Sverre Planke

• Corseri, Romain; Gac, Sebastien; Faleide, Jan Inge & Planke, Sverre (2020). The tectonized central peak of the Mjølnir Impact Crater, Barents Sea. Journal of Structural Geology.  ISSN 0191-8141.  131, s 1- 12 . doi: 10.1016/j.jsg.2019.103953 Fulltekst i vitenarkiv. Vis sammendrag

  The Mjølnir structure, SW Barents Sea, is one of the best-preserved marine impact craters on Earth. After impact on the paleo-seafloor about 142 Ma ago, this crater experienced an atypical deformation of its central peak, which is now elevated ~435 m above the crater rims. Here, we investigate the effect of far-field tectonic stresses on the central peak uplift based on interpretation of new high-resolution P-Cable and conventional seismic reflection data. Nearby wells provided stratigraphic control on the interpreted horizons. The reconstruction of the crater sedimentary infill supports a subdued original central peak relief with a 5 km-wide, gentle mound ~15 m below the rim. Our interpretation shows that subvertical, outward-dipping, impact-induced faults were reactivated by uplifted segments of the central peak up to 500 m above the platform level during one or several contractional episodes. We postulate that post-Albian tectonic compressional events triggered the structural uplift of the Mjølnir central peak. Differential compaction, previously seen as the main deformation process, may have increased the original central peak height by only ~10 m. The mobilization of impact-shattered rocks by tectonic compression provides a new and robust explanation for the structural rise of Mjølnir's central peak.

• Zastrozhnov, Dmitry; Gernigon, Laurent; Gogin, Iakov; Planke, Sverre; Abdelmalak, Mohamed Mansour; Polteau, Stephane; Faleide, Jan Inge; Manton, Ben & Myklebust, Reidun (2020). Regional structure and polyphased Cretaceous-Paleocene rift and basin development of the mid-Norwegian volcanic passive margin. Marine and Petroleum Geology.  ISSN 0264-8172.  115 . doi: 10.1016/j.marpetgeo.2020.104269
• Augland, Lars Eivind; Ryabov, Viktor V.; Vernikovsky, Valery A.; Planke, Sverre; Polozov, Alexander; Callegaro, Sara; Jerram, Dougal Alexander & Svensen, Henrik (2019). The main pulse of the Siberian Traps expanded in size and composition. Scientific Reports.  ISSN 2045-2322.  9 . doi: 10.1038/s41598-019-54023-2 Fulltekst i vitenarkiv. Vis sammendrag

  Emplacement of large volumes of (sub)volcanic rocks during the main pulse of the Siberian Traps occurred within <1 m.y., coinciding with the end-Permian mass extinction. Volcanics from outside the main Siberian Traps, e.g. Taimyr and West Siberia, have since long been correlated, but existing geochronological data cannot resolve at a precision better than ~5 m.y. whether (sub)volcanic activity in these areas actually occurred during the main pulse or later. We report the first high precision U-Pb zircon geochronology from two alkaline ultramafic-felsic layered intrusive complexes from Taimyr, showing synchronicity between these and the main Siberian Traps (sub)volcanic pulse, and the presence of a second Dinerian-Smithian pulse. This is the first documentation of felsic intrusive magmatism occurring during the main pulse, testifying to the Siberian Trap’s compositional diversity. Furthermore, the intrusions cut basal basalts of the Taimyr lava stratigraphy hence providing a minimum age of these basalts of 251.64 ± 0.11 Ma. Synchronicity of (sub)volcanic activity between Taimyr and the Siberian Traps imply that the total area of the Siberian Traps main pulse should include a ~300 000 km2 area north of Norilsk. The vast aerial extent of the (sub)volcanic activity during the Siberian Traps main pulse may explain the severe environmental consequences.

• Bellwald, Benjamin; Planke, Sverre; Lebedeva-Ivanova, Nina; Piasecka, Emilia Daria & Andreassen, Karin (2019). High-resolution landform assemblage along a buried glacio-erosive surface in the SW Barents Sea revealed by P-Cable 3D seismic data. Geomorphology.  ISSN 0169-555X.  332, s 33- 50 . doi: 10.1016/j.geomorph.2019.01.019 Fulltekst i vitenarkiv. Vis sammendrag

  The Quaternary sedimentary record in the Arctic captures a diverse and evolving range of landscapes reflecting cli-mate changes. Here we study the geological landform assemblage of the Upper Regional Unconformity (URU) in theSW Barents Sea. The aims are (i) to characterize buried geological landforms on a meter-scale resolution, (ii) to un-derstand their link with underlying structures, and (iii) to reconstruct paleo-ice-sheet dynamics and configurations.The data consist of a high-resolution three-dimensional (3D) P-Cable seismic cube with an extent of c. 200 km2andan inline separation of 6 m. Dominant frequencies of c. 150 Hz allow to image landforms at URU with a vertical res-olution of 1–5 m and a horizontal resolution of 3–6 m. We conduct detailed horizon-picking and seismic attributeanalysis of the buried URU horizon. We identified four sets of mega-scale glacial lineations, and shear band ridgeslocated to the west of a shear margin moraine. Other characteristic features include hill-hole pairs, transverse ridges,rhombohedral ridges and depressions, iceberg ploughmarks and pockmarks. Polygonal faults below URU anddeeper faults have a strong effect on the location of structures observed on URU. Bedrock packages deformeddown to 30 m below URU and up to 5 m-high transverse ridges at URU are imprints of glacio-tectonic activity.Deformed strata below URU indicate normal faulting superimposed by glaciotectonic deformation. The four setsof mega-scale glacial lineations indicate four streaming events with thawed glacial beds, with shear band ridgesforming in the shearing zone during one of these streaming events. Hill-hole pairs and rhombohedral ridges arefrozen-bed features which indicate a polythermal regime at the base of the Barents Sea Ice Sheet during multiplestreaming phases. This study therefore shows that paleo-ice streams have been temporarily frozen to the groundin the SW Barents Sea, and that landforms evidencing this freezing are associated with underlying faults.

• Berndt, Christian; Planke, Sverre; Teagle, Damon; Huismans, Ritske; Torsvik, Trond Helge; Frieling, Joost; Jones, Morgan Thomas; Jerram, Dougal Alexander; Tegner, Christian; Faleide, Jan Inge; Coxall, Helen & Hong, Wei-Li (2019). Northeast Atlantic breakup volcanism and consequences for Paleogene climate change – MagellanPlus Workshop report. Scientific Drilling.  ISSN 1816-8957.  26, s 69- 85 . doi: 10.5194/sd-26-69-2019 Fulltekst i vitenarkiv. Vis sammendrag

  The northeast Atlantic encompasses archetypal examples of volcanic rifted margins. Twenty-five years after the last ODP (Ocean Drilling Program) leg on these volcanic margins, the reasons for excess melting are still disputed with at least three competing hypotheses being discussed. We are proposing a new drilling campaign that will constrain the timing, rates of volcanism, and vertical movements of rifted margins. This will allow us to parameterise geodynamic models that can distinguish between the hypotheses. Furthermore, the drilling-derived data will help us to understand the role of breakup magmatism as a potential driver for the Palaeocene–Eocene thermal maximum (PETM) and its influence on the oceanographic circulation in the earliest phase of the northeast Atlantic Ocean formation. Tackling these questions with a new drilling campaign in the northeast Atlantic region will advance our understanding of the long-term interactions between tectonics, volcanism, oceanography, and climate and the functioning of subpolar northern ecosystems and climate during intervals of extreme warmth.

• Faleide, Thea Sveva; Midtkandal, Ivar; Planke, Sverre; Corseri, Romain; Faleide, Jan Inge; Serck, Christopher Sæbø & Nystuen, Johan Petter (2019). Characterisation and development of Early Cretaceous shelf platform deposition and faulting in the Hoop area, southwestern Barents Sea—constrained by high-resolution seismic data. Norwegian Journal of Geology.  ISSN 2387-5844.  99(3), s 1- 20 . doi: 10.17850/njg99-3-7 Fulltekst i vitenarkiv. Vis sammendrag

  Regional Early Cretaceous uplift of the northern Barents Sea associated with the High Arctic Large Igneous Province (HALIP) caused the development of the fluvial to open-marine depositional system, terminating in the southwestern Barents Sea. This study has established a new temporal and spatial evolution of the Lower Cretaceous deposits in the Hoop area, in particular the location and age of the intrashelf platform lobe front and subsequent block-faulting. A composite high-resolution 3D and 2.5D P-Cable and conventional 3D seismic dataset image the strata and cross-cutting faults in the Hoop area. The P-Cable data typically have a resolution of 3–7 m in the shallow subsurface, up to four times better than the conventional seismic data, contributing to a new and better mapping hence understanding of the Lower Cretaceous strata and faults. Seismic horizon and facies mapping reveal large-scale clinoforms, with present-day heights of 150–200 m and dips of 0.65–1.13°. The highresolution data furthermore display complex stratigraphic and structural features, such as small-scale clinoforms and numerous faults. The shelf platform succession is block-faulted, and the main Early Cretaceous fault activity thus postdates the arrival of the delta and platform sediments from the northwest. Detailed seismo-stratigraphic ties to the 7324/2–1 (Apollo) and 7325/1–1 (Atlantis) wells, and ties to the adjacent Fingerdjupet Subbasin, document a Barremian age for the shelf platform deposits and an Aptian?–early Albian age for the main faulting event. The faulting was likely initiated in the Aptian, but a hiatus or condensed section above the Barremian strata makes it difficult to constrain the onset of deformation in the Hoop area.

• Greenfield, L.; Millett, John M; Howell, J.A.; Jerram, Dougal Alexander; Watton, Timothy J.; Healy, D; Hole, MJ & Planke, Sverre (2019). The 3D facies architecture and petrophysical properties of hyaloclastite delta deposits: An integrated photogrammetry and petrophysical study from southern Iceland. Basin Research.  ISSN 0950-091X. . doi: 10.1111/bre.12415
• Heimdal, Thea Hatlen; Callegaro, Sara; Svensen, Henrik; Jones, Morgan Thomas; Pereira, Egberto & Planke, Sverre (2019). Evidence for magma–evaporite interactions during the emplacement of the Central Atlantic Magmatic Province (CAMP) in Brazil. Earth and Planetary Science Letters.  ISSN 0012-821X.  506, s 476- 492 . doi: 10.1016/j.epsl.2018.11.018
• Jerram, Dougal Alexander; Millett, John M; Kück, Jochem; Thomas, Donald; Planke, Sverre; Haskins, Eric; Lautze, Nicole & Pierdominici, Simona (2019). Understanding volcanic facies in the subsurface: A combined core, wireline logging and image log data set from the PTA2 and KMA1 boreholes, Big Island, Hawaii. Scientific Drilling.  ISSN 1816-8957.  25, s 15- 33 . doi: 10.5194/sd-25-15-2019 Fulltekst i vitenarkiv.
• Jones, Morgan Thomas; Percival, Lawrence; Stokke, Ella Wulfsberg; Frieling, Joost; Mather, Tasmin A.; Riber, Lars; Schubert, Brian A; Schultz, Bo; Tegner, Christian; Planke, Sverre & Svensen, Henrik (2019). Mercury anomalies across the Palaeocene–Eocene Thermal Maximum. Climate of the Past.  ISSN 1814-9324.  15(1), s 217- 236 . doi: https://doi.org/10.5194/cp-15-217-2019 Fulltekst i vitenarkiv.
• Kjøll, Hans Jørgen; Andersen, Torgeir Bjørge; Corfu, Fernando; Labrousse, Loic; Tegner, Christian; Abdelmalak, Mohamed Mansour & Planke, Sverre (2019). Timing of break-up and thermal evolution of a pre-Caledonian Neoproterozoic exhumed magma-rich rifted margin. Tectonics.  ISSN 0278-7407.  38(6), s 1843- 1862 . doi: 10.1029/2018TC005375 Fulltekst i vitenarkiv. Vis sammendrag

  During the terminal stages of Wilson cycles, remnants of magma-poor margins may be incorporated into the orogens, whereas the magma-rich margins often are lost in subduction due to low buoyancy. The understanding of magma-rich margins is therefore mostly based on drill holes and geophysical observations. In this contribution, we explore the temporal evolution and the ambient conditions of a magma-rich rifted margin preserved within the Scandinavian Caledonides. The Scandinavian Dike Complex was emplaced into a sedimentary basin during the initial break-up and opening of the Iapetus Ocean 615 to 590 million years ago. The dike complex constitutes 70-90% of the magma-rich, syn-rift basins and is locally well-preserved despite the complex Caledonian history. This contribution provides new observations about the geometry, relative timing, and development of the margin. Jadeite-in-clinopyroxene geothermobarometry, titanium-in-biotite geothermometry, and garnet isopleth modeling show that the ambient pressure and temperature conditions were similar for the entire dike complex at 0.25 to 0.45 GPa, with contact metamorphic temperatures up to c. 700°C. In the northernmost part of the study area U-Pb dating of magmatic zircon shows that partial melting of the sedimentary host-rock, at relatively shallow levels, occurred at 612 Ma. This shows that the crust was molten already 6 million years before the northernmost dike swarm was emplaced at 605.7 ± 1.8 Ma. We propose that the locally pervasive partial melting occurred due to high geothermal gradients and introduction of mafic melt in the lower crust. These processes significantly reduced the strength of the crust, eventually facilitating continental break-up.

• Lebedeva-Ivanova, Nina; Polteau, Stephane; Zastrozhnov, Dmitrii; Planke, Sverre; Waage, Malin; Bünz, Stefan; Bellwald, Benjamin; Vanneste, Maarten; Sauvin, Guillaume & Myklebust, Reidun (2019). Meter-Scale 3D Seismic Data for High-Resolution Site Characterization, In  81st EAGE Conference and Exhibition 2019.  European Association of Geoscientists and Engineers (EAGE).  ISBN 978-1-5108-9281-1.  x.  s 1 - 2 Vis sammendrag

  High-resolution 3D site characterization can deliver reliable quantitative property volumes of the subsurface when based on seismic data able to image meter-sized objects. Following the theoretical analysis of seismic wave propagation in the shallow sub-surface, we present case studies based on re-processing of 3D P-Cable seismic data. The case study of data re-processing from the Vestnesa Ridge west of Svalbard and the outer Vøring Basin show that P-Cable 2.5D and 3D data can provide decimeter- to meter-scale vertical resolution of the shallow subsurface. Collection of new 3D P-Cable data with optimized acquisition parameters will provide meter-scale horizontal and vertical resolution. Therefore, 3D seismic volumes will represent the framework for data interpretation, integration and inversion where in situ measurements can be propagated with minimal data interpolation.

• Midtkandal, Ivar; Faleide, Jan Inge; Faleide, Thea Sveva; Serck, Christopher Sæbø; Planke, Sverre; Corseri, Romain; Dimitriou, Myrsini & Nystuen, Johan Petter (2019). Lower Cretaceous Barents Sea strata: epicontinental basin configuration, timing, correlation and depositional dynamics. Geological Magazine.  ISSN 0016-7568. . doi: 10.1017/S0016756819000918
• Midtkandal, Ivar; Faleide, Thea Sveva; Faleide, Jan Inge; Planke, Sverre; Anell, Ingrid Margareta & Nystuen, Johan Petter (2019). Nested intrashelf platform clinoforms—Evidence of shelf platform growth exemplified by Lower Cretaceous strata in the Barents Sea. Basin Research.  ISSN 0950-091X. . doi: 10.1111/bre.12377 Fulltekst i vitenarkiv.
• Svensen, Henrik; Jerram, Dougal Alexander; Polozov, Alexander; Planke, Sverre; Neal, Clive R.; Augland, Lars Eivind & Emeleus, Henry C. (2019). Thinking about LIPs: A brief history of ideas in Large igneous province research. Tectonophysics.  ISSN 0040-1951.  760, s 229- 251 . doi: https://doi.org/10.1016/j.tecto.2018.12.008 Fulltekst i vitenarkiv.
• Tegner, Christian; Andersen, Torgeir Bjørge; Kjøll, Hans Jørgen; Brown, Eric L.; Hagen-Peter, Graham; Corfu, Fernando; Planke, Sverre & Torsvik, Trond Helge (2019). A mantle plume origin for the Scandinavian Dyke Complex: a "piercing point" for 615 Ma plate reconstruction of Baltica?. Geochemistry Geophysics Geosystems.  ISSN 1525-2027.  20(2), s 1075- 1094 . doi: 10.1029/2018GC007941 Fulltekst i vitenarkiv. Vis sammendrag

  Abstract The origin of Large Igneous Provinces (LIPs) associated with continental breakup and the reconstruction of continents older than c. 320 million years (pre-Pangea) are contentious research problems. Here we study the petrology of a 615 - 590 Myr dolerite dyke complex that intruded rift-basins of the magma-rich margin of Baltica and now is exposed in the Scandinavian Caledonides. These dykes are part of the Central Iapetus Magmatic Province (CIMP), a LIP emplaced in Baltica and Laurentia during opening of the Caledonian Wilson Cycle. The >1000 km long dyke complex displays lateral geochemical zonation from enriched to depleted basaltic compositions from south to north. Geochemical modelling of major and trace elements shows these compositions are best explained by melting hot mantle 75-250°C above ambient mantle. Although the trace element modelling solutions are non- unique, the best explanation involves melting a laterally zoned mantle plume with enriched and depleted peridotite lithologies, similar to present-day Iceland and to the North Atlantic Igneous Province. The origin of CIMP appears to have involved several mantle plumes. This is best explained if rifting and breakup magmatism coincided with plume generation zones at the margins of a Large Low Shear-wave Velocity Province (LLSVP) at the core mantle boundary. If the LLSVPs are quasi-stationary back in time as suggested in recent geodynamic models, the CIMP provides a guide for reconstructing the paleogeography of Baltica and Laurentia 615 million years ago to the LLSVP now positioned under the Pacific Ocean. Our results provide a stimulus for using LIPs as piercing points for plate reconstructions.

• Abdelmalak, Mohamed Mansour; Planke, Sverre; Polteau, Stephane; Hartz, Ebbe Hvidegård; Faleide, Jan Inge; Tegner, Christian; Jerram, Dougal Alexander; Millett, John M & Myklebust, Reidun (2018). Breakup volcanism and plate tectonics in the NW Atlantic. Tectonophysics.  ISSN 0040-1951.  760, s 267- 296 . doi: 10.1016/j.tecto.2018.08.002
• Lebedeva-Ivanova, Nina; Polteau, Stephane; Bellwald, Benjamin; Planke, Sverre; Berndt, Christian & Stokke, Henrik Henriksen (2018). Toward one-meter resolution in 3D seismic. The Leading Edge.  ISSN 1070-485X.  37(11), s 818- 828 . doi: 10.1190/tle37110818.1
• Bellwald, Benjamin & Planke, Sverre (2018). Shear margin moraine, mass transport deposits and soft beds revealed by high-resolution P-Cable three dimensional seismic data in the Hoop area, Barents Sea. Geological Society Special Publication.  ISSN 0305-8719.  477(1), s 537- 547 . doi: 10.1144/SP477.29
• Bellwald, Benjamin; Planke, Sverre; Piasecka, Emilia Daria; Matar, Mohammed A. & Andreassen, Karin (2018). Ice-stream dynamics of the SW Barents Sea revealed by high-resolution 3D seismic imaging of glacial deposits in the Hoop area. Marine Geology.  ISSN 0025-3227.  402, s 165- 183 . doi: 10.1016/j.margeo.2018.03.002 Fulltekst i vitenarkiv.
• Corseri, Romain; Faleide, Thea Sveva; Faleide, Jan Inge; Midtkandal, Ivar; Serck, Christopher Sæbø; Trulsvik, Mikal & Planke, Sverre (2018). A diverted submarine channel of Early Cretaceous age revealed by high-resolution seismic data, SW Barents Sea. Marine and Petroleum Geology.  ISSN 0264-8172.  98, s 462- 476 . doi: 10.1016/j.marpetgeo.2018.08.037 Fulltekst i vitenarkiv.
• Galland, Olivier; Bertelsen, Håvard Svanes; Eide, Christian Haug; Guldstrand, Frank Bo Buster; Haug, Øystein Thorden; Leanza, Hector Armando; Mair, Karen; Palma, Octavio; Planke, Sverre; Rabbel, Ole; Rogers, Benjamin David; Schmiedel, Tobias; Souche, Alban & Spacapan, Juan Bautista (2018). Storage and Transport of Magma in the Layered Crust—Formation of Sills and Related Flat-Lying Intrusions, In Steffi Burchardt (ed.),  Volcanic and Igneous Plumbing Systems - Understanding Magma Transport, Storage, and Evolution in the Earth's Crust.  Elsevier.  ISBN 978-0-12-809749-6.  Chapter 5.  s 113 - 138 Vis sammendrag

  Even though dykes are the main upward magma pathways through the Earth’s crust, the last two decades of research showed that significant parts of volcano plumbing systems consist of flat-lying igneous intrusions, namely sills. Sills form mainly in the layered parts of the crust, principally in volcanic deposits and sedimentary basins. Sills exhibit various shapes, strata-concordant, transgressive sheets, and saucer-shaped. Lateral magma flow through sill complexes and networks can reach several hundred kilometres. Sills represent intermediate feeder structures for volcanic eruptions, and therefore better understanding of sill emplacement and evolution is essential for assessing volcanic hazards. Sills emplaced in sedimentary basins also deeply affect petroleum systems and are essential components in exploring hydrocarbons. Finally, the massive and fast emplacement of sills resulting from LIPs in sedimentary basins triggered catastrophic climate changes and mass extinctions during Earth's history.

• Karstens, Jens; Haflidason, Haflidi; Becker, Lukas; Berndt, Christian; Rüpke, Lars Helmuth; Planke, Sverre; Liebetrau, Volker; Schmidt, Markus & Mienert, Jurgen (2018). Glacigenic sedimentation pulses triggered postglacial gas hydrate dissociation. Nature Communications.  ISSN 2041-1723.  9 . doi: 10.1038/s41467-018-03043-z Fulltekst i vitenarkiv.
• Kastner, Felix; Giese, Rudiger; Planke, Sverre; Millett, John M & Flovenz, Olafur G (2018). Seismic imaging in the Krafla high-temperature geothermal field, NE Iceland, using zero- and far-offset vertical seismic profiling (VSP) data. Journal of Volcanology and Geothermal Research.  ISSN 0377-0273. . doi: 10.1016/j.jvolgeores.2018.02.016
• Lerch, Benedikt; Karlsen, Dag Arild; Thießen, Olaf; Abay, Tesfamariam Berhane; van Soelen, Elsbeth Ester; Kürschner, Wolfram Michael; Planke, Sverre & Backer-Owe, Kristian (2018). Investigations on the use of triaromatic dimethylcholesteroids as age-specific biomarkers in bitumens and oils from Arctic Norway. Organic Geochemistry.  ISSN 0146-6380.  122, s 1- 16 . doi: 10.1016/j.orggeochem.2018.04.011
• Millett, J.M.; Planke, Sverre; Kastner, Felix; Blischke, A; Hersir, Gylfi Pall; Halldorsdottir, Sæunn; Flovenz, Olafur G; Arnadottir, S; Helgadottir, H.M.; Vakulenko, Sergey; Buryak, S; Erlendsson, Ögmundur; Giese, Rudiger; Cavailhes, Jehanne P.; Jerram, Dougal Alexander; Gudmundsson, Asgrimur & Juliusson, Egill (2018). Sub-surface geology and velocity structure of the Krafla high temperature geothermal field, Iceland: Integrated ditch cuttings, wireline and zero offset vertical seismic profile analysis.. Journal of Volcanology and Geothermal Research.  ISSN 0377-0273.  391 . doi: 10.1016/j.jvolgeores.2018.03.024
• Planke, Sverre; Rabbel, Ole; Galland, Olivier; Millet, John; Manson, Ben; Jerram, Dougal Alexander; Palma, Octavio & Spacapan, Juan Bautista (2018). Seismic imaging and petroleum implications of igneous intrusions in sedimentary basins constrained by outcrop analogues and seismic data from the Neuquén Basin and the NE Atlantic, In Luis Vernengo; Mario Atencio; Marcela Branca; Eduardo Corti; Tomás D'Biassi; Jorge Dario Enrique; Maximiliano García Torrejón; Luis Pianelli; Alberto Ricardi; Daniel Soubiés & Federico Späth (ed.),  10 Congreso de Exploración y Desarrollo de Hidrocarburos - Simposio de Geofísica: La geofísica como vinculo entre el conocimiento de la tierra y la sociedad.  Instituto Argentino del Petroleo y del Gas.  ISBN 978-987-9139-92-9.  Article.  s 343 - 366
• Polteau, S.; Lebedeva-Ivanova, Nina; Bellwald, Benjamin; Planke, Sverre; Zastrozhnov, Dmitry; Vanneste, Maarten; Sauvin, Guillaume; Myklebust, R.; Bünz, Stefan; Plaza-Faverola, Andreia; Waage, Malin & Berndt, C (2018). High-Resolution 3D Site Characterization, In NN NN (ed.),  3rd Applied Shallow Marine Geophysics Conference, Near Surface Geoscience Conference & Exhibition 2018.  European Association of Geoscientists and Engineers.  ISBN 9789462822641.  x. Vis sammendrag

  We present the results of a novel method for high-resolution 3D site characterization. The strategy is based on using 3D seismic data as the framework for integrating geochemical, geophysical and geotechnical data. The end-results are 3D volumes with various attributes relevant for improved site characterization and ultimately geohazard assessment (i.e. identification of shallow gas, boulders, faults and fractures, leakage, spatial variability, soil strength…). We further show that geochemical data integrated with current high-resolution 3D seismic data can be used to constrain fluid migration pathways to the seafloor. In addition, re-processing focusing on the higher frequencies of 3D seismic data increases the resolution, resulting in a data volume displaying more details on the geology and geomorphology of the sub-surface when compared to data processed for deeper imaging. Finally, we configured an optimized 3D seismic acquisition system, which is fine-tuned for imaging the top 150 m of overburden with a meter-scale lateral and vertical resolution. Such a high-resolution 3D seismic system would provide data volumes that allow well-constrained integration of various type of data.

• Polteau, Stephane; Mazzini, Adriano; Hansen, Geir; Planke, Sverre; Jerram, Dougal Alexander; Millett, John; Abdelmalak, Mohamed Mansour; Blischke, Anett & Myklebust, Reidun (2018). The pre-breakup stratigraphy and petroleum system of the Southern Jan Mayen Ridge revealed by seafloor sampling. Tectonophysics.  ISSN 0040-1951.  760, s 152- 164 . doi: 10.1016/j.tecto.2018.04.016 Vis sammendrag

  The Jan Mayen Microplate Complex (JMMC) in the NE Atlantic is interpreted to mostly consist of continental fragments with possible interstitial embryonic oceanic crust. A complex Cenozoic rifting history accompanied by extensive extrusive and intrusive volcanism have made the geological characterization of the JMMC challenging especially due to poor seismic imaging beneath the breakup basalt succession. The presence of continental crust in the JMMC is inferred by seismic and magnetic data, but ground truthing evidence have yet to be provided. Here, we present the results from a seafloor sampling campaign undertaken in 2011 on the Southern Jan Mayen Ridge complex. Seabed samples were recovered using a gravity corer and a dredge along a 1000 m high escarpment with a 19° slope. Sampling locations were selected based on the interpretation of seismic profiles that suggest the presence of possible pre-breakup successions outcropping along this steep escarpment. Results include a sequence of samples with age diagnostic palynomorph assemblages ranging from Permian/Triassic to Eocene, and including igneous samples related to the Early Eocene breakup volcanism. Importantly, the samples were retrieved from hard substrate in an erosional gully lacking overburden sediments and have ages arranged in younging upward sequential order, supporting their near in-situ position. The sampling results were integrated into a lithostratigraphic pseudo-well that can be used to constrain the evolution and breakup of the JMMC. Additionally, evidence for active migration of Jurassic sourced hydrocarbons comprise the first indication of a working hydrocarbon system, with important implications for the petroleum prospectivity of the Dreki area. Finally, these results confirm that the Southern Jan Mayen Ridge is indeed a sliver of continental crust.

• Reiser, Fabienne; Schmelzbach, Cedric; Sollberger, David; Maurer, Hansruedi; Greenhalgh, Stewart; Planke, Sverre; Kastner, Felix; Flovenz, Olafur G; Giese, Rudiger; Halldorsdottir, Sæunn & Hersir, Gylfi Pall (2018). Imaging the high-temperature geothermal field at Krafla using vertical seismic profiling. Journal of Volcanology and Geothermal Research.  ISSN 0377-0273. . doi: 10.1016/j.jvolgeores.2018.10.019
• Svensen, Henrik; Frolov, Sergei; G., Akhmanov; Polozov, Alexander; Jerram, Dougal Alexander; Shiganova, O.; Melnikov, N.; Iyer, K. & Planke, Sverre (2018). Sills and gas generation in the Siberian Traps. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.  ISSN 1364-503X.  376(2130) . doi: 10.1098/rsta.2017.0080
• Svensen, Henrik; Torsvik, Trond Helge; Callegaro, Sara; Augland, Lars Eivind; Heimdal, Thea Hatlen; Jerram, Dougal Alexander; Planke, Sverre & Pereira, Egberto (2018). Gondwana large igneous provinces: plate reconstructions, volcanic basins and sill volumes. In: Large Igneous Provinces from Gondwana and Adjacent Regions. Geological Society Special Publication.  ISSN 0305-8719.  463, s 17- 40 . doi: 10.1144/SP463.7
• Tasianas, Alexandros; Bünz, Stefan; Bellwald, Benjamin; Hammer, Øyvind; Planke, Sverre; Lebedeva-Ivanova, Nina & Krassakis, Pavlos (2018). High-resolution 3D seismic study of pockmarks and shallow fluid flow systems at the Snøhvit hydrocarbon field in the SW Barents Sea. Marine Geology.  ISSN 0025-3227.  403, s 247- 261 . doi: 10.1016/j.margeo.2018.06.012 Fulltekst i vitenarkiv.
• Zastrozhnov, Dmitrii; Gernigon, Laurent; Gogin, I; Abdelmalak, Mohamed Mansour; Planke, Sverre; Faleide, Jan Inge; Eide, S. & Myklebust, R. (2018). Cretaceous-Paleocene Evolution and Crustal Structure of the Northern V?ring Margin (Offshore Mid-Norway): Results from Integrated Geological and Geophysical Study. Tectonics.  ISSN 0278-7407.  37(2), s 497- 528 . doi: 10.1002/2017TC004655
• Abdelmalak, Mohamed Mansour; Faleide, Jan Inge; Planke, Sverre; Gernigon, Laurent; Zastrozhnov, Dmitry; Shephard, Grace & Myklebust, Reidun (2017). The T-Reflection and the Deep Crustal Structure of the Vøring Margin, Offshore mid-Norway. Tectonics.  ISSN 0278-7407.  36(11), s 2497- 2523 . doi: 10.1002/2017TC004617 Fulltekst i vitenarkiv.
• Angkasa, Syahreza Saidina; Jerram, Dougal Alexander; Millett, John M; Svensen, Henrik; Planke, Sverre; Taylor, Ross A; Schofield, Nick & Howell, John (2017). Mafic intrusions, hydrothermal venting and the basalt-sediment transition: Linking onshore and offshore examples from the north atlantic igneous province. Interpretation.  ISSN 2324-8858.  5(3) . doi: 10.1190/int-2016-0162.1 Fulltekst i vitenarkiv.
• Corseri, Romain; Senger, Kim; Selway, Katherine; Abdelmalak, Mohamed Mansour; Planke, Sverre & Jerram, Dougal Alexander (2017). Magnetotelluric evidence for massive sulphide mineralization in intruded sediments of the outer Vøring Basin, mid-Norway. Tectonophysics.  ISSN 0040-1951.  706-707, s 196- 205 . doi: 10.1016/j.tecto.2017.04.011 Fulltekst i vitenarkiv.
• Fristad, Kirsten; Svensen, Henrik; Polozov, Alexander & Planke, Sverre (2017). Formation and evolution of the end–Permian Oktyabrsk volcanic crater in the Tunguska Basin, Eastern Siberia. Palaeogeography, Palaeoclimatology, Palaeoecology.  ISSN 0031-0182.  468, s 76- 87 . doi: 10.1016/j.palaeo.2016.11.025
• Hafeez, Amer; Planke, Sverre; Jerram, Dougal Alexander; Millett, John M; Maharjan, Dwarika & Prestvik, Tore (2017). Upper paleocene ultramafic igneous rocks offshore mid-Norway: Re-interpretation of the vestbrona formation as a sill complex. Interpretation.  ISSN 2324-8858.  5(3), s SK103- SK120 . doi: 10.1190/int-2016-0143.1 Fulltekst i vitenarkiv.
• Iyer, Karthik Herman; Schmid, Daniel Walter; Planke, Sverre & Millett, John (2017). Modelling hydrothermal venting in volcanic sedimentary basins: Impact on hydrocarbon maturation and paleoclimate. Earth and Planetary Science Letters.  ISSN 0012-821X.  467, s 30- 42 . doi: 10.1016/j.epsl.2017.03.023 Fulltekst i vitenarkiv.
• Jones, Morgan Thomas; Augland, Lars Eivind; Shephard, Grace; Burgess, Seth; Eliassen, Gauti Trygvason; Jochmann, Malte; Friis, Bjarki; Jerram, Dougal Alexander; Planke, Sverre & Svensen, Henrik (2017). Constraining shifts in North Atlantic plate motions during the Palaeocene by U-Pb dating of Svalbard tephra layers. Scientific Reports.  ISSN 2045-2322.  7(1) . doi: 10.1038/s41598-017-06170-7 Fulltekst i vitenarkiv.
• Kjoberg, Sigurd; Schmiedel, Tobias; Planke, Sverre; Svensen, Henrik; Millett, John; Jerram, Dougal Alexander; Galland, Olivier; Lecomte, Isabelle; Schofield, Nick; Haug, Øystein Thorden & Helsem, Andreas (2017). 3D structure and formation of hydrothermal vent complexes at the paleocene-eocene transition, the Møre basin, MID-Norwegian margin. Interpretation.  ISSN 2324-8858.  5(3), s SK65- SK81 . doi: 10.1190/int-2016-0159.1 Fulltekst i vitenarkiv. Vis sammendrag

  The mid-Norwegian margin is regarded as an example of a volcanic-rifted margin, formed prior to and during, Paleogene breakup of the northeast Atlantic. The area is characterized by the presence of voluminous basaltic complexes such as extrusive lava and lava delta sequences, intrusive sills and dikes, and hydrothermal vent complexes. We have developed a detailed 3D seismic analysis of fluid-and gas-induced hydrothermal vent complexes in a 310 km2 area in the Møre Basin, offshore Norway. We find that formation of hydrothermal vent complexes is accommodated by deformation of the host rock when sills are emplaced. Fluids are generated by metamorphic reactions and pore-fluid expansion around sills and are focused around sill tips due to buoyancy. Hydrothermal vent complexes are associated with doming of the overlying strata, leading to the formation of draping mounds above the vent contemporary surface. The morphological characteristics of the upper part and the underlying feeder structure (conduit zone) are imaged and studied in 3D seismic data. Well data indicate that the complexes formed during the early Eocene, linking their formation to the time of the Paleocene-Eocene thermal maximum at c. 56 Ma. The well data further suggest that the hydrothermal vent complexes were active for a considerable time period, corresponding to a c. 100 m thick transition zone unit with primary Apectodinium augustum and redeposited very mature Cretaceous and Jurassic palynomorphs. The newly derived understanding of age, structure, and formation of hydrothermal vent complexes in the Møre Basin contributes to the general understanding of the igneous plumbing system in volcanic basins and their implications for the paleoclimate and petroleum systems.

• Mazzini, Adriano; Svensen, Henrik; Forsberg, Carl Fredrik; Linge, Henriette; Lauritzen, Stein-Erik; Haflidason, Haflidi; Hammer, Øyvind; Planke, Sverre & Tjelta, Tor-Inge (2017). A climatic trigger for the giant Troll pockmark field in the northern North Sea. Earth and Planetary Science Letters.  ISSN 0012-821X.  464, s 24- 34 . doi: 10.1016/j.epsl.2017.02.014 Fulltekst i vitenarkiv. Vis sammendrag

  Pockmarks are seafloor craters usually formed during methane release on continental margins. However, the mechanisms behind their formation and dynamics remain elusive. Here we report detailed investigations on one of the World's largest pockmark fields located in the Troll region in the northern North Sea. Seafloor investigations show that >7000 pockmarks are present in a ∼600 km2 area. A similar density of pockmarks is likely present over a 15,000 km2 region outside our study area. Based on extensive monitoring, coring, geophysical and geochemical analyses, no indications of active gas seepage were found. Still, geochemical data from carbonate blocks collected from these pockmarks indicate a methanogenic origin linked to gas hydrate dissociation and past fluid venting at the seafloor. We have dated the carbonates using the U–Th method in order to constrain the pockmark formation. The carbonates gave an isochron age of 9.59±1.38 ka9.59±1.38 ka, i.e. belonging to the initial Holocene. Moreover, radiocarbon dating of microfossils in the sediments inside the pockmarks is consistent with the ages derived from the carbonates. Based on pressure and temperature modelling, we show that the last deglaciation could have triggered dissociation of gas hydrates present in the region of the northern part of the Norwegian Channel, causing degassing of 0.26 MtCH4/km2 at the seafloor. Our results stress the importance of external climatic forcing of the dynamics of the seafloor, and the role of the rapid warming following the Younger Dryas in pacing the marine gas hydrate reservoir.

• Planke, Sverre; Millett, John M; Maharjan, Dwarika; Jerram, Dougal Alexander; Abdelmalak, Mohamed Mansour; Groth, Audun; Hoffmann, Jasper; Berndt, Christian & Myklebust, Reidun (2017). Igneous seismic geomorphology of buried lava fields and coastal escarpments on the Vøring volcanic rifted margin. Interpretation.  ISSN 2324-8858.  5(3), s SK161- SK177 . doi: 10.1190/INT-2016-0164.1 Fulltekst i vitenarkiv.
• Reynolds, P.; Planke, Sverre; Millett, J.M.; Jerram, Dougal Alexander; Trulsvik, M.; Schofield, N. & Myklebust, R. (2017). Hydrothermal vent complexes offshore Northeast Greenland: A potential role in driving the PETM. Earth and Planetary Science Letters.  ISSN 0012-821X.  467, s 72- 78 . doi: 10.1016/j.epsl.2017.03.031 Fulltekst i vitenarkiv.
• Schmiedel, Tobias; Kjoberg, Sigurd; Planke, Sverre; Magee, Craig; Galland, Olivier; Schofield, Nick; Jackson, Christopher A.-L. & Jerram, Dougal Alexander (2017). Mechanisms of overburden deformation associated with the emplacement of the Tulipan sill, mid-Norwegian margin. Interpretation.  ISSN 2324-8858.  5(3), s SK23- SK38 . doi: 10.1190/INT-2016-0155.1 Fulltekst i vitenarkiv. Vis sammendrag

  The emplacement of igneous intrusions into sedimentary basins mechanically deforms the host rocks and causes hydrocarbon maturation. Existing models of host-rock deformation are investigated using high-quality 3D seismic and industry well data in the western Møre Basin offshore mid-Norway. The models include synemplacement (e.g., elastic bending-related active uplift and volume reduction of metamorphic aureoles) and postemplacement (e.g., differential compaction) mechanisms. We use the seismic interpretations of five horizons in the Cretaceous-Paleogene sequence (Springar, Tang, and Tare Formations) to analyze the host rock deformation induced by the emplacement of the underlying saucer-shaped Tulipan sill. The results show that the sill, emplaced between 55.8 and 54.9 Ma, is responsible for the overlying dome structure observed in the seismic data. Isochron maps of the deformed sediments, as well as deformation of the younger postemplacement sediments, document a good match between the spatial distribution of the dome and the periphery of the sill. The thickness tt of the Tulipan is less than 100 m, whereas the amplitude ff of the overlying dome ranges between 30 and 70 m. Spectral decomposition maps highlight the distribution of fractures in the upper part of the dome. These fractures are observed in between hydrothermal vent complexes in the outer parts of the dome structure. The 3D seismic horizon interpretation and volume rendering visualization of the Tulipan sill reveal fingers and an overall saucer-shaped geometry. We conclude that a combination of different mechanisms of overburden deformation, including (1) elastic bending, (2) shear failure, and (3) differential compaction, is responsible for the synemplacement formation and the postemplacement modification of the observed dome structure in the Tulipan area.

• Senger, Kim; Millett, John; Planke, Sverre; Ogata, Kei; Eide, Christian Haug; Festøy, Marte Hergot; Galland, Olivier & Jerram, Dougal Alexander (2017). Effects of igneous intrusions on the petroleum system: a review. First Break.  ISSN 0263-5046.  35(6), s 47- 56 . doi: 10.3997/1365-2397.2017011
• Spacapan, Juan Bautista; Galland, Olivier; Leanza, Hector Armando & Planke, Sverre (2017). Igneous sill and finger emplacement mechanism in shale-dominated formations: a field study at Cuesta del Chihuido, Neuquén Basin, Argentina. Journal of the Geological Society.  ISSN 0016-7649.  174(3), s 422- 433 . doi: 10.1144/jgs2016-056
• Abdelmalak, Mohamed Mansour; Meyer, Romain; Planke, Sverre; Faleide, Jan Inge; Gernigon, Laurent; Frieling, J; Sluijs, Appy; Reichart, G-J; Zastrozhnov, Dmitrii; Theissen-Krah, Sonja; Said, Aymen & Myklebust, Reidun (2016). Pre-breakup magmatism on the Vøring margin: Insight from new sub-basalt imaging and results from Ocean Drilling program hole 642E. Tectonophysics.  ISSN 0040-1951.  675, s 258- 274 . doi: 10.1016/j.tecto.2016.02.037
• Abdelmalak, Mohamed Mansour; Planke, Sverre; Faleide, Jan Inge; Jerram, Dougal Alexander; Zastrozhnov, Dmitrii; Eide, Sigurd & Myklebust, Reidun (2016). The development of volcanic sequences at rifted margins: New insights from the structure and morphology of the Vøring Escarpment, mid-Norwegian Margin. Journal of Geophysical Research (JGR): Solid Earth.  ISSN 2169-9313.  121(7), s 5212- 5236 . doi: 10.1002/2015JB012788

Se alle arbeider i Cristin

• Faleide, Thea Sveva; Braathen, Alvar; Lecomte, Isabelle; Anell, Ingrid Margareta; Midtkandal, Ivar & Planke, Sverre (2020). Seismic modelling of faults; viable geometries vs seismic resolution in the subsurface. Vis sammendrag

  Resolution and illumination issues in seismic data curtails identification of fault geometries and fault-initiated rock damage when mapping subsurface faults. Seismic modelling can be utilized to bridge the gap in identifying what can be imaged with certainty in seismic data, with respect to the original geology, especially when also comparing to outcrop data. In this study, we explore how seismic modelling can distinguish between real structures versus seismic artefacts. 2(3)D Point-Spread-Function based convolution modelling is used in a sensitivity study. One input is detailed fault interpretations of high-resolution P-Cable data and comparable conventional 3D seismic data from the Hoop area in the Barents Sea. Another dataset comes from detailed fault geometries observed in outcrops, which were used to build geological models as input to the seismic modelling. In addition to the host-rock lithofacies, parameters of importance for the geological model building include overall fault geometry and the distribution of architectural elements (fault facies) within the fault zone. By varying fault input, lithofacies, a wide range of frequencies, and illumination, we analyse a variety of synthetic seismic images. Finally we compare our modelled outcomes with seismic data from the Hoop area. The scope of the workflow is to increase confidence in seismic interpretations and to identify limitations in the analysis of steep, normal faults in seismic data.

• Bellwald, Benjamin; Planke, Sverre; Polteau, Stephane; Lebedeva-Ivanova, Nina; Faleide, Jan Inge; Morris, S; Morse, S. & Castelltort, Sébastien (2019). Bjørnelva: A Pleistocene braided river imaged in high- resolution 3D seismic data in the SW Barents Sea. NGF Abstracts and Proceedings of the Geological Society of Norway.  (1)
• Gernigon, Laurent; Zastrozhnov, Dmitrii; Abdelmalak, Mohamed Mansour; Planke, Sverre; Faleide, Jan Inge & Myklebust, Reidun (2019). A new structural and magmatic elements map of the mid-Norwegian margin. NGF Abstracts and Proceedings of the Geological Society of Norway.  (1)
• Lebedeva-Ivanova, Nina; Polteau, Stephane; Zastrozhnov, Dmitrii; Planke, Sverre; Bellwald, Benjamin; Vanneste, Maarten; Sauvin, Guillaume & Myklebust, Reidun (2019). A new method for offshore meter-scale 3D site characterization. NGF Abstracts and Proceedings of the Geological Society of Norway.  (1)
• Lebedeva-Ivanova, Nina; Polteau, Stephane; Zastrozhnov, Dmitry; Planke, Sverre; Waage, Malin; Bünz, Stefan; Bellwald, Benjamin; Vanneste, Maarten; Sauvin, Guillaume & Myklebust, R. (2019). Meter-Scale 3D Seismic Data for High-Resolution Site Characterization. EarthDoc. . doi: 10.3997/2214-4609.201901933 Fulltekst i vitenarkiv.
• Planke, Sverre; Corseri, Romain; Polteau, Stephane; Faleide, Jan Inge; Midtkandal, Ivar; Faleide, Thea Sveva; Senger, Kim; Myklebust, Reidun & Tegner, Christian (2019). HALIP Implications for Early Cretaceous Sedimentation in the Barents Sea.
• Polteau, Stephane; Zastrozhnov, Dmitrii; Lebedeva-Ivanova, Nina; Planke, Sverre; Schmid, Daniel Walter; Iyer, Karthik Herman; Trulsvik, Mikal & Myklebust, Reidun (2019). An integrated conjugate margin approach for hydrocarbon exploration in the outer Vøring Basin. NGF Abstracts and Proceedings of the Geological Society of Norway.  (1)
• Zastrozhnov, Dmitrii; Gernigon, Laurent; Gogin, I; Planke, Sverre; Faleide, Jan Inge; Manton, Ben; Abdelmalak, Mohamed Mansour; Iyer, Karthik Herman; Schmid, Daniel Walter & Myklebust, Reidun (2019). Cretaceous-Paleocene tectonostratigraphic development of the Møre and Vøring basins, offshore Mid-Norway. NGF Abstracts and Proceedings of the Geological Society of Norway.  (1)
• Barrett, Rachel; Bellwald, Benjamin; Krastel, Sebastian; Gross, Felix; Micallef, Aaron; Planke, Sverre; Berndt, Christian; Talling, Peter & Myklebust, Reidun (2019). New Constraints on the Failure Mechanism and Kinematics of the Tampen Slide (North Sea) from 3D Seismic Data.
• Bellwald, Benjamin; Planke, Sverre; Barrett, Rachel; Batchelor, Christine & Myklebust, Reidun (2019). Characterization of Glacigenic Debris Flows, Megaslides and Contourites of the North Sea Fan from 3D Seismic Data.
• Bellwald, Benjamin; Planke, Sverre; Barrett, Rachel; Berndt, Christian; Manton, Ben & Myklebust, Reidun (2019). Characterization of glacigenic debris flows and megaslides of the North Sea Fan from 3D seismic data. NGF Abstracts and Proceedings of the Geological Society of Norway.  (1)
• Blischke, Anett; Brandsdottir, Bryndis; Erlendsson, Ögmundur; Planke, Sverre & Gaina, Carmen (2019). The Jan Mayen microcontinent and Iceland Plateau volcanic breakup margins.
• Corseri, Romain; Faleide, Thea Sveva; Faleide, Jan Inge; Midtkandal, Ivar; Serck, Christopher Sæbø; Trulsvik, Mikal & Planke, Sverre (2019). A diverted submarine channel of Early Cretaceous age revealed by integration of P-Cable seismic and CSEM data in the SW Barents Sea. NGF Abstracts and Proceedings of the Geological Society of Norway.  (1)
• Faleide, Thea Sveva; Midtkandal, Ivar; Planke, Sverre; Corseri, Romain; Faleide, Jan Inge; Nystuen, Johan Petter; Anell, Ingrid Margareta & Braathen, Alvar (2019). High-resolution seismic imaging and modelling of structural and stratigraphical features in the SW Barents Sea. Vis sammendrag

  Poster at the AAPG 2019 conference, San Antonio, Texas, USA

• Faleide, Thea Sveva; Midtkandal, Ivar; Planke, Sverre; Corseri, Romain; Faleide, Jan Inge; Nystuen, Johan Petter & Braathen, Alvar (2019). Barremian delta and Early Cretaceous faulting revealed by high resolution 3D seismic data in the southwestern Barents Sea. NGF Abstracts and Proceedings of the Geological Society of Norway.  (1)
• Jochmann, Malte Michel; Senger, Kim; Betlem, Peter; Smyrak-Sikora, Aleksandra; Elvevold, Synnøve; Myhre, Per Inge; Heldal, Tom; Planke, Sverre; juul, maria; Milovslavskij, Michail; Kusiak, Monika A & Sielski, Włodzimierz (2019). Svalbard Rock Vault 2020: let us safeguard Svalbard’s geoscientific heritage together.
• Jones, Morgan Thomas; Hammer, Øyvind; Bucher, Hugo; Schneebeli-Hermann, Elke; Mather, Tamsin; Svensen, Henrik & Planke, Sverre (2019). Are Mercury Anomalies a Reliable Proxy for LIP Volcanism? Examples from the End-Permian and Early Triassic.
• Kjøll, Hans Jørgen; Andersen, Torgeir Bjørge; Galland, Olivier; Corfu, Fernando; Labrousse, Loic; Tegner, Christian & Planke, Sverre (2019). Deep section of a Neoproterozoic fossil magma rich rifted margin exposed. Vis sammendrag

  Structures of rifted continental margins are the finite result of active processes when continents rift apart. During the convergent stages of Wilson cycle, remnants of rifted margins may be incorporated into orogens, especially the magma-poor end-member. The magma-rich margins, however, are commonly lost in subduction due to low buoyancy. The understanding of magma-rich margins is therefore mostly based on drill holes and geophysical observations. In this contribution, we explore the temporal evolution and the ambient conditions of a magma-rich rifted margin preserved within the Scandinavian Caledonides. The Scandinavian Dyke Complex was emplaced in a sedimentary basin during the opening of the Iapetus Ocean 615 to 590 million years ago. The dyke complex now constitutes 70-90% of the area and is locally well-preserved despite the complex Caledonian history. Five field seasons in northern Sweden and Norway provide new observations from regional to microscopic scale about the structural geometry, relative timing, and development of the margin. Jadeite in clinopyroxene geothermobarometry, titanium in biotite geothermometry and garnet isopleth modeling show that the ambient pressure and temperature conditions were similar for the entire dyke complex at 0.25 to 0.45 GPa, with contact metamorphic temperatures up to c. 700◦C. Using a photomosaic of a large and well-exposed cliff face we used layers in the metasediments as markers to restore the host-rock back to the pre-dike configuration, allowing us to quantify the average strain accommodated by the dyke swarm. It accommodated for >100% extension and for 27% crustal thickening. From this we infer that the magma influx rate was higher than the tectonic stretching rate, implying that magma was emplaced in a forceful manner, which is also supported by field observations. In the northern part of the study area, high precision dating of magmatic zircon shows that significant partial melting of the sedimentary host-rock, at relatively shallow levels, occurred at 613 ± 1 Ma. This shows that the crust was molten already 6 Ma before the dyke swarm was emplaced at 606 ± 2 Ma. We propose that the locally pervasive partial melting occurred due to high geothermal gradient and introduction of mafic melts in the lower crust. These processes caused a rapid shallowing of the brittle-ductile transition, which thereby significantly reduced the strength of the crust.

• Manton, Ben; Planke, Sverre; Millet, John; Zastrozhnov, Dmitrii; Mazzini, Adriano; Muller, Philipp & Myklebust, Reidun (2019). Hydrothermal vent complexes acting as preferential fluid migration pathway: a comparative study of the NE Atlantic and Indonesia.
• Manton, Ben; Planke, Sverre; Millett, John; Zastrozhnov, Dmitrii; Mazzini, Adriano; Muller, Philipp & Myklebust, Reidun (2019). Hydrothermal vent complexes acting as preferential fluid migration pathways in the Møre and Vøring basins. NGF Abstracts and Proceedings of the Geological Society of Norway.  (1)
• Planke, Sverre (2019). Emplacement processes of large-volume basaltic sequences during the formation of volcanic rifted margins.
• Planke, Sverre; Millett, John; Jerram, Dougal Alexander; Zastrozhnov, Dmitrii; Maharjan, Dwarika; Manton, Ben; Faleide, Jan Inge; Walker, Faye & Myklebust, Reidun (2019). Igneous seismic geomorphology of Paleogene basalts in the West of Shetland, Møre, and Vøring basins. NGF Abstracts and Proceedings of the Geological Society of Norway.  (1)
• Polozov, Alexander; Planke, Sverre; Millett, John; Svensen, Henrik & Jerram, Dougal Alexander (2019). Hybrid rocks formation at onset of the Siberian Traps basalt lavas eruption and shallow intrusions emplacement.
• Svensen, Henrik; John, Timm; Weyer, Stefan; Fristad, Kirsten; Polozov, Alexander; Bajard, Manon Julietto Andree; Jones, Morgan Thomas & Planke, Sverre (2019). Bacterial sulphate- and iron reduction in a Siberian Traps crater lake during the end-Permian crisis.
• Tegner, Christian; Andersen, Torgeir Bjørge; Kjøll, Hans Jørgen; Brown, Eric L.; Hagen-Peter, Graham; Corfu, Fernando; Planke, Sverre & Torsvik, Trond Helge (2018). The pre-Caledonian Scandinavian Dyke Complex and 600 Ma plate reconstructions of Baltica. Vis sammendrag

  A spectacular dyke complex is surprisingly well preserved along c. 1000 km in the Caledonian nappes of central and northern Scandinavia. This dyke complex was originally emplaced into continental sedimentary basins along the rifted margin of Baltica, it is part of the Central Iapetus Magmatic Province (CIMP), and it has U-Pb ages of 615-590 Ma. To constrain its origin and to potentially guide plate reconstructions of Baltica we: (1) re-visited the dyke complexes of the Ottfjället, Sarek, Kebnekaise, Tornetrask and Indre Troms mountains of Sweden and Norway; (2) produced new and compiled published geochemical data; (3) modeled mantle sources and melting dynamics; and (4) extended reconstructions of the paleo-position of Baltica back to 600 Ma. The compiled dataset includes c. 600 analyses that forms a coherent suite dominated by tholeiitic ferrobasalt, but including alkali basalts in the central portion. The tholeiitic dykes display lateral variations in geochemical enrichment (e.g. delta-Nb, La/Sm(N) and Sr isotopes) in the southern and central portions, grading to more depleted compositions in the north. Our petrological modeling suggests melting of asthenospheric mantle involving at least two source compositions at temperatures elevated about 100 °C above ambient mantle, consistent with melting of a zoned mantle plume originating from a plume generation zone at the core-mantle boundary. If the position of the present plume generation zone in the Pacific can be viewed as stationary back to 600 Ma, we entertain the idea that the Scandinavian Dyke Complex may be used to guide plate reconstructions.

• Andersen, Torgeir Bjørge; Jakob, Johannes; Kjøll, Hans Jørgen; Corfu, Fernando; Planke, Sverre; Torsvik, Trond Helge; Tegner, Christian; Labrousse, Loic & Mohn, Geoffroy (2018). The Pre-Caledonian Margin of Baltica: overview and research in progress. Vis sammendrag

  The Caledonian margin of Baltica formed by continental break-up of Rodinia in the Late Proterozoic to Ediacaran. With exception of the dike-swarm near Egersund in SW Norway, the Fennoscandian basement including the autochthonous basement windows along the axis of the mountain belt were little affected by the magmatism associated with the break-up. The distal parts, however, were strongly attenuated, hyper-extended and a 1000 km long segment, intensively intruded by a Large Igneous Province (LIP), the Pre-Caledonian LIP (PC-LIP). Here, we provide glimpses of our work in progress from the vestiges of the margin. More details on several aspects of the margin evolution are presented by co-authors. Here we present a regional model for the pre-Caledonian margin suggesting it was highly complex and included micro-continental sliver(s) and both a hyperextended, magma-poor domain with transition(s) to attenuated embryonic oceanic and magma-rich margin domains. The break-up related PC-LIP magmatism lasted from approximately 615 to 570 Ma, but the most intense activity appears to have been at ~600 Ma. Our ongoing work suggests that the impingement of a mantle plume on the Ediacaran continental lithosphere was associated with a temperature anomaly of ~100oC, causing widespread melting of the asthenosphere and dyke-intrusion of the continental crust and sediments of the margin. We suggest that the pre-Caledonian margin of the Iapetus preserved in the Scandes comprise most of the elements of passive continental margins, and that it probably represents one of the best exposed field analogue for the deeper and least known parts of passive margins.

• Jerram, Dougal Alexander; Svensen, Henrik; Planke, Sverre; Millett, John M; Jones, Morgan Thomas; Augland, Lars Eivind & Abdelmalak, Mansour (2018). Types and styles of volcanism in the North Atlantic Igneous Province: Implications towards understanding their potential climatic impact..
• Jones, Morgan Thomas; Stokke, Ella Wulfsberg; Schultz, Bo; Augland, Lars Eivind; Planke, Sverre; Tegner, Christian; Mather, Tamsin; Percival, Lawrence & Svensen, Henrik (2018). Fur Island in Denmark: A window into Paleocene-Eocene hyperthermals and North Atlantic volcanism.
• Karstens, Jens; Haflidason, Haflidi; Becker, Lukas; Berndt, Christian; Rüpke, Lars Helmuth; Planke, Sverre; Liebetrau, Volker; Schmidt, Mark & Mienert, Jurgen (2018). Correction: Glacigenic sedimentation pulses triggered post-glacial gas hydrate dissociation (Nature Communications DOI: 10.1038/s41467-018-03043-z). Nature Communications.  ISSN 2041-1723.  9(1) . doi: 10.1038/s41467-018-03587-0
• Kjøll, Hans Jørgen; Andersen, Torgeir Bjørge; Tegner, Christian; Labrousse, Loic & Planke, Sverre (2018). A fossil magma-rich margin revealed. Vis sammendrag

  A fossil magma-rich rifted margin revealed Hans Jørgen Kjøll, Torgeir B. Andersen, Christian Tegner, Loic Labrousse and Sverre Planke 1) CEED 2) Aarhus Universite 3) Paris 4) CEED/VBPR The Iapetus opened ~610 Myr ago, when a plume impinged on the lower crust of Baltica and Laurentia. Stretching of the conjoined crystalline crust started in the Neoproteozoic, prior to break-up and provided accommodation for continental and shallow marine syn-rift sediments. An early a-magmatic phase with discrete and localized deformation was followed by pervasive mafic magmatism where dike-emplacement accounted for the majority of the stretching. During the Caledonian orogeny the Baltican margin was thrusted onto Baltica as the Iapetus closed. Now, vestiges of the magma-rich margin resides within nappes from central Sweden to northern Norway. Although, overprinted by Caledonian fabrics, there are localities where pre-Caledonian structures are well-preserved, thereby allowing for detailed studies of deep to intermediate processes at magma-rich rifted margins. We propose the architecture of the magma-rich margin of Baltica and magma-rich rifted margins in general can be studied in the Caledonides. The well-preserved parts of the margin comprise: 1) Parts of a lower crustal magmatic complex w/gabbros and mafic dykes intruding stretched crystalline basement; 2) Strongly stretched and attenuated crystalline basement intruded by mafic dikes; 3) Highly intruded pre- to syn-rift sediments and 4) Extrusive mafic lavas, including pillow basalts, interlayered with metasediments. Together these levels represent a nearly continuous section through a magma-rich rifted margin, with some never-before described levels, such as the lower crustal magmatic complex.

• Svensen, Henrik; Jerram, Dougal Alexander; Polozov, Alexander; Jones, Morgan Thomas; Augland, Lars Eivind & Planke, Sverre (2018). Volcanic causes for the PETM and other past hothouse climates.
• Andersen, Torgeir Bjørge; Jakob, Johannes; Kjøll, Hans Jørgen; Corfu, Fernando; Tegner, Christian; Mohn, Geoffroy; Labrousse, Loic; Planke, Sverre & Abdelmalak, Mohamed Mansour (2017). The Magma-poor and Magma-rich settings; the onshore perspective: The Caledonian case.
• Andersen, Torgeir Bjørge; Jakob, Johannes; Kjøll, Hans Jørgen; Corfu, Fernando; Planke, Sverre; Torsvik, Trond Helge; Tegner, Christian & Labrousse, Loic (2017). The Pre-Caledonian Margin of Baltica. Vis sammendrag

  The pre-Caledonian margin of Baltica formed by the rifting and eventual continental break-up of Rodinia in the Late Proterozoic to Ediacaran. With exception of the ca. 615 Ma dolerite dike-swarm near Egersund in SW Norway, the Fennoscandian basement including the mostly autochthonous basement windows in western Scandinavia (Lofoten, Western Gneiss Region, etc.) were surprisingly little affected by the rifting and the subsequent magmatism associated with the break-up. The distal parts of the margin, however, were strongly attenuated, hyper-extended and in a more than 1000 km long segment, intensively intruded by a break-up related Large-Igneous Province (LIP), here referred to as the Pre-Caledonian LIP (PC-LIP). In this presentation, we provide glimpses of new results and observations as well as work in progress from a large part of the nappe-stack of Scandinavian Caledonides containing the vestiges of the pre-Caledonian margin. More details on several aspects of the Pre-Caledonian margin evolution are presented by co-workers during this meeting. Based on our recent and some previous work, we propose a regional paleogeography model for the pre-Caledonian passive margin as it evolved from the Ediacaran into the late-Cambrian to the early-Ordovician, when the Iapetus Ocean started closing. We suggest that the distal margin architecture was highly complex and included micro-continental sliver(s) and a hyperextended, magma-poor domain with transition(s) to highly attenuated embryonic oceanic and magma-rich passive margin domains. The break-up related PC-LIP magmatism lasted from approximately 615 to 570 Ma, but the most intense dyke-emplacement appears to have been around 600 Ma. Our ongoing structural and metamorphic petrology studies, combined with geochronology, geochemical analyses and petrological modelling suggest that the impingement of a mantle plume on the Ediacaran continental lithosphere may have been associated with a temperature anomaly of up to 100oC, causing widespread melting of the asthenosphere as well as partial melt-generation in highly attenuated and intensely dike-intruded parts of the continental crust and sediments of the margin. It is our opinion that the pre-Caledonian distal margin rocks of the Iapetus as preserved in nappes of Scandinavian Caledonides preserve most of the elements of wide passive margins, and that it probably represents one of the best exposed field analogue for the deeper and least known parts of passive margins.

• Faleide, Jan Inge; Abdelmalak, Mohamed Mansour; Shephard, Grace; Torsvik, Trond Helge; Gaina, Carmen; Tsikalas, Filippos; Blaich, Olav Antonio; Planke, Sverre & Myklebust, Reidun (2017). Quantification and restoration of pre-drift extension across NE Atlantic conjugate margins.
• Jerram, Dougal Alexander; Svensen, Henrik; Planke, Sverre; Millett, John M & Reynolds, Pete (2017). Sill induced hydrothermal venting: A summary of our current understanding..
• Jones, Morgan Thomas; Augland, Lars Eivind; Shephard, Grace; Burgess, Seth; Eliassen, Gauti; Jerram, Dougal Alexander; Jochmann, Malte; Friis, Bjarki; Planke, Sverre & Svensen, Henrik (2017). Bentonite layers in Svalbard: constraining sources of volcanism, geochronology, and relative plate motions during the Paleogene.
• Kjøll, Hans Jørgen; Andersen, Torgeir Bjørge; Tegner, Christian; Corfu, Fernando & Planke, Sverre (2017). Wilson cycle-kick-off: Constraining the influence of a LIP during the Neoproterozoic evolution of the pre-Caledonian margin of Baltica and Laurentia.
• Mazzini, Adriano; Svensen, Henrik; Forsberg, Carl Fredrik; Linge, Henriette; Lauritzen, Stein-Erik; Haflidason, Haflidi; Hammer, Øyvind; Planke, Sverre & Tjelta, Tor-Inge (2017). A Climatic Trigger for the Giant Troll Pockmark Field in the Northern North Sea. Vis sammendrag

  Pockmarks are seafloor craters usually formed during methane release on continental margins. However, the mechanisms behind their formation and dynamics remain elusive. Here we report detailed investigations on one of the World’s largest pockmark fields located in the Troll region in the northern North Sea. Seafloor investigations show that >7000 pockmarks are present in a ~600 km2 area. A similar density of pockmarks is likely present over a 15,000 km2 region outside our study area. Based on extensive monitoring, coring, geophysical and geochemical analyses, no indications of active gas seepage were found. Still, geochemical data from carbonate blocks collected from these pockmarks indicate a methanogenic origin linked to gas hydrate dissociation and past fluid venting at the seafloor. We have dated the carbonates using the U-Th method in order to constrain the pockmark formation. The carbonates gave an isochron age of 9.59 ± 1.38 ka BP, i.e. belonging to the initial Holocene. Moreover, radiocarbon dating of microfossils in the sediments inside the pockmarks are consistent with the ages derived from the carbonates. Based on pressure and temperature modelling, we show that the last deglaciation could have triggered dissociation of gas hydrates present in the region of the northern part of the Norwegian Channel, causing degassing of 0.26 MtCH4/km2 at the seafloor. Our results stress the importance of external climatic forcing of the dynamics of the seafloor, and the role of the rapid warming following the Younger Dryas in pacing the marine gas hydrate reservoir.

• Millett, J.M.; Haskins, Eric; Thomas, Donald; Jerram, Dougal Alexander; Planke, Sverre; Healy, D; Kück, Jochem; Rossetti, Lucas; Farrell, Natalie & Pierdominici, Simona (2017). Porosity and permeability evolution of vesicular basalt reservoirs with increasing depth: constraints from the Big Island of Hawai'i..
• Pierdominici, Simona; Kueck, Jochem; Millett, J.M.; Planke, Sverre; Jerram, Dougal Alexander; Haskins, Eric & Thomas, Donald (2017). Present-day stress state analysis on the Big Island of Hawaíi, USA..
• Planke, Sverre; Millett, John M; Maharjan, Dwarika; Jerram, Dougal Alexander & Abdelmalak, Mohamed Mansour (2017). 3D seismic imaging of voluminous earliest Eocene buried lava fields and coastal escarpments off mid-Norway..
• Planke, Sverre; Millett, John; Jerram, Dougal Alexander; Senger, Kim; Galland, Olivier; Schmid, Daniel Walter & Myklebust, Reidun (2017). Petroleum exploration in volcanic basins: An overview of the impact of igneous processes and deposits.
• Polozov, Alexander; Planke, Sverre; Svensen, Henrik; Jerram, Dougal Alexander & Looy, Cindy (2017). Burned and buried by the Siberian traps: tree trunks in volcaniclastics and lavas..
• Schmiedel, Tobias; Kjoberg, Sigurd; Planke, Sverre; Magee, Craig; Galland, Olivier; Schofield, Nick; Jackson, Christopher A.-L. & Jerram, Dougal Alexander (2017). Mechanisms of overburden deformation associated with the emplacement of the Tulipan sill, mid-Norwegian margin.
• Schmiedel, Tobias; Kjoberg, Sigurd; Planke, Sverre; Magee, Craig; Galland, Olivier; Schofield, Nick; Jackson, Christopher A.-L. & Jerram, Dougal Alexander (2017). Mechanisms of overburden deformation associated with the emplacement of the Tulipan sill, mid-Norwegian margin.
• Tegner, Christian; Andersen, Torgeir Bjørge; Brown, Eric L.; Corfu, Fernando; Planke, Sverre; Kjøll, Hans Jørgen & Torsvik, Trond Helge (2017). The pre-Caledonian Scandinavian Dyke Complex and 600 Ma plate reconstructions of Baltica. Vis sammendrag

  Magmatism of the first known rifting phase of the North Atlantic Wilson cycle is surprisingly well preserved in the Cale- donian nappes of central and northern Scandinavia. Along c. 1000 km the Särv and Seve Nappes are characterised by spectacular dyke complexes and other intrusive forms origi- nally emplaced into continental sedimentary basins along the rifted margin of Iapetus. We refer to this as the magma-rich segment of the pre-Caledonian margin of Baltica, in contrast to the hyper-extended and magma-poor segment exposed in southern Norway (Andersen et al., Jakob et al., this meeting). In the larger picture the Scandinavian Dyke Complex is part of the Central Iapetus Magmatic Province ( ). The intensity, volume and structure of the Scandinavian Dyke Complex is comparable to that of the present passive margins of the North Atlantic large igneous province (Kjøll et al., this meeting) and U-Pb ages suggest magmatism was short-lived at 610-590 Ma. To constrain the origin of the Scandinavian Dyke Complex and to potentially guide plate reconstructions of Baltica we: (1) re-visited the dyke complexes of the Särv, Sarek, Kebnekaise, Tornetrask and Indre Troms mountains of Sweden and Norway; (2) compiled new and published geochemical data for the entire dyke complex; (3) modeled mantle sources and melting dy- namics; and (4) extended reconstructions of the paleo-position of Baltica back to 600 Ma. Although the appearance of the dykes ranges from garnet amphibolite gneiss to pristine mag- matic intrusions, all bulk rock compositions largely reflect the original magmatic rock. The compiled dataset includes c. 600 analyses that essentially forms a coherent suite dominated by tholeiitic ferrobasalt akin to the North Atlantic large igneous province, but including alkali basalts in the central portion where meta-carbonatite is also reported. A few samples (<30) are significantly contaminated with crust, but most are largely uncontaminated. The tholeiitic dykes display systematic lateral variations over c. 1000 km in trace element compositions suggesting geochem- ical enrichment (e.g. delta-Nb and La/Sm(N) relative to mid- ocean ridge basalt) in the southern and central portions, grad- ing to more depleted compositions in the north. The most enriched tholeiites occur in the central portion that also in- cludes alkali basalts. The lateral geochemical zoning is com- parable to e.g. the North Atlantic large igneous province and around Iceland today. Our petrological modeling suggests melting of asthenospheric mantle involving at least two source compositions at temperatures elevated above ambiant mantle. We therefore speculate that the Scandinavian Dyke Complex formed by melting of a zoned mantle plume originating from a plume generation zone (margins of large low shear-wave velocity provinces) at the core-mantle boundary. If the posi- tion of the present plume generation zone in the Pacific can be viewed as stationary back to 600 Ma, we entertain the idea that the Scandinavian Dyke Complex may be used to guide plate reconstructions.

• Tegner, Christian; Andersen, Torgeir Bjørge; Brown, Eric L.; Corfu, Fernando; Planke, Sverre; Kjøll, Hans Jørgen & Torsvik, Trond Helge (2017). The pre-Caledonian Scandinavian Dyke Complex and 600 Ma plate reconstructions of Baltica.
• van Soelen, Elsbeth Ester; Hasic, Edi; Planke, Sverre; Svensen, Henrik; Sleveland, Arve Rein Nes; Midtkandal, Ivar; Twitchett, Richard & Kürschner, Wolfram Michael (2017). Permian-Triassic palynofacies and chemostratigraphy in a core recovered from central Spitsbergen..
• Galland, Olivier; Abdelmalak, Mohamed Mansour; Leanza, Hector Armando; Mourgues, Regis; Planke, Sverre; Scheibert, Julien & Schmiedel, Tobias (2016). Mechanics of Igneous Intrusion Emplacement and implications for Sedimentary Basins.
• Andersen, Torgeir Bjørge & Planke, Sverre (2016, 21. september). Detektiver på havbunn: Geologer samler ny kunnskap om kleber og skifer.  Gudbrandsdølen Dagningen. Vis sammendrag

  Dypdykk i fortid: Geologer fra hele Europa har kommet til Gudbrandsdalen for å undersøke bergarter som kan fortelle oss mer om fortiden. Kleber- og skiferforekomstene i Nord- Gudbrandsdal vil gi geologene fra en rekke land ny kunnskap om hvordan de gamle havområdene ble dannet.

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