Norwegian Journal of Geology最新文献

{"title":"Correlation of the Upper Oligocene–Miocene deltaic to shelfal succession onshore Denmark with similar deposits in the northern North Sea and Norwegian Sea shelf based on Sr isotope-, bio- and seismic stratigraphy—a review","authors":"T. Eidvin, E. Rasmussen, F. Riis, K. Dybkjær, K. Grøsfjeld","doi":"10.17850/njg99-4-1","DOIUrl":"https://doi.org/10.17850/njg99-4-1","url":null,"abstract":"The almost complete, mainly deltaic, upper Paleogene and Neogene succession in Jylland, Denmark, was previously investigated for 87Sr/86Sr ratios in 143 samples from 18 localities. In the present paper, strontium-isotope data from the Upper Oligocene–Lower Miocene parts and foraminiferal and pyritised diatoms data from 94 of these samples were used to correlate with previously published data from Norwegian wells and boreholes and one borehole in the British sector of the North Sea. For the Middle–Upper Miocene parts of the succession the correlation is based mainly on Bolboforma data. The ages of the geological formations in the Danish succession correlate readily with lithological units in the Norwegian North Sea, the Norwegian Sea shelf and the East Shetland Platform, which have all been investigated applying similar methods. The Bolboforma assemblages have their origin in the North Atlantic and the Norwegian Sea and confirm the presence of an open strait in the northern North Sea. This strait was the only seaway passage into the North Sea Basin during the Miocene. The glauconitic Utsira Formation sand (approximately 5.7–4.2 Ma), in the threshold area close to the outlet to the Norwegian Sea, overlies erosional unconformities comprising hiati of 21 my in some areas and 13 my in other areas. We believe that the unconformity below the Utsira Formation was mainly related to a fall in sea level in the Late Miocene, contemporaneous with that partly responsible for the Messinian salinity crisis. Bolboforma and dinoflagellate cysts stratigraphy indicate that the base of the Molo Formation in its southern distribution area (Draugen Field, Trøndelag Platform) is of Late Miocene age (close to 9 Ma). This part of the Molo Formation was contemporaneous with the middle/upper part of the Kai Formation.","PeriodicalId":49741,"journal":{"name":"Norwegian Journal of Geology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43429238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Silurian age for the metasedimentary rocks of the Ekne Group, Trøndelag, Mid-Norwegian Caledonides: and inferences for a peri-Laurentian provenance","authors":"D. Roberts, A. Morton, D. Frei","doi":"10.17850/njg99-4-3","DOIUrl":"https://doi.org/10.17850/njg99-4-3","url":null,"abstract":"","PeriodicalId":49741,"journal":{"name":"Norwegian Journal of Geology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45256135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ophicarbonates of the Feragen Ultramafic Body, central Norway","authors":"K. Dunkel, B. Jamtveit, H. Austrheim","doi":"10.17850/njg99-3-3","DOIUrl":"https://doi.org/10.17850/njg99-3-3","url":null,"abstract":"The carbonation of ultramafic rocks is a common alteration process in ophiolites and can occur in various settings. We provide the first detailed description of the carbonated peridotites (ophicarbonates) of the Feragen Ultramafic Body, central Norway, which have unusually variable compositions and microstructures. Lithologies range from pervasively carbonated serpentinites through carbonated serpentinite breccias to carbonated ultramafic conglomerates. Carbonate phases are Ca-carbonate, magnesite and dolomite. Some breccias are also cemented by coarse-grained brucite. This variability records strong variations in fluid chemistry and/or pressure and temperature conditions, both spatially and temporally. By analysing these altered ultramafic rocks using field relationships, optical microscopy, electron microprobe analysis and oxygen and carbon isotope compositions, we elucidate the history of the Feragen Ultramafic Body in more detail and emphasise the importance of deformation for the extent and type of alteration.","PeriodicalId":49741,"journal":{"name":"Norwegian Journal of Geology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43338659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Re-evaluation of the stratigraphically important olenellid trilobite Holmia cf. mobergi from the Cambrian Series 2, Stage 3 and its implications for the lower Cambrian stratigraphy in the Mjøsa area, Norway","authors":"M. Høyberget, J. R. Ebbestad, Bjørn Funke","doi":"10.17850/njg99-1-04","DOIUrl":"https://doi.org/10.17850/njg99-1-04","url":null,"abstract":"The olenellid trilobite Holmia cf. mobergi, known from a single cephalon in the upper lower Cambrian strata from a river section in Flagstadelva, Hamar, has played a significant stratigraphic role ...","PeriodicalId":49741,"journal":{"name":"Norwegian Journal of Geology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43052122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Late Devonian–Carboniferous faulting and controlling structures and fabrics in NW Finnmark","authors":"Jean-Baptiste P. Koehl, S. Bergh, P. Osmundsen, T. F. Redfield, K. Indrevær, H. Lea, E. Bergø","doi":"10.17850/njg99-3-5","DOIUrl":"https://doi.org/10.17850/njg99-3-5","url":null,"abstract":"1Department of Geosciences, UiT The Arctic University of Norway in Tromsø, N–9037 Tromsø, Norway. 2CAGE Centre for Arctic Gas Hydrate, Environment and Climate, Department of Geosciences, UiT The Arctic University of Norway, Tromsø, Norway. 3Department of Geosciences, University of Oslo, P.O. Box 1047 Blindern, NO–0316 Oslo, Norway. 4Research Centre for Arctic Petroleum Exploration (ARCEx), UiT The Arctic University of Norway in Tromsø, N–9037 Tromsø, Norway. 5Department of Geoscience and Petroleum, NTNU–Norwegian University of Science and Technology, NO-7491 Trondheim, Norway. 6University Center in Svalbard, 9171 Longyearbyen, Norway. 7Geological Survey of Norway (NGU), Post Box 6315 Torgarden, 7491 Trondheim, Norway. 8Norges vassdragsog energidirektorat, Vangsveien 73, Postboks 4223, 2307 Hamar, Norway. 9Equinor ASA, Forusbeen 50, 4035 Stavanger, Norway. 10Herøy Kommune, Rådhusgata 5, 6099 Fosnavåg, Norway.","PeriodicalId":49741,"journal":{"name":"Norwegian Journal of Geology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42326756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterisation and development of Early Cretaceous shelf platform deposition and faulting in the Hoop area, southwestern Barents Sea—constrained by high-resolution seismic data","authors":"T. S. Faleide, I. Midtkandal, S. Planke, R. Corseri, J. Faleide, C. S. Serck, J. P. Nystuen","doi":"10.17850/njg99-3-7","DOIUrl":"https://doi.org/10.17850/njg99-3-7","url":null,"abstract":"Regional Early Cretaceous uplift of the northern Barents Sea associated with the High Arctic Large Igneous Province (HALIP) caused the development of the fluvial to open-marine depositional system, terminating in the southwestern Barents Sea. This study has established a new temporal and spatial evolution of the Lower Cretaceous deposits in the Hoop area, in particular the location and age of the intrashelf platform lobe front and subsequent block-faulting. A composite high-resolution 3D and 2.5D P-Cable and conventional 3D seismic dataset image the strata and cross-cutting faults in the Hoop area. The P-Cable data typically have a resolution of 3–7 m in the shallow subsurface, up to four times better than the conventional seismic data, contributing to a new and better mapping hence understanding of the Lower Cretaceous strata and faults. Seismic horizon and facies mapping reveal large-scale clinoforms, with present-day heights of 150–200 m and dips of 0.65–1.13°. The highresolution data furthermore display complex stratigraphic and structural features, such as small-scale clinoforms and numerous faults. The shelf platform succession is block-faulted, and the main Early Cretaceous fault activity thus postdates the arrival of the delta and platform sediments from the northwest. Detailed seismo-stratigraphic ties to the 7324/2–1 (Apollo) and 7325/1–1 (Atlantis) wells, and ties to the adjacent Fingerdjupet Subbasin, document a Barremian age for the shelf platform deposits and an Aptian?–early Albian age for the main faulting event. The faulting was likely initiated in the Aptian, but a hiatus or condensed section above the Barremian strata makes it difficult to constrain the onset of deformation in the Hoop area.","PeriodicalId":49741,"journal":{"name":"Norwegian Journal of Geology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43030958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Silurian vertebrate remains from the Oslo Region, Norway, and their implications for regional biostratigraphy","authors":"Oskar Bremer, S. Turner, T. Märss, H. Blom","doi":"10.17850/njg99-1-07","DOIUrl":"https://doi.org/10.17850/njg99-1-07","url":null,"abstract":"Several vertebrate assemblages are described from the Silurian of the Oslo Region, Norway, based on the review and revision of previous reports of microremains, as well as unpublished material from ...","PeriodicalId":49741,"journal":{"name":"Norwegian Journal of Geology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47986317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"What is the appropriate sample size for strike and dip measurements? An evaluation from compass, smartphone and LiDAR measurements","authors":"C. Trede, N. Cardozo, Lisa Watson","doi":"10.17850/njg99-3-4","DOIUrl":"https://doi.org/10.17850/njg99-3-4","url":null,"abstract":"Geological planar surfaces are irregular and therefore, an important question is: what is the appropriate sample size for measuring their orientations? We explore this question by measuring the orientation of two metre-sized surfaces, a shallow foliation in an overhang and a more irregular steep joint plane, in Cambro–Ordovician mica schists of the Svarthola cave, Rogaland, SW Norway. We use three methods: a geological compass; smartphones with digital compass clinometer applications, i.e., Stereonet Mobile (iPhone) and Fieldmove Clino (iPhone and Android); and LiDAR scans of increasing resolution. While geological compass measurements are generally robust, they provide inaccurate measurements in the challenging foliation overhang. Stereonet Mobile measurements are more accurate, while Fieldmove Clino is reliable in the iPhone but not in the Android device. Mean surface orientations reach a consistent result after 100–150 smartphone measurements. However, neither the compass nor the smartphone measurements can clearly define the joint-surface orientation. Triangulated surfaces from the LiDAR scans deliver precise but inconsistent results, especially at the highest resolution in the joint plane. Kriging of the surfaces significantly improves the representativeness of the computed orientations to reflect a more realistic model. A best-fit to plane routine using points within a radius, r, delivers the most representative results. At r ~0.5 m, the estimated orientations stabilise, and all scans deliver similar results. This is the appropriate sample size for measuring the studied planes. Similar strategies should be taken into consideration when measuring planes in outcrop (sighting as opposed to direct measurement) or from 3D geological models.","PeriodicalId":49741,"journal":{"name":"Norwegian Journal of Geology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49423439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early history of petroleum exploration offshore Norway and its impact on geoscience teaching and research","authors":"K. Bjørlykke","doi":"10.17850/NJG99-3-2","DOIUrl":"https://doi.org/10.17850/NJG99-3-2","url":null,"abstract":"The Norwegian government and also the universities were unprepared for an offshore oil province. Very little information about the offshore geology was then available due to the thick cover of Quaternary and Tertiary sediments in the North Sea basins. The potential for oil and gas in the North Sea could not have been predicted before the Norwegian Continental Shelf (NCS) was opened for petroleum exploration and drilling in 1965. Statements from the Geological Survey of Norway (NGU) in 1958 that there was no potential for oil offshore Norway referred specifically to the coastal areas, where no oil has been found. The midline principle was introduced in 1964, through an agreement with the UK. A continental shelf committee led by Jens Evensen from 1963 to1965 prepared the legal aspects and the regulations applicable for oil companies applying for licences to explore and produce oil and gas offshore Norway. A proposal for a Norwegian petroleum-related research project in 1964 was not funded and it took several years before petroleum-related teaching and research were established. After several dry wells the Ekofisk Field was discovered late 1969–early 1970, making it clear that Norway would become a significant oil-producing country. However, at that time nearly all the expertise was inside the major international oil companies and petroleum-related research at Norwegian universities and research institutes had a slow start. In 1972, Statoil and the Norwegian Petroleum Directorate (NPD) were established and also government funding for petroleumrelated teaching and research. This was met with considerable scepticism and resistance from some students and faculty and some claimed that a general education in geology would be sufficient. The University of Bergen developed a strong research group in marine geophysics and later one in petroleum geology. The need for petroleum-related teaching and research created a great challenge for the Norwegian universities. The standard was variable and the output of graduates with a professional qualification was generally too low. What we know about sedimentary basins and many fundamental geological processes is the result of petroleum prospecting and data from drilling and seismic data, contributing to Norwegian geology and general geological principles.","PeriodicalId":49741,"journal":{"name":"Norwegian Journal of Geology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42242126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sedimentology and palynology of the Lower Cretaceous succession of central Spitsbergen: integration of subsurface and outcrop data","authors":"S. Grundvåg, M. E. Jelby, K. Śliwińska, H. Nøhr-Hansen, T. Aadland, S. E. Sandvik, Ingrid Tennvassås, T. Engen, S. Olaussen","doi":"10.17850/NJG006","DOIUrl":"https://doi.org/10.17850/NJG006","url":null,"abstract":"Source at https://dx.doi.org/10.17850/njg006. © Copyright the authors. \u0000This work is licensed under a Creative Commons Attribution 4.0 International License.","PeriodicalId":49741,"journal":{"name":"Norwegian Journal of Geology","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49187223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}