Geological evolution of the West Greenland Rifted Margin Composite Tectono-Sedimentary Element

The West Greenland Rifted Margin Composite Tectono-Sedimentary Element is composed of two distinct sedimentary accumulations: (1) pre-rift (pre-Cretaceous) and (2) syn-rift (Early Cretaceous–Danian), which represent individual tectono-sedimentary elements. The pre-rift tectono-sedimentary element includes the oldest and most poorly known offshore sedimentary basins, which mainly evolved in a cratonic platform setting with initial rifting phases. Orogenic phases with folded, rifted and metamorphosed rock successions are well documented onshore but less known in the offshore. Samples of gneiss, supracrustal rocks and some sedimentary rocks have been reported from offshore wells, shallow boreholes and/or seabed samples and tectonism is inferred by fault blocks in basement and pre-Cretaceous successions. These successions include Proterozoic rocks of the Thule Supergroup in NE Baffin Bay and the Thule Basin further north. Paleozoic carbonates are also indicated farther south. In contrast, Cretaceous–lower Paleocene sedimentary basins of the syn-rift tectono-sedimentary element are known from several wells, shallow boreholes and seabed samples, and basins are mapped in most parts of the margin. This element is composed of tectono-stratigraphic mega-units, formed during the early-rift, subsidence and late-rift phases. This element is known to have resource potential, in particular from well documented studies onshore from the Nuussuaq Basin including hydrocarbon seeps and other mineral resources. Large Cretaceous and Paleogene structures are buried below thick mudstone seal units and Paleogene volcanic successions, which are known from outcrops in central West Greenland and wells on the West Greenland continental margin. The geological evolution of the West Greenland margin is connected to the evolution of the conjugate Canadian margin, where similar rocks occur at some locations. The work presented here includes a contribution to the new GSL Memoir 57 on sedimentary successions in the Arctic region.