The Silurian shales of central and western North Greenland: evaluation of hydrocarbon source rock potential

Abstract

The Silurian shales of central and western North Greenland form a more than 400 m thick succession which contains some potential hydrocarbon source rock intervals. Deposition of these organic-rich units was restricted in both time and space and potential source rocks only formed when and where black shales covered wide areas of sballow-water carbonates. Such deposition started in the middle Llandovery in Washington Land and continued tboughout the region in the late Llandovery. Neither the Wenlock nor the Ludlow shales contain sufficient organic matter to be considered as potential source rocks. The potential source rocks are dominated by oil-prone organic matter (large amorphous kerogen particles, mainly type Il) and typically show TOC values between 2% and 6%. The generative potential of immature to early mature samples is high with values up to 30 mg Hag rock. A drastic increase in thermal maturity of surface rocks is observed from south to north and most of the potential drainage area is thermally mature to postmature. This leaves only few chances of finding trapped hydrocarbons sourced by Silurian shales in North Greenland.