HR: 09:15h
AN: T41A-03    [Abstracts]
TI: The Ocean-Continent Transition at the North Atlantic Volcanic Margins
AU: * White, R S
EM: rwhite@esc.cam.ac.uk
AF: Cambridge University, Bullard Laboratories Madingley Rd, Cambridge, CB3 0EZ United Kingdom
AU: Christie, P A
AF: Sclumberger Cambridge Research Ltd, High Cross Madingley Rd, Cambridge, CB3 0EL United Kingdom
AU: Kusznir, N J
AF: Liverpool University, Dept Earth Sciences , Liverpool, L69 3BX United Kingdom
AU: Roberts, A M
AF: Badley Technology Ltd, North Beck House Hundleby , Spilsby, PE23 5NB United Kingdom
AU: Eccles, J
AF: Cambridge University, Bullard Laboratories Madingley Rd, Cambridge, CB3 0EZ United Kingdom
AU: Lunnon, Z
AF: Cambridge University, Bullard Laboratories Madingley Rd, Cambridge, CB3 0EZ United Kingdom
AU: Parkin, C J
AF: Cambridge University, Bullard Laboratories Madingley Rd, Cambridge, CB3 0EZ United Kingdom
AU: Smith, L K
AF: Cambridge University, Bullard Laboratories Madingley Rd, Cambridge, CB3 0EZ United Kingdom
AU: Spitzer, R
AF: Cambridge University, Bullard Laboratories Madingley Rd, Cambridge, CB3 0EZ United Kingdom
AU: Roberts, A W
AF: Cambridge University, Bullard Laboratories Madingley Rd, Cambridge, CB3 0EZ United Kingdom
AB: The continental margins of the northern North Atlantic are the best studied volcanic margins in the world. There is a wealth of integrated wide-angle and deep seismic profiles across the continent-ocean transition and the adjacent oceanic and continental crust, several of which form conjugate margin studies. We show new results from the integrated Seismic Imaging and Modelling of Margins (iSIMM) profiles across the Faroes continental margin which image both the extruded volcanics which generate seaward dipping reflector sequences and the underlying lower-crustal intrusions from which the extruded basalts are fed. This enables estimation of the degree of continental stretching and the total volume of melt generated from the mantle at the time of continental breakup. The new results are set in the context of profiles along the entire northern North Atlantic margins. The pattern of melt generation during continental breakup and the initiation of seafloor spreading allows us to map the pattern of enhanced sub-lithospheric mantle temperatures caused by initiation of the Iceland mantle plume over this period. The initial mantle plume thermal anomalies have the shape of rising hot sheets of mantle up to 2000 km in length, which focus into a more axisymmetric shape under the present location of Iceland. These spatial and temporal variations in the mantle temperature exert important controls on the history of uplift and subsidence and thermal maturation of the sediments near the continental margin and its hinterland. The iSIMM Scientific Team comprises NJ Kusznir, RS White, AM Roberts, PAF Christie, R Spitzer, N Hurst, ZC Lunnon, CJ Parkin, AW Roberts, LK Smith, V Tymms, J Eccles and D Healy. The iSIMM project is supported by Liverpool and Cambridge Universities, Schlumberger Cambridge Research, Badley Technology Limited, WesternGeco, Amerada Hess, Anadarko, BP, ConocoPhillips, ENI-UK, Statoil, Shell, the NERC and DTI. We thank WesternGeco for provision of Q-streamer data.
DE: 3015 Heat flow (benthic) and hydrothermal processes
DE: 3025 Marine seismics (0935)
DE: 3040 Plate tectonics (8150, 8155, 8157, 8158)
DE: 3094 Instruments and techniques
SC: Tectonophysics [T]
MN: 2005 Joint Assembly