"Nares Strait" Arctic Expeditions of the BGR
Report of the project:
Plate tectonic reconstruction for the Greenland/Nares Strait area 50 million years ago
Source: BGR
Background:
Historically, Nares Strait played a prominent role in the development of the theory of continental drift (Wegener, 1912). The Question "Did Greenland drift along Nares Strait" has been debated for more than 80 years. In Dawes’ and Kerr’s (1982) volume "Nares Strait and the Drift of Greenland: a Conflict in Plate Tectonics" the scientific problem was discussed and the onshore geological evidence summarized. Geological evidence in the form of facies considerations were presented that allows an offset of not more than 25 km . In contrast, plate reconstructions published at that time required 220 km or more of sinistral motion. The discussion on the origin of Nares Strait revolves around three hypotheses:
- the strait is a major strike slip fault;
- plate motion has been taken up in a broad zone of deformation
- the strait is not a tectonic boundary and the geology can be correlated across it.
A recent collaborative mapping program between BGR Hannover and Geological Survey of Canada (CSG), Calgary, on Ellesmere Island verifies narrow elongate basins associated with faults. Offshore data from the Strait proper are lacking.
Marine survey of the Nares Strait
The Federal Geological Surveys of Greenland and Canada have decided to collaborate to address this scientific problem. With the support of the Canadian Coast Guard icebreaker "Louis S. St. Laurent" multichannel reflection and refraction seismic data have been collected in the Strait. These data are to tie it to onshore geology to understand the deformation of the region. In addition, geological core sampling together with an aeromagnetic survey and geodetic precision measurements on either side of the Strait are to be undertaken. Onshore programs on fission track uplift dating and dike distribution will complete the investigations. For both surveys scientists from other institutions in Denmark, Germany and Canada were invited to add expertise for critical fields of science not covered by the own experts.
