Evidence for continental crust in the offshore Palaeogene volcanic province, central West Greenland

Abstract

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example:
 Skaarup, N. (2002). Evidence for continental crust in the offshore Palaeogene volcanic province, central West Greenland. Geology of Greenland Survey Bulletin, 191, 97-102. https://doi.org/10.34194/ggub.v191.5135
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 The Palaeogene volcanic province of central West Greenland extends for 550 km from north to south and 200 km from east to west (Henderson 1973; Henderson et al. 1981; Whittaker 1996). In a preliminary interpretation of the area offshore Disko and Nuussuaq, based on older seismic data, Whittaker (1996) described a number of large rotated fault blocks containing structural closures at top volcanic level that could indicate leads capable of trapping hydrocarbons. This work, combined with the discovery of oil in the basalts onshore, led the Geological Survey of Denmark and Greenland (GEUS) to acquire 1960 km of multi-channel 2D seismic data in the area between 68°N and 71°N in 1995 (Fig. 1). These seismic data are the primary data source for the interpretation presented in this paper.

Age of Tertiary volcanic rocks on the West Greenland continental margin: volcanic evolution and event correlation to other parts of the North Atlantic Igneous Province

“…The offshore succession has been studied in seismic sections. Skaarup (2001, 2002) distinguished and described five different seismic units (A–E) in the volcanic succession west of Disko, Nuussuaq and Ubekendt Ejland. The lowermost unit E has a chaotic internal pattern and was interpreted as subaqueous hyaloclastites.…”

“…The youngest, normally magnetized, seismic unit A is not represented onshore. It overlies seismic unit B non-erosively, and Skaarup (2001, 2002) suggested it may be of C24n age. However, it may also include younger rocks unknown in the onshore areas; as shown in Figure 9 there is plenty of ‘room’ for additional volcanic units offshore.…”

“…1); they are therefore not well known. Seismic studies in the northern Labrador Sea, Davis Strait and southern Baffin Bay have revealed the existence of extensive Palaeogene volcanic rocks (Whittaker, 1996; Skaarup, 2002; Skaarup, Jackson & Oakey, 2006; Gregersen & Bidstrup, 2008; Keen, Dickie & Dehler, 2012) and a several kilometres thick magmatic underplate, interpreted as plume-generated, beneath the thinned lithosphere (Funck et al 2007, 2012; Keen, Dickie & Dehler, 2012). On the Greenland side, a scarcity of volcanic rocks between 66°N and 67°30′N separates the volcanic parts into a southern and a northern area.…”

A new model for the Paleogene motion of Greenland relative to North America: Plate reconstructions of the Davis Strait and Nares Strait regions between Canada and Greenland

“…The Disko Volcanic Province in southern Baffin Bay is an offshore continuation of the basalts exposed onshore in the Nuussuaq Basin [ Dam et al , 2009] which erupted during a major episode of volcanic activity (∼61 Ma) [ Storey et al , 1998] and corresponds with the initiation of oceanic seafloor spreading in Labrador Sea. Seismic data and gravity modeling [ Chalmers et al , 1999; Skaarup , 2002; Gregersen and Bidstrup , 2008] show that the picrites and basalts overlie up to 8 km of Cretaceous and possibly older sediments. In the Cape Dyer area of Baffin Island, Paleogene basaltic volcanic rocks are exposed onshore, at the seafloor and within isolated basins.…”

Depleted and ultradepleted basalt and picrite in the Davis Strait: Paleocene volcanism associated with a transform continental margin

“…The nature of the crust in this area has been difficult to interpret, in particular the possible occurrence of oceanic crust (Srivastava et al 1982;Chalmers & Pulvertaft, 2001). Seismic studies in the northern Labrador Sea, Davis Strait and southern Baffin Bay have revealed the existence of extensive Palaeogene volcanic rocks (Whittaker, 1996;Skaarup, 2002;Skaarup et al 2006;Sørensen, 2006;Funck et al 2007Funck et al , 2012Gregersen & Bidstrup, 2008;Gerlings et al 2009;Keen et al 2012Keen et al , 2018aSuckro et al 2012Suckro et al , 2013Gregersen et al 2019) and a magmatic underplate of several kilometres thickness, interpreted as plume-generated, beneath the thinned crust (Funck et al 2007(Funck et al , 2012Gerlings et al 2009;Keen et al 2012;Suckro et al 2013). Hosseinpour et al (2013) presented a map with calculated thicknesses of igneous crust of up to 8 km in the Davis Strait area.…”