Petroleum-related hydrocarbons in deep and subsurface sediments from South-Western Barents Sea

• Published in: Marine Environmental Research
• Language: English
• Published: Elsevier 2012
• Subjects: Biomarkers; hopanes; sediments; pockmarks; PAH; alkanes; Barents Sea; Bergen; Gramberg; Norway; Petrova
• Online Access: http://hdl.handle.net/2262/63615; https://doi.org/10.1016/j.marenvres.2011.04.003

Abstract 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. correspondence: Corresponding author: Tel.: [phone]; fax: [phone]. (Boitsov, Stepan) [e-mail] (Boitsov, Stepan) Institute of Marine Research (IMR) Bergen - NORWAY (Boitsov, Stepan) NORWAY (Boitsov, Stepan) Academician I.S. Gramberg All-Russia Research Institute for Geology and Mineral Resources of the World Ocean (VNIIO) - St. Petersburg--> - RUSSIAN FEDERATION (Petrova, Vera) Geological Survey of Norway (NGU) Trondheim--> - NORWAY (Jensen, Henning K.B.) Academician I.S. Gramberg All-Russia Research Institute for Geology and Mineral Resources of the World Ocean (VNIIO) - St. Petersburg--> - RUSSIAN FEDERATION (Kursheva, Anna) Academician I.S. Gramberg All-Russia Research Institute for Geology and Mineral Resources of the World Ocean (VNIIO) - St. Petersburg--> - RUSSIAN FEDERATION (Litvinenko, Ivan) Geological Survey of Norway (NGU) Trondheim--> - NORWAY (Chen, Yifeng) Institute of Marine Research (IMR) Bergen - NORWAY (Klungs?yr, Jarle) NORWAY RUSSIAN FEDERATION Received: 2011-02-25 Revised: 2011-04-15 Accepted: 2011-04-18