摘要
采用GC-MS技术测定了南海东北部东沙海域沉积物柱样HD196A中的有机物,共检测出90多种烃类化合物:正构烷烃、类异戊二烯、支链烷烃、多环芳烃等化合物。正构烷烃分布曲线的形状、碳数范围、主峰位置以及CPI值和OEP值说明,沉积物中的有机质主要来源是大陆高等植物和海洋浮游生物藻类和细菌源,并以陆源高等植物来源占优势。研究还表明,随着深度增加,柱样中重烃减少,而轻烃增加,奇偶优势指数趋近于1,长链烷烃和支链烷烃减少,芳烃的甲基化和甲基重排作用等,均显示出该区沉积物成熟度较高。同时结合该区已有的研究资料(烃类气体——甲烷、重烃组分分布,以及热释光、有机碳等),其高值异常区与本次研究站位相吻合,显示该海区具有烃渗漏来源,是海底油气和天然气水合物找矿的有利地区。
Organic matters in the sediments core sample HD196A from Dongsha area, northeast of the South China See were measured with GC-MS. More than 90 hydrocarbon compounds were identified, including n-alkanes, isoprenoid, branched alkanes, polycyclic aromatic hydrocarbons （PAHs）, etc. Based on the distribution curve of n-alkanes, range of carbon chain, the position of main peaks and the value of CPI and OEP, it is beleived that organic matter in the sediments was a mixture of terrestrial plants, marine phytoplankton and algae and bacteria, and dominated by terrestrial higher plants. It is revealed that there is a tendency that heavy hydrocarbon decreased, light hydrocarbon increased, odd-even predominance （OEP） value tended to 1, long alkanes and brancked alkanes decreased, methylation and methyl reset of PAHs alone with the depth of the core. These all indicated the organisms in the sediments were matured in this area. Integrating the results of previous work, i. e. , distribution of methane, ethane and other hydrocarbon gas, thermoluminescence and organic carbon, the sampling site fit quite well with the area with high anomalies fueled by hydrocarbon seep. This indicates that the researched area is rather optimistic for oil, gas and/or gas hydrate resources.
出处
《南海地质研究》
2007年第1期1-14,共14页
Gresearch of Eological South China Sea
