From 1 - 3 / 3
  • Geochemical analysis of rock samples acquired by dredging activities in the Scotia Sea between Feb and Mar 2004 aboard James Clark Ross (cruise no JR77). The initial aim of this project was to carry out a higher resolution geochemical study of mantle flow using existing samples. This confirmed flow from the Bouvet domain into the East Scotia Sea and placed constraints on flow pathways. The second stage was to sample further within the West Scotia Sea and to use elemental and isotope (Sr, Nd, Pb, Hf) analyses to fingerprint mantle provenance. The results were used to locate and investigate the nature of the Pacific-South Atlantic mantle domain boundary and thus to contribute to the understanding and quantification of global upper mantle fluxes.

  • Dredging for rock samples was conducted in the West Scotia Sea during James Clark Ross cruise no JR77 between Feb and Mar 2004. The aim was to acquire rock samples to constrain the history of the mantle beneath the Scotia Sea, from which the oceanic crust was derived by melting. Twenty days of rock dredging were conducted at fourteen sites in five main areas. Thirteen dredges were successful in recovering oceanic rocks of mixed sizes, up to and including very large boulders and dredge paths of up to 1 km were followed. The cruise also (remarkably) recovered fresh mantle peridotite nodules from the West Scotia Ridge, the first of its type - to our knowledge - from the world''s ocean ridge system.

  • Dredge sampling was carried out aboard the James Clark Ross (cruise no JR77 ) during Feb and Mar 2004. The dredge target area was along the eastern segments of the West Scotia Ridge, an ocean spreading centre which stopped spreading about 10 million years ago. The spreading centre has high topographic relief and contains an axial rift, which has flanks that are suitable for dredging. The plan was to map the spreading centre using the swath bathymetry system, and then to use this map to locate the best dredging sites. Thirteen dredges were successful in recovering oceanic rocks of mixed sizes, up to and including very large boulders and dredge paths of up to 1 km were followed.