Margin segmentation of Baffin Bay/Davis Strait, eastern Canada based on seismic reflection and potential field data
Section snippets
Geological and geophysical background
Baffin Bay and Davis Strait are located between Baffin Island and Greenland, to the north of the Labrador Sea (Fig. 1). Baffin Bay is believed to have been created by the northward extension of seafloor spreading from the Atlantic Ocean through the Labrador Sea. A review by Balkwill et al. (1990) discussed the debate on the development of Baffin Bay: one group suggests that the region formed by seafloor spreading, and another that continental crust is present. Available refraction profiles are
Description of data, distribution and processing
A regional interpretation of seismic reflection profiles on the Baffin Island margin in the area between 60 and 72°N was undertaken (Fig. 2). Three industry wells, one ODP well and 73 bedrock cores were available to control the seismic analysis. New compilations of magnetic and gravity data (Fig. 3, Fig. 4) from the Baffin Bay and Davis Strait were used to constrain the sub-seabed as well.
The 30,000 km of industry seismic reflection data (Fig. 1) were assembled from 13 different surveys acquired
Regional setting
The Baffin Island margin (60–72°N) can be divided into three areas based on the seismic reflection data (Fig. 1, Fig. 2). Areas 1 and 3 are dominated by extensional features produced during rifting separated by Area 2 created by translation and affected by volcanism. The potential field anomalies vary along the Baffin Island margin (Fig. 3, Fig. 4) consistent with the divisions made on the basis of the seismic data.
Area 1
The fault pattern in Area 1 (69–72°N), is elongate northwest–southeast striking
Discussion
We combine our interpretation of the margin of Baffin Island with that off of Greenland (Fig. 10) based on Chalmers, 1997, Chalmers and Pulvertaft, 2001, Chalmers et al., 1995, Chalmers et al., 1993, Louden and Chian, 1999. For the northern Labrador Sea, we incorporate the results of Roest and Srivastava, 1989, Chalmers, 1991, Chalmers and Laursen, 1995, Chian and Louden, 1992, Chian et al., 1995a, Chian et al., 1995b, Louden and Chian, 1999, Funck and Louden, 1999.
Conclusion
The two major results of this paper are the separation of the Baffin Island margin into non-volcanic and volcanic regions, and a reinterpretation of the COB. The data presented here, in particular the SDRs, the ages of the samples of volcanic rock and the high-frequency magnetic anomalies associated with positive gravity signatures, indicate extensive magmatism associated with the central part of the margin. In contrast, the margin segments to the north and south of the central areas show no to
Acknowledgements
The GEUS and GSC are thanked for providing the means for the principal author to spent 6 months at the GSCA. We thank Brian MacLean for access to the bedrock samples he collected on several cruises to the area. They were a significant constraint for the geology of the region. Jim Chalmers, GEUS and two reviewers Brian MacLean and Hans Wielens from GSCA reviewed the manuscript and made many helpful comments.
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