Integrated Provenance Studies in the NE Atlantic Region

Sandstone provenance studies are fundamental to understanding basin development because they play a crucial role in establishing the paleogeographic framework, identifying sediment input points, constraining intrabasinal sand distribution, and linking tectonic events in the hinterland to sedimentation. There are many techniques that can be used to evaluate provenance, but application of one single method frequently fails to reveal all of the detail and could lead to erroneous conclusions. In this paper, we show the strength of applying an integrated approach, utilizing a variety of techniques such as conventional heavy mineralogy, mineral chemistry, palynology and single grain age dating, and integrating these with field observations, in order to build a more complete characterization of sediment sources that captures information on the lithology, metamorphic history and geochronology of the hinterland. The value of an integrated approach is illustrated using three case studies along the Atlantic margin of Greenland.

Case study 1 deals with Late Cretaceous depositional systems in the Vøring and Møre basins. Two sediment transport systems can be differentiated in this area using heavy mineral ratio data, garnet geochemistry, tourmaline geochemistry and rutile geochemistry. Detrital zircon ages do not differentiate these two transport systems, but their complex age pattern including Archaean and Paleoproterozoic zircons (pre-1850 Ma) indicates Norway was not the source of sediment. The presence of mid-Cretaceous and Permian-Triassic zircons suggest there may have been input from the Arctic.

Case study 2 links Jurassic sandstones (Åre and Garn formations) on the Halten Terrace (offshore mid-Norway) to a source west of Jameson Land in East Greenland. Zircon age data indicate these sandstones were derived from East Greenland, but do not pinpoint the location of the source area. However, garnet and rutile geochemistry of modern moraine and outwash samples identify the source as the migmatite zone west of Jameson Land. Further confirmation is given by rutile geochronology, which indicates the source underwent high-grade metamorphism during the Caledonian orogeny.

Case study 3 concerns Paleocene sandstones of the Faroe-Shetland Basin, where four distinct sand types have been identified using a combination of conventional heavy mineral data, garnet and rutile geochemistry, palynology and detrital zircon age dating. None of the individual techniques discriminate all four sand types. Three of the sand types can be tied back to sources on the eastern (Orkney-Shetland Platform) margin of the basin. By contrast, the fourth had a western source, possibly in East Greenland, although zircon age data rule out input from the Kangerlussuaq area.