Institute of Marine Research (IMR), P.B. 1870 Nordnes, N-5817 Bergen, Norway.
Mar Environ Res. 2011 Jun;71(5):357-68. doi: 10.1016/j.marenvres.2011.04.003. Epub 2011 Apr 28.
Subsurface sediments from a pockmark area in South-Western Barents Sea have been earlier found to contain elevated levels of petroleum-related polycyclic aromatic hydrocarbons. This work describes a comprehensive analysis of various biomarkers, including the highly source-specific hopanes, in a 4.5 m long gravity core from the same area, together with subsurface sediment samples from other areas in the region without pockmarks present ("background samples"). A clear difference between the pockmark gravity core and the background sediment cores was found, both with regard to genesis and the level of transformation of organic matter. A number of indicator parameters, such as methylphenanthrene index (MPI-1), point towards a significantly higher maturity of hydrocarbons in the pockmark core throughout its length as compared to the other sampled locations. Higher contents of microbial hopanoids (hopenes) may indicate the former presence of petroleum. These findings confirm the hypothesis of a natural hydrocarbon source in the deeper strata present in the studied location with pockmarks.
先前在巴伦支海南部的一个麻坑区域的底层沉积物中发现了含有高水平石油相关多环芳烃的物质。本工作描述了对同一区域的 4.5 米长重力核心中的各种生物标志物，包括高度特定于源的藿烷，以及该区域没有麻坑的其他区域的底层沉积物样本（“背景样本”）进行的综合分析。在麻坑重力核心和背景沉积物核心之间发现了明显的差异，无论是在有机物的成因还是转化水平方面。一些指示参数，如甲基菲指数（MPI-1），表明与其他采样点相比，麻坑核心中的烃类物质在整个长度上的成熟度明显更高。微生物藿烷（藿烷）的含量较高可能表明以前存在石油。这些发现证实了在研究区域存在具有麻坑的更深地层中存在自然烃源的假设。
