Detrital zircon ages: a key to understanding the deposition of deep marine sandstones in the Norwegian Sea

The provenance of Cretaceous to Paleocene sandstones from the Norwegian Sea has been determined by laser ablation ICPMS U–Pb and Pb–Pb dating of detrital zircons. The zircon grains were extracted from sandstones sampled in the Møre and the Vøring Basins. The potential source regions for the Norwegian Sea sediments are the surrounding landmasses of East Greenland and Norway. The basement of East Greenland contains both Archaean (3800–2500 Ma) and Early Proterozoic (ca. 2000 Ma) rocks, whereas the main Norwegian basement ages are younger (1000–1600 Ma). Sandstones of known provenance, derived from East Greenland and the Norwegian landmasses, have been analysed for comparison with the investigated sandstones of unknown provenance. The analysed detrital zircons derived from the East Greenland and Norwegian landmasses reflect the known basement ages as the sandstones derived from East Greenland are characterized by a wide detrital zircon age pattern with a considerable Archaean component. The Norwegian-derived detrital zircons show a narrow age pattern with the age maxima between 1000 and 1600 Ma. The Turonian–Maastrichtian sandstone samples from the Vøring Basin show wide-range zircon age patterns, all with a discernible Archaean component, indicating an East Greenland provenance. A sample of Cenomanian sandstone from the Dønna Terrace, located on the eastern flank of the Vøring Basin, shows a narrower detrital zircon age pattern typical of sediments derived from the Norwegian landmass. Sandstones of Maastrichtian–Paleocene ages in the Møre Basin show zircon age patterns that are indicative of an eastern source, whereas a Coniacian sandstone sample from the Møre Basin shows detrital zircon age spectra typical of a western source. The provenance change from a western to an eastern source found in the Møre Basin sandstones was most likely a result of the Baltic margin elevation during Coniacian to Maastrichtian times, resulting in an increased sediment supply from the eastern margin.