Barbados Geology

Unlike most islands in this part of the world, Barbados is not a volcanic island. Instead, it is an outcrop of the northern Barbados accretionary prism – formed by the ~3cm/year westerly and northwesterly underthrusting of the Caribbean plate by Atlantic oceanic crust (DeMets et al., 1990, and Dixon et al, 1998). Barbados is the only part of this acccretionary prism that is subaerially exposed.

There are two types of rocks exposed on Barbados: fossilized coral reefs and complexly folded and faulted bedded marine sedimentary rocks (pelagic shales, sandstones, and siltstones' ash layers, chalks, and radiolarites). The bedded strata are older than and underlie the reef strata.

The reef strata, which range in age from ~600,000 to Holocene, outcrop as a series of terraces that formed in response to tectonic and eustatic sea-level changes.

The paleoreefs are well exposed and easy to examine.

These photos are from the same boulder (fallen from the adjacent terrace):

Unconformities are well exposed in the terraced paleoreefs:

Barbados also produces hydrocarbon. This oil field (the only one on the island) produces approximately 1000 barrels per day. The Barbados National Oil Company ships the oil to Trinidad for refining and then brought back to Barbados for local use. The island produces about 10% of the fossil fuel it consumes.