The sea is located on the Caribbean lithospheric plate and, being one of the largest marine transition zone, separated from the ocean by several different ages island arcs. The youngest of them passes through the Lesser Antilles from the Virgin Islands in the north-east to the island of Trinidad off the coast of Venezuela. This arc was formed in the collision Caribbean plate with the South American plate and includes active and extinct volcanoes, such as the Montagne Pele, Kiel, and Volcanoes National Park, Morne Trois Pitons. The larger islands in the northern part of the Sea (Cuba, Haiti, Jamaica, Puerto Rico) is based on the older island arc to the north of which has already been formed and submaterikovaya continental crust. The arc from south of Cuba, expressed the mountains of Sierra Maestra to the Cayman underwater ridge and trough of the same name, also on the young. In the Cayman Trench is the deepest known points of the Caribbean - 7686 m below sea level.
Geological age of the Caribbean Sea with certainty is not installed. It is assumed that the ancient protokaribsky pool existed in the Devonian period. In the Early Carboniferous, as the movement of Gondwana to the north and its rapprochement with Euramerica, pool decreased in size and graduated from there in the Middle Carboniferous. The next stage of formation of the modern Caribbean began in the Triassic. Powerful rifting led to the formation of narrow depressions, stretching from present-day Newfoundland to the western coast of the Gulf of Mexico, which formed terrigenous marine sediments.
In the Early Jurassic as a result of a powerful transgression water Neotetisa broke into the region of the modern Gulf of Mexico, creating a vast shallow pool here. The emergence of deep hollows Caribbean occurred in the era of Middle Jurassic rifting. The appearance of these basins marked the beginning of the disclosure of the Atlantic Ocean and contributed to degradation of Pangaea II at the end of the Late Jurassic. During the Cretaceous Caribbean acquired the outlines of which are close to modern. In the early Paleogene, as a result of powerful regression Sea Caribbean Sea was separated from the Gulf of Mexico and the Atlantic section of land formed by the islands of Cuba and Haiti, and raised over low land areas. In such a situation the inland Caribbean stayed most of the Cenozoic until the Holocene, when the rising water level of the oceans to recover a message Caribbean Sea with the Atlantic Ocean.
The bottom of the Caribbean crust is composed suboceanic and filled with sediment - a red clay deep in the deep hollows and trenches, calcareous foraminifer silt at elevations and slabomargantsovistymi calcareous oozes on the ridges and continental slopes. Clay minerals are likely to have been handed down from the continent by rivers Orinoco and Magdalena. Sediment on the bottom of the Caribbean Sea and Gulf of Mexico have a thickness of about 1 km. The upper sedimentary layers relate to the period of the Mesozoic to the Cenozoic period (250 million years ago - present), and the lower - to the Paleozoic and Mesozoic. In the process of accumulation of sediment is divided into three phases, with the first two took place without deformation of the Caribbean plate. During the first phase of the Central American Sea (Caribbean Sea and Gulf of Mexico), probably separated from the Atlantic Ocean by the end of the second phase of the small displacement and deformation led to the formation of ridges Aves, and Beate. Isthmus of Panama and the Antilles island arc formed by the impact of vertical forces, with no horizontal displacement. The thickness of the sediment decreases from the center of the basin to the land, although the layers formed during the Cenozoic (past 65 million years), mostly flat, as were formed after the outbreak strain. Straits into the Pacific Ocean occurred in the Cretaceous period (144-65 million years ago), but in the Miocene and Pliocene of North and South American land bridge formed.
West Indies are part of the Antilles, the Caribbean Region of the folded geosynclinal belt of the Cordillera, keeping high volcanic and seismic activity. The latter is particularly observed in just north of Puerto Rico and the Virgin Islands, Puerto Rico Trench. Studies show that in 1670 in the region occurred 13 earthquakes with a magnitude over 7.0, and scientists do not exclude the possibility of a tsunami.