Continental flood basalts of the Faroe Islands and the opening of the North Atlantic (lecture)

The Paleogene Faroe Islands Basalt Group (FIBG) comprises four eruptive sequences or formations, emplaced in a dominantly subaerial environment during the development of the extensive continental flood basalt province that stretches from East Greenland through the Faroe Islands and into the Faroe-Shetland Basin. The Lopra and Beinisvørð formations consist of lava-fed hyaloclastite deltas and fissure-fed simple lava flows that represent the filling and levelling of the pre-existing irregular topography and the progradation of the lava field basinward. A regional hiatus in the lava flow volcanism is marked by Prestfjall Formation consisting of coals and sandstones deposited in mainly lake and swamp environments. Volcanism resumed with airfall tuffs of the Hvannhagi Formation that were subsequently reworked by rivers and mass flows and deposited in localised basins. Lava flow volcanism resumed with the point-sourced shield volcanoes of the Malinstindur Formation consisting of compound lava flows. The final phase of volcanism recorded on the islands is the Enni Formation that consists of a mixture of shield volcanoes and simple flows that tend to fill the accommodation space between the volcanoes. The Malinstindur and Enni formations are punctuated by sedimentary deposits marking pauses in the volcanism, aiding regional correlations and helping to understand the volcanic evolution prior to and during the opening of the North Atlantic Ocean.