Interpretation of the Tectonic Framework of NE Greenland Continental Margin from Regional Seismic Reflection and Gravity Data

Menno Dinkelman

The NE Greenland Tertiary volcanic-rich passive margin prism formed by the rifting of Caledonian orogenic crust and its complex overlying Devonian to Cretaceous cover. Here we use onshore geology, recent regional 2D PSDM marine seismic surveys and regional gravity data to analyze the tectonic architecture of the undrilled NE Greenland Atlantic passive margin. The tectonic evolution of Late Paleozoic successor basins, Mesozoic extensional basins, and Late Cretaceous to Miocene transpressional zones produced a complex architecture now inherited in the segmentation and geometry of the passive margin prism. The Caledonian basement exposed onshore to the west shows a NNE tectonic fabric parallel to the coast that is overprinted by the NW fabric of the late Caledonian Kron Prins Christians Land belt to the north. Along strike to the south, the onshore geology shows Caledonian basement with diverse thrust sheets of crystalline gneiss complexes, Mesoproterozoic metasediments, and Neoproterozoic to Ordovician sedimentary rocks intruded by Silurian granite. In offshore basement uplifts, seismic data express this considerable diversity of fabric, velocity and structure, as well as variable gravity and magnetic features. Below individual basins 7 to 14 km deep, the heterogeneous basement is not easily or consistently mapped or distinguished from inferred overlying Devonian supra-detachment basins and Carboniferous overlap. The Danmarkshavn Basin (DB) is a Carboniferous-Permian successor basin that follows basement trends and is capped by salt. Repeated extension of the Caledonian foundation in Mesozoic time reactivated these trends, culminating in major extension during the Cretaceous which reactivated the basin and generated the Danmarkshavn Ridge and Thetis Basin..

AAPG Search and Discovery Article #90177©3P Arctic, Polar Petroleum Potential Conference & Exhibition, Stavanger, Norway, October 15-18, 2013