Abstract: A Regional Appraisal of Source Rocks North and West of Britain and Ireland

Iain C. Scotchman, Anthony G. Dore

Potential source rocks in the string of basins on the Atlantic Margin north and west of Britain and Ireland range in age from Devonian to Tertiary, although the Jurassic appears to have been effective.

In the Palaeozoic, thick developments of lacustrine Type 1 kerogen rich shales occur in the Lower and Middle Devonian of the Orcadian Basin in northeast Scotland while Carboniferous coals and coaly shales are known from well and outcrop in basins flanking the Rockall Trough.

The Jurassic contains major source rock developments, the Lias Portree and Pabba and the Upper Jurassic Kimmeridge Clay Formation shales which have been correlated to oil shows in the Slyne Trough, and oil discoveries in the West of Shetlands respectively. Anoxic black shales are also tentatively developed in the early Cretaceous.

In the younger section, developments of gas-prone, organic poor basinal shales are known in the Upper Cretaceous and Palaeocene while coals provide a minor gas source in the topmost Palaeocene and Eocene.

Regionally, effective source rocks appear to be concentrated in the Jurassic rift basins extending known trends from the Jeanne D'Arc basin through East Greenland to the North Sea/Mid-Norway through the largely unexplored Atlantic Margin area NW of Britain and Ireland.

AAPG Search and Discovery Article #90956©1995 AAPG International Convention and Exposition Meeting, Nice, France