Exhumed hydrocarbon traps in East Greenland: A comment on Andrews et al. (2020)

In a recent study, Andrews et al. (2020) describe “exhumed hydrocarbon traps” in North-East Greenland. The basic premise for their interpretation is that dark-coloured, pyrobitumen-bearing sandstones represent the remnants of once buried petroleum reservoirs. We do not see the necessary field or analytical evidence to support a model that has strong implications for resource evaluations. Andrews et al. (2020) have not considered previous published information on diagenetic and thermal maturity history of the area. A more probable model would include the intrusion of dykes and sills into a sedimentary succession with immature petroleum source rocks and reservoir-quality sandstones. The heating caused rapid generation of petroleum components and local hydrothermal circulation systems in adjacent porous sandstones. Any petroleum was rapidly destroyed leaving essentially only black grain-coatings and minor particles of pyrobitumen—essentially in one short-lived continuous process. The existence of new plays in the North Atlantic as proposed by Andrews et al. (2020) is in our opinion not substantiated as this requires analytical data from unaltered oils from the less mature parts of the sedimentary succession and considerations of thermal maturity and basin evolution. To draw conclusions that have a serious impact on resource evaluations based on the dark colouration of sandstones without comprehensive analytical data is, in our opinion, ill advised.