CRETACEOUS TECTONIC EVOLUTION OF MEXICO (Invited Presentation)

The geological evolution of Mexico during the Jurassic was dominated, by the rift of the Gulf of Mexico that originated extensional basins, and large lateral faults, and by subduction and supra-subduction rifting in the west. Active extension in the Gulf of Mexico ceased at the end of the Jurassic, and the Arperos back-arc oceanic basin was formed in central-west Mexico. Transtensional tectonics continued during early Cretaceous in southern Mexico, due to separation of South and North America.

East central Mexico was covered by Berriasian-Cenomanian calcareous platforms. Clastic sedimentation dominated in southern Mexico, followed by Aptian to Cenomanian calcareous platforms.

Most authors agree that east-dipping subduction was continuous in western Mexico throughout the Cretaceous (and Jurassic), originating the Alisitos, Vizcaíno and Guerrero Composite terranes of western Mexico. This subduction zone experienced a series of changes in the overriding plate stress field. Previously, three major tectonic stages were identified in the Guerrero Composite terrane, but new mapping and geochronological data suggest that there were more tectonic events.

The Jurassic silicic arc (Volcanic Arc I, VA-I), evolved to early Cretaceous (130-120 Ma) mafic volcanic arc (VA-II), coeval to the Arperos back-arc basin. Those rocks were deformed and partially metamorphosed previous to deposition of VA-III. Metamorphic rocks in the Puerto Vallarta area (Bissig et al., 2008; Schaff, 2020), mylonitic fabrics in Jurassic intrusives of Arteaga area, and Ar/Ar ages of ~ 118–112 Ma from metamorphosed Arperos-basin rocks (Martini et al., 2023), indicate a regional deformational event associated to the closure of the Arperos basin previous or during Aptian time.

Aptian-Cenomanian volcanic rocks, and limestone platforms unconformably covered VA-III. This volcanic arc is in part coeval to the Alisitos arc. This VA-III was in turn folded and trusted over eastern Mexico. A new continental arc VA-IV was unconformably deposit over folded VA-III. This Santonian-Maastrichtian arc (VA-IV) was coeval to deformation and foreland basin sedimentation of the mayor contractional event that originated the Sierra Madre Oriental Fold and Thrust Belt in eastern Mexico.

It is distinctive that Cretaceous rocks in Mexico contain rudist reefs, and detrital zircon inherited signatures of Gondwana affinity.