Organic Geochemical Characterization of Lower Cretaceous Sediments from the Sw Barents Sea

Abstract

Summary The Norwegian Barents Sea is a prolific hydrocarbon province on the Norwegian Continental Shelf (NCS) and is a key region for reconstructing the Early Cretaceous geological history of the Barents Sea region. This study presents a brief overview of the generative potential (TOC & Rock-Eval), thermal maturity and geochemical signature (Isotopes (SARA fractions), Gas-Chromatography/mass spectrometry) of Lower Cretaceous source rocks. The samples from the SW Barents Sea show variation in thermal maturity ranging from immature to mid-mature. The data set exhibits high variability in primary organic matter precursors and hydrocarbon generation potential, which implies heterogeneous organic facies. All samples suggest a mixture of terrestrial and marine organic matter deposited under varying redox depositional environments. Likewise, secondary processes such as thermal maturity and contamination may hamper interpretation of the original organic matter precursors. It can be concluded that the source rock potential of the analyzed Lower Cretaceous samples is of minor importance. Our interpretation, in general, agrees with that of Bjorøy & Hall (1983) who reached a similar conclusion concerning North Sea Cretaceous rocks and in the Lower Cretaceous Kolje and Rurikfjellet formations ( Abay et al, 2018 ).