Abstract

Tectonic interactions in the Caribbean region are driven by two main processes: eastward motion of the Caribbean plate relative to North and South America, with subduction of Atlantic oceanic crust toward the west; and subduction of the Cocos and Nazca plates along the Mexico–middle America trench. This geometry has been maintained since the Eocene. Prior to this, the Caribbean plate entered the space between North and South America (the “proto-Caribbean”) from the Pacific causing polarity reversal of the arc (the Great Arc of the Caribbean) that separated the Pacific–Farallon plates from the proto-Caribbean. This latter region of oceanic crust was created by seafloor spreading between North and South America that started in the Early Jurassic; included in this early motion was the opening of the Gulf of Mexico by independent motion of Yucatan. Although this overall tectonic scheme has been well established for some time, only one quantitative plate model has been published before. This chapter updates that with a larger set of plate polygons and tectonic features in GIS format, along with a set of Euler poles that describe motion of about 350 tectonic elements, which make up the Caribbean and surrounding plates. Constraints on quantitative motions of these blocks comes almost entirely from geologic and geophysical data and a large database compilation of previous work from the Caribbean Basins, Tectonics, and Hydrocarbons and the PLATES consortia; the only well-constrained plate motion vectors come from seafloor spreading magnetic isochrons that record motion between North America and Africa, and between Africa and South America. A less-reliable magnetic chron data set is used to constrain post-Eocene motion of the Caribbean plate along the Cayman Trough. Geologic data used to constrain motion of the smaller blocks include stratigraphy, geochronology, structural mapping, and potential field data. The motion of individual blocks is adjusted until all these data combine to allow for a uniform progression of motion that honors local data as well as interactions among neighboring blocks.