Argon-39, argon-37 and krypton-85 isotopes in Stripa groundwaters
Argon-39, argon-37 and krypton-85 isotopes in Stripa groundwaters
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Stripa 地下水中的氩 39、氩 37 和氪 85 同位素
DOI：
10.1016/0016-7037(89)90303-7
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发表时间：
1989
影响因子：
5
通讯作者：
W. Balderer
中科院分区：
文献类型：
--
作者：
H. Loosli;B. Lehmann;W. Balderer
本文将Stripa花岗岩三个钻孔的地下水样品中的~（39）Ar、~（37）Ar和~（85）Kr活度与~（222）Rn活度和瑞士花岗岩地下水的数据进行了比较，计算了花岗岩块体和裂隙充填矿物的原位产率，地下水中所测的同位素是由岩石基质中的核反应产生的。早先有报道说，由于铀的不寻常的微观分布，它似乎与水相紧密接触，因此大部分原位产生的222 Rn可以逃逸到水相中。对于逃逸因子在5%和25%之间的85 Kr也可以得出同样的结论。Stripa地下水中的39 Ar值是迄今为止测得的最高值，但与U和Th含量较低的花岗岩相比，Stripa地下水中异常高的中子通量是一致的。但由于这是第一次在地下水中发现这种同位素，因此与不同岩层进行比较的基础还太小。这似乎可能是方解石裂缝填充物在Stripa有一个主要的影响，在地下水中的浓度37 Ar。
39Ar,37Ar and85Kr activities in groundwater samples from three boreholes in the Stripa granite are compared with222Rn activities and with data from a granitic groundwater in Switzerland.In situproduction rates in bulk granite and in fracture filling minerals are calculated.The measured isotopes in groundwater have been produced by nuclear reactions in the rock matrix. It was reported earlier that a large fraction of thein situproduced222Rn can escape to the water phase due to the unusual microscopic distribution of U which seems to be in close contact with the water phase. The same conclusion can be drawn for85Kr with escape factors between 5% and 25%.The39Ar values in Stripa groundwaters are the highest measured so far but consistent with the unusually high neutron-flux in Stripa as compared to granites with lower U- and Th-contents.The37Ar concentrations appear to be quite high, but since it is the first time that this isotope has been identified in groundwater the basis for a comparison with different rock formations is still too small. It seems possible that calcite fracture fillings in Stripa have a major influence on the concentration of37Ar in groundwater.