Unusual resinite-rich coals found in northeastern Greenland and along the Norwegian coast: Petrographic and geochemical composition

Middle Jurassic coals unusually rich in resinite/liptinite are known in northeastern Greenland from a few outcrops and from several erratic pieces. In addition, since the mid-1800's a number of loose pieces of resinite-rich coal, the so-called Kvæfjord coal, have been found along the Norwegian coast in or close to the shore zone in places where it would have been impossible for the coal to originate from passing ships. This study presents a comprehensive organic petrographic and geochemical investigation of two new pieces of resinite-rich coal found on Store Koldewey in northeastern Greenland, a resinite-rich core sample from the Norwegian island Andøya, and two pieces of the Norwegian Kvæfjord coal. The coals are thermally immature and contain an extraordinary high content of liptinite and in particular resinite (34.2–93.6 vol.%). The two coal pieces from Store Koldewey and the core sample from Andøya are compositionally comparable to the resinite/liptinite-rich Middle Jurassic coals that crop out on Hochstetter Forland and Kuhn Ø in northeastern Greenland. The two loose pieces of Kvæfjord coal are exceptionally rich in resinite and appear to be slightly different from the other coals, albeit they are compositionally related. The documentation of in situ resinite/liptinite-rich coals on Andøya and the finding of loose pieces along the Atlantic coast of Norway indicate that formation of these unusual coals occurred regionally in the pre-rift North Atlantic region, probably in peat-forming mires with a yet unknown strongly resin-producing vegetation established at the margins of a gradually northward prograding embayment formed during Middle Jurassic rifting between Greenland and Norway. The unique maceral composition makes the coals excellent potential petroleum source rocks with HI values > 400 mg HC/g TOC, but the sketchy knowledge of the regional distribution of the coals combined with the probably restricted areal extent of the coal deposits limits their significance as an additional source rock in the North Atlantic area.

► Coals with up to 94 vol.% resinite are found in northeastern Greenland and along the Norwegian coast.
► The coals have been found in situ but the regional distribution is unknown.
► The coals were formed by an unknown strongly resin-producing vegetation in the pre-rift North Atlantic region.
► The coals constitute excellent petroleum source rocks with HI values > 400 mg HC/g TOC.