Blar i Bergen Open Research Archive på forfatter "Fossen, Haakon"
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3-D seismic images of an extensive igneous sill in the lower crust
Wrona, Thilo; Magee, Craig; Fossen, Haakon; Gawthorpe, Rob; Bell, Rebecca E.; Jackson, Christopher Aiden Lee; Faleide, Jan Inge (Peer reviewed; Journal article, 2019-05-31)When continents rift, magmatism can produce large volumes of melt that migrate upwards from deep below the Earth’s surface. To understand how magmatism impacts rifting, it is critical to understand how much melt is generated ... -
Adamastor – an ocean that never existed?
Konopasek, Jiri; Cavalcante, Carolina; Fossen, Haakon; Janoušek, Vojtěch (Journal article; Peer reviewed, 2020)Existing models of tectonic evolution of the Neoproterozoic orogenic system rimming the shores of the South Atlantic Ocean (the Araçuaí–Ribeira–Congo and Dom Feliciano–Kaoko–Gariep belts) interpret the belts as subduction-related ... -
Basement structure and its influence on the structural configuration of the northern North Sea rift
Fazli Khani, Hamed; Fossen, Haakon; Gawthorpe, Robert; Faleide, Jan Inge; Bell, Rebecca E. (Peer reviewed; Journal article, 2017-06)The northern North Sea rift basin developed on a heterogeneous crust comprising structures inherited from the Caledonian orogeny and Devonian postorogenic extension. Integrating two‐dimensional regional seismic reflection ... -
Brittle basement deformation during the Caledonian Orogeny observed by K-Ar geochronology of illite-bearing fault gouge in west-central Sweden
Almqvist, Bjarne; van der Lelij, Roelant; Högdahl, Karin; Lescoutre, Rodolphe; Schönenberger, Jasmin; Fossen, Haakon; Sjöström, Håkan; Juhlin, Christopher; Luth, Stefan; Grigull, Susanne; Viola, Giulio (Journal article; Peer reviewed, 2023)This study presents K-Ar ages of illite-bearing fault gouges in crystalline basement in central-western Sweden. Samples were taken from two faults that localized brittle deformation marginal to and within mafic dikes that ... -
Comment to “Neoproterozoic magmatic arc systems of the central Ribeira belt, SE-Brazil, in the context of the West-Gondwana pre-collisional history: A review”
Fossen, Haakon; Meira, Vinicius T.; Cavalcante, Carolina; Konopásek, Jiří; Janoušek, Vojtěch (Journal article; Peer reviewed, 2021) -
Complex fault system revealed by 3-D seismic reflection data with deep learning and fault network analysis
Wrona, Thilo; Pan, Indranil; Bell, Rebecca E.; Jackson, Christopher A.-L.; Gawthorpe, Rob; Fossen, Haakon; Osagiede, Edoseghe Edwin; Brune, Sascha (Journal article; Peer reviewed, 2023)Understanding where normal faults are located is critical for an accurate assessment of seismic hazard; the successful exploration for, and production of, natural (including low-carbon) resources; and the safe subsurface ... -
Contractional deformation of porous sandstone: Insights from the Aztec Sandstone, SE Nevada, USA
Fossen, Haakon; Zuluaga, Luisa F.; Ballas, Gregory; Soliva, Roger; Rotevatn, Atle (Peer reviewed; Journal article, 2015-05)Contractional deformation of highly porous sandstones is poorly explored, as compared to extensional deformation of such sedimentary rocks. In this work we explore the highly porous Aztec Sandstone in the footwall to the ... -
A critical discussion of the subduction-collision model for the Neoproterozoic Araçuaí-West Congo orogen
Fossen, Haakon; Cavalcante, Carolina; Konopásek, Jiří; Meira, Vinicius T.; Trompette, Roland; Hollanda, Maria Helena B.M.; Paes de Almeida, Renato (Journal article; Peer reviewed, 2020)The Neoproterozoic Araçuaí-West Congo orogen in Brazil and Congo represents a branch of the Brasiliano/Pan-African orogenic system that is considered to terminate northward into a confined cratonic environment defined by ... -
Deep Crustal Flow Within Postorogenic Metamorphic Core Complexes: Insights From the Southern Western Gneiss Region of Norway
Wiest, Johannes; Osmundsen, Per Terje; Jacobs, Joachim; Fossen, Haakon (Peer reviewed; Journal article, 2019)Viscous crustal flow can exhume once deeply buried rocks in postorogenic metamorphic core complexes (MCCs). While migmatite domes record the flow dynamics of anatectic crust, the mechanics and kinematics of solid‐state ... -
The dilemma of asymmetric porphyroclast systems and sense of shear
Zhang, Qing; Fossen, Haakon (Peer reviewed; Journal article, 2020-01)Asymmetric porphyroclast systems have long been used as independent shear-sense indicators based on their clast-tail asymmetry and/or stair-stepping tail geometry. Over the last two decades, advances in exploring the ... -
Disaggregation bands as an indicator for slow creep activity on blind faults
Brandes, Christian; Tanner, David C.; Fossen, Haakon; Halisch, Matthias; Müller, Katharina (Journal article; Peer reviewed, 2022)Hidden, blind faults have a strong seismic hazard potential. Consequently, there is a great demand for a robust geological indicator of neotectonic activity on such faults. Here, we conduct field measurements of disaggregation ... -
From Caledonian collapse to North Sea Rift: The extended history of a metamorphic core complex
Wiest, Johannes; Wrona, Thilo; Bauck, Marit Stokke; Fossen, Haakon; Gawthorpe, Rob; Osmundsen, Per Terje; Faleide, Jan Inge (Journal article; Peer reviewed, 2020)Extensional systems evolve through different stages due to changes in the rheological state of the lithosphere. It is crucial to distinguish ductile structures formed before and during rifting, as both cases have important ... -
From widespread faulting to localised rifting: Evidence from K-Ar fault gouge dates from the Norwegian North Sea rift shoulder
Fossen, Haakon; Ksienzyk, Anna K.; Rotevatn, Atle; Bauck, Marit Stokke; Wemmer, Klaus (Journal article; Peer reviewed, 2021)Although seismic and stratigraphic well information put tight constraints on rift basin evolution, eroded rift shoulders commonly expose polydeformed prerift basement whose deformation history may be difficult to constrain. ... -
Grain Deformation Processes in Porous Quartz Sandstones – Insight from the Clusters of Cataclastic Deformation Bands
Philit, Sven; Soliva, Roger; Ballas, Gregory; Fossen, Haakon (Peer reviewed; Journal article, 2017)Porous sandstones represent classical reservoirs for water or hydrocarbons. Deformation in such granular material is due to tectonic events and occurs through the process of cataclasis, implying the crushing of the grains ... -
The influence of structural inheritance and multiphase extension on rift development, the northern North Sea
Phillips, Thomas B.; Fazlikhani, Hamed; Gawthorpe, Rob; Fossen, Haakon; Jackson, Christopher Aiden Lee; Bell, Rebecca E.; Faleide, Jan Inge; Rotevatn, Atle (Peer reviewed; Journal article, 2019-11-08)The northern North Sea rift evolved through multiple rift phases within a highly heterogeneous crystalline basement. The geometry and evolution of syn‐rift depocenters during this multiphase evolution and the mechanisms ... -
Late Jurassic to Late Cretaceous canyons on the Måløy Slope: Source to sink fingerprints on the northernmost North Sea rift margin, Norway
Bauck, Marit Stokke; Faleide, Jan Inge; Fossen, Haakon (Journal article; Peer reviewed, 2021)The Måløy Slope is a key area for studying the connection between onshore and offshore geology of South Norway. It has functioned as an area of bypass, erosion and deposition between the Norwegian mainland source area and ... -
Modern field courses and problem-based learning; a comparison between industry and academia
Hesthammer, Jonny; Fossen, Haakon (UPED-skrift nr. 1/2006, Working paper, 2006)Problem-based learning (PBL) can provide an attractive learning situation in relation to field courses. Combined with information technology, the learning effect can be enhanced compared with more traditional courses that ... -
The Patos-Pernambuco shear system of NE Brazil: Partitioned intracontinental transcurrent deformation revealed by enhanced aeromagnetic data
Fossen, Haakon; Harris, Lyal B.; Cavalcante, Carolina; Archanjo, Carlos José; Ávila, Carlos F. (Journal article; Peer reviewed, 2022)The Neoproterozoic-Cambrian (Brasiliano) intracontinental Patos-Pernambuco shear system is developed in Archean to Neoproterozoic crust, reactivating rift margins N of the São Francisco Craton. We here use enhanced ... -
A Pleistocene origin of the strandflat coastal platform in southwestern Scandinavia
Fossen, Haakon (Journal article; Peer reviewed, 2023)An impressively extensive shore platform, the strandflat, is cut 20–50 km into hard crystalline bedrock along most of the Norwegian coastline. Its age and origin have been debated for more than a century, including a model ... -
Quartz textural analysis from an anastomosing shear zone system: Implications for the tectonic evolution of the Ribeira belt, Brazil
Conte, Thailli; Cavalcante, Carolina; Lagoeiro, Leonardo Evangelista; Fossen, Haakon; Silveira, C.S. (Journal article; Peer reviewed, 2020)Strain localization and influence of grain-size reduction processes were investigated from field and microstructural observations, and from quartz textural analysis using EBSD, in rocks deformed along an anastomosing network ...