Massive gas hydrates recovered from various sediment depths at the Umitaka Spur in the Sea of Japan were studied using Raman spectroscopy to determine their burial diagenesis, particularly those initially grown at shallow sediment depths. The samples recovered from sediment depths within 20 m below the seafloor (mbsf) were enriched in H₂S. These depths were greater than the present sulfate–methane transition (SMT) zone distributed within approximately 1 mbsf of the coring area. The anaerobic oxidation of methane within the SMT is generally the only potential source of high H₂S at these depths, whereas the deepening of the SMT to approximately 20 mbsf, greater than that of the reference areas, is improbable. A potential scenario for the depth discrepancy is the sedimentation of gas hydrates that originally grew around the near-seafloor SMT. The CH₄ cage occupancy ratio in each sample becomes <1.08 at sediment depths deeper than 40 mbsf. The more homogeneous CH₄ distribution within the gas hydrate at greater depths is attributed to the longer duration of CH₄ migration through the lattice cage of the gas hydrate. The lack of H₂S in samples at greater depths could also be attributed to the more homogeneous distribution of H₂S by migration and escape from gas hydrates at H₂S-depleted environments.

中文翻译：

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地质时间尺度沉积过程中气体通过天然气水合物晶格的运移


使用拉曼光谱研究了从日本海 Umitaka Spur 不同沉积深度回收的大量天然气水合物，以确定其埋藏成岩作用，特别是那些最初生长在浅沉积物深度的天然气水合物。从海底以下 20 m 以内的沉积物深度 (mbsf) 中回收的样品富含 H ₂ S。这些深度大于目前分布在海底约 1 mbsf 内的硫酸盐-甲烷转变 (SMT) 区域。取芯区。 SMT 内甲烷的厌氧氧化通常是这些深度处高 H ₂ S 的唯一潜在来源，而 SMT 加深至大约 20 mbsf（大于参考区域）是不可能的。深度差异的一个潜在情况是最初在近海底 SMT 周围生长的天然气水合物的沉积。当沉积物深度超过 40 mbsf 时，每个样本中的 CH ₄ 笼占有率变为 <1.08。天然气水合物中更深深度处的 CH ₄ 分布更均匀，归因于 CH ₄ 通过天然气水合物晶格笼迁移的持续时间更长。较深深度的样品中缺乏 H ₂ S 也可归因于 H ₂ S 通过在 H ₂