Revistes Catalanes amb Accés Obert (RACO)

Arguments for and against the Pacific origin of the Caribbean Plate: discussion, finding for an inter-American origin

Keith James

Resum


Arguments in support of the Pacific origin for the Caribbean Plate are discussed along with others that point to an inter-American origin. Entry of a Pacific-derived plate would have involved unlikely, geometrically complex and highly diachronous events. They would have included changes in direction of subduction, changes in direction of plate migration, major (1000s of km) plate migration, major rotation of large parts of a volcanic arc, major rotations of the Maya and Chortis blocks and diachronous development of flysch/wildflysch deposits as the entering plate interacted with neighbouring elements. The internal structural conformity of the Caribbean Plate and of the Maya and Chortis blocks with regional geology of Middle America shows that no major migrations or rotations have occurred. Coeval, regional deposits of Albian shallow water limestones, Paleocene– Middle Eocene flysch/wildflysch deposits, Middle Eocene limestones, and a regional Late Eocene hiatus show an inter-American location, not a changing Pacific-Caribbean location. Neogene displacement of the Caribbean relative to North and South America amounts to no more than 300 km.

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