Lacustrine organic-rich shales have been recorded at three stratigraphic levels within the uppermost Devonian-Lower Permian continental sequence of central east Greenland. The Westphalian lacustrine shales, considered here, are divided into an epilimnic association of silty shale and sandstone dominated by terrestrial organic material, and a hypolimnic association of clay shale dominated by amorphous kerogen and algae. The hypolimnic shales display hydrogen index values between 300 and 900 mg HC/g TOC and TOC between 2 and 10%, and can be characterized as potential oil-prone source rocks.

The lacustrine basins are expected to be 10-15 km wide and tens of kilometers along strike with net source rock thickness in excess of 50 m and generative potential in excess of 3 million m³/km². The shales form a hitherto overlooked potential source rock in the east Greenland basin with implications for areas offshore Norway.