How did the Caribbean Sea floor form from a submarine plateau?

The present-day floor of the Caribbean Sea originated as a submarine plateau composed of unusually thick oceanic crust, which likely formed in the Pacific basin approximately 90 million years ago due to a hot spot now located beneath the Galápagos Islands.12

Between 80 and 60 million years ago, this buoyant plateau arrived at a subduction zone that separated the Pacific basin from the proto-Caribbean gulf. Because the plateau was too buoyant to be subducted, it overrode the proto-Caribbean gulf, carrying the Antilles volcanic arc on its leading edge.2

As the North and South American plates drifted westward, the plateau continued to penetrate the gap between them. This process persisted until the volcanic arc on the plateau's northeastern margin collided with the Bahamas limestone platform between 60 and 35 million years ago, leading to a major reorganization of regional tectonics and the eventual detachment of the Caribbean Plate from the Pacific.12