Double-saloon-door seafloor spreading: A new theory for the breakup of
Summary The double-saloon-door seafloor spreading model was developed in the Western Mediterranean. During subduction rollback, opposite rotational torques are driven by the pull of a sinking slab with a curved hingeline. This propels simultaneous opposite rotations of terranes in a backarc environm...
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Format: | Text |
Language: | English |
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Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.490.784 http://pubs.usgs.gov/of/2007/1047/ea/of2007-1047ea112.pdf |
Summary: | Summary The double-saloon-door seafloor spreading model was developed in the Western Mediterranean. During subduction rollback, opposite rotational torques are driven by the pull of a sinking slab with a curved hingeline. 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 arc-orthogonal rifting and seafloor spreading, 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 accommodated by rollback and simultaneous crustal shortening at the adjacent subduction zone / accretionary wedge. |
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