我国北方地下水年龄测定问题讨论  

A discussion of groundwater dating in northern China

作　　者：陈茜茜[1] 陈建生[1,2] 王婷[2] 

机构地区：[1]河海大学地球科学与工程学院,江苏南京210098 [2]河海大学土木与交通学院,江苏南京210098

出　　处：《水资源保护》2014年第2期1-5,16,共6页Water Resources Protection

基　　金：国家重点基础研究发展计划(973计划)(2012CB417005);教育部高等学校博士点基金(2009009411007)

摘　　要：对我国北方地区地下水的各种现行测年方法所存在的问题进行讨论。地下水中的氚元素特征能满足测定地下水年龄的活塞模型,但由于降水初期氚的浓度不易率定,只能定性或半定量确定地下水的年龄。氟利昂是人工合成化合物,自然界中没有天然成分,是一种理想的示踪剂,但氟利昂测定地下水的年龄限制在20世纪40年代之后降水的入渗补给。14C与4He测定地下水年龄的方法由于受到断裂带中排气影响,不易校正,所以不能适用于断陷盆地或活动断层地区。针对内蒙古高原、鄂尔多斯、华北平原地下水中氚浓度值仍然较高的现象进行讨论,认为该地区地下水的补给源区应该靠近我国西部的核试验场。同位素关系表明,渗漏的纳木错湖水与东部的地下水存在相关性,西藏内流区的渗漏水自西向东补给到了内蒙古高原、鄂尔多斯与华北平原。In this paper, we discuss the groundwater dating methods in northern China. Although tritium in groundwater is an ideal tracer, it can only be used to qualitatively or semi-quantitatively determine the groundwater age in practice since it is not suitable for calibrating the concentration of tritium in the initial stage of precipitation. The synthetic compound CFCs is an ideal tracer, but it is limited to detecting the age of groundwater recharge only after the 1940s. Influenced by the fault exhaust, 14C and 4He dating methods are not suitable for areas of fault basins or active faults. We also discuss the phenomenon that the concentration of tritium in the groundwater in the Inner Mongolia Plateau, Ordos, and the North China Plain is unusually high. By analyzing the results, we conclude that the source of groundwater supplement is close to the western nuclear test site in China. The isotope relationships suggest that there is a correlation between the Namtso Lake leakage and eastern groundwater, and the leakage of the Tibet flow area supplies the Inner Mongolia Plateau, Ordos, and the North China Plain from the west to the east.

关 键 词：地下水年龄 北方干旱区 氚 氟利昂 14MC 

分 类 号：P641[天文地球—地质矿产勘探]