Tectono-stratigraphic history of northern Amdrup Land, eastern North Greenland: implications for the northernmost East Greenland shelf

Abstract

The NW–SE-oriented Sommerterrasserne fault in Amdrup Land marks the southern limit of Mesozoic compression related to the transform plate boundary between North Greenland and Svalbard. Structural style in Amdrup Land changes across the fault; Carboniferous, Permian and Jurassic sediments in northern Amdrup Land north-east of the fault are gently folded, with NE– SW-trending fold axes, whereas they are gently dipping south of the fault. The Sommerterrasserne fault is regarded as the south-eastern extension of the Trolle Land fault zone of eastern Peary Land. Upper Moscovian carbonates of the Foldedal Formation rest unconformably on isoclinally folded Upper Proterozoic sediments of the Independence Fjord Group in northern Amdrup Land and are conformably overlain by chert-rich limestones of the Permian Kim Fjelde and Midnatfjeld Formations. Locally, up to 70 m of Jurassic sandstone and siltstone are preserved in the axes of the synclines, resting conformably on Permian limestones; the folding thus post-dates their deposition. The folding of the sediments to the north-east of the Sommerterrasserne fault most likely took place during the latest Cretaceous; it is post-dated by a post- Paleocene extensional event.