Scheduled Cruises in 2003

Summary of a recent cruise on margins research (CA.031)

Location :   Davis Strait, N Labrador Sea

Research ship and cruise identifier :   CCGS Hudson (NEON)

Sailed :   10th August, 2003; Dartmouth, NS, Canada

Docked :   2nd September, 2003; Dartmouth, NS, Canada

PI :   Thomas Funck

Laboratory :   Danish Lithosphere Centre, Copenhagen, Denmark

Other investigators :   H. Ruth Jackson, Geological Survey of Canada (Atlantic Division), Dartmouth, Nova Scotia, Canada; Keith E. Louden, Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, Canada

E-mail :   tf@dlc.ku.dk

Scientific objectives :    Understanding the crustal structure within Davis Strait is critical for assessing mantle plume dynamics and the formation of transform margins. The purpose of the wide-angle reflection/refraction seismic study is to determine the nature of the crust in the southern Davis Strait at the transition from the non-volcanic style continental margins in the Labrador Sea to the volcanic transform-rifted margin between Baffin Island (Canada) and West Greenland. Previous studies are mainly based on multichannel reflection seismic and magnetic data and result in conflicting interpretations with regard to the deeper crustal structure and the plate reconstruction between Greenland and North America. The two seismic refraction lines in Davis Strait will provide a velocity model for the crust and uppermost mantle, which will help to distinguish between crustal types (oceanic, continental, transitional/serpentinized mantle). This information puts constraints on the rifting history and plate reconstruction. Mapping of magmatic underplating and analysis of the deep crustal structure of the large transform fault system in the strait will show how the Greenland-Iceland mantle plume interacted with the northward extent of the Labrador Sea rift. Transform faults in Davis Strait acted as leaky fracture zones but their deep structure is not known. In addition to the seismic experiment, several heat flow measurements will be carried out.