Role of Caribbean Tectonics in the Tectono-Stratigraphic Evolution of Southern Mexico and the Gulf of Mexico

摘要

Jurassic opening of the Gulf of Mexico and Proto-Caribbean Seaway produced an irregular margin along southern North America. This irregular margin subsequently served as the structurally-variable, over-thrusted foreland during eastwardly- progressive Late Cretaceous-Eocene collision of the Greater Antilles Arc from the Chortis Block to the Bahamas. Following collision, Paleocene development of the southern Mexi-co-Cayman transform system triggered the isostatic rebound of southern Yucatan/ Chiapas and allowed Chortis to migrate transpressionally eastward along the preorogen. These events impacted petroleum systems in southern Gulf of Mexico by influencing Paleogene deposition and initiating salt tectonism in Chiapas and Salinas basins. U-Pb dating of southern Mexican igneous bodies, fission track documentation of regional uplift history, petrographic heavy mineral, and DZ analyses of Paleocene-Eocene deposits in Guatemala and Chiapas (e.g., Sepur, Soyalo, and El Bosque formations), show that the southern Gulf of Mexico received voluminous detritus from outside of Mexico. Eastward migration of Chortis brought it alongside the Chiapas Massif in the Eocene, triggering transpressional uplift with eventual basement exposure of the Massif by the Oligocene. Basement-involved Middle Miocene and younger "Chiapanecan" deformations (e.g., Chiapas Foldbelt, Akal-Reforma Belt, opening of Macuspana/Comalcalco basins, and offshore Campeche folding) post-dated passage of Chortis, and hence were driven by the onset of Cocos subduction as the southern Mexican transform evolved into a trench during passage of the Nazca-Caribbean-Cocos triple junction. Despite the Caribbean Plate being somewhat displaced today, the impact of Caribbean tectonism on the tectono-stratigraphic evolution of the southern Gulf of Mexico was fundamental and must be understood before any comprehensive understanding of southern Mexico is possible.