PALYNOSTRATIGRAPHY ALLOWS TO PLACE THE HISPANIC CORRIDOR ACROSS THE GULF OF MEXICO DURING ITS ORIGIN

Marine and continental Early Liassic palynomorphs from Huayacocotla-El Alamar Basin are essentially the same as those found elsewhere in the world. This rift-basin was connected to the Pacific Ocean by the “Portal del Balsas”, an epicontinental sea formed on the Huayacocotla Block, one of three blocks placed at the Gulf of Mexico region. As ammonite and marine reptiles suggest, palynomorphs from Mexican Gulf sub-basins show a Pacific to Atlantic oceans connection, since Middle Jurassic across the Gulf.

During Late Liassic, Tlaxiaco and Huayacocotla blocks and South America moved southwestward, just before the RRR triple junction formed by the Texas-Boquillas-Sabinas, Campeche Escarpement and, Nautla-Pico de Orizaba arms, bordering the Texas-Louisiana, Western Region of Mexico, and Chiapas-Yucatán subplates. As this one remained joined to South America, up to Late Tithonian, only Texas-Louisiana and Western Region subplates were displaced northwestward. So, the original triple junction separated two land masses with a predominantly ridge boundary, and a failed arm of a ridge connected with the “Portal del Balsas” forming both the “Hispanic Corridor”.

Redbeds, marine and some salt palynostratigraphy from Tampico-Misantla and Southeastern basins provided valuable data which were related to those obtained from the caprock of the Challenger Knoll, drilled in the center of the Gulf of Mexico. They have been useful for understanding the Gulf of Mexico tectonic evolution and also for knowing the existence of the Jurassic Hispanic Corridor, longtime before the “Caribbean Seaway” formed by North and South America continents separation.

Palynological data document a very important unconformity between the basement and Middle Jurassic redbeds in Sabinas and Southeastern sub-basins, also between Liassic rocks and the Middle Jurassic redbeds in Huayacocotla-El Alamar Basin. Only in Tlaxiaco and Tampico-Misantla basins Liassic redbeds gradually change to Middle Jurassic marine tethyan sequence, deposited inside the “Hispanic Corridor”.