Institutt for geovitenskap: Recent submissions
Now showing items 921-940 of 1025
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Submarine gas seepage in a mixed contractional and shear deformation regime: Cases from the Hikurangi oblique-subduction margin
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-02-11) -
Role of tectonic stress in seepage evolution along the gas hydrate-charged Vestnesa Ridge, Fram Strait
(Journal article; Tidsskriftartikkel, 2015-02-03) -
Strukturer og mineralomvandling i Stensundtjern malmfelt, og dannelse av jernmalmene i Dunderlandsformasjonen.
(Master thesis; Mastergradsoppgave, 2014-12-14)Stensundtjern ligger ved Storforshei, en hall times kjøring fra Mo i Rana. Denne mineralforekomsten er en del av en større jernmineralisering som ligger i Dunderlandsdalen. Jernmineraliseringen her har vært kjent siden før 1800 og har gjennom årenes løp vært forsøkt drevet i flere perioder. De første kildene vi har fra området er fra 1799 da Trondheims-bedriften Mostadsmarkens Jernverk gjorde krav ... -
Post-glacial sedimentary processes and slope instabilities off Nordnesfjellet, Lyngenfjorden, northern Norway
(Master thesis; Mastergradsoppgave, 2014-11-15)The Lyngen- and Storfjorden system, Troms County, northern Norway, is surrounded by an alpine landscape, partly with steep mountain sides. Parts of the ~700 m high mountain Nordnesfjellet, on the eastern side of the fjord, are currently moving downslope, and could in the event of sudden failure generate tsunami waves which would affect low-lying areas within a larger region. The main objective of ... -
Hydrothermal Vent Activities At the Gjallar Ridge in the Vøring Basin, mid-Norway
(Master thesis; Mastergradsoppgave, 2014-11-21)The 3D seismic enable a better understanding of phreatomagmatic activity that occurred at the Gjallar ridge in the Vøring basin, mid-Norway. Structures associated with this activity were imaged and a causality relationship was established. Those structures included hydrothermal vent complexes, sill complexes and faults. The Kai formation significantly affected by polygonal faulting that were likely ... -
Multibeam bathymetry and backscatter data analysis of pockmarks at Vestnesa Ridge off NW-Svalbard
(Master thesis; Mastergradsoppgave, 2014-11-09)The Vestnesa Ridge is an elongated sediment drift situated at 79o N on the northwest Svalbard margin in the Fram Strait. It is one of the northernmost documented oceanic gas hydrate provinces. The narrow southeastern part of the ridge is characterized by pockmarks that line up along the apex of the crest. Some of these pockmarks are continuously venting gas while some are inactive. This study looks ... -
Holocene sub-centennial evolution of Atlantic water inflow and sea ice distribution in the western Barents Sea
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-01-23)A marine sediment core (JM09-KA11-GC) from the Kveithola Trough at the western Barents Sea margin has been investigated in order to reconstruct sub-surface temperatures and sea ice distribution at a sub-centennial resolution throughout the Holocene. The relationship between past variability of Atlantic water inflow and sea ice distribution has been established by measurement of planktic foraminifera, ... -
Reconstruction of Atlantic Water variability during the Holocene in the western Barents Sea
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-01-10)The gravity core JM09-KA11-GC from 345m water depth on the western Barents Sea margin was investigated for down-core distribution patterns of benthic Foraminifera, stable isotopes, and sedimentological parameters in order to reconstruct the flow of Atlantic water during the Holocene. The core site is located below the Atlantic water masses flowing into the Arctic Ocean and close to the Arctic front. ... -
Hydrothermal Cu-Zn mineralization at Vanna, West Troms Basement Complex: A geochemical analysis of Archean and Proterozoic rocks with focus on sulfide genesis
(Master thesis; Mastergradsoppgave, 2014-08-16)The hydrothermal Vannareid Cu-Zn mineralization is located on the island of Vanna, West Troms Basement Complex. It was discovered in 2008 and was subject of Store Norske Gull AS' exploration project in 2012. The mineralization is situated along the border between the Archean granitoid basement intruded by tholeiitic and calc-alkaline dykes, and the overlying Neoproterozoic metasedimentary rocks of ... -
First record of catacrinid crinoid from the Lower Permian of Spitsbergen
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)An early Permian (late Artinskian–Roadian) cladid crinoid (Catacrinidae gen. et sp. indet.) is reported for the first time from the Vøringen Member of the Kapp Starostin Formation of Spitsbergen. The specimen is partly articulated and preserves a considerable part of its stalk and a complete cup, but only the proximal portions of its arms. Thus, it can− not be identified with any degree of ... -
Sedimentological and Stratigraphic study of glaciomarine clays and postglacial beach deposits exposed in a raised coastal section beyond the Tromsø Lyngen (Younger Dryas) end moraine at Spåkenes, Lyngen, northern Norway
(Master thesis; Mastergradsoppgave, 2014-05-15)Thick succession of suspension settled muds, deposited from meltwater plumes, which are frequently interbedded with sandy mass flows deposits. Between conformable beds, discrete units have been in intensely deformed, often into large recumbent folds with complex structure. Suspension settled muds are observed in three distinct structural facies, namely massive clays, rhythmically banded muds and ... -
Late Weichselian and Holocene sedimentary processes and glacier dynamics in Woodfjorden, Bockfjorden and Liefdefjorden, North Spitsbergen
(Master thesis; Mastergradsoppgave, 2014-05-31)Abstract Swath bathymetry, high resolution seismic data and sediment cores were analyzed to reconstruct the Late Weichselian and Holocene sedimentary environments and glacier dynamics in Woodfjorden, Bockfjorden and Liefdefjorden, north Spitsbergen. Mega-scale glacial-lineations provide evidence of fast-flowing grounded ice draining the northwestern parts of the Late Weichselian Svalbard Barents ... -
Onshore-offshore correlation in the Andfjorden area and the structural controls on the opening and evolution of the Mesozoic sedimentary basins on Andøya and Andfjorden, northern Norway
(Master thesis; Mastergradsoppgave, 2014-05-14)Onshore-offshore correlation of brittle faults has been undertaken in the Andfjorden area defining the boundary between the passive Lofoten-Vesterålen margin and the transform SW Barents Sea margin. This study has focused its efforts on onshore mapping of faults and fractures, the mapping of offshore faults and associated basin-ridge systems from seismic interpretation and the link between fault ... -
Experimental investigation on the fabric evolution and strain localization of quartz with and without the presence of muscovite
(Master thesis; Mastergradsoppgave, 2014-05-16)Deformation experiments of synthetic quartz–muscovite aggregates were performed to high shear strains at dislocation creep conditions in quartz. In previous studies, axial compression experiments were conducted on quartz aggregates to develop a better understanding of the relationship between flow strength and lattice preferred orientation with varying percentages of muscovite. Other analyses have ... -
Microstructural investigation of shear localization in the Ersfjord granite, Kvaløya, Troms: A case study of kinematics, deformation mechanisms and fabric relationships
(Master thesis; Mastergradsoppgave, 2014-05-15)The present “case study” deals with Paleozoic-Mesozoic oblique-dextral strike-slip shear zones situated within the Ersfjord granite (1,79 Ga), that are believed to give valuable insight into fault- and fluid flow mechanics from the brittle-ductile transition zone. Mesoscopic observations combined with microstructural evidence and geochronology suggests that Late Carbonifereous-Early Triassic fault ... -
Geomorfologisk og sedimentologisk analyse av avsetjingsforløp og skredmekanikk for debris-flow-hendingar frå 14. juli 2012 i Signaldalen, Troms.
(Master thesis; Mastergradsoppgave, 2014-05-13)Debris-flow er ein type lausmasseskred som opptrer i alpine og arktiske landskap. I Noreg representerer dei ein naturfare både på Vestlandet, i Norland og i Troms. Prosessen har lenge vore studert utafor Noreg, men lite arbeid er gjort her i landet; denne oppgåva er meint å auka kunnskapen om debris-flows i Noreg, samt å vinkla den eksisterande kunnskapen mot eit typisk norsk risikoområde. Ein serie ... -
Fjellskred ved Indre Nordnes, Nordnesfjellet, Lyngen, Troms - Berggrunnens indre struktur og bevegelsesmekanismer basert på strukturell analyse og overvakingsdata
(Master thesis; Mastergradsoppgave, 2014-05-16)Gravitasjonell reaktivering av pre-eksisterande kaledonske duktile svakheitsoner i tillegg til post-kaledonske sprø strukturar som truleg har vorte utløyst ved glasial avlasting like etter nedsmeltinga av isen under siste istid har truleg gitt opphav til skråningsdeformasjonen og utviklinga av det ustabile fjellpartiet Indre Nordnes. Skredområde Indre Nordnes er initierande tektonisk styrt der ... -
Relationship between fluid leakage and faulting along the western and northern margin of the Hammerfest Basin
(Master thesis; Mastergradsoppgave, 2014-05-15)Abstract This thesis focuses on establishing a causal relationship between potential fluid sources, fluid migration pathways, shallow gas accumulations and potential gas hydrates in the western part of the Hammerfest Basin, SW Barents Sea. Two 3D seismic surveys (LN0901 and ST8320R00) were used to map fluid flow, stratigraphy, structure, fluid flow and other fluid-related features along the western ... -
Northward advection of Atlantic water in the eastern Nordic Seas over the last 3000 yr
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)Three marine sediment cores distributed along the Norwegian (MD95-2011), Barents Sea (JM09-KA11-GC), and Svalbard (HH11-134-BC) continental margins have been investigated in order to reconstruct changes in the poleward flow of Atlantic waters (AW) and in the nature of upper surface water masses within the eastern Nordic Seas over the last 3000 yr. These reconstructions are based on a limited set ... -
K-Ar illite and apatite fission track constraints onbrittle faulting and the evolution of the northern Norwegian passive margin
(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 ...