Subduction of the Cocos Plate and deep active fracture zone of Mexico.

Abstract

The morphology and parameters of the Wadati-Benioff zone were established on the basis of the distribution of earthquake foci in the region of Mexico. The existence of an intermediate aseismic gap related clearly to the Central America belt of active andesitic volcanoes was confirmed in those parts of the subduction zone were the conditions necessary for partial melting of the downgoing slab were reached. The non-uniform rate of subduction of the Cocos plate could be correlated with the hampering effect of the Orozco fracture zone and Tehuantepec Ridge. Five deep seismically active fracture zone, genetically connected with the process of subduction, were identified in the continental plate as possible feeding channels for active volcanoes of the Transmexican volcanic belt.