Tectonics and Structural Development of the Baffin Bay Region, West Greenland
John R. Hopper, Ulrik Gregersen, and Paul Knutz
Geophysics, Geological Survey of Denmark and Greenland, Copenhagen K, Denmark.
Major Cretaceous extension between Greenland and Arctic Canada resulted in the formation of significant rift basins in the present day Melville and Baffin Bays. Recently acquired geophysical data, in particular seismic reflection and aeromagnetic surveys, provide new constraints on the major regional structures that control the basins and sedimentary systems relevant to hydrocarbon generation and trapping. In this contribution, we present a new structural elements map that gives insight into the tectonic and structural development of the region since the mid- to late-Cretaceous. The Melville Bay (MB) fault parallels the western Greenland coast between 74°N and 76°N and is the major border fault that marks the eastern limit of significant basin formation. The MB graben is a deep half graben system filled with at least 14-15 km of sediment. To the west, the MB ridge is a continuous structural high that follows the coast up to the Kap York and Carey basins to the north. It represents the eastern edge of the Kivioq Basin, which is a complex system of grabens and half grabens which to the south contain thick sequences of syn-rift sediments. The Kivioq Ridge is not a single feature, but instead is comprised of discrete horst blocks that trend NNW to SSE and appear to splay off the MB Ridge, as is evident in the potential field anomalies and confirmed on the seismic reflection data. The MB Ridge is clearly an important structure for understanding basin evolution of the region. Late stage compression between Greenland and Ellesmere Island resulted in inversion structures along the margin, but are mostly confined to the eastern flank of the MB Ridge. Only minor, if any, inversion is observed within the Kivioq basin system. The southern limit of the region is affected by volcanism that is interpreted to be part of the onshore basalt provinces of West Greenland and Baffin Island, which in turn are part of the North Atlantic Igneous Province. The oldest volcanics sampled have been dated to 61 Ma (early- to mid-Paleocene). Offshore, the volcanics cover an area we interpret as Cretaceous to Paleocene basins. North of ~73°N , isolated sills are observed in many of the basins, however evidence for significant volcanism is lacking to north.
AAPG Search and Discover Article #90096©2009 AAPG 3-P Arctic Conference and Exhibition, Moscow, Russia