Caves and Karst of Barbados

Abstract

The island of Barbados is composed of a series of stepped Pleistocene carbonate terraces that overlie Oligocene-Miocene chalk that is draped over deformed deep-sea clastics of Eocene age, the result of Quaternary sea-level fluctuations combined with tectonic uplift. The island is pervasively karstified, as shown by well over 100 caves, hundreds of gullies, and more than 2,800 sinkholes. Barbados has five types of cave: (1) epigene caves formed by fresh-water dissolution; (2) flank margin caves formed by mixing-zone dissolution; (3) littoral caves formed by marine corrasion; (4) ‘mechanical caves’ formed by mass movement of bedrock; and (5) hybrid (polygenetic) caves that formed when an initial cave type and morphology was overprinted by another cave-forming process. Epigene caves are found in the upland interior of the island, yet stream sinks are rare and most springs occur along the coast. Flank margin caves are found on the modern and paleo-coastlines, and along many of the gullies. Calcite speleothems are developed almost exclusively in these two types of caves. Littoral and mechanical caves occur on the modern coastlines. However, the majority of the island’s caves are of the hybrid variety. Flank margin caves are the most common cave type converted to the hybrid or polygenetic state, as they are readily breached and modified by cliff retreat and littoral processes.

The caves of Barbados have been important to humans from the earliest times of inhabitation of the island. When the sugar cane industry wasat its height, caves served as storage and as hideouts for escaped slaves. In modern times most caves on Barbados remain undeveloped, except for Animal Flower Cave at the north coast and Harrison’s Cave in the highlands, which are developed for tourism. In 2007, the collapse of a large cave in the densely populated capital Bridgetown cost a family of five their lives.