中文摘要：

研究了墨西哥湾水深约2 200 m的下陆坡Alaminos Canyon 645区块（AC 645区）冷泉碳酸盐岩中含量较高的烷基环戊烷、烷基环己烷、直链烷基苯及苯基烷烃化合物的组成和分布特征。烷基环戊烷和烷基环己烷以低碳数烃占绝对优势,主峰碳分别为C14和C15,目前发现的烷基环己烷主要来源于嗜热嗜酸的细菌或藻类直链脂肪酸经环化作用的产物。烷基苯碳数分布范围为C13—C23,以C13—C20的低碳数烷基苯为主,主峰碳为C16,具有明显偶碳优势,很可能来源于冷泉渗漏环境中的喜盐细菌。

英文摘要：

Reported in this paper are the composition and distribution of alkyl cyclopentanes,alkyl cyclohexanes,linear alkylbenzenes and phenylalkanes in the seep carbonate from AC 645（Sample AC-E） at the lower slope of Gulf of Mexico,where the water depth is 2 200 m.The distribution of alkyl cyclopentanes and alkyl cyclohexanes is similar to normal alkanes,which are dominated by low molecular weight compounds and maximized at C14,C15,respectively, suggesting that the alkyl cyclopentanes and alkyl cyclohexanes are mainly originated from bacteria and phytoplankton.The carbon number of alkylbenzenes are C13—C23,obviously dominated by even-numbered carbon and maximized at C16,which are probably originated from halophilic bacteria or bacterium or sulfate-reducing bacteria in seep site,and the three group phenylalkanes are likely originated from blue green microalgae and planktonic organisms.