For over two decades, the repeatedly metamorphic and polydeformed rocks of the Acatlán Complex of south- central Mexico have traditionally been linked to the Appalachian mountains of eastern North America and the closure of the Iapetus Ocean. Recent multi- disciplinary studies have refined our understanding of its tectonic evolution and challenge previous Paleozoic tectonic and paleogeographic models. This work presents detailed mapping, petrographic, structural, geochronological, and geochemical data from the northern part of the complex and show that the Acatlán Complex records various styles of deformational events at different times. This finding suggests that the complex''s tectonothermal evolution is associated with the closure of the successor Rheic Ocean during the final assembly of Pangea. This is an ideal book for senior undergraduate and postgraduate students of structural geology, regional tectonics, and continental geodynamics interested in orogenic processes. It is also a valuable reference work for research earth scientists.