3D restoration of a Cretaceous rift basin in Kilen, eastern North Greenland

Abstract

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.

Middle Jurassic sandstone deposition in the Wandel Sea Basin: evidence from cardioceratid and kosmoceratid ammonites in the Mågensfjeld Formation in Kilen, North Greenland

“…Several Cretaceous intervals and units were poorly dated or not dated at all. The succession has been subject to significant thermal influence, which has removed organic palynomorphs hampering the use of dinoflagellate cysts stratigraphy (Håkansson & Pedersen 2001;Svennevig et al 2017;Pedersen et al 2018). Macrofossils are absent or scarce and poorly preserved in several units.…”

“…Parallel to the biostratigraphic and lithostratigraphic work, the structural geology of Kilen was revised based on mapping from oblique photogrammetry and field work (Svennevig et al 2015). A new structural model for Kilen was published, in which it was shown that Late Cretaceous extension caused normal faulting followed by Eurekan compression, which gave rise to folding and thrusting (Svennevig et al 2016(Svennevig et al , 2017.…”

“…Today, Svalbard and the Barents shelf are more than 600 km away from Kilen, but prior to the opening of the Atlantic, they were only 400 and 200 km away, respectively www.geusbulletin.org (Svennevig et al 2017, using Müller et al 2016. The closest (onshore) correlative unit to the Wandel Sea Basin, geologically speaking, is probably found on Svalbard.…”

Regional impact of Early Cretaceous tectono‐magmatic uplift in the Arctic: Implications of new data from eastern North Greenland

“…(2010) and Svennevig et al. (2017). The dashed red line delineates the inferred Barremian coastline position off Greenland and Svalbard, modified after Grundvåg et al.…”

“…Location of the study area in eastern North Greenland on a pre‐break‐up Cretaceous plate reconstruction (Müller et al., 2016, as modified by Svennevig et al., 2017) with Jurassic–Lower Cretaceous structural features from Faleide et al. (2010) and Svennevig et al.…”