Analysis of newly acquired and existing 2-D seismic data from the Rockall Plateau to the Faroe Shelf, has demonstrated that the NE Atlantic Margin is the site of significant active deformation. Seismic data have revealed the presence of numerous compression-related deformation. Seismic data have revealed the presence of numerous compression-related Cenozoic folds, such as the Alpin, Ymir Ridge and Wyville Thomson Ridge anticlines. The presence, timing and nature of these structures have provided new insights into the controls and effects of contractional deformation in the region. Gravity models support the presence of low-density sediments in the core of folds. This is consistent with folds developed due to the inversion of sedimentary basins. The spatial extent of the deformation could thus reflect the differing underlying basin morphologies. The mapping and dating of angular and erosional unconformities that define the folding suggest that the growth of these compressional features occurred in five main phases – Thanetian, late Ypresian, late Lutetian, Late Eocene (C30) and Early Oligocene, each of which appear to have been driven by regional events affecting the NE Atlantic Margin. The late Ypresian, Late Eocene (C30) and Early Oligocene events correlate with the timings of hot-spot influenced ridge-push based on the ages of V-shaped ridges. The late Lutetian event is tentatively also ascribed to hot-spot influenced ridge-push. Mohr-Coulomb circle plots, however, reveal that the forces exerted by hot-spot influenced ridge- push appear to be insufficient to result in the reactivation of faults in the underlying Mesozoic basins. Alpine and Pyrenean Orogenies may have, thus, produced the additional force needed for the inversion of these basins. The Thanetian phase, just prior to Atlantic Ocean spreading, would suggest compression due to depth-dependent stretching and uplift.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:663081 |
| Date | January 2009 |
| Creators | Tuitt, Adrian |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/14591 |
Page generated in 0.0019 seconds