Snorre Olaussen

• Jelby, Mads Engholm; Grundvåg, Sten-Andreas; Sliwinska, Kasia K.; Alsen, Peter; Vickers, Madeleine Larissa & Olaussen, Snorre [Show all 7 contributors for this article] (2024). Lower Cretaceous holostratigraphy in Svalbard: the Arctic key piece of the Boreal basin puzzle. Geological Society of London Memoirs. ISSN 0435-4052. 545. doi: 10.1144/SP545-2023-177. Show summary

  Lower Cretaceous stratigraphy of the high palaeo-latitude Arctic-Boreal Realm is generally more poorly understood than its lower-latitude Tethyan counterpart, prohibiting regional correlations and evaluation of global climate dynamics during this important high-pCO2 period. In this paper, a holostratigraphic scheme and lithostratigraphic revision are presented for the Valanginian-lower Barremian, siliciclastic ramp succession of the Rurikfjellet Formation in Svalbard, drawn from synthesis of the latest published sedimentological, biostratigraphic, petrophysical, sequence stratigraphic, chemostratigraphic and chronostratigraphic results, supplemented by new measured sections from five localities. The offshore mudstone-dominated Wimanfjellet Member (Valanginian-lower Barremian) is retained, whereas three new members are defined according to their distinct geographic, sedimentological and stratigraphic characteristics: The Adventpynten Member (upper(?) Valanginian-lowermost upper Hauterivian) constitutes a thick, relatively localized succession of mass-transport deposits. The Kikutodden Member (Hauterivian-lower Barremian) is discarded and replaced by the northern Bohemanneset Member and southern Fotografryggen Member, representing respectively: heterogeneous prodelta to delta front deposits; and sandy offshore transition to shoreface deposits. The Rurikfjellet Formation records Valanginian-earliest late Hauterivian shoreline progradation followed by late Hauterivian-early Barremian shoreline retreat and flooding across a low-gradient ramp, which never experienced full regression into continental deposits within the extent of the present-day outcrop belt

• Park, Junhee; Stein, Holly Jayne; Hannah, Judith Louise; Georgiev, Svetoslav V.; Hammer, Øyvind & Olaussen, Snorre (2023). Re-Os geochronology of the Middle to Upper Jurassic marine black shales in the Agardhfjellet Formation, Central Spitsbergen, Svalbard: A cornerstone for global faunal correlation and Os isotopic change. Palaeogeography, Palaeoclimatology, Palaeoecology. ISSN 0031-0182. 633. doi: 10.1016/j.palaeo.2023.111878.
• Smelror, Morten; Olaussen, Snorre; Dumais, Marie-Andrée; Grundvåg, Sten-Andreas & Abay, Tesfamariam Berhane (2023). Northern Svalbard Composite Tectono-Sedimentary Element. Geological Society of London Memoirs. ISSN 0435-4052. 57. doi: 10.1144/M57-2023-2. Full text in Research Archive Show summary

  The Northern Svalbard Composite Tectono-Sedimentary Element (CTSE) comprises Proterozoic, Early Paleozoic, and Devonian sedimentary rocks preserved in northern Svalbard and on the adjacent shelf margin. Here, the sedimentary strata of the CTSE are preserved between complexes of metamorphic and crystalline basement rocks. The Northern Svalbard CTSE covers four main tectonostratigraphic elements: Tonian syn-rift, Neoproterozoic to Cambrian post-rift, Ordovician passive margin, and late Silurian?/Devonian syn-extensional basins. The oldest documented sedimentary strata are greywacke and shale deposited after the Greenvillian Orogeny and assumed to be younger than 980-960 Ma. The present CTSE further includes Cambrian-Ordovician sedimentary rocks in Ny-Friesland and Nordaustlandet, while the dominant part of the CTSE are continental Old Red Sandstone sediments of the late Silurian?/Early Devonian Red Bay and Siktefjellet groups and the Early-Late Devonian Andreé Land Group onshore northern Spitsbergen. Locally, the Cambrian-Ordovician formations contain petroleum source rocks with moderate total organic carbon contents and relatively high hydrogen index values, suggesting a good potential for oil generation. There are possible reservoirs, seals, and traps in some of the basins, but the CTSE generally holds a very limited potential as a petroleum province, particularly as the region is under strict environmental protection

• Birchall, Thomas; Jochmann, Malte Michel; Betlem, Peter; Senger, Kim; Hodson, Andrew & Olaussen, Snorre (2023). Permafrost trapped natural gas in Svalbard, Norway. Frontiers in Earth Science. ISSN 2296-6463. 11, p. 1–23. doi: 10.3389/feart.2023.1277027. Full text in Research Archive Show summary

  Permafrost is widespread in the High Arctic, including the Norwegian archipelago of Svalbard. The uppermost permafrost intervals have been well studied, but the processes at its base and the impacts of the underlying geology have been largely overlooked. More than a century of coal, hydrocarbon, and scientific drilling through the permafrost in Svalbard shows that accumulations of natural gas trapped at the base of permafrost are common. These accumulations exist in several stratigraphic intervals throughout Svalbard and show both thermogenic and biogenic origins. The gas, combined with the relatively young permafrost age, is evidence of ongoing gas migration throughout Svalbard. The accumulation sizes are uncertain, but one case demonstrably produced several million cubic metres of gas over 8 years. Heavier gas encountered in two boreholes on Hopen may be situated in the gas hydrate stability zone. While permafrost is demonstrably ice-saturated and acting as seal to gas in lowland areas, in the highlands permafrost is more complex and often dry and permeable. Svalbard shares a similar geological and glacial history with much of the Circum-Arctic, suggesting that sub-permafrost gas accumulations are regionally common. With permafrost thawing in the Arctic, there is a risk that the impacts of releasing of methane trapped beneath permafrost will lead to positive climatic feedback effects.

• Olaussen, Snorre; Grundvåg, Sten-Andreas; Senger, Kim; Anell, Ingrid; Betlem, Peter & Birchall, Thomas [Show all 15 contributors for this article] (2023). Svalbard Composite Tectono-Sedimentary Element, Barents Sea” . Geological Society of London Memoirs. ISSN 0435-4052. 57. doi: 10.1144/M57-2021-36. Full text in Research Archive Show summary

  The Svalbard Composite Tectono-Sedimentary Element (SCTSE) is located on the northwestern corner of the Barents Shelf and comprises a Carboniferous–Pleistocene sedimentary succession. Due to Cenozoic uplift, the succession is subaerially exposed in the Svalbard archipelago. The oldest parts of the succession consist of Carboniferous–Permian mixed siliciclastic, carbonate and evaporite, and spiculitic sediments that developed during multiple phases of extension. The majority of the Mesozoic succession is composed of siliciclastic deposits formed in sag basins and continental platforms. Episodes of Late Jurassic and Early Cretaceous contraction are evident in the eastern part of thearchipelago and in nearby offshore areas. Differential uplift related to the opening of the Amerasian Basin and the Cretaceous emplacement of the High Arctic Large Igneous Province created a major hiatus spanning from the Late Cretaceous and early Danian throughout the SvalbardCTSE. The West Spitsbergen Fold and Thrust Belt and the associated foreland basin in central Spitsbergen (Central Tertiary Basin) formed as a response to the Eurekan Orogeny and the progressive northward opening of the North Atlantic during the Paleogene. This event was followed by the formation of yet another major hiatus spanning the Oligocene–Pliocene. Multiple reservoir and source-rock units exposed in Svalbardprovide analogues to the prolific offshore acreages in the SW Barents Sea, and are important for the de-risking of plays and prospects. However, the archipelago itself is regarded as a high-risk acreage for petroleum exploration. This is due to Paleogene contraction and late Neogene uplift of the western and central parts in particular. There is an absence of mature source rocks in the east, and the entire region is subjected to strict environmental protection

• Rodes, Nil; Betlem, Peter; Senger, Kim; Römer, Miriam; Hodson, Andrew & Liira, Martin [Show all 12 contributors for this article] (2023). Active gas seepage in western Spitsbergen fjords, Svalbard archipelago: spatial extent and geological controls. Frontiers in Earth Science. ISSN 2296-6463. 11. doi: 10.3389/feart.2023.1173477. Full text in Research Archive Show summary

  This study presents the first systematic observations of active gas seepage from the seafloor in the main fjords of western Spitsbergen in the Svalbard archipelago. High-resolution acoustic water column data were acquired throughout two research cruises in August 2015 and June 2021. 883 gas flares have been identified and characterized in Isfjorden, and 115 gas flares in Van Mijenfjorden. The hydroacoustic data indicate active fluid migration into the water column. Interpretation of 1943 km of regional offshore 2D seismic profiles supplemented the water column and existing gas geochemical data by providing geological control on the distribution of source rocks and potential migration pathways for fluids. In the study area, bedrock architecture controls the fluid migration from deep source rocks. Faults, high permeability layers, heavily fractured units and igneous intrusions channel the gas seepage into the water column. The observations of gas seepage presented in this study are an important step towards the assessment of how near-shore seepage impacts upon the carbon budget of Svalbard fjords, which constitute a globally recognized early climate change warning system for the High Arctic.

• Senger, Kim; Nuus, Matthijs Hendrik; Balling, Niels; Betlem, Peter; Birchall, Thomas & Christiansen, Hanne H [Show all 17 contributors for this article] (2023). The subsurface thermal state of Svalbard and implications for geothermal potential. Geothermics. ISSN 0375-6505. 111. doi: 10.1016/j.geothermics.2023.102702. Full text in Research Archive Show summary

  Svalbard is a High Arctic Archipelago at 74–81°N and 15–35 °E under the sovereignty of Norway. All settlements in Svalbard, including the capital of Longyearbyen (population 2400), currently have isolated energy systems with coal or diesel as the main energy source. Geothermal energy is considered as a possible alternative for electricity production, as a heat source in district heating systems or harnessed for heating and cooling using geothermal heat pump installations. In this contribution we present the until now fragmented data sets relevant to characterize and assess the geothermal potential of Svalbard. Data sets include petroleum and deep research boreholes drilled onshore Svalbard, 14 of which have recorded subsurface temperature data at depths below 200 m. Geothermal gradients on Spitsbergen vary from 24 °C/km in the west to 55 °C/km in the south-east, with an average of 33 °C/km. Four deep research boreholes were fully cored and analyzed for thermal conductivity. These analyses were complemented by thermal conductivity calculated from wireline logs in selected boreholes and four measurements on outcrop samples. 1D heat flow modelling on five boreholes calibrated with the measured thermal conductivities offers insights into heat transfer through the heterogeneous sedimentary succession. Offshore petroleum boreholes in the south-western Barents Sea and marine heat flow stations around Svalbard provide a regional framework for discussing spatial variation in heat flow onshore Svalbard, with emphasis on the effects of erosion and deposition on the thermal regime. We conclude that Svalbard's geology is well suited for geothermal exploration and potential production, though challenges related to permafrost, the presence of natural gas, heterogeneous reservoir quality and strongly lateral varying heat flow need to be adequately addressed prior to geothermal energy production. Specifically for Longyearbyen, high geothermal gradients of 40–43 °C/km in the nearest borehole (DH4) suggest promising sub-surface thermal conditions for further exploration of deep geothermal potential near the settlement.

• Lord, Gareth Steven; Mørk, Atle; Haugen, Turid; Boxaspen, Marit Ann; Husteli, Berit & Forsberg, Cathinka Schaanning [Show all 8 contributors for this article] (2022). Stratigraphy and palaeosol profiles of the Upper Triassic Isfjorden Member, Svalbard. Norwegian Journal of Geology. ISSN 2387-5844. 102. doi: 10.17850/njg102-4-02. Full text in Research Archive Show summary

  The Isfjorden Member forms the upper part of the De Geerdalen Formation in Svalbard and is well exposed throughout central and eastern Spitsbergen, including the island of Wilhelmøya. We examine palaeosol profiles identified in the Isfjorden Member and compare these to profiles seen in the remainder of the De Geerdalen Formation. In addition, we address the nuances of the Isfjorden Member, its practicality as a stratigraphic interval and attempt to constrain the unit’s presence, as well as the nature of its lower boundary throughout outcrops in Svalbard. The Isfjorden Member is easily recognised by its conspicuous beds of alternating red and green coloured palaeosols, occasional caliche profiles and bivalve coquina beds. These beds have commonly been used to identify the unit in outcrop and we explore their relevance to the formal stratigraphic definition. The lower boundary is typically difficult to identify, especially when using the original definition; however, we find that placing it at the top of the last major sandstone in the De Geerdalen Formation is a practical solution. The boundary is conformable throughout Spitsbergen with no obvious erosion or break in sedimentation observed.The abundance, thickness and maturity of palaeosols increases upwards through the De Geerdalen Formation. Mature palaeosol and occasional caliche horizons are found to dominate within the Isfjorden Member. Immature palaeosols are in general constrained to the strata below. The position of palaeosols in relation to sedimentary successions is typically restricted to floodplain and interdistributary bay deposits, or atop upper shoreface deposits. The transition from immature palaeosols with common histosols to mature palaeosols and caliche reflects the development of the delta plain from a dynamic paralic setting to a morestable proximal system.

• Abay, Tesfamariam Berhane; Karlsen, Dag Arild; Olaussen, Snorre; Pedersen, Jon Halvard & Hanken, Nils-Martin (2022). Organic geochemistry of Cambro-Ordovician succession of Ny Friesland, Svalbard, High Arctic Norway: Petroleum generation potential and bulk geochemical properties. Journal of Petroleum Science and Engineering. ISSN 0920-4105. 218. doi: 10.1016/j.petrol.2022.111033. Full text in Research Archive Show summary

  Lower Paleozoic source rock (SR) characteristics and paleo-depositional environments are not well understood in the Barents Sea region. Organic and inorganic geochemical analyses of 17 carbonaceous samples from the Lower Cambrian Tokammane Formation, the Lower to Middle Ordovician Kirtonryggen and Valhallfonna formations in Ny Friesland, north-east Spitsbergen, show that there is a striking difference in petroleum generation potential and bulk geochemical properties between the Cambrian and Ordovician samples, and also within the Ordovician samples. TOC contents of <0.20 wt% for the Lower Cambrian Tokammane Formation samples indicate poor source rock richness. TOC contents in the range between 0.3 and 2.1 wt% and HI values between 123 and 424 mg HC/g TOC for the Valhallfonna and Kirtonryggen formation samples suggest significant variation in remaining petroleum generation potential with oil-prone (Type II) to mixed oil- and gas-prone (Type II/III) kerogen. Source rock maturity parameters such as Tmax (range 435–449 °C) and production indices for most Ordovician samples suggest relatively uniform maturity levels, ranging from the early-, to the peak-, of the oil generation window (i.e. ca. 0.70–0.85% Ro). This maturity level could have significant implication on the original petroleum potential assuming early generation from carbonate source rocks. Bulk carbon isotope data show that the Lower Cambrian Tokammane Formation samples are heavier (δ13C range from −28.4 to −28.8‰) than the Lower to Middle Ordovician Valhallfonna Formation samples (δ13C range from −29.7 to −30.9‰). The differences in the source rock richness and kerogen type within the Ordovician samples are attributed to organic facies variation. Tentatively, three categories of source rock organic facies (B, BC and C) are supported based on assumed-initial hydrogen index values for the Ordovician samples. The reliability of the indicated organic facies could be supported by addition of biomarker data from bitumen extracts. To our knowledge, this is the first study revealing the existence of a potential Lower Paleozoic source rocks in this part of the High Arctic, and this facies may also exist on the continental shelf to the north and NE.

• Müller, Reidar; Klausen, T.G.; Line, L.H.; Hafeez, A.; Planke, Sverre & Eide, F. [Show all 10 contributors for this article] (2022). Tectonostratigraphic development of the Upper Triassic to Middle Jurassic in the Hoop Area, Barents Sea: Implications for understanding ultra-condensed reservoir units. Marine and Petroleum Geology. ISSN 0264-8172. 145. doi: 10.1016/j.marpetgeo.2022.105787. Full text in Research Archive Show summary

  The most prolific reservoir intervals in the Barents Sea are found in the Upper Triassic to Middle Jurassic Realgrunnen Subgroup, deposited during a major change in the structural evolution of the basin which greatly influenced its development and distribution. The effects are evident in one of the petroleum provinces in the SW Barents Sea, the Hoop Area. Due to the condensed nature of the succession, the tectonostratigraphic evolution has been enigmatic. We use a range of different methods and dataset, including high-resolution P-Cable seismic to determine the tectono-stratigraphic evolution of the succession. Results are important for exploration and production in the Hoop Area and beyond, but also for a broader understanding of how ultra-condensed successions might evolve during long periods of non-deposition and short bursts of deposition. Seven major phases of deposition and non-deposition/erosion are defined. Stage 1 represents fluvio-deltaic deposition in the Fruholmen Formation (Norian), followed by Stage 2 with significant truncation and non-deposition, lasting up to 35 million years. Deposition resumed with the shallow marine to fluvial Nordmela and Stø formations (Pliensbachian to Bajocian), which both encapsule long periods of erosion and non-deposition (stage 3–6). Stage 7 is represented by transgression and shelf deposition in the Fuglen Formation (Bathonian). The change from a high-accommodation setting with continuous and relatively high rate of accumulation in the Triassic, to a low-accommodation setting with episodic deposition and extensive sediment cannibalization in the Jurassic, resulted in cleaner sandstones with better reservoir properties. The low-accommodation setting also enabled coarse-graded detritus from hinterlands in Fennoscandia to prograde into distal part of the basin and more amalgamation of the sands during the Jurassic. Adversely, the low accommodation setting also caused a fragmented pattern of deposition and preservation that needs to be carefully considered in subsurface datasets, often with limited resolution.

• Klausen, Tore Grane; Rismyhr, Bjarte; Müller, Reidar & Olaussen, Snorre (2022). Changing provenance and stratigraphic signatures across the Triassic–Jurassic boundary in eastern Spitsbergen and the subsurface Barents Sea. Norwegian Journal of Geology. ISSN 2387-5844. 102. doi: 10.17850/njg102-2-1. Full text in Research Archive
• Olaussen, Snorre; Braathen, Alvar; Senger, Kim & Braathen, Catherine (2021). Peer-reviewd publications, graduated PhD and MSc theses that iclude material from UNIS CO2 Lab from 2008 to 2020. Norwegian Journal of Geology. ISSN 2387-5844. 99(2), p. 371–376. doi: 10.17850/njg009.
• Cedeno Motta, Andres Felipe; Ohm, Sverre Ekrene; Escalona Varela, Alejandro; Marin Restrepo, Dora Luz; Olaussen, Snorre & Demchuk, Thomas (2021). Upper Jurassic to Lower Cretaceous source rocks in the Norwegian Barents Sea, part II: Insights from open- and closed-system pyrolysis experiments. Marine and Petroleum Geology. ISSN 0264-8172. 134, p. 1–14. doi: 10.1016/j.marpetgeo.2021.105343. Full text in Research Archive
• Cedeno Motta, Andres Felipe; Ohm, Sverre Ekrene; Escalona Varela, Alejandro; Marin Restrepo, Dora Luz; Olaussen, Snorre & Demchuk, Thomas (2021). Upper Jurassic to Lower Cretaceous source rocks in the Norwegian Barents Sea, part I: Organic geochemical, petrographic, and paleogeographic investigations. Marine and Petroleum Geology. ISSN 0264-8172. 134, p. 1–18. doi: 10.1016/j.marpetgeo.2021.105342. Full text in Research Archive
• Senger, Kim; Betlem, Peter; Grundvåg, Sten-Andreas; Horota, Rafael Kenji; Buckley, Simon John & Smyrak-Sikora, Aleksandra [Show all 15 contributors for this article] (2021). Teaching with digital geology in the high Arctic: Opportunities and challenges. Geoscience Communication. ISSN 2569-7102. 4(3), p. 399–420. doi: 10.5194/gc-4-399-2021. Full text in Research Archive Show summary

  The Covid-19 pandemic occurred at a time of major revolution in the geosciences – the era of digital geology. Digital outcrop models (DOMs) acquired from consumer drones, processed using user-friendly photogrammetric software and shared with the wider audience through online platforms are a cornerstone of this digital geological revolution. Integration of DOMs with other geoscientific data, such as geological maps, satellite imagery, terrain models, geophysical data and field observations, strengthens their application in both research and education. Teaching geology with digital tools advances students' learning experience by providing access to high-quality outcrops, enhancing visualization of 3D geological structures and improving data integration. Similarly, active use of DOMs to integrate new field observations will facilitate more effective fieldwork and quantitative research. From a student's perspective, georeferenced and scaled DOMs allow for an improved appreciation of scale and of 3D architecture, which is a major threshold concept in geoscientific education. DOMs allow us to bring geoscientists to the outcrops digitally, which is particularly important in view of the Covid-19 pandemic that restricts travel and thus direct access to outcrops. At the University Centre in Svalbard (UNIS), located at 78∘ N in Longyearbyen in Arctic Norway, DOMs are actively used even in non-pandemic years, as the summer field season is short and not overlapping with the Bachelor “Arctic Geology” course package held from January to June each year. In 2017, we at UNIS developed a new course (AG222 “Integrated Geological Methods: From Outcrop To Geomodel”) to encourage the use of emerging techniques like DOMs and data integration to solve authentic geoscientific challenges. In parallel, we have established the open-access Svalbox geoscientific portal, which forms the backbone of the AG222 course activities and provides easy access to a growing number of DOMs, 360∘ imagery, subsurface data and published geoscientific data from Svalbard. Considering the rapid onset of the Covid-19 pandemic, the Svalbox portal and the pre-Covid work on digital techniques in AG222 allowed us to rapidly adapt and fulfil at least some of the students' learning objectives during the pandemic. In this contribution, we provide an overview of the course development and share experiences from running the AG222 course and the Svalbox platform, both before and during the Covid-19 pandemic

• Smyrak-Sikora, Aleksandra; Nicolaisen, Jakob; Braathen, Alvar; Johannessen, Erik P.; Olaussen, Snorre & Stemmerik, Lars (2021). Impact of growth faults on mixed siliciclastic-carbonate-evaporite deposits during rift climax and reorganisation—Billefjorden Trough, Svalbard, Norway. Basin Research. ISSN 0950-091X. 33(5), p. 2643–2674. doi: 10.1111/bre.12578. Full text in Research Archive
• Tsikalas, Filippos; Blaich, Olav Antonio; Faleide, Jan Inge & Olaussen, Snorre (2021). Stappen High–Bjørnøya Tectono-Sedimentary Element, Barents Sea. Geological Society of London Memoirs. ISSN 0435-4052. 57. doi: 10.1144/M57-2016-24.
• Matysik, Michal; Stemmerik, Lars; Olaussen, Snorre; Rameil, Niels; Gianotten, Ingrid Piene & Brunstad, Harald (2021). Cherts, spiculites, and collapse breccias – Porosity generation in upper Permian reservoir rocks, Gohta discovery, Loppa High, south-western Barents Sea. Marine and Petroleum Geology. ISSN 0264-8172. 128. doi: 10.1016/j.marpetgeo.2021.105043.
• Yang, Zhang; Ogg, James G; Minguez, Daniel; Hounslow, Mark; Olaussen, Snorre & Gradstein, Felix M. [Show all 7 contributors for this article] (2021). Magnetostratigraphy of U-Pb–dated boreholes in Svalbard, Norway, implies that magnetochron M0r (a proposed Barremian-Aptian boundary marker) begins at 121.2 ± 0.4 Ma. Geology. ISSN 0091-7613. 49(6), p. 733–737. doi: 10.1130/G48591.1.
• Large, David J.; Marshall, Chris; Jochmann, Malte Michel; Jensen, Maria; Spiro, Baruch F. & Olaussen, Snorre (2021). Time, Hydrologic Landscape, and the Long-Term Storage of Peatland Carbon in Sedimentary Basins. Journal of Geophysical Research (JGR): Earth Surface. ISSN 2169-9003. 126(3). doi: 10.1029/2020JF005762.
• Senger, Kim; Birchall, Thomas; Betlem, Peter; Ogata, Kei; Ohm, Sverre Ekrene & Olaussen, Snorre [Show all 7 contributors for this article] (2021). Resistivity of reservoir sandstones and organic rich shales on the Barents Shelf: Implications for interpreting CSEM data. Geoscience Frontiers. ISSN 1674-9871. 12(6), p. 1–17. doi: 10.1016/j.gsf.2020.08.007. Full text in Research Archive Show summary

  Marine controlled source electromagnetic (CSEM) data have been utilized in the past decade during petroleum exploration of the Barents Shelf, particularly for de-risking the highly porous sandstone reservoirs of the Upper Triassic to Middle Jurassic Realgrunnen Subgroup. In this contribution we compare the resistivity response from CSEM data to resistivity from wireline logs in both water- and hydrocarbon-bearing wells. We show that there is a very good match between these types of data, particularly when reservoirs are shallow. CSEM data, however, only provide information on the subsurface resistivity. Careful, geology-driven interpretation of CSEM data is required to maximize the impact on exploration success. This is particularly important when quantifying the relative resistivity contribution of high-saturation hydrocarbon-bearing sandstone and that of the overlying cap rock. In the presented case the cap rock comprises predominantly organic rich Upper Jurassic–Early Cretaceous shales of the Hekkingen Formation (i.e. a regional source rock). The resistivity response of the reservoir and its cap rock become merged in CSEM data due to the transverse resistance equivalence principle. As a result of this, it is imperative to understand both the relative contributions from reservoir and cap rock, and the geological significance of any lateral resistivity variation in each of the units. In this contribution, we quantify the resistivity of organic rich mudstone, i.e. source rock, and reservoir sandstones, using 131 exploration boreholes from the Barents Shelf. The highest resistivity (>10,000 ​Ωm) is evident in the hydrocarbon-bearing Realgrunnen Subgroup which is reported from 48 boreholes, 43 of which are used for this study. Pay zone resistivity is primarily controlled by reservoir quality (i.e. porosity and shale fraction) and fluid phase (i.e. gas, oil and water saturation). In the investigated wells, the shale dominated Hekkingen Formation exhibits enhanced resistivity compared to the background (i.e. the underlying and overlying stratigraphy), though rarely exceeds 20 ​Ωm. Marine mudstones typically show good correlation between measured organic richness and resistivity/sonic velocity log signatures. We conclude that the resistivity contribution to the CSEM response from hydrocarbon-bearing sandstones outweighs that of the organic rich cap rocks

• Hodson, Andrew; Nowak, Aga; Hornum, Mikkel Toft; Senger, Kim; Redeker, Kelly Robert & Christiansen, Hanne H [Show all 12 contributors for this article] (2020). Sub-permafrost methane seepage from open-system pingos in Svalbard. The Cryosphere. ISSN 1994-0416. 14(11), p. 3829–3842. doi: 10.5194/tc-14-3829-2020. Full text in Research Archive
• Haile, Beyene Girma; Line, Lina Hedvig; Klausen, Tore Grane; Olaussen, Snorre; Eide, Christian Haug & Jahren, Jens [Show all 7 contributors for this article] (2020). Quartz overgrowth textures and fluid inclusion thermometry evidence for basin-scale sedimentary recycling: An example from the Mesozoic Barents Sea Basin. Basin Research. ISSN 0950-091X. doi: 10.1111/bre.12531. Full text in Research Archive
• Birchall, Thomas; Senger, Kim; Hornum, Mikkel Toft; Olaussen, Snorre & Braathen, Alvar (2020). Underpressure in the northern Barents shelf: Causes and implications for hydrocarbon exploration . American Association of Petroleum Geologists Bulletin. ISSN 0149-1423. 104(11), p. 2267–2295. doi: 10.1306/02272019146. Full text in Research Archive
• Grundvåg, Sten-Andreas; Jelby, Mads Engholm; Olaussen, Snorre & Sliwinska, Kasia (2020). The role of shelf morphology on storm-bed variability and stratigraphic architecture, Lower Cretaceous, Svalbard. Sedimentology. ISSN 0037-0746. 68(1), p. 196–237. doi: 10.1111/sed.12791. Full text in Research Archive Show summary

  The dominance of isotropic hummocky cross‐stratification, recording deposition solely by oscillatory flows, in many ancient storm‐dominated shoreface–shelf successions is enigmatic. Based on conventional sedimentological investigations, this study shows that storm deposits in three different and stratigraphically separated siliciclastic sediment wedges within the Lower Cretaceous succession in Svalbard record various depositional processes and principally contrasting sequence stratigraphic architectures. The lower wedge is characterized by low, but comparatively steeper, depositional dips than the middle and upper wedges, and records a change from storm‐dominated offshore transition – lower shoreface to storm‐dominated prodelta – distal delta front deposits. The occurrence of anisotropic hummocky cross‐stratification sandstone beds, scour‐and‐fill features of possible hyperpycnal‐flow origin, and wave‐modified turbidites within this part of the wedge suggests that the proximity to a fluvio‐deltaic system influenced the observed storm‐bed variability. The mudstone‐dominated part of the lower wedge records offshore shelf deposition below storm‐wave base. In the middle wedge, scours, gutter casts and anisotropic hummocky cross‐stratified storm beds occur in inferred distal settings in association with bathymetric steps situated across the platform break of retrogradationally stacked parasequences. These steps gave rise to localized, steeper‐gradient depositional dips which promoted the generation of basinward‐directed flows that occasionally scoured into the underlying seafloor. Storm‐wave and tidal current interaction promoted the development and migration of large‐scale, compound bedforms and smaller‐scale hummocky bedforms preserved as anisotropic hummocky cross‐stratification. The upper wedge consists of thick, seaward‐stepping successions of isotropic hummocky cross‐stratification‐bearing sandstone beds attributed to progradation across a shallow, gently dipping ramp‐type shelf. The associated distal facies are characterized by abundant lenticular, wave ripple cross‐laminated sandstone, suggesting that the basin floor was predominantly positioned above, but near, storm‐wave base. Consequently, shelf morphology and physiography, and the nature of the feeder system (for example, proximity to deltaic systems) are inferred to exert some control on storm‐bed variability and the resulting stratigraphic architecture

• Marin Restrepo, Dora Luz; Helleren, Solveig; Escalona Varela, Alejandro; Olaussen, Snorre; Cedeno Motta, Andres Felipe & Nøhr-Hansen, Henrik [Show all 7 contributors for this article] (2020). The Middle Jurassic to lowermost Cretaceous in the SW Barents Sea: Interplay between tectonics, coarse-grained sediment supply and organic matter preservation. Basin Research. ISSN 0950-091X. doi: 10.1111/bre.12504. Full text in Research Archive
• Anell, Ingrid Margareta; Zuchuat, Valentin; Röhnert, A.D.; Smyrak-Sikora, Aleksandra; Buckley, Simon John & Lord, Gareth Steven [Show all 12 contributors for this article] (2020). Tidal amplification and along‐strike process variability in a mixed‐energy paralic system prograding onto a low accommodation shelf, Edgeøya, Svalbard. Basin Research. ISSN 0950-091X. p. 1–35. doi: 10.1111/bre.12482. Full text in Research Archive Show summary

  The study describes the depositional development and sediment partitioning in a prograding paralic Triassic succession. The deposits are associated with the advance of large prism‐scale clinoforms across a shallower platform area. Approaching the platform, the limited accommodation and associated relative higher rates of deposition generated straighter clinoforms with lower foreset angles. The vertical restriction across the platform is interpreted to have amplified the tidal signature. Sediment was redistributed from the coast into increasingly sandy delta‐front deposits, compared to offshore equivalents. The deposits comprise extensive compound dune fields of amalgamated and increasingly clean sandbodies up‐section. Rapid deposition of significant amounts of sand led to differential subsidence and growth‐faulting in the delta front, with downthrown fault blocks further amplifying the tidal energy through funnelling. A mixed‐energy environment created along‐strike variability along the delta front with sedimentation governing process‐regime. Areas of lower sedimentation were reworked by wave and storm‐action, whereas high sedimentation rates preserved fluvially dominated mouth bars. A major transgression, however, favoured tidally dominated deposits also in these areas, attributed to increasing rugosity of the coastline. Formation of an extensive subaqueous platform between the coast and delta front dampened incoming wave energy, and tidally dominated deposits dominate the near‐shore successions. Meanwhile formation of wave‐built sand‐bars atop the platform attest to continued wave influence. The strong tidal regime led to the development of a heterolithic near‐shore tidally dominated channel system, and sandier fluvial channels up‐river. The highly meandering tidal channels incising the subaqueous platform form kilometre wide successions of inclined heterolithic stratification. The fluvially dominated channels which govern deposition on the delta plain are narrower and slightly less deep, straighter, generally symmetric and filled with cleaner sands. This study provides important insight into tidal amplification and sand redistribution during shallowing on a wide shelf, along with along‐strike process‐regime variability resulting from variations in sediment influx.

• Serck, Christopher Sæbø; Braathen, Alvar; Olaussen, Snorre; Osmundsen, Per Terje; Midtkandal, Ivar & van Yperen, Anna Elisabeth [Show all 7 contributors for this article] (2020). Supradetachment to rift basin transition recorded in continental to marine deposition; Paleogene Bandar Jissah Basin, NE Oman. Basin Research. ISSN 0950-091X. doi: 10.1111/bre.12484. Full text in Research Archive
• Jelby, Mads Engholm; Śliwińska, Kasia K.; Koevoets, Maayke Jacqueline; Alsen, Peter; Vickers, Madeleine Larissa & Olaussen, Snorre [Show all 7 contributors for this article] (2020). Arctic reappraisal of global carbon-cycle dynamics across the Jurassic–Cretaceous boundary and Valanginian Weissert Event. Palaeogeography, Palaeoclimatology, Palaeoecology. ISSN 0031-0182. 555:109847, p. 1–18. doi: 10.1016/j.palaeo.2020.109847.
• Śliwińska, Kasia; Jelby, Mads; Grundvåg, Sten-Andreas; Nøhr-Hansen, H.; Alsen, P & Olaussen, Snorre (2020). Dinocyst stratigraphy of the Valanginian-Aptian Rurikfjellet and Helvetiafjellet formations on Spitsbergen, Arctic Norway. Geological Magazine. ISSN 0016-7568. 157(Special Issue 10), p. 1693–1714. doi: 10.1017/S0016756819001249. Full text in Research Archive
• Abay, Tesfamariam Berhane; Karlsen, Dag Arild; Olaussen, Snorre & Pedersen, Jon Halvard (2019). Organic geochemistry of petroleum in the Cambro-Ordovician succession of NY Friesland, Spitsbergen, Svalbard. 29th International Meeting on Organic Geochemistry. doi: 10.3997/2214-4609.201902714.
• Nakrem, Hans Arne; Sorento, Tone; Olaussen, Snorre & Stemmerik, Lars (2019). Depositional environment control on bryozoan faunas, Early Permian (Artinskian) Gipshuken Formation, Spitsbergen, Arctic Norway. Australasian Palaeontological Memoirs. ISSN 2205-8877. 52, p. 101–107. doi: 10.1111/sed.12640.
• Klausen, Tore Grane; Müller, Reidar; Poyatos More, Miquel; Olaussen, Snorre & Stueland, Eirik (2019). Tectonic, provenance and sedimentological controls on reservoir characteristics in the Upper Triassic–Middle Jurassic Realgrunnen Subgroup, SW Barents Sea. Geological Society Special Publication. ISSN 0305-8719. 495, p. 237–261. doi: 10.1144/SP495-2018-165.
• Ohm, Sverre Ekrene; Larsen, Leif; Olaussen, Snorre; Senger, Kim; Birchall, Thomas & Demchuk, Thomas [Show all 11 contributors for this article] (2019). Discovery of shale gas in organic-rich Jurassic successions, Adventdalen, Central Spitsbergen, Norway. Norwegian Journal of Geology. ISSN 2387-5844. 99(2), p. 349–376. doi: 10.17850/njg007. Full text in Research Archive
• Olaussen, Snorre; Senger, Kim; Braathen, Alvar; Grundvåg, Sten-Andreas & Mørk, Atle (2019). You learn as long as you drill; research synthesis from the Longyearbyen CO2 Laboratory, Svalbard, Norway. Norwegian Journal of Geology. ISSN 2387-5844. 99(2), p. 157–188. doi: 10.17850/njg008. Full text in Research Archive
• Jelby, Mads Engholm; Grundvåg, Sten-Andreas; Helland-Hansen, William; Olaussen, Snorre & Stemmerik, Lars (2019). Tempestite facies variability and storm‐depositional processes across a wide ramp: Towards a polygenetic model for hummocky cross‐stratification. Sedimentology. ISSN 0037-0746. 67, p. 742–781. doi: 10.1111/sed.12671. Full text in Research Archive Show summary

  The hydrodynamic mechanisms responsible for the genesis and facies variability of shallow‐marine sandstone storm deposits (tempestites) have been intensely debated, with particular focus on hummocky cross‐stratification. Despite being ubiquitously utilized as diagnostic elements of high‐energy storm events, the full formative process spectrum of tempestites and hummocky cross‐stratification is still to be determined. In this study, detailed sedimentological investigations of more than 950 discrete tempestites within the Lower Cretaceous Rurikfjellet Formation on Spitsbergen, Svalbard, shed new light on the formation and environmental significance of hummocky cross‐stratification, and provide a reference for evaluation of tempestite facies models. Three generic types of tempestites are recognized, representing deposition from: (i) relatively steady and (ii) highly unsteady storm‐wave‐generated oscillatory flows or oscillatory‐dominated combined‐flows; and (iii) various storm‐wave‐modified hyperpycnal flows (including waxing–waning flows) generated directly from plunging rivers. A low‐gradient ramp physiography enhanced both distally progressive deceleration of the hyperpycnal flows and the spatial extent and relative magnitude of wave‐added turbulence. Sandstone beds display a wide range of simple and complex configurations of hummocky cross‐stratification. Features include ripple cross‐lamination and ‘compound’ stratification, soft‐sediment deformation structures, local shifts to quasi‐planar lamination, double draping, metre‐scale channelized bed architectures, gravel‐rich intervals, ‘inverse to normal’ grading, and vertical alternation of sedimentary structures. A polygenetic model is presented to account for the various configurations of hummocky cross‐stratification that may commonly be produced during storms by wave oscillations, hyperpycnal flows and downwelling flows. Inherent storm‐wave unsteadiness probably facilitates the generation of a wide range of hummocky cross‐stratification configurations due to: (i) changes in near‐bed oscillatory shear stresses related to passing wave groups or tidal water‐level variations; (ii) multidirectional combined‐flows related to polymodal and time‐varying orientations of wave oscillations; and (iii) syndepositional liquefaction related to cyclic wave stress. Previous proximal–distal tempestite facies models may only be applicable to relatively high‐gradient shelves, and new models are necessary for low‐gradient settings.

• Grundvåg, Sten-Andreas; Jelby, Mads Engholm; Śliwińska, Kasia Kamila; Nøhr-Hansen, Henrik; Aadland, Tore & Sandvik, Sara Elvelund [Show all 9 contributors for this article] (2019). Sedimentology and palynology of the Lower Cretaceous succession of central Spitsbergen: integration of subsurface and outcrop data. Norwegian Journal of Geology. ISSN 2387-5844. 99(2), p. 253–284. doi: 10.17850/njg006. Full text in Research Archive
• Sorento, Tone; Olaussen, Snorre & Stemmerik, Lars (2019). Controls on deposition of shallow marine carbonates and evaporites – lower Permian Gipshuken Formation, central Spitsbergen, Arctic Norway. Sedimentology. ISSN 0037-0746. 67(1), p. 207–238. doi: 10.1111/sed.12640.
• Rossi, Valentina Marzia; Olaussen, Snorre; Staine, Ivan Nicola & Gennaro, Matteo (2019). Development of the Middle Triassic Kobbe Formation shelf-margin prism and transgressive-regressive cycles on the shelf (Hammerfest Basin, SW Barents Sea). Marine and Petroleum Geology. ISSN 0264-8172. 111, p. 868–885. doi: 10.1016/j.marpetgeo.2019.08.043.
• Lord, Gareth Steven; Mørk, Mai Britt Engeness; Mørk, Atle & Olaussen, Snorre (2019). Sedimentology and petrography of the Svenskøya Formation on Hopen, Svalbard: an analogue to sandstone reservoirs in the Realgrunnen Subgroup. Polar Research. ISSN 0800-0395. 38. doi: 10.33265/polar.v38.3523. Full text in Research Archive
• Senger, Kim; Brugmans, Peter; Grundvåg, Sten-Andreas; Jochmann, Malte Michel; Nøttvedt, Arvid & Olaussen, Snorre [Show all 8 contributors for this article] (2019). Petroleum, coal and research drilling onshore Svalbard: a historical perspective. Norwegian Journal of Geology. ISSN 2387-5844. 99(3). doi: 10.17850/njg99-3-1. Full text in Research Archive Show summary

  The beginning of the Norwegian oil industry is often attributed to the first exploration drilling in the North Sea in 1966, the first discovery in 1967 and the discovery of the supergiant Ekofisk field in 1969. However, petroleum exploration already started onshore Svalbard in 1960 with three mapping groups from Caltex and exploration efforts by the Dutch company Bataaffse (Shell) and the Norwegian private company Norsk Polar Navigasjon AS (NPN). NPN was the first company to spud a well at Kvadehuken near Ny-Ålesund in 1961. This drilling marked the start of an exciting period of petroleum exploration in Svalbard, with eighteen exploration wells drilled in the period from 1961 to 1994. The deepest well so far, Caltex’s Ishøgda-I near Van Mijenfjorden, reached 3304 m in 1966. NPN was involved in nine of the eighteen wells. The remaining wells were drilled by American (Caltex/Amoseas), Belgian (Fina), French (Total), Soviet/Russian (Trust Arktikugol), Swedish (Polargas Prospektering) and Norwegian companies Norsk Hydro and Store Norske Spitsbergen Kulkompani. None of the wells resulted in commercial discoveries, though several wells encountered gas in measureable quantities. Only the two wells drilled in the early 1990s were drilled on structures defined using a sparse 2D seismic grid, while the other wells were drilled based on geological mapping at the surface. Furthermore, more recent research and coal exploration boreholes have confirmed moveable hydrocarbons in close proximity to the Longyearbyen and Pyramiden settlements. In this contribution, we present a historical and brief geological overview of the petroleum exploration wells onshore Svalbard. We illustrate that the eighteen petroleum exploration wells have together penetrated over 29 km of stratigraphy, with the Late Palaeozoic–Mesozoic successions particularly well covered. Coal exploration and research boreholes primarily focus on the Mesozoic–Cenozoic successions. As such, the boreholes represent an important window to decipher the stratigraphic evolution of both Svalbard and the greater Barents Shelf.

• Müller, Reidar; Klausen, Tore Grane; Faleide, Jan Inge; Olaussen, Snorre; Eide, Christian Haug & Suslova, Anna A. (2019). Linking regional unconformities in the Barents Sea to compression-induced forebulge uplift at the Triassic-Jurassic transition. Tectonophysics. ISSN 0040-1951. 765, p. 35–51. doi: 10.1016/j.tecto.2019.04.006. Full text in Research Archive
• Hammer, Øyvind; Alsen, Peter; Grundvåg, Sten-Andreas; Jelby, Mads E.; Nøhr-Hansen, Henrik & Olaussen, Snorre [Show all 9 contributors for this article] (2019). Comment on ‘Redox conditions, productivity, and volcanic inputduring deposition of uppermost Jurassic and Lower Cretaceousorganic-rich siltstones in Spitsbergen, Norway’ by Rakocinski et al.(2018). Cretaceous research (Print). ISSN 0195-6671. 96, p. 241–243. doi: 10.1016/j.cretres.2018.09.017.
• Liira, Martin; Noormets, Riko; Seep, Holar; Kekisev, Ott; Maddison, Martin & Olaussen, Snorre (2019). Sediment geochemical study of hydrocarbon seeps in Isfjorden and Mohnbukta: a comparison between western and eastern Spitsbergen, Svalbard. Arktos. ISSN 2364-9453. 5, p. 49–62. doi: 10.1007/s41063-019-00067-7.
• Nicolaisen, Jakob; Elvebakk, Geir; Ahokas, Juha Matti; Bojesen- Koefoed, J.A.; Olaussen, Snorre & Rinna, J. [Show all 8 contributors for this article] (2019). Characterization of upper palaeozoic organic-rich units in Svalbard: implications for the petroleum systems of the Norwegian Barents shelf. Journal of Petroleum Geology. ISSN 0141-6421. 42(1), p. 59–78. doi: 10.1111/jpg.12724.
• Smelror, Morten; Larssen, Geir Birger; Olaussen, Snorre; Rømuld, Arnfinn & Williams, Robert W (2018). Late Triassic to Early Cretaceous palynostratigraphy of Kong Karls Land, Svalbard, Arctic Norway, with correlations to Franz Josef Land, Arctic Russia. Norwegian Journal of Geology. ISSN 2387-5844. 98(4). doi: 10.17850/njg004.
• Olaussen, Snorre; Larssen, Geir Birger; Helland-Hansen, William; Johannessen, Erik P.; Nøttvedt, Arvid & Riis, Fridtjof [Show all 9 contributors for this article] (2018). Mesozoic strata of Kong Karls Land, Svalbard, Norway; a link to the northern Barents Sea basins and platforms. Norwegian Journal of Geology. ISSN 2387-5844. 98(4), p. 1–69. doi: 10.17850/njg98-4-06.
• Smyrak-Sikora, Aleksandra; Johannessen, Erik P.; Olaussen, Snorre; Sandal, Geir Løken & Braathen, Alvar (2018). Sedimentary architecture during Carboniferous rift initiation – the arid Billefjorden Trough, Svalbard. Journal of the Geological Society. ISSN 0016-7649. 176(2), p. 225–252. doi: 10.1144/jgs2018-100.
• Mulrooney, Mark Joseph; Larsen, Leif; Van Stappen, Jeroen; Rismyhr, Bjarte; Senger, Kim & Braathen, Alvar [Show all 10 contributors for this article] (2018). Fluid flow properties of the Wilhelmøya Subgroup, a potential unconventional CO2 storage unit in central Spitsbergen. Norwegian Journal of Geology. ISSN 2387-5844. 99(4), p. 85–116. doi: 10.17850/njg002. Full text in Research Archive
• Rismyhr, Bjarte; Bjærke, Tor; Olaussen, Snorre; Mulrooney, Mark Joseph & Senger, Kim (2018). Facies, palynostratigraphy and sequence stratigraphy of the Wilhelmøya Subgroup (Upper Triassic–Middle Jurassic) in western central Spitsbergen, Svalbard. Norwegian Journal of Geology. ISSN 2387-5844. 99(4), p. 35–64. doi: 10.17850/njg001. Full text in Research Archive
• Van Stappen, Jeroen; Meftah, Reduane; Boone, Marijn A.; Bultreys, Tom; De Kock, Tim & Blykers, Benjamin [Show all 9 contributors for this article] (2018). In situ triaxial testing to determine fracture permeability and aperture distribution for CO2 sequestration in Svalbard, Norway. Environmental Science and Technology. ISSN 0013-936X. 52(8), p. 4546–4554. doi: 10.1021/acs.est.8b00861.
• Koevoets, Maayke Jacqueline; Hammer, Øyvind; Olaussen, Snorre; Senger, Kim & Smelror, Morten (2018). Integrating subsurface and outcrop data of the Middle Jurassic to Lower Cretaceous Agardhfjellet Formation in central Spitsbergen. Norwegian Journal of Geology. ISSN 2387-5844. 98(4). doi: 10.17850/njg98-4-01. Full text in Research Archive
• Mulrooney, Mark; Rismyhr, Bjarte; Yenwongfai, Honore Dzekamelive; Leutscher, Johan; Olaussen, Snorre & Braathen, Alvar (2018). Impacts of small-scale faults on continental to coastal plain deposition: Evidence from the Realgrunnen Subgroup in the Goliat field, southwest Barents Sea, Norway. Marine and Petroleum Geology. ISSN 0264-8172. 95, p. 276–302. doi: 10.1016/j.marpetgeo.2018.04.023. Full text in Research Archive
• Tågholt, Tone Sorento; Stemmerik, Lars & Olaussen, Snorre (2018). Upper Permian carbonates at the northern edge of the Zechstein basin, Utsira High, Norwegian North Sea. Marine and Petroleum Geology. ISSN 0264-8172. 89(3), p. 635–652. doi: 10.1016/j.marpetgeo.2017.10.030.
• Matysik, Michal; Stemmerik, Lars; Olaussen, Snorre & Brunstad, Harald (2018). Diagenesis of spiculites and carbonates in a Permian temperate ramp succession-Tempelfjorden Group,Spitsbergen, Arctic Norway. Sedimentology. ISSN 0037-0746. 65(3), p. 745–774. doi: 10.1111/sed.12404.
• Abay, Tesfamariam Berhane; Karlsen, Dag Arild; Pedersen, Jon Halvard; Olaussen, Snorre & Backer-Owe, Kristian (2018). Thermal maturity, hydrocarbon potential and kerogen type of some Triassic-Lower Cretaceous sediments from the SW Barents Sea and Svalbard. Petroleum Geoscience. ISSN 1354-0793. 24(3), p. 349–373. doi: 10.1144/petgeo2017-035.
• Marin Restrepo, Dora Luz; Escalona Varela, Alejandro; Grundvåg, Sten-Andreas; Olaussen, Snorre; Sandvik, Sara & Sliwinska, Kasia (2018). Unravelling key controls on the rift climax to post-rift fill of marine rift basins: insights from 3D seismic analysis of the Lower Cretaceous of the Hammerfest Basin, SW Barents Sea. Basin Research. ISSN 0950-091X. 30(4), p. 587–612. doi: 10.1111/bre.12266. Full text in Research Archive

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• Stemmerik, Lars; Olaussen, Snorre & Braathen, Alvar (2022). Late Permian-Early Triassic synrift basin fill: Breakup of Pangea and the first brick in the puzzle of NE Atlantic-Arctic Mesozoic-early Cenozoic continental extension.
• Knarud, Ragnar; Mørk, Atle; Nakrem, Hans Arne & Olaussen, Snorre (2022). David Worsley (1943-2022). Geonytt. ISSN 0802-6173. 27(2), p. 14–17.
• Dahlin, Anders; Smyrak-Sikora, Aleksandra; Blinkenberg, Kasper; Olaussen, Snorre & Stemmerik, Lars (2021). Digital outcrop models of Upper Paleozoic mixed carbonate-siliciclastic deposits, Svalbard, Arctic Norway: Strengths and challenges.
• Olaussen, Snorre; Grundvåg, Sten-Andreas; Hurum, Jørn Harald & Senger, Kim (2021). Back when the dinosaurs were ash-stranded. Appell. ISSN 0804-7758.
• Serck, Christopher Sæbø; Poyatos-Moré, Miquel; Midtkandal, Ivar; Braathen, Alvar; Olaussen, Snorre & Osmundsen, Per Terje [Show all 7 contributors for this article] (2021). Tectonic basins around basement domes, Oman II.
• Haile, Beyene Girma; Line, Lina Hedvig; Klausen, Tore Grane; Olaussen, Snorre; Eide, Christian Haug & Jahren, Jens [Show all 7 contributors for this article] (2021). Identifying and constraining sedimentary recycling from microscopic fluid inclusions in quartz overgrowth.
• Park, Juni; Stein, Holly J.; Hannah, Judith L.; Georgiev, Svetoslav; Yang, Gang & Hammer, Øyvind [Show all 7 contributors for this article] (2021). Re-Os geochronology of black shale from Central Spitsbergen, Svalbard: a stepping stone toward establishing the age of the J/K boundary. . Show summary

  Stage boundaries are determined by integrating bio-, magneto-, and chrono-stratigraphic units. Numerical ages of stage boundaries ideally should be constrained or verified by reliable radiometric ages of sedimentary strata – a challenging task in the absence of ash layers suitable for U-Pb zircon dating. For example, the numerical age of the Jurassic – Cretaceous (J/K) boundary is still uncertain. Recent efforts provided some ammonite biostratigraphy across the J/K boundary in the Slottsmøya Member of the Agardhfjellet Formation on Spitsbergen. However, the age and duration of the uppermost Jurassic (Volgiann stage) and the lowermost Cretaceous (Ryazanian stage) in the Boreal realm remain loosely defined. Our study adds new radiometric ages for this controversial stage boundary and presents geochemical data to evaluate paleoenvironmental settings. Three black shale intervals from two drill cores (DH2 and DH5) located ~7 km apart in Central Spitsbergen provide three Re-Os ages. In DH2, shales from the Slottsmøya Member previously provided conflicting biostratigraphic results (Volgian toRyazanian)[1]. An isochron derived from samples at 497m depth yields an imprecise 146.8 ± 6.8 Ma age, suggesting deposition in the Upper Volgian rather th precludes confirmation. Large uncertainties near the J/K boundary are typical for this region[2, 3]. Two Re-Os isochron ages from the Oppdalen Member (DH2 at 724 and DH5 at 658 m) yield similar ages of 157.6 ± 3.3 Ma and 157.9 ± 2.9 Ma, respectively. These ages are close to the GTS Oxfordian – Kimmeridgian stage boundary and, even within their uncertainties, suggest Oxfordian – Kimmeridgian deposition. The agreement between these correlative intervals in the two cores[4] lends credence to the accuracy of the Re-Os age. Biostratigraphic data, however, suggest a somewhat older age. Seafloor erosion, reworking and redeposition, could create this discrepancy between geochronologic and biostratigraphic age determinations. Given that biostratigraphy between the Boreal and Tethyan realms is poorly correlated, the radiometric ages provided by this study could be a stepping stone toward better connecting the Boreal with the Tethyan realm. But further work, on all fronts, is needed. Acknowledgements. Thanks to the UNIS CO2 LAB for access to the drill cores. HS acknowledges the supportof ACS-PRF award # 59965-ND2. References: [1] Koevoets, M.J., Hammer, Ø. & Little, C.T.S. (2019). Norwegian Journal of Geology 99, 1-24. [2] Georgiev, S.V., Stein, H.J., Hannah, J.L., Xu, G.,Bingen, B., & Weiss, H.M. (2017). EPSL, 461, 151-162. [3] Markey, R., Stein, H.J., Hannah, J.L., Georgiev,.V., Pedersen, J.H., & Dons, C.E.(2017). Palaeogeography, Palaeoclimatology, Palaeoecology, 466, 209-220. [4] Koevoets, M.J., Abay, T.B., Hammer, Ø., & Olaussen, S. (2016). Palaeogeography, Palaeoclimatology, Palaeoecology, 449, 266-274

• Olaussen, Snorre; Larsen, Bjørn Tore & Dahlgren, Sven (2021). Late Carboniferous deposits in the Oslo Graben – a regional overview. .
• Würtzen, Camilla Louise; Smyrak-Sikora, Aleksandra; Janocha, Julian; Johannesen, Erik; Olaussen, Snorre & Stemmerik, Lars (2021). Facies variability of the continental Lower Carboniferous Billefjorden Group in Central Spitsbergen, Svalbard.
• Dahlin, Anders; Olaussen, Snorre; Smyrak-Sikora, Aleksandra; Stemmerik, Lars & Braathen, Alvar (2021). Late Palaeozoic syn-rift basin fill at the Sørkapp-Hornsund High, Southern Spitsbergen. .
• Olaussen, Snorre; Grundvåg, Sten-Andreas; Hurum, Jørn Harald & Senger, Kim (2020). Den gangen dinosaurene var askefaste. Svalbardposten.
• Smyrak-Sikora, Aleksandra; Braathen, Alvar; Julian, Joshua Benjamin; Johannessen, E.P.; Lord, Gabriel & Olaussen, Snorre [Show all 9 contributors for this article] (2020). How digital outcrop analysis enhances understanding of rift basin architecture (Billefjorden Trough Svalbard)?
• Smyrak-Sikora, Aleksandra; Braathen, Alvar; Janocha, Julian; Johannessen, E.P.; Lord, Gabriel & Olaussen, Snorre [Show all 8 contributors for this article] (2020). On-offshore correlations of the Billefjorden Fault Zone, Svalbard. .
• Würtzen, Camilla Louise; Stemmerik, Lars; Olaussen, Snorre & Ahokas, Juha Matti (2019). Facies analysis of the Uppermost Devonian to Lower Carboniferous Billefjorden Group, Central Spitsbergen, Svalbard .
• Olaussen, Snorre; Escalona Varela, Alejandro; Grundvåg, Sten-Andreas; Marin Restrepo, Dora Luz; Senger, Kim & Ohm, Sverre Ekrene (2019). Middle Jurassic to Lower Cretaceous Clastic Wedges in the north Atlantic, Barents Sea and High Arctic.
• Olaussen, Snorre; Escalona Varela, Alejandro; Grundvåg, Sten-Andreas; Marin Restrepo, Dora Luz; Ohm, Sverre Ekrene & Senger, Kim (2019). Middle Jurassic to Lower Cretaceous Clastic Wedges in the north Atlantic, Barents Sea and High Arctic.
• Grundvåg, Sten-Andreas; Senger, Kim; Larssen, Geir Birger; Olaussen, Snorre & Riis, Fridtjof (2019). Late Jurassic – Early Cretaceous sedimentary response to opening of the Amerasian Basin and HALIP activity in Svalbard. Show summary

  The Upper Jurassic to Lower Cretaceous succession in Svalbard consists of two prominent clastic wedges that prograded in a general southeastward (and later also southwestward) direction in response to recurrent uplift of northern Svalbard and adjacent terranes from the Late Jurassic onwards (Fig. 1A). A strong HALIP signal is well known from the Lower Cretaceous part of the succession. Numerous dolerite intrusions of Early Cretaceous age (Fig. 1B) are present across the entire outcrop belt (with sills predominantly penetrating Permian to Triassic strata) and in nearby offshore areas as revealed by reflection seismic data east and south of Svalbard. Bentonites occur locally as documented in onshore research boreholes. Previously published absolute datings of several intrusions and one bentonite bed yields ages in the range of 123.3–124.7 Ma, pointing to peak HALIP activity in the earliest Aptian. In addition, a regional provenance switch from quartz arenites to plagioclase-rich lithic arenites and volcanic clasts is evident in the Barremian–Aptian part of the succession (Fig. 1C, D, E). In eastern Spitsbergen, paleo-current directions also indicate an emerging provenance area to the NE. Further east at Kong Karls Land, basaltic lava flows occur interbedded with paralic deposits of late Barremian to Aptian age. Collectively, this indicate significant HALIP influence on the sedimentary system in Svalbard during the Early Cretaceous. Less known is the tectono-sedimentary response directly related to the opening of the Amerasian Basin, which pre-dates the short-lived HALIP activity. Several regional unconformities occur in the Upper Jurassic–lowermost Cretaceous succession, including the Oxfordian, the Volgian to lowermost Ryazanian, and the lower Barremian unconformities (Fig. 1A). Although the development and exact timing of the two former unconformities is yet to be investigated, the latter is commonly attributed to regional upwarping and southeastward tilting prior to the main HALIP pulse. Shallow marine and shelf sandstone units in the Upper Jurassic–lowermost Cretaceous succession typically pinch out to the SE, thus indicating a clear northwestern provenance area. We suggest that these sandstone units may record the initial sedimentary response to rift-shoulder uplift during opening of the Amerasian Basin north of Svalbard.

• Abay, Tesfamariam Berhane; Karlsen, Dag Arild; Olaussen, Snorre & Pedersen, Jon Halvard (2019). Organic Geochemistry of Petroleum in the Cambro-Ordovician Succession of Ny Friesland, Spitsbergen, Norway.
• Grundvåg, Sten-Andreas; Olaussen, Snorre; Midtkandal, Ivar & Sliwinska, Kasia (2019). On the trace of a lower Aptian source rock in Svalbard.
• Senger, Kim; Brugmans, Peter; Grundvåg, Sten-Andreas; Jochmann, Malte Michel; Nøttvedt, Arvid & Olaussen, Snorre [Show all 8 contributors for this article] (2019). Petroleum Exploration Onshore Svalbard: A Historical Perspective on the Start of the Norwegian Oil Adventure.
• Würtzen, Camilla Louise; Stemmerik, Lars; Olaussen, Snorre & Ahokas, Juha Matti (2018). Facies analysis of the uppermost Devonian to Lower Carboniferous Billefjorden Group, Central Spitsbergen, Svalbard.
• Olaussen, Snorre; Larssen, Geir Birger; Helland-Hansen, William; Johannessen, Erik P.; Nøttvedt, Arvid & Riis, Fritjof [Show all 9 contributors for this article] (2018). The outcropping strata in Kong Karls Land archipelago, Arctic Norway; a key reference point for the Upper Triassic to Lower Cretaceous succession in the northern Barents Sea.
• Olaussen, Snorre; Senger, Kim; Birchall, Thomas; Braathen, Alvar; Grundvåg, Sten-Andreas & Hammer, Øyvind [Show all 13 contributors for this article] (2018). The Longyearbyen CO2 lab project: lessons learned from a decade of characterizing an unconventional reservoir-caprock system.
• Olaussen, Snorre; Grundvåg, Sten-Andreas; Senger, Kim; Birchall, Thomas & Smyrak-Sikora, Aleksandra (2018). Understanding Barents Sea Play Concepts Based on 18 wildcats, and some R&D wells, in Svalbard.
• Birchall, Thomas; Senger, Kim & Olaussen, Snorre (2018). Subnormal Pressure Regimes of the Northern Barents Shelf: Causes and Implications for Hydrocarbon Exploration.
• Olaussen, Snorre; Larssen, Geir Birger; Helland-Hansen, William; Johannessen, Erik P.; Nøttvedt, Arvid & Riis, Fridtjof [Show all 9 contributors for this article] (2018). The outcropping strata in the Kong Karls Land archipelago, Arctic Norway; a key reference point for the Upper Triassic to Lower Cretaceous succession in the northern Barents Sea.
• Olaussen, Snorre & Rismyhr, Bjarte (2018). Large scale tectonics as controlling factor of the Upper Triassic to Middle Jurassic basin fills in Svalbard and nearby pan‐Arctic Basins.
• Koehl, Jean-Baptiste P.; Bergh, Steffen G; Henningsen, Tormod; Faleide, Jan Inge; Smyrak-Sikora, Aleksandra & Olaussen, Snorre [Show all 7 contributors for this article] (2018). Mid/Late Devonian-early Carboniferous collapse basins in the Barents Sea and Svalbard.
• Senger, Kim; Farnsworth, Wesley Randall; Christiansen, Hanne H; Gilbert, Graham Lewis; Hancock, Holt John & Hodson, Andrew J. [Show all 16 contributors for this article] (2018). Field-based geology education in the high Arctic: How digital tools can support active learning.
• Grundvåg, Sten-Andreas; Jelby, Mads; Midtkandal, Ivar; Sliwinska, Kasia; Nøhr-Hansen, Henrik & Marin Restrepo, Dora Luz [Show all 9 contributors for this article] (2017). The Lower Cretaceous of Svalbard and its relevance for exploration in the northern Barents Sea. Full text in Research Archive
• Smyrak-Sikora, Aleksandra Anna; Osmundsen, Per Terje; Braathen, Alvar; Ogata, Kei; Anell, Ingrid Margareta & Husteli, Berit [Show all 8 contributors for this article] (2017). Sedimentary architecture of siliciclastic, syntectonic graben and halfgraben fill in Kvalpynten, Edgeøya, Svalbard. Show summary

  An array of ten grabens/ half-grabens and their associated syntectonic basin fill (averaging approx. 700 m across) are exposed along a 9 km cliff section at Kvalpynten, Edgeøya, offering a unique opportunity to study the silisiclastic architecture of listric graben basin fill. The exposures at Kvalpynten provide a unique opportunity to correlate fault-controlled sedimentary architecture on the scale of meters to hundreds of meters with detailed facies relationships, and thus fault-induced differential accommodation with the depositional environments that filled it. The basins developed in the Late Triassic, during the deposition of the Early Carnian to Early Norian deltaic successions of Tchermakfjellet and De Geerdalen formations which is approximately the onshore equivalent to the offshore Snadd Formation. The lowermost part of the ca 400 m high Kvalpynten cliff section reveals a number of NW–SE striking growth faults with 50–100 m offset, which bound basins filled with shale and sandstone wedges. Up section, the growth faults tip out, and are buried by undeformed deltaic deposits. Integrated field studies including sedimentology and structural geology combined with surfaces mapping on a photogrammetric virtual outcrop model allowed incremental reconstruction of the grabens/ half-grabens evolution. Four transgressive surfaces were identified and mapped, allowing correlation of the sandstone packages between each basin. The sequence of faulting has been defined with respect to the mapped flooding surfaces. Faulting clearly occurred in several phases as evident by the syn-kinematic fault’s control on sediments of different ages, and from the occurrence of later forming faults rotating earlier formed fault blocks. In general, early faults defined a relatively symmetrical basin configuration whereas later phases of movement were localized mainly along south-dipping faults. This gave rise to a change to more asymmetric basins and to the formation of asymmetric, composite sedimentary bodies with stacked shoreface and offshore transition deposits. Locally, fault crests were eroded. Our sedimentological observations suggest that tidal processes were dominant during sandstone deposition within the grabens/half-grabens, expressed by the widespread occurrence of tidal bar and tidal flat deposits.

• Olaussen, Snorre (2017). Review of the Middle Jurassic to Lower Cretaceous clastic wedge in Svalbard and the Barents Sea. Oral presentation at CASE – Circum-Arctic Structural Events, March 2017, Hannover, Germany.
• Olaussen, Snorre (2017). Oil and gas resources in the Arctic from a geological perspective. Oral presentation at ARCEx Annual Conference 2017, 10-11 May, Malangen, Norway.
• Jochmann, Malte Michel; Jensen, Maria; Olaussen, Snorre; Helland-Hansen, William; Appleyard, Tyler Ross & Marshall, Chris [Show all 10 contributors for this article] (2017). Spitsbergen and Greenland Paleogene Basins.
• Olaussen, Snorre (2017). Upper Triassic to Middle Jurassic key sequence stratigraphic surfaces onshore offshore Arctic Norway; guidelines for prediction of facies development.
• Mulrooney, Mark; Rismyhr, Bjarte; Yenwongfai, Honore Dzekamelive; Leutscher, Johan; Olaussen, Snorre & Braathen, Alvar (2017). Impacts of small‐scale faults on continental to coastal plain deposition: Evidence from the Realgrunnen Subgroup in the Goliat field, Southwest Barents Sea, Norway.
• Ogata, Kei; Mulrooney, Mark; Braathen, Alvar; Maher, Harmon; Smyrak-Sikora, Aleksandra Anna & Anell, Ingrid Margareta [Show all 12 contributors for this article] (2017). Architecture, deformation style and petrophysical properties of a Late Triassic growth fault system in southern Edgeøya, East Svalbard.
• Anell, Ingrid Margareta; Braathen, Alvar; Røhnert, Daniela; Ogata, Kei; Osmundsen, Per Terje & Smyrak-Sikora, Aleksandra Anna [Show all 10 contributors for this article] (2017). Findings of five field foragings. Sandbody distribution, clinoform geometries and depositional environments of Edgeøya, Svalbard.
• Braathen, Alvar; Mulrooney, Mark; Haile, Beyene Girma; Appleyard, Tyler Ross; van Yperen, Anna Elisabeth & Smyrak-Sikora, Aleksandra Anna [Show all 12 contributors for this article] (2017). “Delta collapse” – Edgeøya delta system compared to the Ferron delta (Utah) .
• Senger, Kim; Mulrooney, Mark; Schaaf, Niklas; Tveranger, Jan; Braathen, Alvar & Ogata, Kei [Show all 7 contributors for this article] (2017). Characterization and Modelling of a Naturally Fractured Reservoir-Caprock Unit Targeted for CO2 Storage in Arctic Norway.
• Senger, Kim; Birchall, Thomas; Ohm, Sverre Ekrene; Olaussen, Snorre & Ogata, Kei (2017). Review of Geological Controls on Resistivity in Uplifted Basins: Insights from the Norwegian Barents Shelf.
• Solvang, Ole-Marius; Eide, Christian Haug; Helland-Hansen, William; Mangerud, Gunn & Olaussen, Snorre (2017). Sedimentological and petrographical investigations of the Early Triassic Vardebukta Formation on western Spitsbergen. Universitetet i Bergen.
• Lord, Gareth Steven; Mørk, Atle & Olaussen, Snorre (2017). Sequence stratigraphy and facies Development of the Triassic succession of Svalbard and the Northern Barents Sea. Norges teknisk-naturvitenskapelige universitet. ISSN 978-82-326-2465-2.

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