Seismic stratigraphic analyses of the late Palaeocene-Present transitional to post-rift succession in the Faroe-Shetland Basin and Faroe Graben (FSC) on the NE Atlantic volcanic passive continental margin have revealed the occurrence of a early Eocene dendritic palaeo-drainage system and Middle Eocene-Miocene contractional inversion structures. The palaeo-drainage system consists of a significant NNW-SSE trending distributary channel (40km long, 5km wide and up to 400m deep), fed by numerous tributaries (100m deep). The drainage system incised into a major delta system (Colsay Sandstone Member) and was subsequently unfilled and draped by estuarine deposits (Hildasay Sandstone Member and Balder Formation). The excellent preservation of the palaeo-valleys indicates that uplift, incision and subsequent infilling of the drainage system occurred relatively rapid (biostratigraphically constrained to 1.45 My). The uplifting responsible for the incision event at c. 54.75 Ma, earliest Ypresian) was widespread and extends as far as the North Sea (Bressay area) and SE England (London Basin). Furthermore, coeval volcanic activity is consistent with the drainage system having resulted from transient uplift driven by a mantle-plume. This transient uplift event (incision and infill) in the FSC provides important new evidence for the evolution of the ancestral Iceland mantle plume and its influence on stratigraphic development. The inversion structures, developed in Middle Eocene, Oligocene and Middle Miocene, are marked by folding with the syn/post inversion stratigraphy onlapping and thinning over the structures. The location and orientation of the inversion structures suggest that the underlying Mesozoic structural configuration, especially the NW-SE transfer zones, influenced their development. The timing and nature of the movement of the inversion structures in the FSC provide new temporal constraints which help to understand better the controlling mechanism of passive continental margins.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:641652 |
| Date | January 2004 |
| Creators | Biskopstø, Fridbjorg |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/10818 |
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