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This thesis presents the results of august Sea Surface Temperature reconstructions from marine diatom assemblages in samples from core Ga3-2 retrieved from Narsaq Sound, inside the Ikersuad fjord, South Greenland. The diatom samples provide a high-resolution (~30-year) reconstruction dating between 890 and 1660 CE (common era). The results show variable conditions with warm periods between 960 and 1010 CE and from 1370 to 1590 CE and cold periods from 890 to 960 CE and from 1010 to 1190 CE. This means cold summer Sea Surface temperatures during the Medieval Climate anomaly and warm temperatures during the Little Ice age. These results are compared to other records from the area, including diatom assemblages from other cores and temperature reconstructions from ice cores, as well as other sea temperature proxies like foraminiferal assemblages or alkenones from haptophyte algae. The comparisons show a complex relation between different proxies and indicate an opposite summer temperature trend between the Northeast Atlantic and South Greenland, probably linked to heat transport by the North Atlantic Current and its two branches, the Northwest Atlantic Current and the Irminger Current.

A quantitative analysis of seasonal and regional forcing on the terminus of Store Glacier, Greenland, from high resolution photogrammetry for the period between 10 May 2014 and 13 June 2014. Imagery is analyzed through ImGRAFT processing to create a detailed velocity and strain rate for the proglacial mélange and glacial terminus in order to investigate changes to glacial calving dynamics during mélange move out.

Methane is a greenhouse gas contributing to contemporaneous global warming, and seepage is one of the ways through which it migrates from the deep sedimentary basins, all the way up to the hydro- and atmosphere. The study of methane seepage is still young as scientists are yet to discover most seep sites as well as seep associated biological species. A record of past methane seepage can be derived from the δ 13C stored in the foraminiferal tests and in the seafloor sediments via precipitation of carbonate minerals by microbial oxidation of methane. In this study, the stable isotopes of carbon and oxygen of the foraminiferal tests were used alongside sediment geochemistry and organic compounds of the sediment as proxies to investigate methane seepage at the Svyatogor Ridge, Arctic Ocean. Two lithological units were recognised from the gravity core (GC3), corresponding to different sedimentation patterns during the last deglaciation. 158 - 162 cm and 137 – 142 cm intervals of the gravity core were impacted by anaerobic oxidation of methane (AOM) processes based on the Ba/Ti peaks which represent barite fronts immediately above sulfate-methane transition zones (SMTZs). Also, the vertical shift in between the paleo-SMTZs shows an upward fluid flow. The paleo-SMTZs in the gravity core (GC3) formed later than 14.5 ca ka BP. The organic matter in the blade core (BlaC3) is highly depleted due to bacterial mat biomass which incorporated methane-derived carbon. The stable carbon and oxygen isotopes of the tests show that the foraminifera calcified under normal marine conditions and during the Younger Dryas post-Bølling period. The C/N (Carbon/Nitrogen) elemental ratios show a predominantly marine origin for the sedimentary organic matter with some mix of land-derived and marine-derived organic matter. The organic carbon concentration (%C) shows that the sediments are of low productivity. An interval rich in ice-rafted debris with bivalve shells associated with high C/N values was found at 120 to 140 cm interval in the gravity core, suggesting sedimentary inputs from nearby Svalbard margin. A foraminiferal δ 13C of -12.73 ‰ ~10 cm below this level indicates some secondary MDAC (Methane-derived authigenic carbonate) formation. It remains unclear whether the bivalves represent an ancient seep habitat or have been transported by icebergs from nearby Svalbard margin.

This thesis examined gas flares found in the Cruise log 20-2 from CAGE and correlated them to subsurface seismic data in south of Barents Sea. The cruise log passed several hydrocarbon discoveries/fields such as Goliat, Caurus/Langlitinden, Norvarg and Wisting/Hanssen. The aim of the thesis is to investigate the relationship between shallow geology and the observed gas flares and seabed leakages. Multibeam echosounder data and Water Column Imaging (WCI) is used to hunt the flares along the cruise, 12 flare locations are detected mostly over the hydrocarbon discoveries/fields. Well data is also used to investigate if or how some of the flares might be connected to the drilling activities. However, not all amplitude anomalies in the WCI are gas flares, thus a protocol to define gas flares in WCI is applied. Tectonic movements and uplift in the study area cause faulting and fault reactivation, which open migration pathways from reservoir levels and fluids escape towards the seabed. Additionally, erosion and removal of as much as 2km sediments reduce the overburden pressure, causing the reservoir fluids to expand and escape. Repeated glaciation events during the last ice age formed an unconformity surface (URU) where many potential shallow gas accumulations locate. Shallow accumulation/seismic anomaly along the URU is the main target of this thesis. Some of the observed gas flares are closely related to hydrocarbon wells in the study area, gas might migrate through well-induced fractures along the wellpath. The relationship between deeper gas accumulations, hydrocarbon wells, shallow gas accumulation and potential leakage of gas into the water column is not straight forward. More empirical data and investigations needs to be applied to increase the knowledge of these interrelated and complicated processes

The Paleoproterozoic Greenstone Belts of Fennoscandia are metamorphosed and deformed volcanic and sedimentary basins with a high metallic ore potential. One of those, the Alta-Kvænangen Tectonic Window (AKTW), is exposed as a window below the Caledonides of Northern Norway. The Kåfjord area located within the AKTW hosts numerous known Cu occurrences. The Cu mineralisation in Kåfjord occurs mostly in the form of quartz-carbonate-sulphide veins hosted by magmatic and sedimentary lithologies. While there is a demand for new ore deposits that can support the green energy transition, undiscovered deposits are partly or completely buried which has made exploration in recent years less efficient and more expensive. Streams carry material from their upstream drainage area, and therefore stream sediments can be used for exploration geochemistry to assess nearby mineralisation. The purpose of this master thesis is to identify the geochemical footprint and multi-element dispersion patterns of the Cu mineralisation in stream sediments sampled from streams draining the known Cu deposits in Kåfjord. Identification and analysis of the distribution of chemical elements will contribute to a more efficient targeting of Cu occurrences in the Fennoscandian Shield. Stream sediments from three streams draining; (1) the sediment-hosted Cu mineralisation, (2) the mafic rock-hosted Cu mineralisation and (3) both the sediment- and mafic rock-hosted Cu mineralisation have shown different geochemical footprints. The bulk chemical composition of stream sediments exhibit a correlation between Cu and elements associated with the hydrothermal mineralisation in all three streams. Additionally, content of Cu in stream sediments seems to be associated with the respective lithologies hosting the mineralisation. Carbonate grains separated from stream sediments have isotopic compositions resembling the carbonates associated with both sediment- and mafic rock-hosted Cu mineralisation. LA-ICP-MS analyses of individual grains separated from stream sediments resulted in multi-element data sets with minor and trace element compositions of specific minerals. The hydrothermal signature of sulphides separated from stream sediments is characterised by high contents of Ag and Se, but low concentrations of Ga. Furthermore, the hydrothermal signature of sulphides seem to be preserved in mineral aggregates derived from the oxidation of sulphides, in so-called Fe-oxy-hydroxides. Thus, Fe-oxy-hydroxides can have the potential to be used as indicators for Cu mineralisation in the Kåfjord area.

On June 3rd, 2020 a major quick clay landslide occurred at Kråknes in Alta municipality, Northern Norway. The landslide event destroyed eight buildings and was estimated to be 650 meters wide and 40 meters high. Two days later, another landslide occurred, this time causing the old E6 road above the previous landslide area to slip out towards the sea. People lost cabins and other valuable possessions, but there were no casualties. Landslide events in sensitive clay along the Norwegian coastline pose a threat to coastal communities and infrastructure and have frequently caused fatalities and damage throughout recent history. To avoid and prepare for potential landslide disasters, it is crucial to study and understand the development of sensitive clay landslides. In this study, the Kråknes landslide in Alta, Northern Norway has been reconstructed based on field observations, geotechnical data and numerical modeling in DAN3D to gain insight into the sequence of events and better understand and prepare for potential landslide events in the future. The results show that the topography and stratigraphy of Kråknes make the area unstable and sensitive to external forces due to alternating permeable and impermeable layers in a moderately dipping fjord sequence created by the ice sheets during deglaciation and exposed by isostatic uplift. This stratigraphy provides good conditions for groundwater flow and the creation of highly sensitive clay and weak layers when exposed to excess pore pressure. Human activity has further increased the instability through loading of fill material during the construction of a cabin in 2015. After heavy amounts of snowfall during winter season 2019/2020, hydrometric data show that the ground was up to 100% saturated due to snowmelt in the days prior to the landslide. The high amounts of meltwater caused an increase in the pore water pressure in the already unstable study area and initially triggered the landslide event. Two scenarios on how the landslide event occurred are proposed and simulated in DAN3D, where one is initiated below sea level and the other is initiated above sea level. Based on the results, it is concluded that the landslide was triggered on land as a progressive landslide, which continued to retrogress backward and laterally in several slabs. The rapid deposition of landslide mass on the seafloor initiated an underwater slide, which later caused further retrogression on land due to lack of support from the buttressing mass in front. The expansion of residential areas and infrastructure below the marine limit can cause drastic changes in the stability of areas with sensitive clay. With the ongoing climate change we see today, the shifts in temperature and rain and snow patterns may increase the amount of groundwater compared to previous years. In fjords, the stratigraphies' ability to feed already unstable slopes with high amounts of groundwater should therefore be examined closely before constructions are made that could create weak layers and shear bands.

A 513 cm long sediment core from the Lofoten Contourite Drift at the continental slope west of the Lofoten Islands has been investigated. The aim was to reconstruct the paleoceanography during the Last Glacial Maximum (LGM). The Lofoten Contourite drift was relatively protected by the Lofoten Islands from the ice streams of the Scandinavian Ice Sheet during LGM. An age model was constructed based on four 14C dates from the core and correlations to nearby cores described in Vorren et al. (2015) and Weinelt et al. (2003). The core dates range throughout most of the LGM from at least 17,000 to 24,500 years BP. The results are based on multiproxy analysis of the sediment core. Lithology log, x-ray, physical properties, grain size analysis, sortable silt analysis and IRD analysis was used to reveal the sedimentary processes, glaciation, and current speeds. The foraminifera analysis, Mg/Ca analysis and stable oxygen – and carbon isotope provides information about bioproductivity, ventilation, bottom environment, surface freshening and bottom water temperature. The core holds unique data. There are Mg/Ca samples for almost every ~100 years on average for the LGM record (~23-18.5cal. ka BP), so it is possible to resolve centennial changes, which is new for the LGM in the Nordic Seas. The Mg/Ca showed a consistently cold Bottom Water Temperature (BWT) throughout the record. The bottom water temperature is colder than expected for the North Atlantic Intermediate Water during the LGM. The minima in the BWT correlate with low δ13C, low abundance of planktic and benthic foraminifera and reduction of the current strength. This may indicate intermediate water formation and interruption of the warm North Atlantic Intermediate Water. There is also a cold period between 20 and 19.8 cal. ka BP with high bioproductivity which is believed to a be a period with polynyas and mixed water masses.

Rockfalls and snow avalanches are a major natural hazard and common phenomenon in mountainous areas in Norway, endangering people and infrastructure. Svarthola, on Fv 862, Senja, is a 100 m long unprotected stretch of road that experiences a high frequency of mass movements. The road is situated at a tunnel portal, between a 100 m high cliff and the fjord. As such, it is the only short access route between the northern and western parts of the island, and frequent road closures have created safety and access issues. It is therefore classified by Troms and Finnmark County as one of the most dangerous roads in the region, and the installation of a protection structure is considered necessary. This study focuses on the impact dynamics from rockfalls (kinetic energy, velocity, jump height) and snow avalanches (snow pressure, velocity, flow height) at Svarthola for protection design. An analysis of the hazard at the site was performed through fieldwork and desktop mapping in order to estimate the size of the mass movements relevant for the design. This data were used in numerical modelling to obtain the impact dynamics. The road experiences frequent rock fall inundation, with boulders up to 2 m3 causing damage and road closures. Rockfall analysis shows variable impact dynamics for the different event scenarios, ranging from 1,700 kJ for annual events up to 7,100 kJ for a 100-year event. The analysis showed impact velocities between 22 and 50 m/s. The median jump heights were 0.9-1.2 m, where some rock blocks can jump >20 m if they hit the lower cliff part above the road. The fall height of a block can be up to 100 m. The road experiences a lower frequency of snow avalanches but they are often leading to road closures. Impact dynamics were obtained through numerical modelling and physical formulas. The impact dynamics for a 100-year dry-slab avalanche event with a volume of 16,900 m3 is estimated as follows: snow pressure of 130-270 kPa, impact velocity between 20 and 37 m/s and flow height of 2-3.7 m in the northern part of the road and up to 1.2 m in the southern part. Finally, an analysis of the relationship between the rockfall and avalanche history and climate factors were done with the aim to propose the implications of climate change. Svarthola will most likely experience more rockfall events in the future due to the projected increase in rainfall intensity and frequency. The dry-snow avalanche hazard may disappear completely due to the rarity of snow cover in these low coastal areas, but the likelihood of wet-snow avalanches and slushflows may increase in a wetter climate.

This study investigates the sedimentology of the Klubbnasen and Andersby formations of the Late Precambrian (Neoproterozoic) succession in Varanger, eastern Finnmark. Additionally, the lower parts of the Fugleberget and Paddeby formations overlying the Klubbnasen and Andersby formations, respectively, were superficially investigated in order to provide stratigraphic context. The investigated formations are part of the Vadsø Group, which have previously been interpreted to represent a syn-rift succession of Late Riphean age. The present study is based on extensive field work along the northern coastline of the Varangerfjorden and document storm-bed (i.e. tempestite) variability within the Klubbnasen and Andersby formations, and interpret their depositional environments and sequence stratigraphic development. Ten lithofacies were identified based on outcrop investigations, which further are grouped into four lithofacies associations reflecting outer shelf deposits (FA1), storm-influenced prodelta deposits (FA2), storm-influenced delta front deposits (FA3) and braided river deposits (FA4; only occurring in the Fugleberget and Paddeby formations). The numerous tempestite beds of Klubbnasen and Andersby formations were mainly governed by wave-enhanced turbidity currents and storm waves producing a variety of storm-bed architectures (e.g. wave-modified turbidite). Deposition of a typical tempestite (e.g. wave-modified turbidite) was typically preceded by erosion of strong, but decelerating, offshore-directed turbidity currents, which were followed by a gradually more oscillatory-dominated flow governed by storm waves. The beds are characterized by high aggradation rates where the bed-architecture was controlled by the temporal and spatial evolution of the two transporting agents. Seafloor topography may also have affected the deposition. The abundancy of soft-sediment deformation structures, including the presence of a laterally extensive slump deposit, suggest a trigger mechanism related to seismic activity. The cyclic stacking trend of that the Klubbnasen-Fugleberget and the Andersby-Paddeby formations and the sharp, erosive boundaries within these stratigraphic couplets, may suggest deposition within a seismically active rift-basin where the basin fill evolution was largely governed by hanging wall-subsidence and limited sediment supply (due to small catchment area).Periods of increasing subsidence rates may have led to the formation of marine flooding surfaces (as observed in the Klubbnasen and Andersby formations), while sudden uplifts of the footwall resulted in episodes of extensive erosion of the underlying deltaic units and the formation subaerial unconformities (as observed at the bases of the Fugleberget and Paddeby formations). Tectonic uplift and exposure of larger areas eventually promoted the generation of extensive braided river systems (as represented by the cross-bedded sandstone of the Fugleberget and Paddeby formations).

Ledd i Billefjordforkastningssonen kan man finne på begge sidene av Sassenfjorden. Disse leddene er forsøkt knyttet sammen i denne analysen. Batymetriske data fra Sassenfjordens fjordbunn avslører rygger og andre strukturer som har en spennende innvirkning på de seismiske dataene. Hovedfunnene i denne analysen er kategorisert i tre kategorier. Kategori 1 omtaler en obskur sone på seismikken som kan relateres direkte til Billefjordforkastningssonen med steile forkastninger og oppknust berggrunn som ikke lar seg godt avbilde på seismikk. Funn som er plassert i kategori 2 er tolket til å være mesozoiske magmatiske ganger som skaper amplitudeanomalier og fremstående strukturer. Med lokalt skarpe kontraster i intern hastigheter relativt til sedimentære bergarter kan det være at de også påvirker seismikken i området mer enn antatt ved første øyekast. Konturer og strukturer i fjorden som gir en brå endring i vanndyp er plassert i kategori 3. Det er også en skarp kontrast i intern hastighet mellom vann og sedimentære bergarter, noe som tilsynelatende påvirker store og små deler av den seismiske avbildningen. Det kan se ut som fjorder sammenfaller med synklinaler og odder med antiklinaler. Disse syn- og antiklinalene er ikke observerbare på land.

The Dom Feliciano Belt in Uruguay represents a counterpart of the Gariep Belt in Namibia and these two belts are presently considered as relics of one orogen split by the Atlantic Ocean. In this study, two presumed flysch samples from the Marmora Terrane of the Gariep Belt in Namibia, and five samples from potential source areas in the Nico Perez Terrane of the Dom Feliciano Belt in Uruguay have been dated to determine the possible source regions for the flysch sedimentation on the Namibian side of the orogenic system. Two granites from the Nico Perez Terrane show Neoproterozoic ages of c. 614 Ma, interpreted as the crystallization ages. These data are compatible with the magmatic activity found in the Dom Feliciano Belt from 634 – 564 Ma. A metavolcanic sample from the Zanja del Tigre Complex presents crystallization age of 1.45 Ga. One of the metasedimentary samples from the Nico Perez Terrane shows zircon ages with dominant Mesoproterozoic peak at ca. 1.45 Ga interpreted as an age of volcanic admixture, and minor amount of Paleoproterozoic and Archean zircon. interpreted as detrital grains. Another sample of metasedimentary rock shows only Paleoproterozoic to Archean zircon ages. The detrital zircon population is interpreted as a result of erosion of the surrounding geological units. Two presumed samples of metamorphosed flysch sediments from the Marmora Terrane present very different detrital zircon age spectra. One of the samples shows mainly Meso- and Paleoproterozoic ages, with individual Archean ages. This sample is interpreted as possibly connected with sedimentation in the rifting stage of the orogenic cycle. The second sample has a detrital zircon age spectrum that is consistent with syn-orogenic nature of flysch sedimentation, and shows several peaks at c. 650 Ma, 750 Ma, 1.0 Ga and 1.85 Ga. When comparing the zircon signature in the flysch sample with protolith ages found in the surrounding geological units (the Nico Perez Terrane, The Punta del Este Terrane, SouthAfrican sources and the Rio de la Plata Craton), it becomes clear that the flysch sediment is a result of erosion of the Punta del Este Terrane basement, which contains the only nearby source of the c. 650 Ma zircons, the c. 800-750 Ma zircons and inherited zircons dated at 1.2 – 1.0 Ga. The sample also shows the same detrital zircon pattern found by other workers in their studies of flysch sediments in the Dom Feliciano – Gariep Belt.

The late Cenozoic evolution of the outer continental shelf and slope on the northern part of the mid-Norwegian margin is studied using 3D seismic data. The late Cenozoic stratigraphy is subdivided into four main seismic units: unit A (oldest) to D and correlated to the established stratigraphic framework of the Naust Formation, where the oldest unit in this study correlates to the upper part of Naust unit A. The internal seismic signature of the units and the geomorphology of the unit boundaries form the basis for reconstructing the margin evolution. Palaeo-troughs and mega-scale glacial lineations (MSGLs) observed on buried shelf horizons suggest that fast-flowing ice streams drained from the Scandinavian mainland, traversed the shelf within Trænadjupet and Sklinnadjupet troughs, and reached the shelf break. Consequently, the palaeo-slope prograded westwards as downslope processes build out the margin. Based on seismic facies and geophysical attributes, the slope sediments were predominantly deposited by debris flows, but turbidity currents have also occurred. Large amount of glacial till was subglacially transported and deposited on the outer shelf and upper slope, before the sediments became unstable and redistributed downslope by gravity driven processes. The sediment distribution of the area suggests that both Trænadjupet and Sklinnadjupet troughs have been active during the glaciations; however, Sklinnadjupet Trough has been the main source of sediment during deposition of Naust A, U, S and T. Iceberg plough marks on all the buried surfaces testify to free-floating icebergs of sizes capable of eroding the outer shelf and upper slope. The Norwegian Atlantic Current was active during the margin buildout, as suggested by along slope drifting iceberg directions and the presence of the Nyk Drift on the slope.

The aim of this study is to investigate the tectonic- and evolutionary differences between major structural elements of the Barents Sea South East (BSSE) during the uppermost Triassic to lower Cretaceous. The study area comprises the following structural elements: the Bjarmeland- and Finnmark platforms, the Nordkapp- and Tiddlybanken basins, the Signalhorn-, Haapet- and Veslekari domes and the Fedynsky High. Interpretation of seismic 2D- and well-data from the exploration well 7435/12-1 have provided the stratigraphic framework on the uppermost Triassic to lower Cretaceous, represented by the Realgrunnen Subgroup (late Norian to Bajocian), the Fuglen Formation (Callovian to Oxfordian) and the Hekkingen Formation (late Oxfordian to Tithonian). Thickness variations, and seismic stratigraphy as reflection geometries and terminations were applied to identify structural events such as uplift, subsidence and periods of erosion. Insight in the tectono-stratigraphic evolution of the Barents Sea South East have been provided by variations in the thickness and termination patterns of the uppermost Triassic to lower Cretaceous units. This study suggests a late Norian to Bajocian (represented by the Realgrunnen Subgroup) elevation of the Fedynsky High, Finnmark Platform, Veslekari- and Signalhorn domes. During the same period, a relatively stable platform configuration was valid for the Bjarmeland Platform and northern section of the Finnmark Platform, and concurrent basin configuration of the Nordkapp Basin, what today is the Haapet Dome and the area northeast of the dome structure. The structural trends valid for the late Norian to Bajocian continued into the Callovian to Oxfordian (represented by the Fuglen Formation), excluding the Haapet Dome, Bjarmeland Platform and north part of the Finnmark Platform in which the former experienced uplift and the two latter experienced subsidence during this period. The tectono-stratigraphic evolution of the Callovian to Oxfordian persisted through the late Oxfordian to Tithonian, accompanied by a rise in relative sea-level (represented by the Hekkingen Formation), in addition to subsidence of the Tiddlybanken Basin. Late Norian to Tithonian structuring of the BSSE are suggested to be linked to the possible reactivation of deep lineaments by the final upthrusting of the Novaya Zemlya (Late Triassic – Early Jurassic) and also the tectonic events that influenced the NE Atlantic rifting (Late Jurassic – Early Cretaceous) and later opening

This study investigates the north-east-subbasin of the Nordkapp Basin in the Barents Sea. Main focus has been on mapping shallow seismic anomalies from 3D data, their potential association with faulting and sub-surface structures, and further to compare the occurrence of seismic anomalies to possible gas-flares above the seabed from water column data. The stratigraphic intervals from Triassic to Cretaceous have been mapped and several seismic anomalies interpreted to be bright spots are identified. The majority of the anomalies are observed in the Cretaceous Kolmule- and Kolje formations, and several are associated with rotated fault blocks giving rise to structural closures (structure A and B) along the Thor Iversen Fault Complex. A possible meteorite impact crater is observed within the Kolmule Formation, suggested to form during Early Albian and is referred to as structure C. Bright spots were observed along the flanks of this structure. Water column data suggest, no gas flares observed above structure A-C, which could indicate that these structures are sealing. In total, seven lines with gas flares was observed, associated with shallow faults, truncations and shallow anomalies. The potential gas flares had a relatively weak amplitude, suggesting a corresponding weak gas flow and might indicate low concentration/supply of gas or sealing of potential gas migrating upwards. Locally, other seismic amplitude anomalies were identified below the URU/seafloor, however still without clear observations of gas flares in the water column above. A possible explanation for this lack of gas flares above such shallow anomalies, might suggest that glacigenic sediments, usually dense and mudrich, could in places act as an impermeable barrier for gas into the water.

During the Late Weichselian glaciation, the Bjørnøyrenna ice stream was the main outlet of the Barents Sea Ice Sheet. In this thesis, a 3D seismic dataset from the Loppa High, located in the main ice stream trunk, has been used to study the glacial sediment package, revealing details on pastglacial dynamics, fluid flow processes and gas hydrate formation. Three seismic horizons have been interpreted: the seabed, an intra Quaternary horizon and the Upper Regional Unconformity (URU), which corresponds to the base of the Quaternary glacial sediment package. On the intra Quaternary horizon, megascale glacial lineations (MSGL) and a glacitectonic line of depressions are observed, 10 km apart. The MSGL are suggested to indicate fast flowing ice and a warm based bed while the glacitectonic line of depressions indicate cold base and slow ice flow velocities. Seismic indications of fluid flow and gas hydrate formation are associated with the glacitectonic line of depressions. We therefore suggest that gas hydrate formation promoted the freeze-on of subglacial material to the base of the ice stream, triggering glacitectonic erosion, excavating the line of depressions. On URU, bedrock ridges and a subglacial meltwater channel are interpreted. The meltwater channel follows the outline of the Bjørnøyrenna Fault Complex which is suggested be a weakness zone prone to glacial and meltwater erosion. The subglacial meltwater channel is proposed to have accelerated the flow of the overlying ice due to lower basal drag. The surrounding areas on URU consist of bedrock ridges. Their formation is attributed to the differential resistance to glacial erosion of alternating soft and hard interbeds in the underlying bedrock. It is suggested that this created a rough subglacial bed, and this, together with the fact that no landforms indicative of fast flowing ice are observed associated with these bedrock ridges, is consistent with slower ice flow velocities in this area compared to within the meltwater channel.

Submarine glacial landforms have been identified and mapped in order to reconstruct ice sheet dynamics and to describe postglacial sedimentary processes of coastal Søre Sunnmøre in southwestern Norway which lies between 62 and 62.5⁰N. Landform identification has been accomplished through analysis of high-resolution multibeam echosounder (MBES) bathymetric data, backscatter data, LiDAR data, video recordings, and seismic data using ArcGIS (geographical information system). The submarine landscape architecture of coastal Søre Sunnmøre has been largely shaped by glacialinterglacial cycles. The majority of present-day glacial landforms and deposits are a result of growth and decay cycles of the Fennoscandian Ice Sheet during the late Weichselian glaciation of the Pleistocene. A simplified model describing ice sheet dynamics from maximum glacial conditions until final deglaciation is proposed based on evidence including glacial lineations, glacial troughs, morainal banks, and De Geer moraines. Søre Sunnmøre’s dissected and discontinuous distribution of high elevation alpine environments has resulted in a unique glacial dynamics narrative which differs from other localities of southwestern Norway. Sedimentary processes active during final deglaciation up until the present have continued to rework glacially deposited sediment and alter glacial landforms. Fluvial systems and terrestrial mass wasting events continue to supply sediment to marine environments. The occurrence of slope failures, potentially triggered by postglacial isostatic rebound, is indicated by evidence such as submarine rock avalanche deposits and slide scars.

Seismic interpretation, water column data, and well information have enabled a thorough review of shallow amplitude anomalies and subsurface faulting, in conjunction with possible migration pathways in the Haapet Dome area. The processed water column data from the MAREANO-program was presented and evaluated in accordance with potential gas leakage from the seafloor. Water column imaging illustrates that hydroacoustic signatures, which are representative of gas bubble leakage, are probably of non-existence in the Haapet Dome area. A correlation with subsurface stratigraphy illustrates that the possible gas accumulations are situated in the Stø and Nordmela formations, and the Early Cretaceous unit. Given that no apparent evidence of gas leakage is occurring suggests that a sealing lithology is constraining the assumed gas accumulations. Several models were introduced to discuss and evaluate the possible gas accumulations according to entrapment capability and the possibility of minor gas release. The analysed water column data did not indicate observable gas leakage, where acoustic distortion made detection of potential gas bubbles difficult. The Upper Regional Unconformity (URU) with overlying glacial sediments was assumed to act as a potential trapping mechanism for underlying zones of potential shallow gas accumulations. A gas hydrate stability model was established, which showed that gas hydrates could develop in the study area, dependent on the gas composition. Consequently, local zones of potential gas hydrates could act as hydrocarbon barriers. A possible Permian source rock was suggested to have generated and expelled gas, which is probably represented by its present-day shallow accumulations. The models presented suggest that no source rocks are generating and expelling hydrocarbons at present-day in the study area. The assumed shallow gas accumulations are thereby represented by a possible older working petroleum system. A shut-down petroleum system, with no or very little influx of hydrocarbons to the study area, combined with shallow sealing lithologies, might be one reason for lack of observed gas seepage in the water column.

Marine studies reconstructing ice sheet conditions on the Northeast Greenland shelf and adjacent fjords since the Last Glacial Maximum (LGM) are sparse. As a result, the timing and origin of the deglaciation of the ice sheet over marine areas is not well constrained. This thesis aims to improve our understanding of the LGM, deglaciation, and Holocene ice dynamics of the Greenland Ice Sheet (GrIS) near the southern outlet of the Northeast Greenland Ice Stream (NGIS), as well as reconstruct the palaeoenvironment of this region since the LGM. Here, swath bathymetry data and the multi-proxy analysis of three sediment gravity cores from southwestern Dove Bugt and Bessel Fjord were integrated. Dove Bugt is an embayment that is positioned to the east of Storstrømmen, the southern outlet of the NGIS. Bessel Fjord is a W-E oriented fjord that lies south of Storstrømmen and is connected to southern Dove Bugt via the Store Bælt sound. Bathymetric analysis of Dove Bugt revealed north-south oriented streamlined landforms which have been interpreted as the product of a fast-flowing, topographically bound branch of the NGIS that flowed southwards during the LGM. The sedimentology of a gravity core from southwestern Dove Bugt suggests that the NGIS may have retreat from the region around 11,190 cal. yr. BP, in conformity with previous onshore results. The presence of only a few, small retreat moraines implies that the deglaciation was rapid but may have had brief intervals of halting and/or readvancement. Sedimentation during the remainder of the Holocene is attributed to input from local ice caps and glaciers as well as mass wasting processes. The bathymetry of Bessel Fjord reveals several basins and sub-basin that are separated by basin thresholds. The configuration of geomorphic features suggests that glacial ice may have conformed to the topography during ice expansion and reached the outer fjord. The position of recessional moraines suggests that ice had undergone multiple halts and/or readvances and was topographically bound during deglaciation. Sediments from a gravity core collected in the inner fjord reflect a gradual transition from ice proximal to ice distal settings and an absence of glacial ice after 7,160 cal. yr. BP. A gravity core collected from a mid-fjord basin contains a transition from mud to muddy sand layers at ~4,000 yr. BP, which is believed to be the result of increased sediment input from nearby ice caps. This suggests that local ice caps in Bessel Fjord may have fluctuated with greater sensitivity to changing climatic conditions than the GrIS.

Rock avalanches and subsequent displacement waves represented the deadliest natural disaster in Norway in the past century. The two deep-seated and unstable slopes Dusnjarga and Låvan in Troms county (Norway) are clearly defined by morphological deformation features. Due to the steep fjord setting, a potential catastrophic rock avalanche could pose a severe threat to people and infrastructure along the fjord and in particular for the settlement below Låvan. Firstly, an analysis of Quaternary deposits and landforms in the study area was performed which involved e.g. the creation of a detailed Quaternary geological map, the sedimentary logs and particle size analyzes. The former glaciation and deglaciation were expressed by thin till layers, glaciomarine and redeposited glaciofluvial deposits as well as paleo-shorelines. Their analysis and interaction with the rock slope deformation allowed for several interpretations on the temporal behavior of the instabilities. For instance, for Dusnjarga’s central and eastern parts, strong deformation is suggested for the approximate period of the Tapes transgression. Due to the general scarcity of Quaternary deposits in the study area further reaching chronological interpretations would however require the use of absolute dating methods. Secondly, the rock slope deformation Låvan was investigated in detail using digital resources as well as data from the field which comprised structural measurements, scanline data and observations on the morphology and rock mass. Four discontinuity sets were clearly expressed in both the structural data and the morpho-structures: the foliation (SC) and the joint sets JN1, JN2 and JN3. Kinematically, planar failure on SC and wedge failure on JN1 and SC stood out as the most likely failure mechanisms. Bilinear compound sliding on multiple sliding surfaces was suggested as the controlling style of deformation. Sliding occurs as suggested principally on SC with the steeply dipping JN2 forming the linkage between low-persistent fractures. A change of the orientation of SC complicates the sliding movement in the lower slope and leads to compact blocks being pushed out frontally. This might pose a hazard for the settlement situated right below. However, the final hazard analysis resulted in a classification of Låvan as a low-hazard object which classification is largely based on the absence of significant displacement. In the future, some of the high uncertainties could be reduced by investigating longer time series and establishing further monitoring points.

The Barents Sea is a large epicontinental sea and petroliferous basin, which is fairly unexplored compared to other regions of the Norwegian Continental Shelf (NCS). The structural configuration of the SW Barents Sea is characterized by a complex mosaic of structural highs, platforms and basins, reflecting the interplay between multiple tectonic phases. Late Cenozoic glacially induced subsidence and uplift, and extensive differential erosion, may have had a major impact on the petroleum systems in the area, causing a reconfiguration of the fluid flow systems by gas expansion, oil-spill, migration and remigration of hydrocarbons into the shallower subsurface. Subsequent accumulations of shallow gas may represent significant drilling hazards, potential commercial hydrocarbon resources or be indicative of deeper prospective reservoirs, and are as such important exploration targets. Identification and analysis of fluid flow indications and their relationship to the structural development and denudation history of the Loppa High will provide a better insight to the controlling mechanisms of fluid flow systems on both a local and regional scale. Seismic interpretation, spatial visualization and analysis of 2D and 3D data from the northern margin of the Loppa High have revealed numerous fluid flow indications such as leaking faults, gas chimneys, shallow gas accumulations and buried and exposed depressions. The complex structural development of the Loppa High has led to the development of several sets of faults, which have been classified as deep-seated Permian, vertically extensive Permian-Triassic and shallow Triassic. The larger-scale structural geology of the study area encompasses narrow grabens and extensive horsts, believed to reflect Carboniferous-Permian rifting, extensional faulting related to the proto-Atlantic rift system and later rifting events associated with the opening of the Norwegian-Greenland Sea. The numerous faults identified may constitute a larger network of potential fluid conduits, connecting deeper reservoirs with shallower, suggesting a structural control on the fluid flow systems in the study area. Gas chimneys and high-amplitude anomalies occurring at several levels within the subsurface strata, and the presence of both buried and exposed seabed depressions, testifies to vertical and lateral migration from deeper source rock intervals, gas accumulations along faults and URU, and episodes of potential gas release at the seabed. Observations and results largely correspond to similar studies carried out in the SW Barents Sea region, supporting the theory that fluid flow systems in the area are at least partially structurally controlled and that the distribution of fluid flow systems may have been altered by Late Cenozoic tectonic readjustments through extensive uplift and erosion.

Gámanjunni 3 er et av de ustabile fjellpartiene i Norge med høyest bevegelseshastighet. Hovedmålet med studiet er å sammenstille gamle og nye feltdata, bevegelsesdata og geofysiske data fra tidligere studier ved Gámanjunni 3 til en helhetlig geologisk modell i 3D, og undersøke hvilke interne og eksterne faktorer som kontrollerer fjellpartiet. I tillegg skal det fokuseres på bevegelsesdynamikk, sesongvariasjoner i deformasjonshastighet og om det er mulig å dele opp fjellpartiet beroende på strukturer, morfologiske elementer og bevegelsesdata. Berggrunnen ved Gámanjunni 3 består av kaledonske, mekanisk ulike glimmerskifre, med varierende innhold av muskovitt og biotitt. Fjellpartiet er dominert av to listriske sprekkesett strykende fra NV-SØ med fall mot SV og fra NØ-SV med fall mot NV, som kan sees i sammenheng med post-kaledonsk sprø rifting. De to distinkte bakskrentene og subsidiære skrenter har samme orientering som sprekkesettene. Flere ulike skredmekanismer er observert lokalt i skredet, primært kileutglidning, men også planarutglidning og utvelting, hvor de utgående glideplanene trolig er foliasjonsparallelle svakt hellende sprø og duktile plan. Morfologiske elementer kan sees i sammenheng med strukturelementer, der f.eks. store mengder talus observeres i underkant av skrenter. Overvåkingsdata viser at hastigheten og stupningen på bevegelsene endrer seg nedover fjellpartiet, fra høy i øvre del til lav i nedre del. Retningen på bevegelsene til fjellpartiet er primært VSV til VNV. Temperaturdata viser en forvarmende trend i fjellpartiet. Overvåkningsdata sammenstilt med temperaturdata viser at det er høyere hastighet på sommerhalvåret enn vinterhalvåret, trolig kontrollert av eksterne faktorer som høyere temperaturer og mer vann i sprekkesystemene. Fjellpartiet viser også god respons på perioder med mye regn og høyere temperaturer, derfor vil økning av temperatur i fremtiden trolig føre til økt deformasjon i fjellpartiet. Sammenlikning av strukturer, morfologiske elementer og bevegelsesdata, viser at det er mulig å dele inn skredet i flere mindre deler. Spesielt ett område i tåa, som har beveget seg uavhengig av omkringliggende områder i fjellpartiet. Gámanjunni 3 subsidierer langs bakskrentene i øvre del, og bevegelsene blir i midten av fjellpartiet overført til slakere utgående bevegelse langs foliasjonsparallelle plan i nedre del. Fjellpartiet kategoriseres som et bi-planar sammensatt skred, i et kompleks felt med flere segmenter og lokale uavhengige utglidninger.

In many parts of Scandinavia, the glacial history is more well established than in northern Sweden. The Veiki moraines in northeastern Sweden presumably store information about the Weichselian glaciations. The moraines were formed when stagnant ice was slowly melting under a thick debris cover, forming water filled sinkholes, that were left as elevated ice-walled lake plains when the ice finally melted. The latest age estimations of the Veiki moraines suggest that the landscape was formed during a Middle Weichselian interstadial. The late Weichselian ice sheet that covered much of northern Europe was presumably partially cold based and left the Veiki moraines nearly untouched. However, the age of the moraines had previously been suggested to be Early Weichselian and therefore possibly overridden by two consequent ice sheets. To this day, the ages of the moraines have been disputed. The highly irregular shapes of the moraines have caused some obscurity in the genesis of the Veiki moraines and in this report, subsequent processes are suggested as contributory factors in the formation of the landscape. The obtained OSL ages reinforce that the Veiki moraines were formed during a Middle Weichselian interstadial. The most prominent moraine plateaus were formed in well insulated parts of the ice where the debris cover was thick, while the less prominent moraine plateaus were in poorly insulated parts of the ice. The poorly insulated lakes were affected by faster melting rates and consequently they merged with surrounding lakes, forming a landscape of highly irregular merged ice-walled lake plains once the ice melted. A faster melting rate likely caused differences in the ice surface gradient and led to collapsing lakes in the downslopes. The landscape was later only slightly reworked by the Late Weichselian ice. Reworking by later fluvial processes makes the reconstruction of the original ice-walled lakes somewhat challenging. A geomorphologically unique Veiki moraine plateau has been studied using sedimentological and stratigraphical data, ground penetrating radar (GPR) and high-resolution LiDAR data. Two dating techniques have been applied including optically stimulated luminescence (OSL) and radiocarbon. To improve the chronostratigraphical correlations of the sediments, a few samples have been scanned and checked for most common pollen taxa.

The unstable rock slope (URS) Jettan is located at Nordnesfjellet in Kåfjorden municipality in Troms and Finnmark County, 800 m above the fjord. The rockslide has an estimated volume of 6 Mm3, and moving at a rate of up to 50 mm a-1. Jettan is considered a “high risk object” within the Norwegian unstable mountain framework. This is due to the potential displacement wave impact to housings, infrastructure and industry. As such there has been a scientific interest in the site since 1999 generating several studies, reports, investigations and theses. Continuous monitoring began in 2007. The goal of this thesis was to gain a larger understanding of the unstable rock slope and its driving mechanisms. To do this, exiting data on lithology and structure, geophysics, borehole investigations, seasonal movement trends, past avalanche activity, published geological models and engineering geology studies were reviewed. This array of data was complimented by the work of this thesis including in-depth lithological study, rock mass descriptions, detailed geomorphological mapping, an updated analysis of movement and external drivers. The existing data, and the data gaps covered by this thesis, allowed the construction of a 3D model. Previous studies have shown that Jettan is highly seasonally controlled. High movement rates are recorded in the spring due to snow melting and a continuous deformation in the autumn is considered to be due to permafrost processes. Analysis in this thesis confirmed seasonal variations at Jettan, with high deformation in the summer, lower deformation in the winter and a lower but continuous deformation in the autumn. Jettan is a complex URS with areas showing different morphology, movement direction and movement rates. As dip of the foliation is rarely above 25°, a possible sliding surface is assumed to be a combination of foliation planes and joint sets building a stepped sliding surface. In field a repeating weakness zone was found parallel to the foliation, and it is suggested that it contributes to the overall reduction of the stability for the slope together with groundwater processes. In the boreholes the main sliding surface was interpreted to be at 45 m bgl. The 3D model supports both a stepped and planar sliding surface, and suggested several possible failure scenarios. New volume estimates gave a volume of 7.87 Mm3, for the most realistic larger failure scenario. This is a larger estimate than previous studies, and the greater depth to the sliding surface in this interpretation is seen as the main reason for a larger volume in the 3D model.

The Karasjok Greenstone Belt (KGB) is a N-S trending supracrustal belt in Northern Norway. The KGB may comprise economically important mineral resources. Thus, a better understanding of ore genesis and structural architecture is key information for future exploration. The purpose of this master thesis is to perform detailed structural analysis based on field work in the northern part of KGB. Field data will be combined with exsiting geological data and integrated with high-resolution ortho-photos and aeromagnetic data from Lakselv. This will be used as a basis for interpreting the structural architecture in more detail and to compare it with other areas of the KGB. The present work shows that the stratigraphic sequence is partly inverted. This is likely due to macro-scale overturned folding and possible imbrication. A detailed study of F1 and F2 folds show Ramsey type 2 interference fold patterns. The type 2 pattern suggests NW directed folding and imbricate shearing which is partly in contrast with previous D1 deformation models. The D1 deformation event is followed by strongly asymmetric SW vergent D2 shear folding. Finally, small scale ductile D3 shear zones produced moderately plunging drag folds and fault-propagation folds. The D1 and D3 events in the Lakselv area are not evident farther south in the KGB. Here, the magnetic data mostly show linear NW-SE striking anomalies. This might correspond to D2 structural trends seen in Lakselv. The southernmost part of the KGB shows an anomaly pattern that resembles the refolded pattern in Lakselv. The proposed new D1 model with imbricate folding and associated local inversion may correspond with structures in the northeastern parts of the Kautokeino Greenstone Belt, the Repparfjorden Tectonic Window, and magnetic anomalies within the Jergul Gneiss Complex. The relative timing of the deformation as well as the tectonic evolution correspond with both Svecofennian- and Lapland-Kola deformation. Further work is needed to confirm that the D1 phase within the study area is not a local anomaly and also constrain the deformation event in time.

Video about the field work at https://vimeo.com/495735567/e0c4e93871. Skandinavias glasiasjonshistorie er enda ikke kontinuerlig sammensatt for weichselistiden. I forhold til det fennoskandiske isskjoldet har nye studier avdekket alternative geokronologiske tolkninger for tidlig og midt weichsel i Nord-Sverige. Veikimorenelandskapet ble dannet over en stadial-interstadial syklus korrelert til tidlig weichsel av Lagerbäck (1988). Dette motstrides av moderne vitenskapelige dateringsmetoder som indikerer midt weichsel alder. I utvidet skala utgjør veikimorener to parallelle sett med morenebelter i terrenget hvor den nordligste tungen eller buen av det østlige morenebeltet er navngitt Lainiobuen. Veikimorener tilhørende Lainiobuen ble i denne oppgaven sett på fra et nytt lys ved geomorfologisk tilnærming støttet med feltarbeid og GPR-profilanalyser. Hovedmålet var å bevise eller motbevise teorien fra Lagerbäck (1988) om supraglasial dannelse. Teoretisk forarbeid basert på glasiasjonshistorie, tidligere studier og dannelsesprosesser ble gjennomført for å få oversikt over mulige relasjoner til veikimorener. Feltobservasjoner fra oktober 2019 styrker kartleggingen gjort i ArcGIS Pro og GPR-profilanalyser. Datasett fra Lantmäteriet og SGU ble implementert i kartleggingen, og GPR-profiler originalt fra et feltarbeid utført i 2012 ble tildelt av Helena Alexanderson. Flere generasjoner av inaktive elveleier i kartbildet formidlet et landskap påvirket av glasifluvial drenering. Begge hovedelementene relatert til veikimorener, platåer og kantrygger, er stedvis påvirket av glasifluvial erosjon. Kantryggbrudd forekommer regelmessig og ble assosiert med inaktive elveleier. Forekomst av ekstra kantryggsett er relatert til en to stegs nedsmeltningsprosess, men i noen tilfeller er det antydet fluviale tilknytninger. Platåkomplekser ble definert som sammensatte ellipsoideformer med areal større enn 0,34 km2, og dannet i sammenheng med fusjonering og utvidelse av isvegginnsjøer langs supraglasiale ismarginale sprekkesystemer. Platåer ble antatt å ikke ha en generell orienteringstrend. Glasilakustrin kollaps ble påvist ved Raakejärvet-veikimorenen og relatert til østlig isoverflategradient. GPR-profilet av Heinävumanjärvi-veikimorenen antydet en intern oppbygging av veikimorener lik forslaget til Lagerbäck (1988). Sammenfallende orienteringstrend av Lainiobuen og tidlig weichsel landformer ble tolket som et resultat av gjentakende isstrømning langs Torneälv-dalen, og fastslår dermed ikke tidlig weichsel alder av veikimorener som antatt av Lagerbäck (1988). Fra et geomorfologisk perspektiv ble Lagerbäck (1988) sin supraglasiale teori om isvegginnsjøer dannet i et dødislandskap forårsaket av en passiv ismargin støttet, men ikke antakelsen om tidlig weichsel alder.

The primary goal for this thesis was the reprocessing and interpretation of 2D seismic lines in the Fram Strait and West Svalbard Margin (WSM). Seismic data quality was significantly improved through the implementation of new processing steps that had previously not been applied, incl. e.g. burst removal and a more advanced type of migration. The reprocessed lines were acquired by CAGE over multiple years prior to 2016 and were integrated in a seismic database with a number of seismic surveys in the study area to comprise a regional database. This database, together with bathymetric data collected in the area, made up the basis of interpretations, which focused on stratigraphic development of the deep-water area of the West Svalbard Margin and Fram Strait in relation to contourite drift development, neotectonic setting and processes of submarine landslides in the area. Notable features in this deep-water setting were several smaller and larger drift deposits, among which the Vestnesa Ridge is well-known and well-studied for its active fluid flow system. The seismic database allowed extending stratigraphic correlations of the 1.5 Ma and 2.78 Ma horizons from ODP sites and existing stratigraphy on the Yermak Plateu further south and into the deep-water area. This facilitated studying the differences in sedimentation rates on the WSM and revealed high sedimentation rates at Vestnesa Ridge as well as slightly thicker sediment packages south on WSM than north. Two main seismic facies were identified in the data and were characterized by 1) Parallel and horizontal and 2) subparallel and wavy reflection patterns. Parallel and horizontal reflection patterns were observed along the gentler sloped areas east on the WSM and are related to hemipelagic settling and sheeted drift structures. Subparallel and wavy reflection patterns were interpreted to be related to drift deposits with moat-levee structures and were observed exclusively on the deeper and steeper parts of the western slope along the WSM, indicating strong bottom currents along the Molloy Ridge. Landslides were observed on the western slope of WSM and are related to the development of drift deposits on the steeper slopes, which have contributed to slope instability. Combined with toe erosion of the slope by normal faults related to the Knipovich and Molloy Ridges and earthquakes these conditions may have triggered the landslides observed.

A meteor impact event on the Bjameland Platform in the Norwegian Barents Sea about 142 ± 2.6 million years ago formed the Mjølnir Impact Crater. The structure has diameter of 40 km impacting the Mesozoic stratigraphy, and has previously been investigated with emphasis on the dynamics of the impact, the structure formation, sedimentation and post-impact tectonics. Impact structures have proven to be petroliferous elsewhere in the world. By applying new seismic 2D- and P-cable data and integrating prior studies, this thesis focuses on how the structure of the Mjølnir Impact Crater might represent a petroleum system in the Barents Sea. The structural setting of the Mjølnir impact Crater shows several potential structural traps, including horst and graben structures within the crater, and listric rim faults at the periphery. A simplified 1D maturation model of potential source rocks in the area, indicate that the Hekkingen and Steinkobbe formations are sufficiently matured and have generated oil, while the Lower Triassic formations have generated gas. These source rocks may potentially charge the Mjølnir Impact Crater by petroleum migration vertically along deep-seated faults and laterally in the southward dipping stratigraphy, from the Nordkapp Basin area. The southern section of the Mjølnir Impact Crater is considered have the highest hydrocarbon potential, due to a thicker overburden and favorable migration pathways. Five seismic anomalies of high amplitude have been identified in the southern Mjølnir Impact Crater. These are interpreted to represent hydrocarbon accumulations, structurally trapped in horsts and by listric rim faults, and overlain by Upper Jurassic shales with sealing properties. Volumetric calculations for one of the amplitude anomalies suggest that 24,4 MMSm3 of oil may be accumulated at the southern boundary of the crater. In conclusion, presence of source rocks, migration pathways, reservoir and traps supported by observations of seismic amplitude anomalies suggests that the Mjølnir Impact Crater represents a potential hydrocarbon system.

During initial exploration efforts in the Barents Sea several gas prone and underfilled prospects were drilled which significantly dropped the interest in the area. The Hammerfest Basin however turned out to hold significant hydrocarbon volumes. Although still mostly underfilled, the discoveries here today make up the Snøhvit oil and gas field. The Hammerfest Basin is an overfilled petroleum basin, meaning that the several source intervals have produced enough hydrocarbons over time to fill all the traps. This, and the hydrocarbon shows below the hydrocarbon-water contacts inside the traps indicate that the reason behind underfilled structures is leakage. This means that the main exploration risk in the area is trap integrity. Given the large amount of evidence for fault-assisted remigration, this thesis focuses on explaining the hydrocarbon column heights observed today in these structures with the help of fault valve theory. The theory suggests that a subset of faults oriented at the right angles to the stress field can control the pore pressures in a pressure compartment in a dynamic equilibrium. When pressure increases with hydrocarbon charge, or gas dissolution the effective stress drops which can reactivate the faults leading to the leakage of hydrocarbons from the trap. In this study, the slip tendencies of faults around the Albatross, Snøhvit and Askeladd structures were calculated and plotted on the interpreted fault planes. This gave the critical pressure perturbations of the faults, i.e. the pressure increase needed to cause slip on them. Faults and fault segments with low critical pressure perturbations are regarded as areas of high risk of leakage. After identifying high risk segments, their intersection with the top reservoir was found and compared with the level of hydrocarbon-water contacts. On Albatross Sør and Snøhvit Nord high risk faults and fault intersections intersect the top reservoir on the level of the gas-water contact. On Albatross and Snøhvit, both of which have leaked considerably, high risk faults were identified near the culmination of the trap. Askeladd, Askeladd Vest and Askeladd Gamma which are not as severely underfilled, the fault planes show higher critical pressure perturbations. Delta Vest, an empty structure also has higher pressure perturbations, however it has a fault intersection right at the culmination. Askeladd Beta, the second dry structure showed higher risk on a fault directly at the top of the structure.

Rock slope failures are known major contributors to landscape evolution in alpine Norway, and also pose a threat to people and infrastructure in the present day. By examining the history of rock slope failures at active rockslide sites an understanding of recurrence intervals and triggering mechanisms can be achieved. The focus of this study is to form a complete picture of the evolution of an area of Vannøya, Troms, where an unstable slope sits above large failure deposits indicative of a sequenced failure history. The deformation of the URS, geomorphology of the area and geochronology of the deposits has been examined to provide a context and timing for the failure evolution of the slope and the larger area. Skredkallen is a 1.1 Million cubic meters actively deforming unstable rock slope (URS) located on the steep E-facing slope of Laukvikfjellet on Vannøya. Sitting at the base of the unstable slope is a c. 13 Million cubic meters rock avalanche deposit, stretching to 1.4 km from the unstable area, and consisting of blocks ranging in size up to c. 1000 cubic meters. Morphostructural mapping suggests a biplanar compound slide (dominated by more than one sliding surface) formed by a step-path geometry between the gently-dipping foliation and steep joint sets. A prominent column (Kallen), controlled by orthogonal joints, formts the outer boundary of the URS and is toppling at c. ≤12 mm/yr towards the E. Deglaciation of the area occurred 15 – 13 ka, followed by isostatic rebound and relative sealevel changes, resulting in three prominent shorelines. The failure deposits are characterized by 3 domains (inner, middle and outer) by geometry and runout distance. The two outermost domains show evidence of marine erosion and deposition at elevations consistent with the Main and Tapes shorelines. 14C dating of a lake sediments on top of the inner domain revealed an age of 1642 cal. yr BP. These relative timing constraints suggest a rock avalanche or series of avalanches occurring between the formation of the marine limit and Main shoreline (deglaciation at 15-13 ka and Younger Dryas glacial advance at 11-10 ka). The age difference between the relative dating and the age of the sediments on top of the deposits suggests that one or multiple failures may have occurred following the emplacement of the main rock avalanche event, after which the (dated) lake formed.

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 (L1-L3) are defined. A glacial till (U1/L1) covers most of the area, though it is sometimes lost over bedrock highs and is not visible beneath thicker sediment sequences. The overlying sediments are divided into two units representing glacier-proximal (U2/L2) and -distal (U3/L3) glaciomarine depositional settings. Both tend to drape the underlying till. Suspension settling from meltwater plumes and rivers is the primary source of such sediments. The origin of the suspended sediments fluctuates in the glacier-proximal sediments; laminations of sediments with different colours, densities, and element ratios reflect sources in either the southwest and Woodfjorden, or in the northwest and east of Wijdefjorden. The glacier-distal sediments are massive, indicating a greater distance from fluctuating sources and more stable conditions. Sediments from the southwest have a greater influence in the inner fjord, while and sediments from the east are more important in the outer fjord . In the central fjord sediments derived from both sides are important. Beyond the mouth of the fjord, sediments from Woodfjorden are present. The glaciomarine sediments also have IRD-rich (ice rafted debris) intervals in the cores, which generally correlate with internal reflections in the chirp profile and reflect periods of enhanced sea ice rafting. The deglaciation of the shelf likely occurred before ~16 cal. ka BP, and the presence of IRD on the shelf after ~14.8 cal. ka BP likely indicates the beginning of the retreat of ice into the fjords. The transition from glacier-proximal to -distal sedimentation on the shelf, signalling a weakening glacial influence beyond the fjord, occurred around 12.2 cal. ka BP despite the Younger Dryas cooling. At ~11.5 cal. ka BP, glacier-distal sediments were deposited in the central fjord, indicating that glaciers had receded into the inner fjord. There is little IRD in the cores from ~9.3 cal. ka BP to ~3.5 cal. ka BP, signalling a period with reduced glacial activity. In the inner fjord, a transition from glacier-proximal to glacier-distal sediments occurred around 7.2 cal. ka BP, later by ~4 cal. ka than other Svalbard fjords and at a time of generally cooler conditions. This is perhaps due to locally more active glaciers or rivers near the core site prior to that time. Around ~3.5 cal. ka BP, there is increasing IRD in the cores, with a maximum from ~1.5-1.0 cal. ka BP. This is likely due to the generally cool conditions that have encouraged glacial advance since ~4 cal. ka BP.

This study has investigated salt movements in the Nordkapp Basin, on the Loppa High (Svalis Dome) and on the Bjarmeland Platform (Samson- and Norvarg domes). The aim is to discuss how differences in salt growth potentially relates to the structural evolution of - and differences between - these three provinces. Evaluation of seismic 2D- and 3D data together with well correlation, allowed a regional stratigraphic framework to be established for the Permian-Quaternary succession. Four stratigraphic units were defined: Lower Triassic, Lower to Middle Triassic, Middle Triassic-Jurassic and Cretaceous-recent. Thickness variations and reflection configurations within these units, together with salt morphology, documented the timing of salt growth. In the Nordkapp Basin, several phases of salt growth occurred throughout the Triassic, a period usually referred to as tectonically quiet in the southwestern Barents Sea. Extensional forces locally lead to subsidence and faulting/steepening of the basin margins. A regional extensional event lead to renewed salt growth during the Cretaceous, before Cenozoic regional compression squeezed the diapirs, resulting in a final growth phase. At the Svalis Dome, a salt pillow grew during the Early to Middle Triassic-Jurassic. Later uplift and erosion of the dome resulted in renewed growth and diapirism. Little or no salt movements are observed on the Samson- and Norvarg domes during the Mesozoic, but Cenozoic compression appears to have mobilized the salt. The main differences in salt growth between the three provinces seem to relate to the different structural settings; in the Nordkapp Basin, diapirs grew already in the Triassic possibly due to extensional forces in and adjacent to the basin. On the Svalis Dome, the salt growth seems to relate to a large degree of uplift of the Loppa High. At the Bjarmeland Platform, a late initial growth stage reflects a tectonically stable environment until Cenozoic regional compression mobilized the salt.

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 på den strukturelle utviklingen av denne kvartsfeltspatiske gneisenheten, samt den strukturelle relasjonen til det underliggende gneisunderlaget og overliggende Skipsfjorddekket. Feltundersøkelser viser at bergartene i den midtre kvartsfeltspatiske gneisenheten har flere likhetstrekk med bergartene i den metasedimentære Vannagruppen, ved antatt primær lagning og veksling mellom metapsammittiske og metapelittiske bergarter. Strukturell studie har avdekket to faser av deformasjon (D1 og D2) ved NV-SØ rettet skorpeforkortning i studieområdet. D1-fasen representerer en fase med SØ til ØSØ-rettet transport og inkluderer utviklingen av skyvesystemer. Den viser in-sequence innskyvning av den kvartsfeltspatiske gneisenheten, kontrollert av svakt skråstilte ramper i gneisunderlaget, og out-of-sequence overskyvning av Skipsfjorddekket. Dette har resultert i dannelsen av isoklinale og transponerte F1-folder med tilhørende akseplankløv (S1). D2-fasen representerer en senere fase av NV-SØ forkortning, ved horisontal kompresjon som har ført til dannelsen av F2-folder og tilhørende S2-akseplan i form av kinkfolder og chevronfolder i den kvartsfeltspatiske gneisenheten og i Skipsfjorddekket. Denne studien viser at den kvartsfeltspatiske gneisen har en sedimentær opprinnelse og ble vertikalstilt og deformert under NV-SØ rettet skorpeforkortning. I tillegg viser hovedenhetene i studieområdet imbrikerte skyvesystemer som indikerer at disse bergartene er deformert som en del av et svekofennisk tykkhudet folde-skyvebelte. Regionalt samsvarer deformasjonsmønsteret med tidligere foreslåtte modeller for den svekofenniske D3-hendelsen i Vest-Troms gneisregionen.

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 schist, displaying Caledonian ductile and Post-Caledonian brittle structures. NNW-SSE and NNE-SSW-striking backscarps delimit the unstable area and align with the strike of the Post-Caledonian regional brittle structures. The backscarps seem to control the extent of the unstable rock slopes, as displacement from InSAR shows a downslope movement inside the areas delimited by the backscarps. Structural analysis based on traditional field data revealed two structural domains (Mellomfjellet 1 and 2) each with three joint sets: Mellomfjellet 1: J1 (029/72±16), J2 (288/84±21) and J3 (075/67±12); and Mellomfjellet 2: J1 (022/81±14), J2 (108/88±15) and J3 (075/47±17). J1 and J2 were most dominant joint sets, striking parallel to subparallel with the backscarps. J3 was found only found adjacent to two E-W striking lineaments, cross-cutting the two instabilities. The undulating foliation (155/13±17 and 183/11±15, Mellomfjellet 1 and 2 respectively) is shallowly dipping downslope, and gently folded with a fold axis (237->13) also plunging downslope. Structural analysis based on a photogrammetric point cloud identified both J1, J2 and the foliation, and showed the same orientations as the field data when taking the variance into account. Kinematic analysis and field observations suggest planar sliding along a failure surface stepping between sub vertical joints (J1 and J2) and the foliation. Mellomfjellet 1 shows morphological features similar with a DSGSD, complex fields and a biplanar compound slide. Mellomfjellet 2 show features similar with a slide topple, and a biplanar compound slide. A failure scenario for each of the instabilities was determined, based on the delimiting backscarps and morphological features, where both scenarios lie in the medium hazard class. Mellomfjellet 1 has an estimated volume of 1.12x106 m3 and Mellomfjellet 2 has an estimated volume of 3.05x106 m3. The run-out analysis showed that Mellomfjellet 1 will not reach any infrastructure or buildings, while Mellomfjellet 2 is likely to reach a construction site where a new power line is being established. Both of the instabilities are classified as low risk sites.

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 dolomitic and calcitic marble units intercalated with various types of calcareous schists. Although having been described as a world-class iron deposit, it has not been a subject of detailed geochemical studies. In order to determine the controlling mechanisms of hematite and magnetite formation, the present study mainly focuses on investigating the geochemical characteristics of the mineralization and host rocks within a structural framework. In addition, the fluid inclusion study gives insight into the post-ore P-T-X evolution of the studied area. Deformation processes, recrystallization of ore and gangue minerals as well as remobilization of metals during the Caledonian Orogeny affected the ore textures and mineral chemistry of the mineralization. Strain variations in ore bodies and host rocks, which are evident in both macro- and micro-scale, have given rise to different generations of Fe-oxides characterized by significantly different morphologies. The major element characteristics and REE patterns of mineralized samples indicate that the primary mineralizing events involved mixing of a low-temperature hydrothermal source of iron with a detrital component in a rift-related environment. 𝛿�13C and 𝛿�18O values of gangue carbonates support a deposition under the influence of hydrothermal fluids. Geochemical data, along with the age interval of host rock marble (800 to 730 Ma, Melezhik et al., 2015) have led the author to suggest that the Fe-mineralization of the Dunderland Formation accumulated in glacially and hydrothermally influenced passive margin rift-basins or back-arc basins. Fluid inclusion studies of recrystallized quartz witness a complex post-ore tectonic evolution during the Caledonian Orogeny.

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 deformation at this field site is from a Paleoproterozoic thrust sheet, ‘Skipsfjord Nappe’, from Svecofennian deformation. Skredkallen is an actively deforming URS located on the steep eastern slope of Laukvikfjellet. Previous failure events have occurred in the URS, resulting in rock avalanche deposits of varying size below the slope. What is left is multiple detached terraces and a tall column of rock ‘Kaillen’, which is still actively deforming. The URS has been identified as moving downslope towards NE by means of satellite InSAR. The location of Skredkallen, as well as a rock slope failure on a mountain ridge further west, align with a thrust boundary. This suggests that there might be a regional pattern between the two instabilities and a possibility of a tectonic boundary forming the rupture surface of the URS. Geophysical data indicates a fault being present close to Skredkallen, and brittle fault structures have played an important role in the origin of the URS. The structural mapping showed four main joint sets; J1(034/82±16.9), J2(205/68±9.0), J3(309/68±10.5) and J4(117/83±15.5). J1 and J4 were the most dominant joint sets, both near-vertical and dipping towards ESE and SW respectively. The foliation (292/14±13.8) dipping towards NNE is oblique to the NE facing slope. The main failure mechanism is planar sliding along a NE-dipping failure surface, probably contributing to a biplanar compound slide made up by J3 and SF, which together have developed a step-path geometry effectively working as a listric sliding plane. The rock column Kaillen is toppling towards E from the intersection between J1 and J4. The failure on Skredkallen can be considered as a possible DSGSD based on the complexity of geometries made by the surface morphostructures, and from the inferred brittle fault and fracture geometries traced in the bedrock. The two proposed scenarios involve a worst case scenario with a minimum mass of 1.1 Million cubic meters sliding down the steep eastern slope of Laukvikfjellet, and the collapse of Kaillen (11,193 cubic meters). However there are no settlements immediately below the slope, and a failure only poses a threat to an uninhabited cabin and hiking trails and is therefore low risk.

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 glacial scouring and a glacial origin (i.e. a tillite). Correlations of similar deposits from the same era elsewhere in the world have resulted in theories of a world-spanning glaciation, the “snowball Earth”-theory, where great amounts of the Earth was covered by snow and ice. However, the theory is criticized by many, and better understanding of diamictite deposits in general have caused several re-evaluations (globally) of these presumed tillites, which apparently can be easily confused with various coarse-grained gravity flow deposits (i.e. debrites and slump deposits). In this thesis, the classical type locality for the Varanger Ice Age at Bigganjárgga in Varangerbotn, eastern Finnmark, has been scrutinized with one question in mind, is the Bigganjárgga Tillite really a tillite or may it represent something else? In order to answer this question, a detailed facies analysis is combined with a digital outcrop model and thin section analysis. From the facies analysis, four facies associations are recognized: FA 1 – thin-bedded sandstone (representing fluvial deposits), FA 2 – thick-bedded diamictite (representing tillite or debrite deposits), FA 3 – thin-bedded sandstone (representing turbidites) and FA 4 – thin-bedded diamictite (representing fine-grained debrite or slump deposit). The appearance of rip-up mud clasts and several associated negative imprints within FA 1 suggest that the unit most likely was consolidated before erosion of the Bigganjárgga Unconformity (a part of the regional Varangerfjorden Unconformity) and deposition of the Bigganjárgga Diamictite (FA 2) took place. A confirmation to this was given by stylolite observations in the field and imbricated grains (with irregular grain-grain contacts), and quartz cementation in the petrographic analysis consistent with pressure solution occurring at a considerable burial depth (c. 2 km in sedimentary basins with normal geothermal gradient). Thus, it seems likely that the debated striations associated to the Bigganjárgga Unconformity developed in consolidated material, implying glacial abrasion. The Bigganjárgga Unconformity at the outcrop is seen in relation to the extensive regional Varangerfjorden Unconformity where clear evidences for glacial erosion have been reported in previous studies. Therefore, it is assumed that the investigated unconformity was made by glacial erosion that occurred at regional scale. The Bigganjárgga Diamictite (FA 2) itself is seen in relation to the surrounding units below and above. Due to the appearance of FA 3 (turbidite sandstones) and FA 4 above (fine-grained gravity flow deposits) the diamictite, a regional relative sea level rise is assumed eventually drowning and flooding the diamictite body. The preserved evidence surrounding the Bigganjárgga Diamictite that caused the glacial origin assumptions are the cemented sandstone and the regional unconformity below with striations correlative to nearby glacial direction features, the burial by fine-grained turbidites and fine-grained gravity flow deposits with randomly clasts up to cobble size units above the diamictite associated with subsidence and ice rafted debris.

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 Fennoscandian Platform in the north, coupled with growth and melt of the Antarctic Ice Sheet. Stages of rising sea-level are reflected by low-angle, sigmoidal clinoforms with ascending shelf-break trajectories deposited simultaneously to rapid basin subsidence. Periods of a relative fall in sea-level are characterized by complex-oblique clinoform stacking patterns, with a distal displacement of the shelf and descending shelf-break trajectories. Falling stage system tracts are dominated by the evolution and progradation of complex channel systems and erosion of the exposed shelf. Lowstand system tracts are recognized where coarser, sand-rich material was deposited towards the distal basin margins. The results provide new insight on the subsurface drainage system, as well as an evaluation of a potential Oligocene reservoir rock, the Vade Formation, which in general showed good reservoir properties. This work proposes an updated depositional model for the sandstone, with a newly defined lateral reach, extending beyond the previously established boundaries of this formation. The suggested model describing the petroleum system favours lateral drainage with migration focused sub-horizontally through the permeable Vade Formation which is capped by transgressive, sealing lithologies. Here a persuasive correlation to a Jurassic source rock, the Mandal Formation, is outlined, providing a tentative basis on which to endorse a thermogenic origin of the observed hydrocarbon indications with long distance lateral migration enabling accumulations to form far from the petroleum kitchen area. A differential entrapment model alongside potential leakage and well-information, provides an explanation for the dry wells adjacent to possible hydrocarbon accumulations in the region. The evaluation of the petroleum system sheds new light on the potential for several hydrocarbon filled structures in the subsurface of the Norwegian southern North Sea.

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 bergarter, med fokus på geometriske og kinematiske analyser av duktile skjærsoner i Skipsfjorddekkets undre del, på Vanna i Troms. Arbeidet har påvist en ca. 900 meter tykk sekvens med steiltstående antatte metasedimentære bergarter, kartlagt i nordøstlige deler av Vanna, mellom Svartbergan og Laukvika. Sekvensen ligger med tektoniske kontakter over et neoarkeisk tonalittisk gneisunderlag, og under Skipsfjorddekkets bergarter. Det tonalittiske gneisunderlaget ligger med en orientering N-S og et fall mot vest, mens de overliggende bergartene har en orientering NØ-SV, hhv. med fall mot NV. Det som skiller den metasedimentære enheten fra Skipsfjorddekket, er fallvinkelen. De antatte metasedimentære bergartene inneholder strukturgeologiske orienteringsdata som strekningslineasjoner (L1) og krenulasjonslineasjoner (L2), foliasjonsparallelle folder (F1-folder), og folder med akseplan nesten vinkelrett på hovedfoliasjonen (F2-folder). To tektoniske modeller er foreslått. Modell 1 har tolket den metasedimentære enheten til å være en separat allokton enhet og/eller en undre del av Skipsfjorddekket. Den baserer seg på imbrikerte skyvesystemer, og er en såkalt «in sequence» forkastning. Modell 2 baserer seg på en paraautokton enhet som kan korreleres med Vannagruppen. Reaktiverte/inverterte normalforkastninger har ført til en subvertikal posisjon til de sedimentære enhetene, og Skipsfjorddekket har kommet over som en lavvinklet «out of sequence» skyveforkastning. Lokalt har det forekommet to tektoniske hendelser i feltområdet. Innskyving fra NV mot SØ av Skipsfjorddekket dannet opprette makrofolder (F1) med vergens mot SØ (D1- hendelse). Deretter har F2-folder blitt dannet i mesoskopisk skala, med en NNV-SSØ- orientert skorpekompresjon, som har ført til folding av strekningslineasjoner (L1) (D2-hendelse). De lokale tektoniske hendelsene samsvarer godt med den regionale D3-hendelsen i Vest-Troms gneisregionen, som innebærer orogenparallell skjærbevegelse og kompresjon.

The late Cenozoic evolution of the southwestern Barents Sea shelf includes periods of uplift, erosion and glaciations. This part of the stratigraphy has been studied using 2D and 3D seismic data, with emphasis on the interplay between uplift, erosion and glaciations and salt movement. The study area comprises the Svalis, Samson and Norvarg domes and the Nordkapp Basin, where halokinesis has been a major influence on the tectonostratigraphic evolution. The study includes systemization and categorization of the timing of salt activity relative to the erosion of the shelf, in the Nordkapp Basin, and on the Svalis, Samson and Norvarg domes. Very late to almost recent salt movement has occurred within some of the diapirs in the Nordkapp Basin and the Svalis Dome, evidenced by uplift of the Upper Regional Unconformity (URU) surface and the seafloor above the salt. Furthermore, the study reveals significant local variations in salt movement of the diapirs in the Nordkapp Basin, with a trend of more late salt movement towards the northeast. This is possibly attributed to a larger original salt thickness in this part of the basin compared to in the southwest. A mini-basin filled with glacigenic sediments is found adjacent to the Svalis Dome, and this is assumed to be a result of a combination of deeper glacial erosion of less resistant strata on the Loppa High, and less exposure to erosion due to the continuous salt rise and elevation of the adjacent dome. The Norvarg and Samson domes are not found to be influenced by late Cenozoic salt movement, which is attributed to factors such as original salt thickness, overburden strength and early Cenozoic erosion. Spatial variations in lithology due to salt-related doming and faulting is assumed to have influenced both the pre-glacial and later glacial erosion of the Norvarg Dome during the Cenozoic. Overall, the relationship between salt diapirism, erosion and glacial influence is found to be complex. The structural elements within the study area have experienced different pre-Cenozoic evolutions and have been exposed to varying degrees of erosion and also phases of grounded glaciers. The halokinetic history of the structural elements is also different, causing the salt structures within the study area to have different responses to the late Cenozoic uplift, erosion and glaciation of the shelf.

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 blocks in the glacially eroded Reisadalen in Northern Troms. Geological mapping of Mellomfjellet showed that the bedrock consists predominantly of amphibolite. The area was divided into two domains (MF1 and MF2) where MF1 comprised of a foliation (strike/dip; 169°/15°±18.9°) and three joint sets: J1 (029°/72°±16. 3°), J2 (286°/83°±21.8°) and J3 (075°/67°±12.3°). MF2 comprised of a foliation (183°/11°±14.3°) and three joint sets: J1 (022°/82°±14.7°), J2 (108°/88°±15.3°) J3 and (071°/52°±12.7°). Joint set J3 was for both domains found in relation to two E – W-trending morphological depressions. The mapped joint sets correlated well with joint sets determined from drone photogrammetry, and InSAR displacement showed structural trends, delineated by mapped bedrock structures and morphological elements. The kinematic analysis from MF1 showed that flexural toppling along J1 was a partly feasible failure mechanism. Planar failure along the foliation was feasible for some of the foliation and therefore a bi-planar compound slide comprising of J1 and the foliation is proposed as the main failure mechanism. At MF2 flexural toppling along J1 is the main failure mechanism and slide topple is proposed, as there is feasibility for planar sliding along some of the foliation. The mapped bedrock structures align with regional structural geological trends and are interpreted to govern the failure mechanisms and delineation of the URS at Mellomfjellet. Worst-case scenarios for each domain where delineated based on geomorphological features in order to assess consequences connected to the URS. The scenarios ranged from 1 to 3 Mm3 in volume and the run-out modeling showed that no settlement was reached and therefore the risk is low for both scenarios.

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 active seeping sites. A simplified maturation modeling of source rocks suggested that the Botneheia Formation and Billefjorden Group is gas generating. Gas is believed to migrate vertically from these formations through leaking faults (F1, F2, F4, F6 and FZ) and gas chimneys (GC1-GC3 and GCZ). Direct migration from the Botneheia Formation source rock to the reservoir of De Geerdalen/Snadd Formation is also possible in the gas mature areas of the Olga basin and potentially in the deeper parts of the Storbanken high. Post-Early Cretaceous extension, most likely related to the uplift of Storbanken high, is believed to developed NW-SE striking normal faults (FZ). The normal fault zone (FZ) is regarded as a vital migration pathway potentially transporting gas from the Botneheia Formation source rock and distributing gas from the reservoir of the De Geerdalen/Snadd Formation to the Realgrunnen Subgroup. NE-SW striking reverse faults (F5) at the Kong Karls Land platform has suggested compression in Early Cretaceous, an important tectonic event tilting the stratigraphy towards the northwest favoring lateral migration towards the Storbanken high. Gas flares identified above outcropping formations has indicated lateral migration along the cap rocks of the Flatsalen Formation and Agardhfjellet Formation. Pockmarks were mainly restricted to the intersection of the Olga basin and Storbanken high. The distinct distribution is believed to be governed by the glacigenic sediments which accumulated within a glacial trough carved by the lithologically controlled erosion of the Agardhfjellet Formation. The pockmarks, craters and craters with associated mounds were found to be inactive. Earlier massive gas expulsion related to the retreating ice sheet acting as a seal or the dissociation of sub-glacial gas hydrates after the LGM is therefore suggested as a potential generating mechanism. Modeling of the gas hydrate stability zone has indicated favorable conditions for gas hydrates SII at Storbanken high suggesting the potential for ongoing gas hydrate dissociation as a gas leakage mechanism in the study area.

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 northern side, where there are no active seepage areas. The cores were worked on in the lab, samples were taken and sieved. After this were planktic (Neogloboquadrina pachyderma s/d) and benthic (Cassidulina neoteretis) foraminifera were picked. Isotope analyses were done on From the planktic (Neogloboquadrina pachyderma s/d) foraminifera were an isotope analysis done, providing the carbon (δ13C) and oxygen (δ18O) isotope measurements. These values were used to identify if methane seepage had affected the cores. Two of the four cores indicted methane seepage (HH-13-197 and HH-13-215) indicated methane seepage. Both the distinctly negative δ13C and the magnetic susceptibility data indicated methane seepage for these two cores. The isotope signals were used to identify past SMTZ, while the present SMTZ were found in core HH-13-197 from pore water data showing sulphate measurements.

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 og dioritt med folde- og skyvestrukturer, som i denne oppgaven er detaljert kartlagt for å utrede kontaktforholdene til dioritten, analysere folder, kløv, og duktile skjærsoner med vekt på kinematikken i skjærsoner og dens relasjon til folde- og skyveenheter lenger nord på Vanna. De metasedimentære bergartene i feltområdet er tolket å være metasandsteiner og metapelitter tilhørende Vannagruppens stratigrafisk øverste formasjon, kjent som Bukkheiaformasjonen. Kontaktsonene mellom metasandsteiner/metapelitter og dioritt viser økende grad av metamorf omvandlig, og teksturell og strukturell formforandring, og er tolket å være semiduktile til duktile skjærsoner (S1). I tillegg er lignende skjærsoner kartlagt i dioritt med linser av metasandstein, som viser internt komplekse geometriske mønstre. S1-skjærsonene stryker NØ-SV til VNV-ØSØ, faller slakt mot henholdsvis NV og NNØ, og har strekningslineasjoner og interne, isoklinale folder (F1) med foldakser som stuper slakt mot ØSØ, og som indikerer revers skyvebevegelse mot SØ, og stedvis skrå sidelengs skyvebevegelser mot øst. Videre har F1-foldene blitt refoldet av opprette, lokalt asymmetriske F2-folder som vergerer svakt mot sør, med foldeakser som stuper slakt mot øst. I dioritt er S1-folierte bergarter kuttet av NNØ-SSV-strykende, og steile, VNV fallende, sinistrale, duktile S3-skjærsone som inneholder asymmetriske F3-skjærfolder som vergerer mot sør, med steilt stupende foldeakser. For utviklingen av deformasjonsstrukturene er det foreslått en flerfasemodell (D1-D3). Den første deformasjonssfasen er transpresjon med forkortning i NV-SØ-retning, revers skyvebevegelse samt dekstral sidebevegelse med topp-mot-SØ (D1). For den andre deformasjonsfasen (D2) viser dataene forkortning i omtrentlig N-S-retning (D2), mens den siste hendelsen (D3) skjedde ved skorpeforkortning og sinistral sidebevegelse i Ø-V-retning. Resultatene er sammenliknet med deformasjonen i Vannagruppens undre enheter og kontakt til TTG-gneiser ved Vikan lenger nord, som viser flere geometriske og kinematiske likhetstrekk, men også betydelige ulikheter. Ved Vikan er lagrekken foldet av mer åpne, NØ-SV-strykende F1-folder med akseplanfoliasjon (S1) og sinistrale sidebevegelser langs strøket til S1, mens det ved Larstangen-Fakkekeila er tolket dekstrale sidebevegelser. Det er også større variasjon i de estimerte tektoniske transportretningene for deformasjonsstrukturene ved Larstangen-Fakkekeila, noe som kan skyldes tilstedeværelsen av den massive, kompetente dioritten som en uregelmessig laggang (sill) mellom de to områdene. D1-D3-deformasjonsstrukturene kartlagt i denne oppgaven tolkes å skyldes innskyvningen av Skipsfjorddekket mot SØ med dannelsen av F1 og F2-folder og S1-S2 skyveforkastninger, og relaterte sideforkastninger (S3) i fronten av et transprespressivt forlands- folde- og skyvebelte, sannsynligvis av svekofennisk alder.

Hovedformålet med denne oppgaven er å beskrive og tolke skredavsetninger og -prosesser i den sørvestre dalsiden i Kåfjorddalen i Troms. I tillegg blir det gjort en overordnet vurdering av hvordan sedimenttransporten kan ha vært gjennom holocen og hvordan skredaktiviteten forventes å bli som følge av klimaendringene. Fjorten skredvifter er beskrevet og tolket. Beskrivelsene og tolkningene av skredviftene er basert på feltobservasjoner, feltbilder og tolkning av Digital Terrengmodell (DTM). For skredvifte III er også flyfoto benyttet. Skredviftene III, IV, XI og XIII som er befart i felt, er omtalt mer omfattende enn de øvrige. Dominerende skredprosesser i studieområdet i dag er snøskred, flomskred og steinsprang. Snøskred og flomskred preger den midtre og vestlige delen av studieområdet, mens flomskred er mer markant i østlig del. Noe steinsprang forekommer på alle viftene. Steinskred/steinsprang synes å ha vært den dominerende skredprosessen tidlig i holocen i tiden før holocen temperaturmaksimum (HTM), mens flomskred og snøskred, som også hadde høy frekvens tidlig i holocen, har vært de dominerende prosessene i perioden etter HTM. HTM synes å ha vært en periode med mindre skredaktivitet. Skredviftene i studieområdet er i hovedsak bygd opp av steinskred/steinsprang tidlig i holocen og modifisert av flomskred- og snøskredaktivitet. Et betydelig avvik i estimert volum av dagens vifter i studieområdet og volum antatt fjernet fra kildeområdene, viser at det må ha vært høy skredaktivitet i Kåfjorddalen i tiden før holocen. Det er forventet at et varmere og våtere fremtidig klima med mer ekstremvær, vil øke antall flomskred og mindre steinspranghendelser i studieområdet. Antall snøskred er forventet å øke de kommende tiårene, men vil muligens reduseres mot slutten av århundret.

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 dolomittisk og kalsittisk marmor, som har gjennomgått metamorfose i amfibolitt fase. Sekvensen med bergarter som jernmalmen inngår i, ble avsatt i neoproterozoikum. Bergartene ble deformert gjennom flere faser (D1-D3) under den kaledonske fjellkjededannelsen. D1 omfatter F1 folder som er resultat av Ø-V strykende makro- til meso og mikro-skala isoklinale skjærfolder av antatt primærsedimentære lag, som har medført repetisjoner av stratigrafien, og samtidig utviklet en gjennomgående akseplanfoliasjon (S1). Foliasjonen er i dag subvertikal og inneholder blant annet strekningslineasjoner og mylonittiske skjærsoner med interne, disharmoniske F1-folder og komplekst transponerte foldehengsler. D2 førte til refolding av S1 og tilhørende intrafoliale strukturelementer gjennom asymmetriske og svakt overbikkede tett til moderat åpne folder (F2), koaksialt til F1 folder, og sannsynligvis var årsaken til vertikalstilling av lagrekken. Det siste duktile deformasjonsstadiet foregikk gjennom refolding av hele dekkesekvensen i makro skala. Mikroteksturelle studier av hematitt- og magnetittmalm har påvist tidlig hematitt langs rytmiske lag/bånd sammen med kompetente kvartsrike lag. Større tabulær hematitt (spekularitt) er utviklet parallelt med S1 i forbindelse med den første påviste foldefasen, og en enda senere generasjon langs F2 akseplan. Magnetitt utgjør større anhedrale korn som har vokst over hematitt og indikerer en senere dannelse. Magnetitt opptrer også som mindre idioblastiske korn, og indikerer krystallisering av gjennom to ulike stadier. Remobilisering av hematitt og magnetitt har også ført til at jernmalm er lokalisert i hengselssoner av F1 og F2 folder.

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 performed with an aim to compare thermal conditions during their metamorphic evolution with those of the Porongos Metamorphic Complex and other related parts of the Dom Feliciano Belt foreland during orogenesis. Petrographic and field observations of metapelitic samples suggest that the southern part of the complex can be subdivided into three metamorphic zones: one zone corresponding to greenschist facies conditions and two zones corresponding to lower and middle amphibolite facies conditions, respectively. Phase equilibrium modelling of samples from the southeastern (staurolite- and garnet-bearing) zone suggests that garnet started to crystallize at ca. 515-555°C and 2.7-4.8 kbar. Estimated peak metamorphic conditions suggest temperatures of ca. 535-590°C and pressures of ca. 4.7-7.6 kbar. Assuming an average crust density of 2.8 g/ cm3, these conditions suggest an apparent thermal gradient of ca. 35-55°C/km during the onset of garnet growth, and 19-35°C/km for the equilibration of garnet rims and the matrix mineral assemblage. Phase equilibrium modelling of one sample from the southern zone (garnet-bearing) zone suggests that garnet started to crystallize at ca. 485°C and 2.6 kbar, and that peak metamorphic conditions were reached at temperatures of ca. 500-550°C and pressures of ca. 5.3-7.0 kbar. These conditions suggest an apparent thermal gradient of ca. 50°C/km for the onset of garnet growth and a decrease to ca. 20-29°C/km during peak metamorphic conditions. The rocks were thrust down to depths of ca. 17-28 km with a decrease in the apparent thermal gradient towards the equilibration of the matrix mineral assemblage. Contact metamorphism is evident close to the ca. 560 Ma Caçapava Granite, indicating that a local thermal event (M2) occurred after the complex reached its peak metamorphic conditions.The modelling results are similar to those from the easterly exposed Porongos Metamorphic Complex, suggesting that the protolith rocks of the Passo Feio Complex could have originally represented the same rift basin that was inverted during the formation of the Dom Feliciano Belt in the state of Rio Grande do Sul in the time interval between ca. 650 and 560 Ma.

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 horizons (Q1-Q4) and the seafloor. A correlation to established seismic stratigraphies suggests that the units A1-A3 were deposited during middle Pleistocene and A4-A5 during late Pleistocene. The internal seismic signature of the units is described and the geomorphologies of the main surfaces are mapped. This forms the basis for a reconstruction of the ice-sheet dynamics and depositional environment during the late Quaternary evolution of the outer Ingøydjupet area. Mega-scale glacial lineations and troughs observed on the paleo-surfaces confirm that fast-flowing ice streams have occupied and eroded the outer Ingøydjupet area at least five times since the formation of the URU. The orientation of the lineations suggests that both the Ingøydjupet- and the Bjørnøyrenna Ice Streams have been active in the area during these glaciations. Buried sediment blocks, which are interpreted to have been entrained, transported and re-deposited by the paleo-ice streams indicate that the ice streams underwent phases of basal freezing. The recessional features on the URU and the seafloor suggest complex and dynamic retreats of the ice sheet following glacial maxima, where repeated halts and re-advances characterized the deglaciation. The intra-glacial horizons on the other hand show evidence of rather rapid ice sheet retreats, where mega-scale glacial lineations are preserved on the paleo-surfaces.

Slettind in Flaktstad municipality, Lofoten in Nordland, has numerous rockfalls throughout the year. Rockfalls hit Fv 805 on a weekly basis, and it is estimated the most dangerous road in Nordland county. A rock avalanche hit the road winter 2017 closing it for 2 weeks, and isolating the small village Myrland. Statens Vegvesen consider to build a tunnel to protect the road but the failure mechanisms has been little understood, as it is deemed too dangerous for traditional fieldwork to access the mountain in a safe manner. Traditional fieldwork involves shear strenght testing of joint sets and infill, as well as mapping of joint orientations, roughness, and volumes of blocks, using Barthons Q method, Rock Mass Index or GSI. However as it has not been feasible to attend the wall for such mapping, due to the steepness, height and risk for rockfall, new techniques for rockfall hazard assessment have been put in use. The purpose of this master thesis has been to use photogrammetry from UAV images, and Structure-for-Motion to create a 3D modell and identify joint surfaces, orientations and evaluate the failure mechanisms. The workflow has been compared and evaluated against traditional mapping methods. Photogrammetry from drone images has proven valuable for understanding the structures and driving forces in a rock mass, and is a more flexible and cheaper option than LiDAR or similar, to build point clouds. As such, a validated semi-automated workflow is a resource for evaluating steep, inaccessible mountainsides.

Several ultramafic outcrops are located along a specific tectono-stratigraphic unit in the Trondheim Nappe Complex, Central Scandinavian Caledonides. The relative timing and kinematics of these rocks are investigated by the use of structural, petrographical and mineralogical data from its host rocks. The metasedimentary host rocks are part of the Sel and Heidal Groups of the Røros and Remsklepp Nappe Complex, in the Upper and Middle Allochthon. The investigated area is located in Folldal and Dovre municipalities, 145 km south of Trondheim, in Hedmark County, in the southern Trondheim Region Caledonides. A geological map compiling data from petrographic and field observations show a wide range of mainly metasedimentary rocks hosting the ultramafic rocks. The most dominant host rocks are garnet-mica schists and quartz mylonites, but the various amount of mica and quartz generates several similar rock types, such as quartzites and metapsammites. After mica and quartz, garnets and chlorite are the most abundant minerals. The dominant fabric in the area is the main foliation, with a gentle, general dip toward southwest, referred to as S1 and a result of a D1 deformation event. Porphyroblasts of garnet and amphibole are interpreted to be from this phase. Mylonites, with amphibolite facies mineral assemblage are prominent at the contacts of the thrust nappes, indicating they formed during peak metamorphism, just before or during the D2 event. The metasedimentary rocks further away from the thrust nappes show greenschist facies assemblage without any obvious kinematic indicators, indicating less strain. Presence of chlorite indicates retrograde metamorphism from the D3 event. The ultramafic rocks are altered through serpentinization, with soapstone at some local sites. The serpentinites contain various amounts of chromite and magnetite and locally large amounts of talc. They have a sharp contact with the host rocks, and no sign of contact metamorphism or partial melting is observed, indicating the ultramafic rocks were tectonically placed on top of the Heidal Group in the late Precambrian or early Paleozoic, before sedimentation of the Sel Group.

This study is conducted in Ranfjorden in northern Norway with the goal of gaining a better understanding of the interaction between natural and anthropologic sediments within the fjord. Ranfjorden is of interest due to the fact that it has experienced extensive anthropologic impacts over the last 100 years with the submarine tailings placement (STP) of mine tailings ongoing. The analysis of this study uses the combination of 6 Niemistö sediment cores, 10 sediment grabs, swath bathymetry and high resolution seismic data to identify natural and anthropologic sediments and determine how their distribution has impacted the fjord. The sediment cores were analyzed to determine their physical properties including magnetic susceptibility, geochemical element measurements, grainsize analysis and lithological analysis. The resulting data showed mine tailings sediments to be characterized by a darker red color, higher magnetic susceptibility and Fe/Sum values with low fluctuations in Fe/Sum values. The more natural fjord sediments are characterized by gray colors, lower magnetic susceptibility and Fe/Sum values with higher fluctuations in Fe/Sum values. Using these identifying traits it was shown that the majority of the inner fjord has experience varied levels of impact from the mine tailings, with all the sediment cores showing traces of mine tailings. The mean grainsize of the sampled mine tailings was shown to vary from fine sand to very fine silt. The fjord slopes surrounding the mine tailings discharge points at the head of the fjord appeared in the swath bathymetry to have experienced extensive erosion in the form of mass movement and gravity flows. This is attributed to the accumulation of finer mine tailings along these slopes due to back flowing estuarine circulation currents. These currents accompanied by the river-induced halocline appear to capture rising sediment plumes in the water column and concentrate them in those areas. The eroded sediments from those slopes combined with coarser mine tailings are carried further out into the fjord by turbidity currents within a larger submarine channel seen on the swath bathymetry and TOPAS seismic profiles. Samples from the channel show sandy tailing deposits consistent with turbidity currents while areas outside the channels show massive layers of finer tailing sediments consistent with sediment plume fallout. Sandy mine tailing sediments transported by turbidity currents were found 17 km from the discharge point. Shallower samples in the same vicinity showed potential evidence of fine tailing sediments from suspension plume settling. The discharge of large amounts of tailings at shallower depths combined with the hydrological characteristics of the fjord has allowed for the submarine tailing placement (STP) sediments to have spread throughout the inner fjord basin by turbidity currents and suspension plumes.