Abstract Stable isotopes (δ 2 H and δ 18 O) of water can help our understanding of origin, mixing and migration of groundwater. In the formation with low permeability, it provides information about migration mechanism of ion such as diffusion and/or advection. Thus it has been realized as very important information to understand the migration of water and ions in it. However, in formation with low permeability it is difficult to obtain the ground water sample as liquid and water in pores needs to be extracted to estimate it. Compressing rock is the most common and widely used method of extracting water in pores. However, changes in δ 2 H and δ 18 O may take place during compression because changes in ion concentration have been reported in previous studies. In this study, two natural rocks were compressed, and the changes in the δ 2 H and δ 18 O with compression pressure were investigated. Mechanisms for the changes in water isotopes observed during the compression were then discussed. In addition, δ 2 H and δ 18 O of water in pores were also evaluated by direct vapor equilibration and laser spectrometry (DVE-LS) and δ 2 H and δ 18 O were compared with those obtained by compression. δ 2 H was found to change during the compression and a part of this change was found to be explained by the effect of water from closed pores extracted by compression. In addition, water isotopes in both open and closed pores were estimated by combining the results of 2 kinds of compression experiments. Water isotopes evaluated by compression that not be affected by water from closed pores showed good agreements with those obtained by DVE-LS indicating compression could show the mixed information of water from open and closed pores, while DVE-LS could show the information only for open pores. Thus, the comparison of water isotopes obtained by compression and DVE-LS could provide the information about water isotopes in closed and open pores.

中文翻译：

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压缩法提取的孔隙中水的δ 2 H 和δ 18 O 评价-闭孔的影响与直接蒸汽平衡法和激光光谱法的比较-

摘要 水的稳定同位素（δ 2 H 和δ 18 O）有助于我们了解地下水的来源、混合和迁移。在低渗透性地层中，它提供了有关离子迁移机制的信息，例如扩散和/或平流。因此，了解水和离子在其中的迁移已成为非常重要的信息。然而，在渗透率低的地层中，由于需要提取孔隙中的液体和水进行估算，因此很难获得地下水样品。压缩岩石是最常见和最广泛使用的提取孔隙中水分的方法。然而，δ 2 H 和δ 18 O 的变化可能会在压缩过程中发生，因为在之前的研究中已经报道了离子浓度的变化。在这项研究中，两块天然岩石被压缩，并研究了δ 2 H和δ 18 O随压缩压力的变化。然后讨论了在压缩过程中观察到的水同位素变化的机制。此外，还通过直接蒸汽平衡和激光光谱法（DVE-LS）评估了孔隙中水的 δ 2 H 和 δ 18 O，并将 δ 2 H 和 δ 18 O 与通过压缩获得的水进行了比较。δ 2 H 被发现在压缩过程中发生了变化，并且发现这种变化的一部分是通过压缩提取的封闭孔隙中的水的影响来解释的。此外，结合2种压缩实验的结果，估算了开孔和闭孔中的水同位素。压缩评价的不受闭孔水影响的水同位素与 DVE-LS 得到的水同位素有很好的一致性，表明压缩可以显示开孔和闭孔水的混合信息，而 DVE-LS 只能显示开孔水的信息。毛孔。因此，通过压缩和 DVE-LS 获得的水同位素的比较可以提供有关闭孔和开孔中水同位素的信息。