东太平洋海隆13°N附近沉积物中类脂化合物的分布特征及其对热液活动的指示

Distribution of lipid compounds in the sediments of the East Pacific Rise near 13°N and its implications for hydrothermal activity

深海热液区的热液物质喷发扩散会对周围海底的沉积物产生影响,研究沉积物中类脂物有助于进一步了解热液活动对其产生的影响。对东太平洋海隆西翼13°N附近E271和E272站位沉积物中的正构烷烃和脂肪酸进行了气相色谱-质谱(GCMS)分析。在两个站位的沉积物中检测到链长C_(11)-C_(35)的正构烷烃,其以双峰型分布为主,其中短链烷烃和长链烷烃分别指示了海洋细菌等微生物、陆源高等植物和热液物质的输入,且陆源输入主要来自大气输送的美洲物质。进一步,通过分析沉积物中正构烷烃的含量及组成,结果表明E272站位的沉积物经历了早期成岩作用。在两站位的沉积物中均检测到32种脂肪酸,其链长为C_(8)-C_(24)不等,总脂肪酸含量分别为93.55和50.71~87.05μg/g。同时,通过探讨沉积物中特征脂肪酸的组成和分布证实其受到了热液活动的影响。

The eruption and diffusion of hydrothermal materials will affect the surrounding sediments, and the study on the lipid in the sediments affected by hydrothermal activity is helpful to understand the influence of hydrothermal activity on sediments. In this research, Nalkanes and fatty acids in the sediments from E271 and E272 stations on the west flank of the East Pacific Rise near 13°N are analyzed by gas chromatography and mass spectrometry(GC-MS). C_(11)-C_(35) N-alkanes, which are mainly distributed in a bimodal pattern, are detected in the sediments, in which short-chain alkanes and long-chain alkanes indicate the inputs of marine bacteria, terrestrial higher plants and materials from hydrothermal activities, respectively. Terrestrial materials are mainly from the American continent transported by wind. Furthermore, the composition and distribution of n-alkanes in the sediments suggest that the sediments of E272 station have experienced early diagenesis. 32 types of fatty acids are detected in the sediments from the stations of E271 and E272, which ranged from C_(8)to C_(24), and the total fatty acid contents of the two stations are 93.55 and 50.71~87.05 μg/g, respectively. The composition and distribution of characteristic fatty acids in the sediments exhibit the characteristics of hydrothermal input, indicating that the sediments have been affected by hydrothermal activities.