Institutt for geovitenskap: Recent submissions

Now showing items 521-540 of 1012

    • How is the carbon and oxygen isotope composition of foraminiferal tests influenced by methane seepage? 

      Bruvik, Kine Liland (Master thesis; Mastergradsoppgave, 2019-06-05)
      The focus of this thesis is how methane seepage influences foraminifera l tests. Specifically, How how carbon and oxygen isotopes in planktic foraminifera tests are influenced by methane seepage. The study area is Vestnesa Ridge were four gravity cores were collected during a CAGE cruise in 2013. The cores were taken both from the southern side, where flares has have been recorded, and from the ...

    • Methane release from pingo-like features across the South Kara Sea shelf, an area of thawing offshore permafrost 

      Serov, Pavel; Portnov, Aleksei D; Mienert, Jurgen; Semenov, Peter; Ilatovskaya, Polonia (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-07-16)
      The Holocene marine transgression starting at ~19 ka flooded the Arctic shelves driving extensive thawing of terrestrial permafrost. It thereby promoted methanogenesis within sediments, the dissociation of gas hydrates, and the release of formerly trapped gas, with the accumulation in pressure of released methane eventually triggering blowouts through weakened zones in the overlying and thinned ...

    • Structural assessment and characterisation of the rock slope failure at Skredkallen, Vannøya. Structural analysis using field and desktop methods 

      Trønnes, Leif (Master thesis; Mastergradsoppgave, 2019-05-15)
      The University of Tromsø has carried out multiple studies by master students on unstable rock slopes (URS) in Troms County, Northern Norway. This thesis differs from other studies in Troms as Skredkallen is located in Pre-Cambrian rocks as part of West Troms Basement Complex (WTBC). The rocks of the WTBC have been subjected to multiple phases of deformation, and the main structural features from ...

    • Structural assessment and characterization of the unstable rock slopes at Mellomfjellet, Nordreisa 

      Vik, Bernt Kristian Flekstad (Master thesis; Mastergradsoppgave, 2019-05-15)
      The aim of this study has been to structurally assess and characterize the unstable rock slopes (URS) at Mellomfjellet using an interdisciplinary approach of structural geological analysis, geomorphological mapping, photogrammetry and remote sensing. The URS are located on the west-facing slopes of Mellomfjellet and display a dramatic geomorphology with deep ice filled fractures and clearly displaced ...

    • Geochemical investigations of northern Norwegian fjord sediments - Sources and spatial variability of marine and terrigenous components 

      Canzler, Lea Philine (Master thesis; Mastergradsoppgave, 2016-05-11)
      Fjords represent unique coastal marine environments with high sedimentation rates. They can be used for intensive investigations focusing on geochemical, mineralogical, biological, and sedimentological processes. In this study I investigate 42 surface sediment samples from the outer and inner parts of the Vestfjord, Ofotfjord, Tysfjord and tributary fjord arms in northern Norway. Samples were analysed ...

    • Basin analysis and diagenetic investigations of Early and Middle Triassic sediments on Mariaholmen, Svalbard 

      Riise, Henrik Erevik (Master thesis; Mastergradsoppgave, 2016-05-09)
      Subsequent to a widespread hiatus at the top of the Permian on western Svalbard, the Triassic Vardebukta, Tvillingodden and Bravaisberget formations were deposited. In this thesis, the sedimentology, geochemistry and diagenesis are investigated to determine the depositional environment and basinal setting of the Triassic deposits. In the investigated profile on Mariaholmen, only the upper part ...

    • Strukturell og kinematisk analyse av Skipsfjorddekket og underliggende bergarter i nordøstlige del av Vanna, Vest-Troms gneisregion 

      Karlsen, Siri Elén (Master thesis; Mastergradsoppgave, 2019-05-15)
      Vanna tilhører den nordøstlige delen av Vest-Troms gneisregion, og består av arkeiske til paleoproterozoiske bergarter, og deformasjonsstrukturer av antatt svekofennisk alder. Nordøst på Vanna er det nylig blitt avdekket en steiltstående kvartsfeltspatisk sekvens som tidligere er blitt kartlagt som en del av det sterkt folierte og delvis mylonittiserte Skipsfjorddekket. Denne studien har fokusert ...

    • Cross-disciplinary investigation of gas seepage at Storbanken high and the Olga basin, The northern Barents Sea 

      Amdal, Frank Andreas (Master thesis; Mastergradsoppgave, 2019-05-15)
      The eastern parts of the northern Barents Sea is a little explored sector of the Barents Sea which currently is not open for petroleum activity. This thesis focuses on the processes and mechanisms controlling gas seepage activity in the Olga basin and Storbanken high. 2D seismic and bathymetric data has been correlated with water column acoustic data to identify gas bubbles in the water column and ...

    • The Bigganjárgga Tillite re-visited: a stratigraphic and sedimentological study 

      Edvardsen, Egil (Master thesis; Mastergradsoppgave, 2019-05-15)
      The Neoproterozoic “tillite”-bearing sequences of the Smalfjord Formation in Varanger, northern Norway have retrieved considerable attention in geological literature since first described and discovered over a century ago. Much of the attention relates to the so-called Reusch’s Moraine also known as the Bigganjárgga Tillite, which rests directly on top of a striated sandstone surface pointing to ...

    • Geometrisk og kinematisk analyse av duktile skjærsoner i metasedimentære og intrusive bergarter i Vannagruppen, Vest-Troms gneisregion, Troms, og deres relasjon til svekofenniske folde- og skyvestrukturer 

      Kolsum, Sofie (Master thesis; Mastergradsoppgave, 2019-05-15)
      Øya Vanna nordøst i Vest-Troms gneisregionen består av TTG-gneiser (2.8 Ga), 2.4 Ga mafiske intrusivganger, en overliggende metasedimentær enhet i sør kalt Vannagruppen intrudert av en dioritt (sill) datert til 2221 ± 3 Ma, og Skipsfjorddekket i nord, en allokton enhet skjøvet mot SØ. Studieområdet befinner seg sørøst på Vanna, i området Larstangen-Fakkekeila. Her opptrer metasedimentære bergarter ...

    • A new numerical model for understanding free and dissolved gasprogression toward the atmosphere in aquatic methane seepage systems 

      Jansson, Pär; Ferré, Benedicte; Silyakova, Anna; Dølven, Knut Ola; Omstedt, Anders (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-01-16)
      We present a marine two‐phase gas model in one dimension (M2PG1) resolving interaction between the free and dissolved gas phases and the gas propagation toward the atmosphere in aquatic environments. The motivation for the model development was to improve the understanding of benthic methane seepage impact on aquatic environments and its effect on atmospheric greenhouse gas composition. Rising, ...

    • Geometrisk og kinematisk analyse av paleoproterozoiske duktile skjærsoner i Skipsfjorddekkets undre del, Vanna, Vest-Troms gneisregionen, og relasjon til metasedimentære bergarter i Vannagruppen 

      Rønningen, Ida Ulvik (Master thesis; Mastergradsoppgave, 2019-05-13)
      Vannas geologi er unik, og strukturer av komplekse folde- og skyvebelter med antatt sensvekofennisk alder karakteriserer deformasjoner av neoarkeiske tonalittiske gneisbergarter (2,9-2,4 Ga), paleoproterozoiske metasedimentære og intrusive bergarter på øya, helt nord i Vest- Troms gneisregionen. Hovedhensikten med dette arbeidet har vært kartlegging og strukturell analyse av antatte metasedimentære ...

    • Metamorphic evolution of the Passo Feio Complex (central part of the Dom Feliciano Belt, southern Brazil) 

      Tennholm, Tonje (Master thesis; Mastergradsoppgave, 2019-05-15)
      The Passo Feio Complex is considered as a part of the São Gabriel Terrane, located to the west of the Dom Feliciano Belt in the state of Rio Grande do Sul (Brazil), but shows numerous similarities with the easterly exposed Porongos Metamorphic Complex which is a part of the Schist Belt in that area. P-T phase equilibrium modelling of metamorphosed sedimentary rocks from the Passo Feio Complex was ...

    • A structural, geomorphological and InSAR study of the unstable rock slopes at Mellomfjellet, Nordreisa 

      Sikveland, Gaute (Master thesis; Mastergradsoppgave, 2019-05-15)
      The focus of this study has been to combine structural data with morphological observations and displacement data to characterise the unstable rock slopes at Mellomfjellet. The site contains two instabilities (Mellomfjellet 1 and 2) and is located along a west-facing slope in Reisadalen, a glacially eroded valley, in Nordreisa, Troms. The bedrock consists mainly of Caledonian amphibolite and hornblende ...

    • Strukturell kontroll av stratiform jernmalm ved Kvannevann øst, Dunderlandsdalen, Nordland 

      Lie, Fredrik (Master thesis; Mastergradsoppgave, 2019-05-16)
      Stratiform jernmalm av verdensklasse fremgår i Dunderlandsdalen, der de prinsipielle malmmineralene består av hematitt og magnetitt. Jernmalmen tilhører Dunderlandsformasjonen, som er del av Ramnålidekket innenfor Rødingsfjell dekkekompleks i det øverste allokton av den kaledonske fjellkjeden. Sidebergartene til jernmalmen består av godt folierte glimmerskifere, metapsammitter og tykke lagpakker av ...

    • 3D-seismic interpretation of the glacial deposits in the outer Ingøydjupet area, SW Barents Sea. Ice sheet dynamics reconstructed from glacial landforms 

      Strømme, Kristine (Master thesis; Mastergradsoppgave, 2019-05-15)
      The late Quaternary evolution of the outer Ingøydjupet area (SW Barents Sea) is studied using a merge of conventional 3D-seismic cubes and a new generation of high-resolution 3D-seismic (TopSeis). The glacigenic sequence is subdivided into five main seismic units: unit A1 (oldest) to A5. These are separated by six glacially eroded boundaries: the Upper Regional Unconformity (URU), intra-glacial ...

    • Geochemistry of the stratiform iron Dunderlandsdalen deposits, Nordland 

      Rolsted Lie, Kristian (Master thesis; Mastergradsoppgave, 2019-05-15)
      The Dunderlandsdalen iron district, Northern Norway, hosts a world-class stratiform Fe-mineralization (total tonnage of ~500 Mt at 33% Fe). The iron ore units belong to the Dunderland Formation in the Ramnålia Nappe, which further belongs to the Rødingsfjellet Nappe of the Caledonian Uppermost Allochthon. Hematite and magnetite represent the principal ore minerals and are hosted by amphibolite grade ...

    • Late Weichselian and Holocene glacier dynamics and sedimentary processes in and north of the Wijdefjorden-Austfjorden fjord system, north Spitsbergen 

      Braun, Carmen (Master thesis; Mastergradsoppgave, 2019-05-16)
      Multi-proxy analyses (lithostratigraphy, physical properties, XRF core scanning, and grain size analysis) of five sediment cores and high resolution seismic (chirp) data were integrated to reconstruct the Late Weichselian and Holocene sedimentary environments and glacial history in and on the shelf north of Wijdefjorden. Three acoustic units (U1-U3) correlating with three lithostratigraphic units ...

    • Seismic sequence analysis and petroleum system indicators at the Oligocene-Miocene level in the southern North Sea 

      Poulsen, Johanne Schøning (Master thesis; Mastergradsoppgave, 2019-05-14)
      A thorough review of the Oligocene-Miocene stratigraphic evolution and depositional environments in the Norwegian part of the southern North Sea is presented and considered alongside observations of petroleum system indicators, from seismic-, core- and well-data. The reconstructed paleo-environments show a trend of fluctuating eustatic sea-levels, controlled by basin subsidence and uplift of the ...

    • 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 ...