摘要
水化学及同位素是研究地热成因机制的重要方法,本文对湖南省84个地下热水点开展水化学与氢氧稳定同位素采样与测试,并基于测试结果开展湖南省地下热水化学及同位素空间分异特征分析,以期为地下水资源勘查、开发提供参考。测试结果表明,湖南省地热水化学类型在空间上具有明显差异,省内地下热水主要属Ca·Mg型、HCO_(3)型,但幕阜山、湘西北、湘东南、宁远—江永盆地有多个地下热水点表现为Na^(+)K型,湘西北、湘东南、衡阳盆地等地有相当一部分地下热水表现为SO_(4)型。雪峰山、湘东南、衡阳盆地地下热水水化学表现为3个主因子,而湘西北和岳阳—长株潭盆地则表现为2个主因子。雪峰山、湘东南与幕阜山—长株潭区的地下热水的地下水化学成分受岩浆岩矿物控制,湘西北地区地下热水成因可能与硫酸盐矿物等有关,衡阳盆地则表现出了明显的蒸发岩特性。湖南省地热水中Na^(+)和K+多来源于硅酸盐矿物的溶解,Ca^(2+)和Mg^(2+)来源于含镁和钙的硅酸盐矿物的溶解。湖南省内地下热水的δ^(18)O和δD散点图具有明显“区内积聚”的特点,湘东南大部分地下热水点、长株潭盆地部分热水点和衡阳盆地部分地下热水δ^(18)O和δD散点沿近水平线分布,这些地下热水点发生明显“δ^(18)O飘移”,其他地下热水点δ^(18)O和δD散点沿蒸发线分布。
Hydrochemistry and isotopes are important methods to study the genetic mechanism of geothermal.Samples and tests of hydrochemistry and stable isotopes of hydrogen and oxygen were carried out at 84 underground hot water points in Hunan Province in this paper.Based on the test results,the spatial differentiation characteristics of the chemistry and isotopes of underground hot water in Hunan Province were analyzed,with a view to providing references for the exploration and development of groundwater resources.The test results show that the chemical types of geothermal water in Hunan Province are obviously different in space.The underground hot water in Hunan Province mainly belongs to Ca-Mg type and HCO_(3)type,but there are many underground hot water points in Mufushan,northwest Hunan,southeast Hunan,Ningyuan-Jiangyong Basin as Na^(+)K type,and a considerable part of underground hot water in northwest Hunan,southeast Hunan and Hengyang Basin as SO_(4) type.The hydrochemistry of underground hot water in Xuefengshan,southeast Hunan and Hengyang Basin is 3 main fac⁃tors,while that in northwest Hunan and Yueyang-Changzhutan Basin is 2 main factors.The chemical composition of groundwater in Xuefengshan,southeast Hunan and Mufushan-Changzhutan area is controlled by magmatic miner⁃als,the origin of groundwater hot water in northwest Hunan may be related to sulfate minerals,and the Hengyang Basin shows obvious evaporite characteristics.Na^(+)and K+in the geothermal water of Hunan Province mostly come from the dissolution of silicate minerals,and Ca^(2+)and Mg^(2+)come from the dissolution of silicate minerals containing magnesium and calcium.Theδ^(18)O andδD scatter maps of lower hot water in the interior of Hunan Province have obvious characteristics of"regional accumulation".Theδ^(18)O andδD scatter points of most underground hot water points in southeast Hunan Province,some hot water points in Changzhutan Basin and some hot water points in Hengyang Basin are distributed along near-horizontal lines,and these underground hot water points have obvious"δ^(18)O drift".Theδ^(18)O andδD scatter points of other underground hot water points are distributed along the evapora⁃tion line.
作者
景营利
帅焕
孙杨艳
JING Yingli;SHUAI Huan;SUN Yangyan(Survey and Monitoring Institute of Hydrogeology and Environment Geology of Hunan Province,Changsha 410129,Hunan,China)
出处
《矿产勘查》
2023年第8期1412-1420,共9页
Mineral Exploration
基金
湖南省地质院科研基金(201908)资助。
关键词
地下热水
水化学特征
氢氧同位素特征
空间分异
湖南
geothermal water
hydrochemical characteristics
hydrogen and oxygen isotope characteristics
spatial differentiation
Hunan Province
作者简介
第一作者:景营利,男,1984年生,高级工程师,主要从事地下水资源调查、勘查及评价,E-mail:309328488@qq.com。
