Mesozoic Plate Tectonics in the Proto-Caribbean Zone of Interfering North Atlantic - South Atlantic Mantle Stress Fields

Predicted interaction of North and South Atlantic geodynamic stresses in the proto-Caribbean seaway offers new insights into early Gulf of Mexico basin evolution. Euler sums of North America to Africa and South America to Africa rotation poles provide Yucatan to North America rotation geometries that explain Yucatan microplate – proto-Caribbean seaway paleogeography and the distribution of sedimentary and volcanic rocks. According to this view, seafloor spreading in the western Gulf Basin attains a relatively slow maximum spreading rate of ca. 1.2 cm/yr toward the end of the Barremian ca. 125 MaBP, coincident with the commencement of spreading between South America and Africa. Seafloor creation in the western Gulf appears to be associated with back-arc spreading behind a Greater Antillean arc-trench system characterized by west-dipping subduction of proto-Caribbean crust. Thick basin margin sediments accumulate in the nascent western Gulf Basin, asymmetrically loading salt deposited in an antecedent Callovian rift system, ca. 160 Ma BP. Resulting salt-lubricated detachments cover much of the newly formed oceanic crust with large allochthons of pre-drift strata. It is arguable that slow but significant seafloor spreading persists in the western Gulf of Mexico through the Early Albian, ca. 109-102 Ma BP. Kinematic analysis predicts that most Gulf of Mexico oceanic crust (~60 %) was created during the Early Cretaceous period of stable geomagnetic polarity ca. 125 - 83 Ma BP. The absence of obvious rift-parallel magnetic lineations in the western basin is therefore a predictable element of Gulf evolution. In this view, widespread Late Cretaceous calc-alkaline volcanism in the region is explained by slab detachment corresponding to the cessation of Greater Antillean arc-subduction. Complicated Caribbean strike-slip tectonics in the Cenozoic later shear Greater Antillean arc terranes off the eastern margin of the Yucatan microplate, transporting them northeastward to create the exotic Cretaceous arc rock terranes of Cuba.