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2017
3D restoration of a Cretaceous rift basin in Kilen, eastern North Greenland
97
1
21-32

The semi-nunatak Kilen is a key area to understand the setting of the Cretaceous sedimentary basin in eastern North Greenland. The basin geometry has been obscured by later N–S compression and inversion of presumable Palaeocene–Eocene age. A 3D restoration of the Cretaceous basin is presented based on new oblique photogrammetry and field data combined with published data. The 3D restoration focuses on the main faults and a well constrained mid-Cretaceous horizon. The restoration shows that the horizon was offset down-to-the-ENE by several NNW–SSE-striking normal faults and highlights the similarity of the pre-folding basin to a normal rifted margin. The northwestern part of the restored area comprises five fault blocks divided by four NNW–SSE-striking normal faults dipping to the ENE, whereas the southeastern part consists of a single large fault block deformed by minor antithetic faulting. Minimum offsets on exposed normal faults are between 780 and 1200 m, and the fault blocks are between 1.5 and more than 10 km in width. The restoration and interpretation of the Cretaceous basin at Kilen as extensional opens for a similar interpretation for NNW–SSE-oriented faults affecting Mesozoic sediments elsewhere in the Wandel Sea Basin which were previously interpreted as having formed in a strike-slip setting. The basin restored at Kilen has several similarities to basins on the southwestern Barents Sea margin, especially the Bjørnøya Basin, located just 100–200 km east of Kilen in pre-North Atlantic opening times. The two basins were separated by the Stappen High and the basin at Kilen could be the western part of a successful rift that eventually resulted in the opening of the North Atlantic.

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