Crustal structure east of the Faroe Islands: mapping sub-basalt sediments using wide-angle seismic data

We use normal-incidence and wide-angle seismic data recorded on the Faroe I slands to study the crustal structure along two profiles extending east fro m the islands, across the Faroe shelf and into the Faroe-Shetland Basin. We show that massive basaltic lava flows extend eastward away from the Faroe Islands, having flowed across an older Mesozoic and early Paleocene sedimen tary basin, and feathering out near the centre of the Faroe-Shetland Basin. Sediments beneath the basalts reach a thickness of several kilometres in t he basin, but do not extend with a resolvable thickness beneath the Faroe I slands. The crustal thickness decreases toward the centre of the Faroe-Shet land Basin, showing that the basement beneath the centre of the basin has b een stretched and thinned by a factor of at least two. The Faroe Islands th emselves lie on a continental fragment, which had a total thickness of abou t 10-15 km of igneous rock added as extrusive lavas at the top, and as high -velocity intrusives near the base of the crust at the time of continental break-up in the Paleocene.