Scheduled Cruises in 2003

Summary of a scheduled cruise on margins research (UK.031)

Location :   NW Indian Ocean

Research ship and cruise identifier :   RRS Charles Darwin 144

Sailed :   13 January 2003  from:     Muscat, Oman

Docked :   22 February 2003  in: Mahé, Seychelles

Principal Scientist/Investigator:   JS Collier

Laboratory :   Imperial College, University of London, UK

Other investigators :   M Kendall, PR Miles, T Minshull, RB Whitmarsh

E-mail contact for further information :   jenny.collier@ic.ac.uk

Scientific objectives :   We collected a comprehensive normal incidence and wide-angle seismic dataset to determine the deep structure and rift architecture of a conjugate pair of continental margins where initial spreading rate was fast (> 50 mm/yr) i.e. the north Seychelles and Laxmi Ridge margins. The results will be compared to predictions from numerical models to validate the models and improve our understanding of continental rifting and breakup. Numerical models developed to explain the magmatic and tectonic behaviour of rifted continental margins have been heavily influenced by observations made at margins where the initial seafloor spreading rate was slow (<25 mm/yr half rate). Further, the models have been devised largely to match observations from just one side of the continental rift which may or may not be representative of the conjugate rifted margin. We also collected gravity, magnetic, 3.5 kHz and swath-bathymetry profiles and obtained rocks from two dredge hauls on the N Seychelles margin.