Friday, 31 August 2007 - 11:00 AM
5.A.B-2

Double-saloon-door seafloor spreading: a new theory for the breakup of Gondwana

Alexander Keith Martin, Direccion General Upstream, Repsol YPF, Al Fattan Plaza, PO Box 35700, Dubai, United Arab Emirates

The double-saloon-door seafloor spreading model was developed in the Western Mediterranean. During subduction rollback, opposite rotational torques are driven by the central pull of a sinking slab relative to two lateral areas where no subduction rollback occurs. This propels simultaneous opposite rotations of terranes in a backarc environment. The process also occurred in the Pannonian, Aegean, Caribbean and Japan Sea basins. Unlike previous models, this novel theory, when applied to Gondwana breakup, explains clockwise and counterclockwise rotations of the Falkland Islands Block and the Ellsworth Whitmore Terrane, the separation of these terranes in a northwest southeast direction, and their eventual accretion to South America and East Antarctica respectively. As in other cases, the Gondwana terranes comprise parts of a pre-existing retroarc fold / thrust belt (the Permo-Triassic Gondwanide Orogeny). Extension and microplate rotations in the backarc are accomodated by simultaneous crustal shortening at the adjacent subduction zone / accretionary wedge.

[Manuscript]

See more of Supercontinent breakup history and processes   ORAL
See more of General Submissions

See more of The 10th International Symposium on Antarctic Earth Sciences (Aug. 26 to Sept 1, 2007)