HR: 1340h
AN: T23B-2035    [Abstracts]
TI: Subduction Zone Diversity and Nature of the Plate Contact
AU: DeFranco, R
EM: defranco@geo.uu.nl
AF: Earth Sciences Dept., Utrecht University, P.O. Box 80.021, Utrecht, 3508TA, Netherlands
AU: * Govers, R
EM: govers@geo.uu.nl
AF: Earth Sciences Dept., Utrecht University, P.O. Box 80.021, Utrecht, 3508TA, Netherlands
AU: Wortel, R
EM: wortel@geo.uu.nl
AF: Earth Sciences Dept., Utrecht University, P.O. Box 80.021, Utrecht, 3508TA, Netherlands
AB: We recently showed that the overall dynamics of subduction and initial collision depends on whether the plate contact is a fault or a channel. Here, we combine results of our numerical experiments with a re-analysis of published observations. Overall, our synthesis connects seismic moment release with back-arc deformation and tectonic processes at the margin. It leads us to identify four classes of subduction zones. The first two classes results directly from our numerical experiments. In class 1, subduction zones are characterized by a plate contact that is largely fault-like with an accretionary margin. In class 2, the plate contacts are largely channel-type and have an erosive margin. Class 3, where the plate contact is entirely channel-like, consists of accretionary margins with a high sediment supply. Subduction zones of class 4, mostly characterized by an erosive convergent margin (northern Chili, Peru, Honshu and Kuril), are more complicated. They can be explained by incorporating regional observations.
DE: 3060 Subduction zone processes (1031, 3613, 8170, 8413)
DE: 7240 Subduction zones (1207, 1219, 1240)
DE: 8104 Continental margins: convergent
DE: 8170 Subduction zone processes (1031, 3060, 3613, 8413)
SC: Tectonophysics [T]
MN: 2008 Fall Meeting