The Isrand Formation: a Middle Triassic Daonella-bearing, black shale unit in Kilen, North Greenland (with a note on the Triassic in Amdrup Land)

Triassic sedimentary rocks in the Wandel Sea Basin in North Greenland have hitherto been considered restricted to eastern Peary Land, but are here, based on fossil evidence, reported from additional two areas. The discovery of the halobiid bivalve Daonella subarctica Popov 1946 and the ammonoid Nathorstites cf.. N. macconnelli (Whiteaves 1889) provide evidence of Upper Ladinian Middle Triassic strata at Kilen (Kronprins Christian Land) in rocks previously mapped as Jurassic. They occur in a succession of black laminated shales that are referred to a new formation - the Isrand Formation. A revision of ammonoids from strata previously considered Jurassic adds records of Lower Triassic outcrops in Amdrup Land (also Kronprins Christian Land). The available data suggest that the new Isrand Formation closely resembles the Botneheia Formation in Svalbard, which is considered the onshore equivalent to petroleum source rock units in the western Barents Sea assigned to the Steinkobbe Formation.