TECTONIC EVOLUTION OF CHIAPAS: FROM RODINIA TO THE PRESENT

The geology of Chiapas is crucial to understanding the tectonic evolution of the southern margin of North America. This Mexican state contains a geological record spanning from the Proterozoic to the present, with a wide variety of deformation structures, including faults, shear zones and fold belts. These structures demonstrate the presence of lithospheric weakness zones that have been reactivated over time, influencing the formation of tectonic elements and geological processes since the amalgamation of Rodinia and Pangea to active volcanism. This study presents an overview of the most important tectonic features of Chiapas and Oaxaca, combining geophysical data (crustal models from magnetoteluric soundings) with surface geological observations and petrogenetic studies of igneous rocks. The results reveal the continuity of structures at depth and allow the definition of the boundaries between lithospheric blocks, shedding light on the complex tectonic history.

We present an updated geological map of the state of Chiapas, which shows the distribution of the main lithostratigraphic and structural elements of the region, as well as geological sections through lithospheric structures of the area, and an updated review of the stratigraphy of this important region of Mexico. In light of this information, we review the main tectonic events that affected the southern margin of the North American continent, from the consolidation and breakup of Rodinia, shortening events in the early Paleozoic, development of basins in the Carboniferous-Permian, consolidation and breakup of Pangea, opening of the Gulf of Mexico, Eocene shortening, Miocene strike-slip faulting, and the development of the triple junction between the North American, Cocos and Caribbean plates.