环境与工程》2024年第2期175-180,203,共7页Resources Environment & Engineering

基　　金：湖北省咸宁市地热资源专项调查(面上调查)。

摘　　要：湖北省咸宁地区广泛发育地热异常,产出多个地热田。选择温泉、浪口、王家庄、五洪山和小蛇屋山等5个地热田,系统采集地热流体样品并进行H、O、稀有气体同位素测试,浅析该区地热流体的同位素特征和成因机制。结果表明,各地热流体样品中,^(3)He/^(4)He比值为0.70×10^(-7)~2.52×10^(-7),^(20)Ne/^(22)Ne比值为10.15~10.40,^(21)Ne/^(22)Ne比值为0.029 6~0.030 8,^(36)Ar/^(38)Ar比值为4.98~5.29,^(40)Ar/^(36)Ar比值为301.7~357.2,说明地热流体中的He、Ne、Ar为大气源和地壳源的混合,以大气源为主;δ^(2)H为-59.29‰~-44.47‰,δ^(18)O为-9.29‰~-7.08‰,^(3)H含量<3.2TU,指示地热流体主要来源于大气降水补给,可能包含核爆之前补给的地下水和新近补给的地下水。综合分析认为,王家庄地热田的补给区主要位于幕阜山地区,其他地热田的补给区主要位于大幕山地区;区内地热系统封闭性较低,这与区内地热田的产出受区域性断裂控制、导水构造较发育的特征相符合。Geothermal anomalies are widely developed in Xianning area of Hubei Province,and multiple geothermal fields are produced.Five geothermal fields,including Wenquan,Langkou,Wangjiazhuang,Wuhongshan and Xiaoshewushan,were selected.Geothermal fluid samples were systematically collected and H,O and rare gas isotopes were tested to analyze the isotopic characteristics and genetic mechanism of geothermal fluids in this area.The results show that in the various geothermal fluid samples,the ^(3)He/^(4)He ratio is 0.70×10^(-7) to 2.52×10^(-7),^(20)Ne/^(22)Ne ratio is 10.15 to 10.40,^(21)Ne/^(22)Ne ratio is 0.0296 to 0.0308,^(36)Ar/^(38)Ar ratio is 4.98 to 5.29,^(40)Ar/^(36)Ar ratio is 301.7 to 357.2,which indicates that He,Ne and Ar in geothermal fluid are the mixture of atmospheric source and crustal source,and the atmospheric source is the main source.Theδ^(2) H values are-59.29‰to-44.47‰,theδ^(18) O values are-9.29‰to-7.08‰,and the ^(3)H content is less than 3.2 TU,it indicates that the geothermal fluids are mainly derived from the recharge of atmospheric precipitation,it is possible to include groundwater recharged before the nuclear explosion and newly recharged groundwater.The comprehensive analysis shows that the recharge area of Wangjiazhuang geothermal field is Mufushan area,and the recharge area of other geothermal fields is Damushan area.The sealing of the geothermal system in the area is low,which is consistent with the characteristics that the output of the geothermal field in the area is controlled by regional faults.

关 键 词：地热流体 稀有气体同位素 氢氧同位素 咸宁 

分 类 号：P314.1[天文地球—固体地球物理学] P597[天文地球—地球物理学]