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dc.contributor.authorWesenlund, Fredrik
dc.contributor.authorGrundvåg, Sten-Andreas
dc.contributor.authorEngelschiøn, Victoria Sjøholt
dc.contributor.authorThießen, Olaf
dc.contributor.authorPedersen, Jon Halvard
dc.date.accessioned2021-09-23T08:07:17Z
dc.date.available2021-09-23T08:07:17Z
dc.date.issued2021-06-03
dc.description.abstractThe organic-rich shales of the Middle Triassic Botneheia Formation in Svalbard and its correlative units offshore are considered important source rock intervals for oil and gas generation in the Norwegian Barents Shelf region. Detailed investigation of these intervals is essential to better understand the intra source rock variations and thus to improve exploration models. As source rocks are rarely cored during exploration campaigns, outcrop studies of analogue source rocks onshore Svalbard are of great importance for gaining a comprehensive understanding of the Triassic petroleum system offshore. This integrated sedimentological and geochemical study of the Botneheia Formation investigates the intricate relationship between mudstone facies, total sulfur, total organic/inorganic carbon, and the absolute and relative abundance of bulk bitumen content. Both the Muen Member (Anisian) and the overlying Blanknuten Member (mostly Ladinian) of the Botneheia Formation were densely sampled and analyzed from three outcrop localities on Edgeøya, eastern Svalbard. The results show that total sulfur, total organic carbon, bitumen richness, and relative and absolute aromatic hydrocarbon content increase from bioturbated, gray-colored shales in the lower to middle Muen Member upwards into non-bioturbated, phosphogenic black shales in the middle part of the Blanknuten Member. From here, organic carbon and bulk bitumen richness subsequently decrease upwards in concert with the occurrence of bioturbated, calcareous mudstones and impure limestones towards the top of the Blanknuten Member. Optical vitrinite reflectance variations do not suggest significant maturity variations with depth in the sample profiles, highlighting that the total organic carbon and bulk bitumen content are dominantly coupled with the developing source facies. These facies and chemostratigraphic trends mirror the implied marine vs. terrigenous organic matter sedimentation and benthic preservation potential, which were at a maximum in the middle Blanknuten Member. These processes appear to be closely related to the supply of nutritious upwelled waters that are further linked with an evolving pan-Arctic 2nd order Middle Triassic transgressive–regressive sequence. Facies and multivariate analyses of the geochemical data show that the lower to middle Muen Member are comparable to the pro-delta mudstones of the younger Tschermakfjellet Formation (Carnian), and that both units are clearly distinct from the increased source rock potential and richness in the upper part of the Muen Member and the entire Blanknuten Member. This provides evidence of genetically different paleo-depositional environments and source rock properties that are confined to the lower and upper parts of the Middle Triassic Botneheia Formation, and may have wide applications for Triassic source rock assessment in the offshore Norwegian Barents Seaen_US
dc.identifier.citationWesenlund F, Grundvåg S.-A., Engelschiøn VSE, Thießen O, Pedersen JH. Linking facies variations, organic carbon richness and bulk bitumen content – A case study of the organic-rich Middle Triassic shales from eastern Svalbard. Marine and Petroleum Geology. 2021;132en_US
dc.identifier.cristinIDFRIDAID 1931035
dc.identifier.doi10.1016/j.marpetgeo.2021.105168
dc.identifier.issn0264-8172
dc.identifier.issn1873-4073
dc.identifier.urihttps://hdl.handle.net/10037/22623
dc.language.isoengen_US
dc.publisherElsevieren_US
dc.relation.ispartofWesenlund, F. (2022). Lithostratigraphy and chemostratigraphy of Triassic black shales on Edgeøya, eastern Svalbard: Implications for understanding Triassic source rock formation on the Norwegian Barents Shelf. (Doctoral thesis). <a href=https://hdl.handle.net/10037/24363>https://hdl.handle.net/10037/24363</a>.
dc.relation.journalMarine and Petroleum Geology
dc.relation.projectIDNorges forskningsråd: 228107en_US
dc.relation.projectIDinfo:eu-repo/grantAgreement/RCN/PETROSENTR/228107/Norway/Research Centre for Arctic Petroleum Exploration - ARCEx/ARCEx/en_US
dc.rights.accessRightsopenAccessen_US
dc.rights.holderCopyright 2021 The Author(s)en_US
dc.subjectVDP::Mathematics and natural science: 400::Geosciences: 450en_US
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Geofag: 450en_US
dc.titleLinking facies variations, organic carbon richness and bulk bitumen content – A case study of the organic-rich Middle Triassic shales from eastern Svalbarden_US
dc.type.versionpublishedVersionen_US
dc.typeJournal articleen_US
dc.typeTidsskriftartikkelen_US
dc.typePeer revieweden_US


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