Late Cenozoic Sedimentary Outbuilding Offshore Mid-Norway:A Sequence Stratigraphic Analysis
Geologically the mid-Norwegian continental shelf (62°-69°30’N) has undergone several phases of rifting, uplifting and erosion, but the present shape of the shelf/margin developed during Plio/Pleistocene time. During late Neogene a thick succession of Naust Formation prograded westward. This progradi...
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| Format: | Master Thesis |
| Language: | English |
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2011
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| Online Access: | http://hdl.handle.net/10852/12639 http://urn.nb.no/URN:NBN:no-31754 |
| Summary: | Geologically the mid-Norwegian continental shelf (62°-69°30’N) has undergone several phases of rifting, uplifting and erosion, but the present shape of the shelf/margin developed during Plio/Pleistocene time. During late Neogene a thick succession of Naust Formation prograded westward. This prograding wedge built out as an interaction of several processes like climatic fluctuations, relative sea level changes, glacial processes, basin infill and development of continental ice sheets in Scandinavia. The purpose of this study is to do sequence stratigraphic analysis of the Late-Cenozoic outbuilding. Ten 2D seismic lines of high resolution from offshore mid-Norway were interpreted. Sequence stratigraphic analysis reveals 32 seismic sequences developed by 30 glaciation during last 2.8 m.y. Facies analysis describes different kinds of sedimentary environments that was active during deposition of Naust Formation. Ages of the seismic sequences within the Naust Formation (2.8Ma-Present) have been interpolated between key horizons dated in previous studies. The known glaciations from Iceland and Svalbard margin are correlated with this study. The correlations indicate chances of more glaciations during last 2.8 m.y than resolved by the existing date from Iceland and Svalbard margins if high resolution data is available. Relative sea level changes occurred frequently during deposition of the Naust Formation. During early Naust time (SS1-SS13) the depocentre was northeastern Vøring Basin and northeastern Trøndelag Platform which gradually shifted towards the south with increase in sedimentation rate. After URU the tilting of the continental margin stopped and accommodation space was created by sea level changes and sediment loading resulting in the development of aggradating and weakly progradating stacking pattern. |
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