Late Paleocene to Miocene compression in the Faeroe–Rockall area

Abstract

Compressional structures are observed at several locations in the Faeroe-Rockall Area. One of these, the Wyville-Thomson Ridge Complex, is part of the Scotland Greenland Ridge which forms a barrier to the south-flowing deep cold arctic water from the Norwegian Sea. Interpretation of seismic multichannel reflection profiles suggests that the Wyville-Thomson Ridge Complex is the result of compression and that the Ymir Ridge and the Wyville-Thomson Ridge are ramp anticlines connected with a fault plane dipping to the north. A number of small highs offset by reverse faults to the south of the complex are interpreted as foreland thrust folds developed in relation to the tectonic evolution of the ridge complex. At least three Eocene to Miocene compressional phases are recognized. The first took place in late Paleocene-early Eocene and the second in Oligocene times. These compressional phases coincide with pronounced changes in the sea floor spreading geometry in the NE Atlantic. The third phase, in the middle or late Miocene, may possibly be associated with the complex Miocene spreading history of Iceland. I 1 0 100 Km Fig. 1. Bathymetric sketch map of the Faeroe-Rockall area (contour interval of 250 m) and the four major tectonic provinces discussed in the text. Location of the seismic sections A to E in Figs 4-8 is also shown.

Understanding the offshore flood basalt sequence using onshore volcanic facies analogues: an example from the Faroe–Shetland basin

“…The reflection is characterized by being the strongest amplitude reflection below that of the sea bed, and by the rugose nature of its top surface. The top lava sequence 1 pick is heavily affected by the Eocene to Miocene compressional phases associated with changes in the spreading dynamics of the NE Atlantic (Boldreel & Andersen 1993), and the surface is faulted in much of the GFA-99 area. A characteristic feature of the top lava sequence 1 is the presence of thrust faults that pierce the surface and the presence of associated thrust-tip folds (e.g.…”

Controls on the location of compressional deformation on the NW European margin

“…2b), and has a maximum fold amplitude of 3000 m and a bathymetric expression along its length. Boldreel & Andersen (1993 recognized PaleoceneEocene and Eocene -Oligocene compressive growth phases, and thinning and onlap in seismic reflection data suggest an enhanced phase of growth in the Mid-Miocene (Fig. 2b), as well as possible further growth during Pliocene to Recent times (Ritchie et al 2003;Johnson et al 2005;Stoker et al 2005a).…”

“…To the south of the Faroe Platform, the Munkagrunnur Ridge is a NNW-trending 135 km-long anticline with seabed expression (Boldreel & Andersen 1993;Johnson et al 2005;Ritchie et al 2008Ritchie et al , 2011. Boldreel & Andersen (1993) suggested that the ridge is part of a set of ramp-anticlines, along with the Ymir and Wyville Thomson ridges, which formed during the Late Paleocene -Eocene above a northwards-dipping crustal fault in response to seafloor spreading.…”

“…Boldreel & Andersen (1993) suggested that the ridge is part of a set of ramp-anticlines, along with the Ymir and Wyville Thomson ridges, which formed during the Late Paleocene -Eocene above a northwards-dipping crustal fault in response to seafloor spreading. The Faroe Bank Channel, which separates the Wyville Thomson and Munkagrunnur ridges, may be a synclinal feature formed in response to the growth of those anticlines, especially in the late Palaeogene -early Neogene, and is an important part of the North Atlantic deep-water circulation system (Stoker et al 2005a).…”

“…The Wyville Thomson Ridge is a 200 km-long WNW-trending basalt anticline with a maximum fold amplitude of 4000 m, a width of around 20 km and clear bathymetric expression (Boldreel & Andersen 1993;Johnson et al 2005;Stoker et al 2005a, b;Ritchie et al 2011). A well-imaged succession on the NE side of the ridge shows thinning of Paleocene lavas and Early and Mid-Eocene sediments towards its axis, indicative of growth periods (Fig.…”