云南西北部温泉氢、氧稳定同位素研究

发布时间：2018-03-21 09:55

  本文选题：氢氧稳定同位素　切入点：地下热水　出处：《中国地质大学(北京)》2017年硕士论文　论文类型：学位论文

【摘要】：云南省西北部是地热资源比较丰富的地区,研究该地区温泉的形成具有重要的理论和实际意义。在地下热水的同位素研究方面,利用放射性同位素测定地下水年龄和判断热储温度及冷热水混合等问题前人开展了一些研究,而对于云南省西北部温泉δ2H和δ18O稳定同位素的研究较为缺乏。自2013-2015年在西藏芒康县到云南保山市陆续采集了65个水样。其中包括温泉水、盐泉水、咸温泉水及盐井水,以温泉水为主。本文依据已有δ2H和δ18O测试水样对云南西北部温泉的δ2H和δ18O时空变化及其影响因素进行分析。结果表明,水样点的δ2H,δ18O值从南向北有逐渐偏负的趋势。从全球大气降水与δ2H、δ18O关系得出,研究区水样来源于当地大气降水。所以影响大气降水中δ2H、δ18O值的因素必然也是影响地下热水中δ2H、δ18O值的因素。研究区纬度跨度不超过5°,可以看到δ2H、δ18O值呈现出越来越负的变化范围,δ2H、δ18O值分别从63号水样北纬24.65o保山龙陵(YL1)的-68‰和-9.9‰,降至1号水样北纬29.08o西藏曲孜卡(XZQZK)的-145.5‰和-16.7‰。变化幅度已经非常大。δ2H值相对于δ18O值变化更明显;从中国大气降水中δ2H、δ18O值的全国等值线图和研究区内地下热水的δ2H、δ18O值的等值线图可以看出,从我国东南方向的海岸区向西北方向的大陆内部,呈现出δ2H、δ18O值呈现越来越负的趋势;从我国国内降雨的特征来看,研究区处于我国西南地区大气降水中δ2H、δ18O值呈负值也是不容置疑;研究区地形起伏较大且无规律可言,从研究区温泉中δ2H、δ18O值与温泉采样点的高程对比图可以看出采样点高程为3443m的下给温泉δ2H和δ18O值分别为-130.3‰和-16.2‰,而样点高程为1267m的邦腊掌温泉δ2H和δ18O值分别为-68‰和-9.9‰,呈明显的负相关关系。利用高程效应计算各个温泉的补给高程,并且研究区温泉中δ2H、δ18O值与温泉采样点的补给高程仍然呈明显的负相关关系;由于研究区夏季受到西南季风的影响,使得夏季虽然高温但是降雨量很大,地下热水中的δ2H、δ18O值一般也会比冬天偏负。
[Abstract]:Northwest Yunnan Province is rich in geothermal resources. It is of great theoretical and practical significance to study the formation of hot springs in this area. Some previous studies have been carried out on the determination of groundwater age and the determination of heat storage temperature and mixing of cold and hot water with radioisotope. However, the study of 未 2H and 未 18O stable isotopes in hot springs in northwestern Yunnan Province is relatively scarce. From Mengkang County, Tibet, to Baoshan City, Yunnan Province, 65 water samples were collected from 2013-2015, including hot spring water, salt spring water, salty hot spring water and salt well water. In this paper, the temporal and spatial variations of 未 2H and 未 18O in hot springs in northwest Yunnan and their influencing factors are analyzed according to the existing 未 2H and 未 18O test water samples. The 未 _ 2H, 未 _ 18O values of water samples tend to be negative from south to north, and the relationship between global precipitation and 未 _ 2H, 未 _ (18) O is obtained. The water samples in the study area come from the local atmospheric precipitation. Therefore, the factors influencing 未 2H and 未 18O values in the precipitation must also be the factors affecting the 未 2H and 未 18O values in the geothermal water. The latitude span of the studied area is less than 5 掳, and it can be seen that 未 2H and 未 18O values are becoming more and more negative. The values of 未 _ 2H and 未 _ 18O are from -68 鈥，

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