Large-scale glaciotectonic-imbricated thrust sheets on three-dimensional seismic data: facts or artefacts?

Autor: Karin Andreassen, Luppo W. Kuilman, Kai Hogstad, Bjarne Rafaelsen
Rok vydání: 2007
Předmět:
Zdroj: Basin Research. 19:87-103
ISSN: 1365-2117
0950-091X
DOI: 10.1111/j.1365-2117.2007.00313.x
Popis: Imbricate reflections commonly occur in the glacigenic section of seismic profiles from the Bjornoya Trough. This was the main drainage pathway for fast-flowing ice-streams from the former Barents Sea and Scandinavian ice sheets. Industry three-dimensional (3D) seismic data from the southern flank of the Bjornoya Trough are used here to investigate these imbricate reflections. Integration of vertical seismic sections with 3D plan view images and attribute maps reveal that imbricate reflections at the SW Barents Sea Margin are mega-scale sediment blocks with a glacigenic origin. Imbricate reflections in two regions to the east of the survey appear on plan-view as well-developed lineations of U-shaped crescents; however, following detailed analysis of their location, geometry and relation to sailing direction during data acquisition, we can demonstrate that these are seismic artefacts. These artefacts are related to the straight parts of east–west-trending plough marks on the sea floor, having a dip direction that is directly related to the sailing direction of the ship during seismic acquisition. By analysing both real glacigenic imbrications and false imbrications or artefacts, we are able to demonstrate the critical distinguishing criterion.
Databáze: OpenAIRE
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