Per Terje Osmundsen

• Koehl, Jean-Baptiste P.; Bergh, Steffen G; Osmundsen, Per Terje; Redfield, Thomas Fitzmaurice; Indrevær, Kjetil; Lea, Halldis & Bergø, Espen (2019). Late Devonian–Carboniferous faulting and controlling structures and fabrics in NW Finnmark. Norwegian Journal of Geology.  ISSN 2387-5844.  99(3) . doi: 10.17850/njg99-3-05 Vis sammendrag

  In the SW Barents Sea, Devonian–Carboniferous collapse led to the formation of major basins and faults, e.g., the Hammerfest Basin bounded by the Troms–Finnmark Fault Complex, and rhomboid- to sigma-shaped (half-)grabens on the Finnmark Platform. High-resolution aeromagnetic and bathymetry data from the shallow shelf show that analogue fault systems are present in coastal and onshore areas of NW Finnmark. We provide new documentation for the Langfjorden–Vargsundet fault, a post-Caledonian, NW-dipping, zigzag-shaped, margin-parallel fault complex consisting of alternating linear to sub-linear, NNE–SSW- and ENE–WSW-striking, down-NW normal fault segments. This fault formed as an extensional splay-fault of inverted, Caledonian, brittle–ductile thrusts, e.g, the Talvik and Kvenklubben faults, which the fault eventually truncated and offset. In northern Finnmark, the Langfjorden–Vargsundet fault is offset laterally by up to 28 km by a system of WNW–ESE-trending faults notably including potential segments and splays of the Trollfjorden–Komagelva Fault Zone, a reactivated Neoproterozoic, margin-orthogonal transfer fault, separating NW Finnmark from the eastern Finnmark Platform. This fault system likely dies out westwards, and portions of the system’s process zone may crop out on the island of Magerøya. Similarly, the WNW–ESE- to ENE–WSW-striking Akkarfjord fault offsets the Langfjorden–Vargsundet fault by c. 2 km left-laterally. This fault may have formed as a conjugate to the Trollfjorden–Komagelva Fault Zone in Neoproterozoic (Timanian?) times. Steeply NW-plunging, upright and gently NE-plunging, inclined folds in Archaean–Palaeoproterozoic basement rocks and margin-parallel Caledonian thrusts may have controlled the formation and geometry of post-Caledonian faults. A Late Devonian–Carboniferous age for the Langfjorden–Vargsundet fault is supported by geochronological dating of onshore dykes and fault gouge, and by syn-tectonic sedimentary wedges along the offshore extension of the Langfjorden–Vargsundet fault. Mini-basins bounded by the Langfjorden– Vargsundet fault on the Finnmark Platform and on the shallow shelf, e.g., the Ryggefjorden trough, may represent analogues to deep, offshore, Devonian–Carboniferous basins, like the Nordkapp Basin, prior to the deposition of late Palaeozoic evaporites.

• Smyrak-Sikora, Aleksandra; Osmundsen, Per Terje; Braathen, Alvar; Ogata, Kei; Anell, Ingrid Margareta; Mulrooney, Mark Joseph & Zuchuat, Valentin (2019). Architecture of growth basins in a tidally influenced, prodelta to delta-front setting: The Triassic succession of Kvalpynten, East Svalbard. Basin Research.  ISSN 0950-091X.  s 1- 30 . doi: 10.1111/bre.12410
• Braathen, Alvar; Osmundsen, Per Terje; Maher, Harmon; Maher, Harmon & Ganerød, Morgan (2018). The Keisarhjelmen detachment records Silurian-Devonian extensional collapse in Northern Svalbard. Terra Nova.  ISSN 0954-4879.  30(1), s 34- 39 . doi: 10.1111/ter.12305
• Ogata, Kei; Mulrooney, Mark; Braathen, Alvar; Maher, Harmon; Osmundsen, Per Terje; Anell, Ingrid Margareta; Smyrak-Sikora, Aleksandra & Balsamo, Fabrizio (2018). Architecture, deformation style and petrophysical properties of growth fault systems: the Late Triassic deltaic succession of southern Edgeøya (East Svalbard). Basin Research.  ISSN 0950-091X.  30(5), s 1042- 1073 . doi: 10.1111/bre.12296 Fulltekst i vitenarkiv.
• Osmundsen, Per Terje & Peron-Pinvidic, Gwenn (2018). Crustal-Scale Fault Interaction at Rifted Margins and the Formation of Domain-Bounding Breakaway Complexes: Insights From Offshore Norway. Tectonics.  ISSN 0278-7407.  37(3), s 935- 964 . doi: 10.1002/2017TC004792
• Naliboff, John B.; Buiter, Susanne; Péron-Pinvidic, Gwenn; Osmundsen, Per Terje & Tetreault, Joya (2017). Complex fault interaction controls continental rifting. Nature Communications.  ISSN 2041-1723.  8 . doi: 10.1038/s41467-017-00904-x Fulltekst i vitenarkiv.
• Osmundsen, Per Terje; Péron-Pinvidic, Gwenn; Ebbing, Jørg; Erratt, Duncan; Fjellanger, Erik; Bergslien, Dag & Syvertsen, Svein Erik (2017). Extension, hyperextension and mantle exhumation offshore Norway: A discussion based on 6 crustal transects. Norsk Geologisk Tidsskrift.  ISSN 0029-196X.  96(4), s 343- 372 . doi: 10.17850/njg96-4-05
• Hansen, John-Are; Bergh, Steffen G; Osmundsen, Per Terje & Redfield, Timothy Fitzgerald (2015). Stress inversion of heterogeneous fault-slip data with unknown slip sense: An objective function algorithm contouring method. Journal of Structural Geology.  ISSN 0191-8141.  70, s 119- 140 . doi: 10.1016/j.jsg.2014.11.005
• Osmundsen, Per Terje; Braathen, Alvar; Rød, Rita Sande & Hynne, Ingrid Bjørnerheim (2014). Styles of normal faulting and fault controlled sedimentation in the Triassic deposits of Eastern Svalbard. Norwegian Petroleum Directorate Bulletin.  ISSN 0808-1409.  (11), s 61- 79
• Redfield, Thomas Fitzmaurice & Osmundsen, Per Terje (2014). Some remarks on the earthquakes of Fennoscandia: A conceptual seismological model drawn from the perspective of hyperextension. Norsk Geologisk Tidsskrift.  ISSN 0029-196X.  94(4), s 233- 262
• Anell, Ingrid Margareta; Braathen, Alvar; Osmundsen, Per Terje & Olaussen, Snorre (2013). Evidence of faulting contradicting a Triassic quiescent northern Barents Shelf. First Break.  ISSN 0263-5046.  31(6), s 67- 76 . doi: 10.3997/1365-2397.2013017
• Anell, Ingrid Margareta; Braathen, Alvar; Senger, Kim & Osmundsen, Per Terje (2013). Evidence of faulting contradicts a quiescent northern Barents Shelf during the Triassic. First Break.  ISSN 0263-5046.  31(6), s 67- 76 . doi: 10.3997/1365-2397.2013017
• Braathen, Alvar; Anell, Ingrid Margareta; Osmundsen, Per Terje & Olaussen, Snorre (2013). Just how quiescent was the northern Barents Shelf during the Triassic?. First Break.  ISSN 0263-5046.  31(9), s 71- 72
• Braathen, Alvar; Osmundsen, Per Terje; Hauso, Harald Ove; Semshaug, Siv Lise; Fredman, Niclas & Buckley, Simon John (2013). Fault-induced deformation in a poorly consolidated, siliciclastic growth basin: A study from the Devonian in Norway. Tectonophysics.  ISSN 0040-1951.  586, s 112- 129 . doi: 10.1016/j.tecto.2012.11.008
• Redfield, T.F. & Osmundsen, Per Terje (2012). The long-term topographic response of a continent adjacent to a hyperextended margin: A case study from Scandinavia. Geological Society of America Bulletin.  ISSN 0016-7606.  125(1-2), s 184- 200 . doi: 10.1130/B30691.1
• Osmundsen, Per Terje & Redfield, T.F. (2011). Crustal taper and topography at passive continental margins. Terra Nova.  ISSN 0954-4879.  23(6), s 349- 361 . doi: 10.1111/j.1365-3121.2011.01014.x Vis sammendrag

  The long-term evolution of kilometre(s) high, seaward-facing escarpments at passive margins is linked directly to the crustal thinning gradient. The development of post-rift faults in the onshore parts of the margin and the associated distribution of drainage patterns, landscape types and sediment dispersal patterns reflect this linkage. For the seismically well-imaged Norwegian margin as well as for a number of passive margins worldwide, we identify a scaling relationship that correlates escarpment height with the distance to the highly extended distal margin or, more specifically, the taper break. The highest escarpments and the most asymmetric margin topography are found inboard of sharply tapering crystalline crust, independent of margin age. Conversely, escarpments are lower where the taper is gentle. Thus, the topography of passive margins does not primarily reflect age, magmatism, climate or mantle convection, but more probably the response to loading of the laterally variable, fault-controlled architecture of the crystalline crust.

• Osmundsen, Per Terje; Redfield, T.F.; Hendriks, B.H.W.; Bergh, S.; Hansen, J.-A.; Henderson, I.H.C.; Dehls, J.; Lauknes, Tom Rune; Larsen, Yngvar; Anda, E. & Davidsen, B. (2010). Fault-controlled alpine topography in Norway. Journal of the Geological Society.  ISSN 0016-7649.  167(1), s 83- 98 . doi: 10.1144/0016-76492009-019
• Osmundsen, Per Terje; Henderson, I.; Lauknes, Tom Rune; Larsen, yngvar; Redfield, T.F. & Dehls, J. (2009). Active normal fault control on landscape and rock-slope failure in northern Norway. Geology.  ISSN 0091-7613.  37(2), s 135- 138 . doi: 10.1130/G25208A.1

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• Schaaf, Niklas; Osmundsen, Per Terje; Van Der Lelij, Roelant; Lenz, Olaf & Senger, Kim (2019). Tectono-stratigraphic evolution of the Forlandsundet Graben – new insights from Sarsøyra, Western Svalbard, Arctic Norway.
• Wiest, Johannes; Jacobs, Joachim; Fossen, Haakon & Osmundsen, Per Terje (2019). Post-orogenic exhumation of metamorphic core complexes in the SW Scandinavian Caledonides – A comparison of structures and processes.
• Braathen, Alvar; Osmundsen, Per Terje; Maher, Harmon & Ganerød, Morgan (2018). Reply to Comment on ?The Keisarhjelmen detachment records Silurian?Devonian extensional collapse in Northern Svalbard?. Terra Nova.  ISSN 0954-4879.  30(4), s 322- 324 . doi: 10.1111/ter.12334
• Osmundsen, Per Terje (2018). Linking onshore and off shore structures and their role in basin development on the continental margin..
• Schaaf, Niklas; Osmundsen, Per Terje & Senger, Kim (2018). Tectono-sedimentary evolution of the Paleogene Forlandsundet Graben - new insights from Sarsøyra, Western Spitsbergen, Arctic Norway.
• Braathen, Alvar; Mulrooney, Mark; Haile, Beyene Girma; Appleyard, Tyler Ross; van Yperen, Anna Elisabeth; Smyrak-Sikora, Aleksandra Anna; Anell, Ingrid Margareta; Ogata, Kei; Midtkandal, Ivar; Osmundsen, Per Terje; Maher, Harmon & Olaussen, Snorre (2017). “Delta collapse” – Edgeøya delta system compared to the Ferron delta (Utah).
• Maher, Harmon; Braathen, Alvar; Mulrooney, Mark; Ogata, Kei; Osmundsen, Per Terje; Senger, Kim & Smyrak-Sikora, Aleksandra Anna (2017). Regional fracture systems & local fracture domains in Svalbard's diabase sills.
• Ogata, Kei; Mulrooney, Mark; Braathen, Alvar; Maher, Harmon; Smyrak-Sikora, Aleksandra Anna; Anell, Ingrid Margareta; Osmundsen, Per Terje; Olaussen, Snorre; Cavozzi, Christian; Balsamo, Fabrizio; Nestola, Yago & Storti, Fabrizio (2017). Architecture, deformation style and petrophysical properties of a Late Triassic growth fault system in southern Edgeøya, East Svalbard.
• Smyrak-Sikora, Aleksandra Anna; Osmundsen, Per Terje; Braathen, Alvar; Ogata, Kei; Anell, Ingrid Margareta; Husteli, Berit; Mulrooney, Mark & Olaussen, Snorre (2017). Sedimentary architecture of siliciclastic, syntectonic graben and halfgraben fill in Kvalpynten, Edgeøya, Svalbard. Vis sammendrag

  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.

• Anell, Ingrid Margareta; Braathen, Alvar; Røhnert, Daniela; Ogata, Kei; Osmundsen, Per Terje; Smyrak-Sikora, Aleksandra Anna; Lord, Gareth Steven; Buckley, Simon John; Maher, Harmon & Olaussen, Snorre (2017). Findings of five field foragings. Sandbody distribution, clinoform geometries and depositional environments of Edgeøya, Svalbard.
• Svendby, Anne Katrine; Osmundsen, Per Terje; Andresen, Arild & Andersen, Torgeir Bjørge (2017). Transtensional basins from fault growth to bulk constriction: insights from the `Old Red´ basins of western Norway.
• Maher, Harmon; Senger, Kim; Ogata, Kei; Braathen, Alvar; Mulrooney, Mark; Smyrak-Sikora, Aleksandra Anna & Osmundsen, Per Terje (2016). Mesozoic Regional Stress Field Evolution in Svalbard.
• Ogata, Kei; Mulrooney, Mark; Braathen, Alvar; Maher, Harmon; Smyrak-Sikora, Aleksandra Anna; Anell, Ingrid Margareta; Osmundsen, Per Terje; Olaussen, Snorre; Cavozzi, Cristian; Balsamo, Fabrizio; Nestola, Yago & Storti, Fabrizio (2016). Field-based characterisation and analogue modelling of the South Edgeøya growth faults systems.
• Smyrak-Sikora, Aleksandra Anna; Osmundsen, Per Terje; Braathen, Alvar; Mulrooney, Mark & Olaussen, Snorre (2016). Three-dimensional model of facies distribution within a Triassic half-graben, SW Edgeøya, Svalbard.
• Koehl, Jean Baptiste; Tveranger, Jan; Osmundsen, Per Terje; Braathen, Alvar; Taule, Christoffer & Collombin, Maxim (2016). Fault-growth deposits in a Carboniferous rift-basin: the Billefjorden Trough, Svalbard.
• Koehl, Jean-Baptiste; Tveranger, Jan; Osmundsen, Per Terje; Braathen, Alvar; Taule, Christopher & Collombin, Maxime (2016). Fault-growth deposit in a Carboniferous rift-basin: the Billefjorden Trough, Svalbard.
• Braathen, Alvar; Anell, Ingrid Margareta; Smyrak-Sikora, Aleksandra Anna; Mulrooney, Mark; Haile, Beyene Girma; Ogata, Kei; Osmundsen, Per Terje; Maher, Harmon; Buckley, Simon John; Hellevang, Helge & Olaussen, Snorre (2015). Tectonic influence on platform infill patterns in the mid-late Triassic, Southern Edgeøya, Svalbard.
• Braathen, Alvar; Mulrooney, Mark; Ogata, Kei; Anell, Ingrid Margareta; Smyrak-Sikora, Aleksandra Anna; Lecomte, Isabelle; Osmundsen, Per Terje & Maher, Harmon (2015). Trias North: Late Triassic shallow faulting in Edgeøya, Svalbard; structural style, deformation mechanisms and seismic expression.
• Maher, Harmon; Braathen, Alvar; Mulrooney, Mark; Ogata, Kei; Osmundsen, Per Terje & Smyrak-Sikora, Aleksandra Anna (2015). South Edgeøya shale detachment geometry and mechanics.
• Anell, Ingrid Margareta; Braathen, Alvar; Midtkandal, Ivar; Smyrak-Sikora, Aleksandra Anna; Husteli, Berit; Ogata, Kei & Osmundsen, Per Terje (2015). Tracking the Triassic platform-edge: Inferences on onshore clinoform geometries upon reaching the Edgeøya platform.
• Osmundsen, Per Terje; Braathen, Alvar & Maher, Harmon (2015). First crustal-scale extension at the Arctic margin: the Devonian Keiserhjelmen Detachment, Svalbard.
• Osmundsen, Per Terje; Braathen, Alvar & Maher, Harmon (2015). Structural framework at the NE Atlantic-Arctic margin junction: the Devonian Keiserhjelmen Detachment, Northern Svalbard.
• Osmundsen, Per Terje; Smyrak-Sikora, Aleksandra Anna; Braathen, Alvar; Olaussen, Snorre; Ogata, Kei & Anell, Ingrid Margareta (2015). Growth basins at Edgeøya: sedimentary architecture and facies relationships.
• Osmundsen, Per Terje; Smyrak-Sikora, Aleksandra Anna; Braathen, Alvar; Olaussen, Snorre; Ogata, Kei & Anell, Ingrid Margareta (2015). Sedimentary architecture and facies distribution in Late Triassic, reservoir-scale half-graben, De Geerdalen Formation, East Svalbard.
• Smyrak-Sikora, Aleksandra Anna; Osmundsen, Per Terje; Braathen, Alvar; Ogata, Kei; Anell, Ingrid Margareta; Husteli, Berit & Olaussen, Snorre (2015). Depositional setting and internal architecture of syn-tectonic, siliciclastic half-graben fill, Edgeøya, Svalbard.
• Svendby, Anne Katrine; Osmundsen, Per Terje; Andresen, Arild & Andersen, Torgeir Bjørge (2015). Syntectonic sedimentation in the constructional Kvamshesten basin, western Norway..
• Ogata, Kei; Anell, Ingrid Margareta; Braathen, Alvar; Osmundsen, Per Terje; Smyrak-Sikora, Aleksandra Anna; Husteli, Berit; Olaussen, Snorre & Maher, Hermon (2014). Syndepositional faulting in the Late Triassic succession of Kvalpynten, Edgeøya, East Svalbard.
• Braathen, Alvar; Anell, Ingrid Margareta; Osmundsen, Per Terje & Olaussen, Snorre (2013). Exploring the Triassic of the Northern Barents Shelf – Sag-basins Interacting with Growth-faults.
• Braathen, Alvar; Olaussen, Snorre & Osmundsen, Per Terje (2012). Trias i nord - opptur i Barentshavet. Geo.  ISSN 1500-8371.  (15/5), s 18- 21
• Osmundsen, Per Terje; Braathen, Alvar & Maher, Hermon (2012). The geology of Svalbard: structural, stratigraphic and geomorphic response to the formation of two passive margins.
• Braathen, Alvar; Osmundsen, Per Terje & Olaussen, Snorre (2011). Tectonic events of the NW Barents Shelf; on-offshore correlations with implications for development of the eastern shelf area.
• Bergh, Steffen G; Hansen, John-Are; McCaffrey, K.; Wilson, R.; Kløvjan, O.; Osmundsen, P. T.; Davidsen, B.; Corner, Geoffrey D.; Hendriks, B. & Redfield, T. (2008). Application of terrestrial laser scanning to constrain the 3D outcrop geometry of passive margin normal faults and tilted fault blocks: The Jurassic-Cretaceous Sortlandsundet Graben, Vesterålen, North Norway.
• Osmundsen, P. T.; Redfield, Thomas Fitzmaurice; Henderson, I.; Dehls, J.; Lauknes, T. R.; Larsen, Y.; Davidsen, B.; Bergh, Steffen G & Anda, E. (2008). Tectonically controlled alpine ranges in Norway: A recipe for disaster.

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