How were the Cayman Islands formed geologically?

The Cayman Islands are geologically significant as the surface outcroppings of a submarine mountain range that stretches northeastward from Belize to Cuba.1

The islands are situated on the boundary between two tectonic plates that are moving in opposite directions, a process that occasionally results in minor seismic tremors. The landmasses themselves are generally low-lying and characterized by ironshore—limestone fringes containing numerous marine fossils—interspersed with sandy beaches and surrounded by coral reefs.2

While the islands are relatively flat, Cayman Brac features a prominent central bluff that makes up the vast majority of its landmass and provides the highest elevation in the territory, rising 140 feet (42 metres) above sea level. The islands are located near the Cayman Trench, a deep submarine trough that separates the Cayman Ridge from the Jamaica Ridge.23