The Taxco-San Miguel de Allende fault system and the Trans-Mexican Volcanic Belt: Two tectonic boundaries in central México active during the Cenozoic
Por:
Alaniz-Álvarez S.A., Nieto-Samaniego A.F.
Publicada:
1 ene 2007
Categoría:
Geology
Resumen:
The Trans-Mexican Volcanic Belt has been recognized as a major volcanic arc, which crosses México from the Pacific Coast to the Gulf of México, that has displayed normal faulting and volcanism since the Miocene. In this work we present the deformation events that have been recorded N and S of the belt in order to establish when the crustal discontinuity originated and also to determine the deformation field precursor of the volcanic arc emplacement. In Mesa Central, the post-Laramide deformation occurred in three exten- sional events during the Eocene, Oligocene, and Miocene-Recent. The three events produced extension in two horizontal directions and shortening in a vertical direction. The direction of the principal extension in the Eocene is not well known. A 20% extension in an ?ENE-WSW direction is recorded for the Oligocene event. The most recent event, active since the middle Miocene, has developed in the Trans-Mexican Volcanic Belt and along its northern boundary. In the Sierra Madre Oriental, Cenozoic deformation has been minimal. In the Taxco region, there were two post-Laramide deformation events, mainly a result of NW-SE and N-S lateral faults. The first one occurred in the late Eocene with a NNW-SSE horizontal extension direction. The second event was early Oligocene with a maximum extension to the NE-SW. It is concluded that since the Eocene, the deformation style has been different in Mesa Central and in the Sierra Madre del Sur, which implies the presence of a detachment zone between these provinces.©2007 The Geological Society of America.
Filiaciones:
Alaniz-Álvarez S.A.:
Centro de Geociencias, Universidad Nacional Autónoma de México, Campus Juriquilla, Apartado Postal 1-742, 76001 Querétaro, Qro., Mexico
Nieto-Samaniego A.F.:
Centro de Geociencias, Universidad Nacional Autónoma de México, Campus Juriquilla, Apartado Postal 1-742, 76001 Querétaro, Qro., Mexico
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