Triassic sediment pathways in the North Atlantic region

Sediment pathways in the North Atlantic during the Triassic are poorly constrained. Understanding the drainage network evolution at this time is important for reservoir prediction. Provenance studies provide an opportunity to investigate source to sink relationships across large regions.

Conventional heavy mineral and single grain geochemistry data have been acquired across the North Atlantic region, from the northern Rockall Trough and southern end of the Viking Graben in the south to the Nordland Ridge in the north. These data reveal that major regional and stratigraphic variations in provenance exist in the Triassic succession. Five distinct provenance domains have been recognised: the northern Rockall Trough and southern Faroe-Shetland Basin; the northeastern part of the North Sea; the northern margin of the Shetland Platform and southern Møre Basin; the southern Viking Graben; and the Nordland Ridge.

The Triassic of the northern Rockall Trough and southern Faroe-Shetland Basin is dominated by a southern East Greenland source, whilst the northeastern part of the North Sea displays a uniform provenance signature which typifies local sourcing from the adjacent southern Norway region. Further north, on the northern margin of the Shetland Platform and in the southern Møre Basin, Triassic sediments display a provenance signature closely matching source characteristics of the Milne Land – Renland region of East Greenland. This source has also been identified in the Mid Triassic of the southern Viking Graben. This provides strong evidence for the establishment of a significant axial drainage system at this time. The Triassic of the Nordland Ridge is also characterised by the sediments derived from the Milne Land – Renland region which suggests that a drainage divide between systems draining northwards to the Boreal Ocean, and those flowing southward to the Tethys Sea, lies adjacent to the Milne Land – Renland region.