Palaeogene evolution of the Ymir and Wyville Thomson ridges, European North Atlantic margin

Abstract

Abstract The region to the SW of the Faroe Islands is an enigmatic area where the structural trends of the Faroe–Shetland and North Rockall basins meet. The Munkagrunnur, Wyville Thomson and Ymir ridges are major tectonic features within the area and arc approximately perpendicular to the primary Caledonian structural trend. Previous studies have suggested that these ridges formed as a result of compressive forces during the Eocene, Oligocene and Miocene. However, this study suggests that these ridges were initiated by a transient rifting event in the early Paleocene. This rifting event was accompanied by an igneous phase which emplaced large volumes of intrusive and extrusive igneous rocks. The igneous centres within the study area are located on older structural features, indicating exploitation of pre-existing structural weaknesses. The same structural weaknesses were later exploited by compressive events, which resulted in the generation of Ymir Ridge South, and also influenced the orientation and shape of the other segments of Ymir Ridge and the Wyville Thomson Ridge.