13C isotope depletion in ikaite crystals: evidence for methane release from the Siberian shelves ?
13C isotope depletion in ikaite crystals: evidence for methane release from the Siberian shelves ?
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伊卡石晶体中的 13C 同位素耗尽：西伯利亚陆架释放甲烷的证据？
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
M. Kriews
中科院分区：
文献类型：
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作者：
Carsten J. Schubert;Dirk Nürnberg;Norbert Scheele;F. Pauer;M. Kriews
摘要在拉普捷夫海陆缘204 m水深的Polarstern PS 2460 -4号R/V岩心中，于232- 238 cm沉积深度处发现了伊凯特晶体（CaCO 3 × 6 H2O）。 该相的δ 13 C值平均为−36.3±0.4‰ PDB（N=2），明显超出了正常海相碳酸盐岩的范围。伊卡岩沉淀过程中的CO2最有可能来自甲烷，而甲烷的13 C同位素值极低。这些沉积物中甲烷的两个可能来源是：（1）甲烷生成（在厌氧条件下有机物质的分解）;和（2）天然气水合物，这是已知的西伯利亚大陆架地区。
Abstract Ikaite crystals (CaCO3×6H2O) have been found at 232- to 238-cm sediment depth in R/V Polarstern core PS2460-4 from the Laptev Sea continental margin in a water depth of 204 m. δ13C values of this phase average −36.3±0.4‰ PDB (N=2), which is significantly outside the range of normal marine carbonates. The CO2 involved in the precipitation of the ikaite is most probably derived from methane, which has extremely depleted 13C isotope values. Two possible sources of methane in these sediments are: (1) methanogenesis (decomposition of organic matter under anaerobic conditions); and (2) gas hydrates, which are known to occur in the Siberian shelf regions.