• Direct 40Ar/39Ar K‐feldspar dating of Late Permian–Early Triassic brittle faulting in Northern Norway 

      Davids, Corine; Benowitz, Jeff A.; Layer, Paul; Bergh, Steffen G (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-04-23)
      While the offshore post‐Caledonian extensional history of the north Norwegian passive margin is well constrained, the tectonic relationship between onshore and offshore regions is less clear because of limited age constraints on the timing of rifting onshore. <sup>40</sup>Ar/<sup>39</sup>Ar dating of K‐feldspar from hydrothermally altered fault rocks in a Precambrian gneiss complex in northern Norway ...
    • Evolution and temporal constraints of a multiphase postglacial rock slope failure 

      Vick, Louise Mary; Mikkelsen, Martin; Corner, Geoffrey; Kjellman, Sofia Elisabeth; Trønnes, Leif; Hormes, Anne; Allaart, Lis; Bergh, Steffen G (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-05)
      Large rock slope failures are temporal processes which act to modify the landscape after glacial retreat. The slope failure process often shows a lag time of thousands of years after deglaciation, with multiple failure events possible. While global datasets constrain this lag time from extensive mapping and dating of paraglacial rock avalanches, the timeline is poorly refined in northern Norway. We ...
    • Fault-controlled asymmetric landscapes and low-relief surfaces on Vestvågøya, Lofoten, North Norway: inherited Mesozoic rift-margin structures? 

      Bergh, Steffen G; Liland, Kristian; Corner, Geoffrey D.; Henningsen, Tormod; Lundekvam, Petter (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-11-20)
      The Lofoten Ridge is an integral basement horst of the hyperextended continental rift-margin off northern Norway. It is a key area for studying onshore–offshore rift-related faults, and for evaluating tectonic control on landscape development along the North Atlantic margin. This paper combines onshore geomorphological relief/aspect data and fault/fracture analysis with offshore bathymetric and ...
    • The First Magnetotelluric Image of the Lithospheric-Scale Geological Architecture in Central Svalbard, Arctic Norway 

      Beka, Thomas Ibsa; Smirnov, Maxim; Bergh, Steffen G; Birkelund, Yngve (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-12-17)
      Magnetotelluric data, collected from 30 stations on Spitsbergen as part of a reconnaissance geothermal resource assessment along a profile with 0.53-km spacing in 0.0031000-s period range, were used to develop a lithospheric-scale two-dimensional (2D) resistivity model, heretofore unavailable for the region. Inverting the determinant of the impedance tensor in 2D, we found the smoothest model ...
    • K-Ar illite and apatite fission track constraints onbrittle faulting and the evolution of the northern Norwegian passive margin 

      Davids, Corine; Wemmer, Klaus; Zwingmann, Horst; Kohlmann, Fabian; Jacobs, Joachim; Bergh, Steffen G (Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
      Determining the timing of post-Caledonian brittle faulting in northern Norway is important for the understanding of the extensional tectonic evolution of the north Norwegian continental margin. Fault gouges from the Troms and Vesterålen regions of northern Norway yield Carboniferous to Permian and Carboniferous to Cretaceous K–Ar illite ages, respectively. The results show a contrast in fault activity ...
    • Late Devonian–Carboniferous faulting and controlling structures and fabrics in NW Finnmark 

      Koehl, Jean-Baptiste P.; Bergh, Steffen G; Osmundsen, Per Terje; Redfield, Thomas Fitzmaurice; Indrevær, Kjetil; Lea, Halldis; Bergø, Espen (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-10)
      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 ...
    • Late Palaeozoic fault-controlled hydrothermal Cu–Zn mineralisation on Vanna island, West Troms Basement Complex, northern Norway 

      Paulsen, Hanne-Kristin; Bergh, Steffen G; Strmic Palinkas, Sabina (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-31)
      The Vannareid–Burøysund fault is a major, brittle, normal fault in northern Norway, with cohesive fault rocks (cataclasites) that host Cu–Zn-bearing quartz-carbonate veins. The fault is exposed on the island of Vanna in the Neoarchaean to Palaeoproterozoic West Troms Basement Complex, separating variably deformed tonalitic gneisses in the footwall from mylonitised metasedimentary rocks and tonalites ...
    • Magnetotelluric signatures of the complex tertiary fold–thrust belt and extensional fault architecture beneath Brøggerhalvøya, Svalbard 

      Beka, Thomas Ibsa; Bergh, Steffen G; Smirnov, Maxim; Birkelund, Yngve (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-12-18)
      Magnetotelluric (MT) data were recently collected on Brøggerhalvøya, Svalbard, in a 0.003–1000 s period range along a curved WNW–ESE profile. The collected data manifested strong three-dimensional (3D) effects. We modelled the full impedance tensor with tipper and bathymetry included in 3D, and benchmarked the result with determinant data two-dimensional (2D) inversion. The final inversion results ...
    • Middle to Late Devonian–Carboniferous collapse basins on the Finnmark Platform and in the southwesternmost Nordkapp basin, SW Barents Sea 

      Koehl, Jean-Baptiste; Bergh, Steffen G; Henningsen, Tormod; Faleide, Jan Inge (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-03-28)
      The SW Barents Sea margin experienced a pulse of extensional deformation in the Middle–Late Devonian through the Carboniferous, after the Caledonian Orogeny terminated. These events marked the initial stages of formation of major offshore basins such as the Hammerfest and Nordkapp basins. We mapped and analyzed three major fault complexes, (i) the Måsøy Fault Complex, (ii) the Rolvsøya fault, and ...
    • Neoproterozoic and post-Caledonian exhumation and shallow faulting in NW Finnmark from K–Ar dating and p/T analysis of fault rocks 

      Koehl, Jean-Baptiste P.; Bergh, Steffen G; Wemmer, Klaus (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-07-20)
      Well-preserved fault gouge along brittle faults in Paleoproterozoic, volcano-sedimentary rocks of the Raipas Supergroup exposed in the Alta–Kvænangen tectonic window in northern Norway yielded latest Mesoproterozoic (approximately 1050 15 Ma) to mid-Neoproterozoic (approximately 825–810 18 Ma) K–Ar ages. Pressure–temperature estimates from microtextural and mineralogy analyses of fault ...
    • On Palaeozoic-Mesozoic brittle normal faults along the SW Barents Sea margin: fault processes and implications for basement permeability and margin evolution 

      Indrevær, Kjetil; Stunitz, Holger; Bergh, Steffen G (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)
    • Palaeoproterozoic foreland fold-thrust belt structures and lateral faults in the West Troms Basement Complex, northern Norway, and their relation to inverted metasedimentary sequences 

      Paulsen, Hanne-Kristin; Bergh, Steffen G; Palinkas, Sabina Strmic; Karlsen, Siri; Kolsum, Sofie; Rønningen, Ida Ulvik; Armitage, Paul E.B.; Nasuti, Aziz (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-15)
      Palaeoproterozoic fold-thrust belt structures and steep, lateral shear zones characterize the foreland deformation of Neoarchaean basement tonalites in Vanna, West Troms Basement Complex, northern Norway. Low-grade par-autochthonous and allochthonous cover units (2.4–2.2. Ga) with sandstones and calcareous metapelites exist in separate areas of the foreland. They were formed as intracontinental rift- ...
    • Polyphase kinematic history of transpression along the Mecca Hills segment of the San Andreas fault, southern California 

      Bergh, Steffen G; Sylvester, Arthur G.; Damte, Alula; Indrevær, Kjetil (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-09)
      Miocene–Pliocene sedimentary rocks in the Mecca Hills, southern California, were uplifted and deformed by transpression along a restraining bend in the San Andreas fault trace between the Orocopia and San Bernardino Mountains in Pleistocene time. This paper presents field evidence for three stages of structural evolution of a complex, asymmetric wedge-like flower structure, expressed as: (1) ...
    • Relating 3D surface displacement from satellite- and ground-based InSAR to structures and geomorphology of the Jettan rockslide, northern Norway 

      Eriksen, Harald Øverli; Bergh, Steffen G; Larsen, Yngvar; Skrede, Ingrid; Kristensen, Lene; Lauknes, Tom Rune; Blikra, Lars Harald; Kierulf, Halfdan Pascal (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-12-13)
      This study combines remote sensing data from ground- and satellite-based radar to calculate 3D displacement vectors for the Jettan rockslide, Troms, northern Norway. Using 3D displacement vectors, aspect data and strain rates in conjunction with structure (foliation, faults, fractures), geomorphological elements (ridges, scarps, terraces, depressions), topography and borehole data, we identify zones ...
    • Structurally controlled rock slope deformation in northern Norway 

      Vick, Louise Mary; Böhme, Martina; Rouyet, Line; Bergh, Steffen G; Corner, Geoffrey D.; Lauknes, Tom Rune (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-11)
      Gravitational forcing of oversteepened rock mass leads to progressive failure, including rupture, creeping, sliding and eventual avalanching of the unstable mass. As the point of rupture initiation typically follows pre-existing structural discontinuities within the rock mass, understanding the structural setting of slopes is necessary for an accurate characterisation of the hazards and estimation ...
    • Visualizing and interpreting surface displacement patterns on unstable slopes using multi-geometry satellite SAR interferometry (2D InSAR) 

      Eriksen, Harald Øverli; Lauknes, Tom Rune; Larsen, Yngvar; Corner, Geoffrey D.; Bergh, Steffen G; Dehls, John; Kierulf, Halfdan Pascal (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-02-05)
      It is well known that satellite radar interferometry (InSAR) is capable of measuring surface displacement with a typical accuracy on the order of millimeters to centimeters. However, when the true deformation vector differs from the satellite line-of-sight (LOS), the sensitivity decreases and interpretation of InSAR deformationmeasurements becomes challenging. By combining displacement data ...