Combined microstructural and geochronological analysis of ductile deformation in the Sierra de Juarez Complex (Southern Mexico).

The Sierra de Juárez Complex (SJC), located in Oaxaca, Mexico, comprises a N-S trending belt of deformed igneous and metamorphic rocks with a complex history of multistage deformation and metamorphism. The SJC exhibits penetrative mylonitic deformation attributed to Mesozoic tectonics; however, the timing and kinematics of this event remain poorly constrained.

New Rb-Sr geochronology on muscovite reveals ages ranging from ~164 to ~151 Ma, corresponding to a Middle to Late Jurassic event, and a younger age of ~67 Ma, associated with the Laramide Orogeny. Ongoing microstructural analyses, including traditional optical methods and Electron Backscatter Diffraction (EBSD), aim to characterize the kinematics and deformation style of the mylonitic belt.

The integration of geochronological and microstructural data will enhance our understanding of the role of the SJC in the tectonic evolution of southern Mexico during the Mesozoic, providing new insights into the broader tectonic framework of western equatorial Pangea.