Your Ultimate Guide To Barbados

Geology in Barbados

Situated strategically in the Atlantic Ocean to the east of other West Indies islands, Barbados occupies coordinates at Latitude 13º10' N and Longitude 59º 32' W, marking it as the easternmost island in the English Caribbean chain (Lesser Antilles).

The geological formation of Barbados stems from a natural collision between the Atlantic and Caribbean plates. Over approximately one million years, the island emerged through the gradual accumulation of oceanic sediments and periodic tectonic uplifts, wherein the Atlantic plate subducted beneath the Caribbean plate, compelling Barbados to rise.

Barbados' landscape evolved over half a million years, characterized by the gradual emergence of coral reefs in shallow, clear waters surrounding the exposed Barbados ridge. Periodic tectonic uplifts between 500,000 to 120,000 years ago further expanded the island, pushing these reefs above sea level. These former sea reefs now manifest as inland terraces and cliffs visible throughout the island.

The unique geological activity of Barbados also accounts for its numerous caves, notably the renowned Harrison’s Caves. These caves formed over time as rainwater and groundwater eroded underground coral beds. The porous nature of coral limestone bedrock additionally acts as a natural filtration system for rainwater, contributing to Barbados' potable water supply.

Unique Rock Formations in Scotland District, St. Andrew, Barbados Guidebook

Scotland District in St. Andrew is distinguished by its possession of the oldest rock formations on the island. These formations consist of thick-bedded sandstones, coarse grits, bituminous sandstones, shales, dark-grey clays, and mottled clays with ironstone nodules. Folded into numerous flexures and curves, these beds are intersected by several faults, making precise measurement of their total thickness challenging. Approximately 550 to 600 feet of these formations are exposed on the island, though the base remains concealed, precluding exact determination of their complete thickness.

Except for the highlands, the deformed Tertiary strata are overlaid by a sequence of Pleistocene reef terraces that slope downward toward the northern, eastern, and southern coastlines in almost concentric fashion, with younger terraces nearer the coastline. The Upper Reef Terrace predates 600,000 years, while the youngest submerged off the Lower Reef Terrace dates to the Holocene-Recent period. These terraces formed due to tectonic uplift and sea-level changes, resulting in multiple episodes of relative sea-level decline.