My OperaRidge Subduction
Friday, March 30, 2007 6:11:54 PM
Ridge subduction is inevitable on a world covered with plates: there are six present-day examples and probably hundreds of past instances related to former plate configurations. Ridge subduction means that an oceanic spreading center is subducted beneath a tectonic plate.
The clearest example of active spreadng ridge subduction can be observed in detail where the Chile Ridge (red line) subducts beneath South America along the Chile Trench (purple line). See http://seismology.geology.ufl.edu/chile/index.php?page/Subduction. This ridge subduction has been going on from the Miocene to the present.
At ridge subduction spreading stops beneath the overriding plate and the ridge widens into an inter-slab gap called a slab window. A block diagram of a slab window beneath Central America, where the Cocos Plate and the Nazca Plate are subducted beneath the Caribbean plate is shown at http://www.sfu.ca/~dthorkel/slab.htm.
For 90 million years oceanic spreading ridges have subducted beneath the North American plate.
Between 61 and 50 million years ago, an oceanic spreading center was subducted beneath Alaska ( http://alaska.usgs.gov/portal/project_details.php?project_id=59 ).
The clearest example of active spreadng ridge subduction can be observed in detail where the Chile Ridge (red line) subducts beneath South America along the Chile Trench (purple line). See http://seismology.geology.ufl.edu/chile/index.php?page/Subduction. This ridge subduction has been going on from the Miocene to the present.At ridge subduction spreading stops beneath the overriding plate and the ridge widens into an inter-slab gap called a slab window. A block diagram of a slab window beneath Central America, where the Cocos Plate and the Nazca Plate are subducted beneath the Caribbean plate is shown at http://www.sfu.ca/~dthorkel/slab.htm.
For 90 million years oceanic spreading ridges have subducted beneath the North American plate.
Between 61 and 50 million years ago, an oceanic spreading center was subducted beneath Alaska ( http://alaska.usgs.gov/portal/project_details.php?project_id=59 ).
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