The Turks and Caicos Islands are part of a large and impressive carbonate platform built over millions of years. Cave systems and sinkholes are found throughout this limestone structure and are formed as a result of chemical dissolution of the limestone when:
Rainwater percolates downward through the rock on its way to the water table.
The fresh and saltwater meet and form a boundary or mixing layer.
This manifests itself in the Turks and Caicos as open sub-aerial cave systems, vertical deep sub-aqueous sinkholes (blue holes), and horizontal sub-aqueous passages. These caverns formed during the lower sea levels stands of the Pleistocene epoch when the Caicos Bank was completely exposed and the annual rainfall was higher than today.
The caves, when exposed to air, can form all variety of dripstone features, which are collectively called speleothems. Water, rich in calcium carbonate, drips through the roof of the cave or along the sides of the tunnel wall or cavern. In the cave air some of the carbon dioxide in the solution is lost and the calcium carbonate is deposited, on the roof (stalacite), the floor (stalagmite), or the wall (curtain). The red or orange tinge is due to the presence of iron oxides derived from the rock or soil above.
Exploration & study
Some variety of cave or sinkholes is found on all the islands and cays in the Turks and Caicos. The Caicos Caves Project, of which the owner of Amphibious Adventures is a founding member, has been exploring the caves of the Turks and Caicos Islands since 1999. Their main focus has been in exploring the underwater caves systems but some of these are located beneath the dry cave systems found primarily on the larger islands. Underwater passages are often tidal and exhibit a large range of tidal flow.
Examples of above water caves (sub-aerial):
1)Village and Indian caves near Conch Bar on Middle Caicos2)Airport cave on Providenciales (small)
Examples of underwater/flooded caves and blue holes (sub-aqueous):
1)Tunnels in Lake Catherine on West Caicos.2)Cottage Pond and Thomas Hill Pond on North Caicos.3)Village caves and boiling holes on Middle Caicos.4)Cathedral cave on East Caicos.5)The ‘Boiling Hole’ on South Caicos
6)South Creek on Salt Cay
Many of the caves are delicate in nature and protected by law in the Turks and Caicos Islands. Do not touch any ‘live’ speleothems as the grease on your fingers will hinder the deposition of calcium carbonate. The ‘dormant’ features are also easily broken and great care should be taken when viewing them and moving around the cave. It is mandatory that you enter any cave with a local guide and first seek permission from the Department of Environmental and Coastal Resources (DECR) and/or the Turks and Caicos National Trust. The underwater sections of the caves are extremely hazardous; nobody should enter these caves without adequate training and equipment. It is highly recommended to seek advise from either Amphibious Adventures or the Caicos Caves Project before attempting to do so. For more information on the geology and location of the caves in the TCI please contact Amphibious Adventures
“255ft into Cottage Pond” by Mark Parrish is an account of a diving expedition to reach the bottom of this deep blue hole on North Caicos.
The caves of the Turks and Caicos have a fascinating history. They were first used by the Lucayan (or Taino) Indians and many artefacts and some petroglyphs have been found in the caves on Middle and East Caicos. Even human remains, believed to be those of these early inhabitants, have been found in an underwater cave system in the Caicos Islands.
Read “Talking Taino” By Dr Bill Keegan and Dr Betsy Carlson for more information.
Much later, in the 19th century, the caves on Middle and East Caicos were extensively mined for bat guano. This proved to be a very nutritious fertilizer and was used on the sugar plantations in Jamaica.There is plenty of evidence of these operations including pumping equipment found in a cave on East Caicos.
There is more information on the history of the caves in H.E.Sadler’s comprehensive history book on the Turks and Caicos, ‘Turk's Island Landfall’.