Vol. 26 No. 2 (1987)
Articles

MORPHOLOGICAL AND STRUCTURAL ANALYSIS OF THE CENTRAL SECTOR OF THE TRANSMEXICAN VOLCANIC BELT

G. PASQUARE
Dispatimento di Scienze dell Terra dell’Universitá degli studi di Milano., Milano, ITALY.
L. FERRARI
Dispatimento di Scienze dell Terra dell’Universitá degli studi di Milano., Milano, ITALY.
V. PERAZZOLI
Dispatimento di Scienze dell Terra dell’Universitá degli studi di Milano., Milano, ITALY.
M. TIBERI
Dispatimento di Scienze dell Terra dell’Universitá degli studi di Milano., Milano, ITALY.
F. TURCHETTI
Dispatimento di Scienze dell Terra dell’Universitá degli studi di Milano., Milano, ITALY.

Published 1987-04-01

How to Cite

PASQUARE, G., FERRARI, L., PERAZZOLI, V., TIBERI, M., & TURCHETTI, F. (1987). MORPHOLOGICAL AND STRUCTURAL ANALYSIS OF THE CENTRAL SECTOR OF THE TRANSMEXICAN VOLCANIC BELT. Geofísica Internacional, 26(2), 177-193. https://doi.org/10.22201/igeof.00167169p.1987.26.2.1108

Abstract

In this paper the post-orogenic evolution of a central sector of the Mexican Volcanic Belt (MVB) in the states of Guanajuato and Michoacán is analyzed. The main structural units are recognized on the basis of a morphological analysis and geological data. Four categories of morphological units were established. These are:

1. Reliefs belonging to geological formations older than MVB and characterized by Laramide orogenic deformation.

2. Pre-MVB planar structural surfaces.

3. Depositional surfaces belonging to sedimentary orvolcanoclastic infilling of post-orogenic tectonic depressions.

4. Surfaces of MVB volcanoes.

In this analysis the main morphogenetic stages were recognized; these were related to tensional tectonic phases and to the main volcanic events. An early tensional tectonic phase is associated with the volcanic activity which formed the pre-Miocene deposits of the Sierra Madre Occidental. A NNW-SSE trending system is dominant during the late Miocene and is related to the "Basin and Range" province of western U. S. A. NW-SE faulting during Pliocene along Californian trends is responsible for the initial volcanic activity of the MVB. Late Pliocene trends are WSW-ENE. The last tensional phase causes N-S and NNE-SSW grabens, as a possible reactivation of "Basin and Range" structures.