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Horizontal subduction and truncation of the Cocos Plate beneath central Mexico
Author(s) -
PérezCampos Xyoli,
Kim YoungHee,
Husker Allen,
Davis Paul M.,
Clayton Robert W.,
Iglesias Arturo,
Pacheco Javier F.,
Singh Shri K.,
Manea Vlad Constantin,
Gurnis Michael
Publication year - 2008
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2008gl035127
Subject(s) - subduction , geology , seismology , slab , slab window , trench , crust , volcanic belt , volcanic arc , volcanism , underplating , volcano , oceanic crust , tectonics , geophysics , volcanic rock , chemistry , organic chemistry , layer (electronics)
Based on analysis of data from a trans‐Mexico temporary broadband seismic network centered on Mexico City, we report that the subducting Cocos Plate beneath central Mexico is horizontal, and tectonically underplates the base of the crust for a distance of 250 km from the trench. It is decoupled from the crust by a very thin low viscosity zone. The plate plunges into the mantle near Mexico City but is truncated at a depth of 500 km, probably due to an E‐W propagating tear in the Cocos slab. Unlike the shallow slab subduction in Peru and Chile, there is active volcanism along the Trans Mexican Volcanic Belt (TMVB) that lies much further inland than regions to either side where subduction dip is not horizontal. Geodynamical modeling indicates that a thin weak layer such as imaged by the seismic experiment can explain the flat subduction geometry.