Acatlán Complex, southern Mexico: Record spanning the assembly and breakup of Pangea

Abstract

New structural, geochronological, and geochemical data from the Acatlan Complex of southern Mexico show that it preserves a complete history of Pangea, from assembly to breakup. Previously interpreted to be a vestige of the Iapetus suture, the Acatlan Complex records a history that can be sequentially linked to the Rheic Ocean, the paleo-Pacific, and the Gulf of Mexico. This record is interpreted to reflect: (1) the development of a rift-passive margin on the southern flank of the Rheic Ocean in the Cambrian–Ordovician; (2) the formation of an extensional regime along the formerly active northern margin of Gondwana throughout the Ordovician; (3) closure of the Rheic Ocean documented by subduction-related eclogite facies metamorphism and exhumation during the Late Devonian–Mississippian; (4) Permian–Triassic convergent tectonics on the paleo-Pacific margin of Pangea; and (5) interaction with a Jurassic mantle plume coeval with the opening of the Gulf of Mexico.