Low Angle Contact Between the Oaxaca and Juárez Terranes Deduced From Magnetotelluric Data
Por:
Arzate-Flores, Jorge A., Molina-Garza, Roberto, Corbo-Camargo, Fernando, Marquez-Ramirez, Victor
Publicada:
1 oct 2016
Resumen:
We present the electrical resistivity model along a profile perpendicular to the Middle America trench in southern Mexico that reveals previously unrecognized tectonic features at upper to mid-crustal depths. Our results support the hypotheses that the upper crust of the Oaxaca terrane is a residual ~20 km thick crust composed by an ~10 km thick faulted crustal upper layer and an ~10 km thick hydrated and/or mineralized layer. Oaxaca basement overthrust the younger Juárez (or Cuicateco) terrane. The electrical resistivity model supports the interpretation of a slab subducting at a low angle below Oaxaca. Uplift in the Oaxaca region appears to be related to fault reactivation induced by low angle subduction. In the Juárez terrane, isostatic forces may contribute to uplift because it is largely uncompensated. In the Sierra Madre del Sur, closer to the coast, uplift is facilitated by slab-dehydration driven buoyancy. Both gravity and resistivity models are consistent with a thinned upper crust in the northeast end of the profile. © 2016, Springer International Publishing.
Filiaciones:
Univ Nacl Autonoma Mexico, Ctr Geociencias, Blvd Juriquilla 3000, Juriquilla 76230, Qro, Mexico
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