East Greenland Ridge in the North Atlantic Ocean: An integrated geophysical study of a continental sliver in a boundary transform fault setting

Abstract

The combined Greenland‐Senja Fracture Zones (GSFZ) represent a first‐order plate tectonic feature in the North Atlantic Ocean. The GSFZ defines an abrupt change in the character of magnetic anomalies with well‐defined seafloor spreading anomalies in the Greenland and Norwegian basins to the south but ambiguous and weak magnetic anomalies in the Boreas Basin to the north. Substantial uncertainty exists concerning the plate tectonic evolution of the latter area, including the role of the East Greenland Ridge, which is situated along the Greenland Fracture Zone. In 2002, a combined ocean‐bottom seismometer and multichannel seismic (MCS) survey acquired two intersecting wide‐angle reflection and coincident MCS profiles across and along the East Greenland Ridge. We present the results of integrated reflection seismic interpretation, first‐arrival tomography, 2D kinematic raytracing, full‐wave amplitude modeling, and gravity modeling of the intersecting profiles. The results show that (1) the Greenland Basin is characterized by a normal oceanic crustal velocity structure, (2) the velocity structure of the East Greenland Ridge is of overall continental type, and (3) a major faulted basin province above highly extended continental crust exists to the NE of the ridge. The results further suggest that a zone of extremely thin and faulted continental crust above partially serpentinized mantle peridotite defines the NW edge of the East Greenland Ridge and the transition to the NE Greenland margin.

A review of the NE Atlantic conjugate margins based on seismic refraction data

“…Immediately to the north of the EGR in the SW Boreas Basin, seismic refraction and coincident reflection data indicate the presence of an extremely thin and faulted transitional crust (Døssing et al 2008). The exact extent of this crust is unknown, but can be correlated at least 40 km to the north of the central part of the EGR (Døssing et al 2008).…”

“…The strike-slip shear margin did not develop into a fully passive margin before the Oligocene (Faleide et al 1996). The East Greenland Ridge is a sliver of continental crust that was sheared off the NE Greenland margin (Døssing et al 2008;Døssing & Funck 2012). Another bathymetric high in this shear region is the Hovgaard Ridge, the crustal affinity of which is not yet fully resolved (Engen et al 2008).…”

“…The exact extent of this crust is unknown, but can be correlated at least 40 km to the north of the central part of the EGR (Døssing et al 2008). Discontinuous and often weak magnetic lineations characterize the Boreas Basin (cf.…”

An integrated geophysical study of Vestbakken Volcanic Province, western Barents Sea continental margin, and adjacent oceanic crust

“…1) and a deepwater connection to the Arctic Ocean basin in Early Miocene Jakobsson et al 2007). The extensional component also detached two continental slivers from the western Barents margin: the East Greenland Ridge (Døssing et al 2008) and the Hovgård Ridge (Myhre et al 1982) (Fig. 1).…”

Chapter 42 Greenland petroleum exploration: history, breakthroughs in understanding and future challenges

“…Recently GEUS acquired some geophysical data on the east Greenland Ridge (in relation to UNCLOS Article 76) in 2002 (see Døssing et al 2008) and 2007, and expects to undertake further data acquisition in the coming years (bathymetry, refraction seismics and seabed sampling).…”