Source rock modelling of the central Arctic Ocean: First quantitative data from a real frontier area

• Main Authors: Mann, U., Knies, J., Zweigel, J., Chand, S., Jokat, Wilfried, Stein, Rüdiger
• Format: Conference Object
• Language: unknown
• Published: 2007
• Subjects: amundsen basin; Arctic; Arctic Ocean; Lomonosov Ridge; Low Rock
• Online Access: https://epic.awi.de/id/eprint/16551/; https://hdl.handle.net/10013/epic.26433

With the recently recovered organic-rich sediments of early Tertiary age from the Lomonosov Ridge by the Integrated Ocean Drilling Program (IODP) Leg 302, first direct source rock data are now attainable for the central basins of the Arctic Ocean. Results on seismic interpretations and sedimentological, micropalaeontological and organic geochemical data from Leg 302 have been published (Backman et al. 2006, Brinkhuis et al. 2006, Jokat et al. 1992, Jokat 2005, Knies et al. 2007, Moran et al. 2006, Sluijs et al. 2006, Stein et al. 2006, Stein 2007) and provided the framework for the first quantitative assessment of source rock quality and distribution of the Palaeogene sediments in the central Arctic Ocean.Three major objectives were addressed in the modelling study: (1) Application of new proxy data for input in the source rock modelling; (2) Improvement of the understanding of the major processes and the Palaeogene depositional environment, testing of different conceptual scenarios; (3) Quantitative assessment of the source rock potential in an area stretching over the Lomonosov Ridge into the adjacent Amundsen Basin.The modelling results can be summarized as follows: An approximately 80 m thick sedimentary sequence of continuous good to very good source rock quality is identified along a 75 km long transect across the Lomonosov Ridge. Even though in-situ generation of hydrocarbons is rather unlikely as overburden (~200-250 m) and thermal maturity are too low, Rock Eval data indicate an early generation or impregnation of the sediments with hydrocarbons (Stein 2007). This is supported by our modelling approach showing that the initial richness of the sediments might have been higher then measured HI values indicate. However, burial history and thermal modelling revealed that an overburden of at least 1000 m is necessary to start generation at place. Based on that, we tested if lateral equivalents of the rich Lomonosov Ridge sequence may continue into the adjacent Amundsen Basin where an overburden of ca. 1000 ...