摘要
A group of 2,6,10,15,19-pentamethyli- cosenes (PMIΔ) containing 1―5 unsaturated double bonds has been identified in the sea floor sediments from the Gulf of Mexico at the Green Canyon 238 site.These PMIΔ compounds are distributed between nC22 and nC24 on the mass chromatogram of aliphatic fraction. Their δ 13C values are very much depleted in 13C and in the range of ?86.7‰ to ?115.5‰, whereas the δ 13C values of companion n-alkanes range from ?28.4‰ to ?34.6‰. These unsaturated PMIΔ com-pounds are typical biomarkers derived from the an-aerobic oxidation of methane mediated by meth-ane-oxidizing archaeal bacteria and indicative of the gas seeps or even the occurrence of gas hydrates in the deep sea sediments.
A group of 2,6,10,15,19-pentamethylicosenes （PMIA） containing 1--5 unsaturated double bonds has been identified in the sea floor sediments from the Gulf of Mexico at the Green Canyon 238 site. These PMIA compounds are distributed between nC22 and nC24 on the mass chromatogram of aliphatic fraction. Their δ^13C values are very much depleted in 13C and in the range of -86.7‰ to -115.5‰, whereas the 813C values of companion n-alkanes range from -28.4‰ to -34.6‰. These unsaturated PMIA compounds are typical biomarkers derived from the anaerobic oxidation of methane mediated by methane-oxidizing archaeal bacteria and indicative of the gas seeps or even the occurrence of gas hydrates in the deep sea sediments.
作者
SONG Zhiguang1,2 & WANG Cuiping1,31. State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
2. Guangzhou Research Center of Gas Hydrate, Chinese Academy of Sciences, Guangzhou 510640, China
3. Graduate School of Chinese Academy of Sciences, Beijing 100039, China
关键词
生物标志
墨西哥湾
沉积物
PMIA
天然气水化物
sediments from the Gulf of Mexico, methanogenic archaea, PMIA biomarkers, sea floor gas seepage, gas hydrates.
