Artikler, rapporter og annet (geovitenskap): Recent submissions
Now showing items 61-80 of 730
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Stress Constraints From Shear-Wave Analysis in Shallow Sediments at an Actively Seeping Pockmark on the W-Svalbard Margin
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-28)Mechanisms related to sub-seabed fluid flow processes are complex and inadequately understood. Petrophysical properties, availability of gases, topography, stress directions, and various geological parameters determine the location and intensity of leakage which change over time. From tens of seafloor pockmarks mapped along Vestnesa Ridge on the west-Svalbard margin, only six show persistent present-day ... -
Implications of transient methane flux on associated biological communities in high-arctic seep habitats, Storbanken, Norwegian Barents sea
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-21)The continental margins of the Arctic Ocean basin contain methane seeps, where transient fluxes of seafloor methane are released due to the thermal dissociation of gas hydrates. An increase in shallow methane seeps identified over the past decade, potentially due to enhanced warming of the Arctic Ocean bottom water and associated destabilization of hydrate structure. Biological communities associated ... -
Centre for Ice, Cryosphere, Carbon and Climate (iC3). Closing large-scale uncertainty in Polar ice sheet impacts on the global carbon cycle
(Conference object; Konferansebidrag, 2023-09) -
A time-transgressive perspective of glacial erosion and meltwater beneath the Eurasian ice sheet
(Conference object; Konferansebidrag, 2023-08)The efficacy and controls governing glacial erosion over geological timescales are intricately linked yet remain poorly understood and contended. By assimilating geophysical data with modelling of the Eurasian Ice Sheet - the third largest Quaternary ice mass that spanned 49°N - 82°N - we decipher its erosional footprint during the last ~110 ka glacial cycle. Our results demonstrate extreme ... -
Lithium enrichment of the magmatic-hydrothermal fluid in albite-spodumene pegmatite from Lijiagou, Eastern Tibetan Plateau: Evidence from fluid inclusions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-19)Albite-spodumene pegmatites, which are remarkable resources of Li worldwide, may experience both magmatic-hydrothermal transition and sub-solidus hydrothermal alteration during their formation and evolution. However, fluids involved in the different stages of the evolution of a spodumene-bearing pegmatitic systems are not well defined, especially at the magmatic-hydrothermal transition stage. In the ... -
Mind the gap – Relevant design for laboratory oil exposure of fish as informed by a numerical impact assessment model
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-09)Laboratory experiments provide knowledge of species-specific effects thresholds that are used to parameterize impact assessment models of oil contamination on marine ecosystems. Such experiments typically place individuals of species and life stages in tanks with different contaminant concentrations. Exposure concentrations are usually fixed, and the individuals experience a shock treatment being ... -
Geochronology and chemostratigraphy of the 2.47–1.96 Ga rift-related volcano-sedimentary succession in the Karasjok Greenstone Belt, northern Norway, and its regional correlation within the Fennoscandian Shield
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-09)New geochronological data for the amphibolite-facies volcano-sedimentary Karasjok Greenstone Belt in northwestern Fennoscandia bracket its age between 2.47 and 1.96 Ga. The volcano-sedimentary units were deposited on the 3005 24 to 2776 69 Ma crystalline basement rocks of the Jergul Gneiss Complex. The lowermost Vuomegielas Formation contains rhyodacites dated at 2469 12 Ma that were deposited in ... -
The Cenozoic evolution and sedimentary successions of the southwestern Eurasia Basin and the northern Svalbard/Barents Sea continental margin
(Conference object; Konferansebidrag, 2017)<p>The geologic history of the SW Eurasian Basin and the northern Svalbard/Barents Sea continental margin started in Late Cretaceous / early Tertiary. Since about 50 Ma seafloor spreading has been active in the Eurasian Basin splitting off the Lomonosov Ridge from the northern Eurasian Shelf. Since Miocene, rifting and seafloor spreading have been also established in between NE Greenland and Svalbard, ... -
Late Cenozoic paleoenvironment and erosion estimates for the NE Svalbard continental margin – preliminary results
(Conference object; Konferansebidrag, 2017) -
Linking tectonostratigraphy and denudation history: insights from a mass balance approach
(Conference object; Konferansebidrag, 2017)<p>The offshore deep-sea stratigraphy provides the archive for reconstructing the paleoenvironment of the surrounding land and continental shelf areas. Mapping of seismic reflections as well as borehole correlation may identify the processes and timing of basin infilling. Regional and local tectonic events will be linked to other controlling factors in defining the structural configuration in order ... -
Holocene relative shore-level changes and development of the Ģipka lagoon in the western Gulf of Riga
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-07-13)Holocene relative shore-level changes and development of the G ipka palaeolagoon in the western Gulf of Riga are reconstructed using multiproxy analyses by combining litho-, biostratigraphical and chronological data with remote sensing and geophysical data. The results show the development of the G ipka basin from the Ancylus Lake/Initial Litorina Sea coastal zone (before c. 9.1 cal. ka BP) to ... -
Seal integrity in the uplifted basins in the greater Hoop area on the Northern Barents Shelf
(Conference object; Konferansebidrag, 2019)The geological evolution of the northern Barents Shelf is complex, and the area has undergone several phases of tectonic activity leading to a mosaic of several deep and shallow basins, platforms, salt-cored domes and structural highs. The area is highly gas prone with some very few commercial oil discoveries, and only two fields currently in production. Deep burial and subsequent Late Cretaceous–Cenozoic ... -
Trap and seal analysis of the northern Barents Shelf
(Conference object; Konferansebidrag, 2018)Although the majority of exploration wells in the Barents Sea has encountered hydrocarbons, only two fields, the Snøhvit (gas) and Goliat (oil) fields are currently in production. The geological evolution of the area, including previous deep burial and subsequent exhumation, has contributed to the leakage of hydrocarbon from many traps. Understanding the timing of hydrocarbon generation and migration, ... -
The Cenozoic pre-glacial tectono-sedimentary development of the western Barents Sea margin: implications for uplift and erosion of the sediment source areas
(Conference object; Konferansebidrag, 2017)<p>The Cenozoic development of the western Barents Sea continental margin is strongly related to the rifting and seafloor spreading between Norway and Greenland. The margin is characterized by a series of highs and basins that formed as part of the development of a mega-transform zone. To the north, the Spitsbergen Fold and Thrust Belt and the Eocene clinoform development in the Central Basin that ... -
Self-similarity of intrasalt thrust faults: Lessons from offshore Levant Basin and the Dead Sea
(Conference object; Konferansebidrag, 2017)The Levant Basin in the eastern Mediterranean Sea developed during rifting episodes occurring from Permian to the Early Jurassic (Netzeband et al. 2006; Gardosh et al. 2010), and has been a deep-water basin with a passive continental margin at least since the Cretaceous (Gardosh et al. 2008). Thick sequences of halite and interbedded shales (stringers) were deposited during the infamous Messinian ... -
Glacigenic landforms and sediments in Store Koldewey Trough, NE Greenland – preliminary results
(Conference object; Konferansebidrag, 2018-04)The glaciation history of NE Greenland remains poorly constrained, resulting in conceptual and uncertain reconstructions of the configuration of the Greenland Ice Sheet during the Last Glacial Maximum (c. 24-19 ka BP), as well as the timing and the dynamics of the deglaciation. New studies suggests that the ice sheet in NE Greenland probably was more dynamic than previously thought, extending all ... -
The Early to Middle Cenozoic Paleoenvironment and Erosion Estimates for the northwestern Barents Sea
(Conference object; Konferansebidrag, 2017)<p>The northwestern Barents Sea continental margin is a structurally complex area characterized by a series of basins and highs. It’s Cenozoic development was influenced by: 1) the formation of the Spitsbergen fold-andthrust belt towards the north and a pull-apart basin, the Vestbakken Volcanic Province, to the south, and 2) the subsequent rifting and opening of the Fram Strait, the deep-water gateway ... -
Turbidites in the Eocene of Spitsbergen: Can they tell us something about the Sørvestsnaget Basin?
(Conference object; Konferansebidrag, 2017)<p>The Eocene of Spitsbergen, Svalbard, has received considerable attention in the literature because of its spectacular seismic-scale clinforms exposed along many fiords and valleys. High quality outcrops enables downdip tracing of facies belts from the proximal shelf through the shelf-edge and down-slope into the basin floor. Previous publications particularly focused on the shelf-edge to slope ... -
The Lower Cretaceous of Svalbard and its relevance for exploration in the northern Barents Sea
(Conference object; Konferansebidrag, 2017)The Lower Cretaceous succession in the Barents Sea is listed as a potential play model by the Norwegian Petroleum Directorate. Reservoirs may occur in deep to shallow marine clastic wedges located in proximity to palaeo-highs and along basin margins. In addition, shelf-prism-scale clinoforms with high amplitude anomalies in their top- and bottomsets have been reported from reflection seismic but ... -
Evidence of hyperpycnally fed turbidites in a basin floor setting, Eocene of Spitsbergen, Arctic Norway
(Conference object; Konferansebidrag, 2018)The Eocene of Spitsbergen, Svalbard, has received considerable attention in the literature because of its spectacular seismic-scale clinoforms exposed along many fiords and valleys. Previous investigations particularly focused on the slope segment of the clinoforms and demonstrated how sustained-type, hyperpycnal flows deriving from shelf-edge deltas played a major role in bringing sand onto the ...