Analog modeling of Mexican Fold and Thrust Belt in central México
Alberto Vasquez Serrano, Universidad Nacional Autonoma de Mexico
Gustavo Tolson, Universidad Nacional Autonoma de Mexico
In central Mexico, the Mexican Fold and Thrust Belt (MFTB) presented a particular characteristics that are different to the other fold-thrust belts. The presence of important facies change in the pre-tectonic units play an important role in the deformation style, shortening accommodation and kinematic evolution. Field observations and new dates of deformation have been contributed to understand the development of this orogenic wedge. Nevertheless, there are some fundamental aspects that we need know, like: what is the importance of the facies change in the history of deformation? How is the activity of deformation in the borders of the facies change? What is the influence of lateral mechanical characteristics of the pre-tectonic units on the deformation of the syntectonic deposits? What is the role of superficial processes (erosion and sedimentation) in the deformation of the orogenic wedge in central México?
To answer these questions, we use the scale analog models, due to be used in the study the kinematic evolution of fold and thrust belts. The sand-box modeling is frequently used to generate orogenic wedge to scale in natural gravity behavior. For the models, we used different sands with different frictional angles for modeling the following paleogeographic elements extracted from field data: Tolimán Sequences, El Doctor Platform, Zimapán Basin, Valles-San Luis Potosí Platform, and Tampico Misantla Basin. Our results indicate that the kinematic evolution, deformation style and shortening variations of the MFTB is related specially with the lateral facies change product of different paleogeographic elements. These results are congruent withe the field observations and shortening estimations made in others works.