Organic matter geochemical characteristics of bottom sediments of the northern Barents Sea as an indicator of hydrocarbon migration from deep source

Abstract

Group and molecular compositions of organic matter from bottom sediments of the northern sector of the Barents Sea were analysed. The sites where bottom sediments contain organic matter of molecular composition similar to that of oil are identified. Thermally mature hydrocarbon compounds detected in extracts from sediment samples indicates ongoing migration from deeply buried strata and fluid discharge processes on seafloor within the studied areas. Molecular compositions of extracts from bottom sediments were compared with and showed geochemical characteristics similar to some series described for the closest onshore to the study areas. That allows an assumption that the source for migrated hydrocarbons identified in studied bottom sediments can be Mid-Triassic organic-rich claystone intervals which are a part of sedimentary succession of the North Barents deep depression.

Keywords

• arctic shelf
• the barents sea
• bottom sediments
• organic matter
• fluid discharge
• hydrocarbon-biomarkers