Methane occurrences displaying signatures of a possible abiotic origin had previously been reported in the South‐West Carpathians (Romania). Such an accumulation, at Tisoviţa, was intercepted by a well drilled in an ophiolitic rocks massif, whereas in two other localities—situated tens of kilometres faraway—the concerned methane is released via thermal groundwater outflows that are apparently not associated with any ultramafic products. By using groundwater ionic compositions, corroborated with previously published isotopic (¹³C‐CH₄, ²H‐CH₄, ³He/⁴He) and molecular gas analyses, we assessed in more detail the conjectured abiotic provenance of methane, and quantitatively investigated the hypothesis of a progressive mixing between two, abiotic and thermogenic, methane end‐members. The corresponding geofluids behaviour was modelled by hypothesizing a “concealed” ophiolite serpentinization setting (largely similar to that at Tisoviţa), whose abiotic methane production was “diverted” towards remote discharges at ground surface, via a ~20‐km‐long flowpath supposedly generated by recently operating extensional tectonics.

中文翻译：

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土流的多公里长迁移路径：有关蛇绿石蛇纹岩化背景的线索可能是推断西南喀尔巴阡山脉（罗马尼亚）热水流出中甲烷非生物来源的原因

西南喀尔巴阡山脉（罗马尼亚）先前曾报道过甲烷事件，显示出可能是非生物起源的特征。在蒂索维萨（Tisovi accumulationa）的这种堆积被一处在石质岩质断层中的一口井拦截，而在另外两个地点（相距数十公里），相关的甲烷则通过地下水的热流出而释放，而这些地下水显然与任何超镁铁质产物都不相关。通过使用地下水离子组合物中，与先前公布的同位素（确证¹³ C-CH ₄，² H-CH ₄，³他/ ⁴他）和分子气体分析，我们更详细地评估了推测的非生物甲烷产地，并定量研究了非生物和产热甲烷终端成员之间逐渐混合的假说。通过假设“隐蔽的”蛇绿岩蛇纹岩化环境（与蒂索维萨的情况类似）来模拟相应的地流体行为，该环境的非生物甲烷产生“通过”大约20公里长的流动路径“转向”了地面的远距离排放。通过最近经营的伸展构造。