The Geology of Grand Bahama

Grand Bahama is composed mainly of oolitic limestone. Paradoxically it is a land created in and by the sea since much of the oolite, which is the main substance of the island, was formed by chemical means underwater on the Bank. This process is continuing today.

The island is generally flat with a maximum elevation of about 50 feet. Under most of the island there is a freshwater lens that ensures a good supply of fresh water. Ridges and small outcroppings of rock known as ‘hammocks’ were formed in antiquity by the action of the wind piling up the oolite and shell detritus. This higher land clearly shows the action of the sea when it rose to about 25 feet above its present level some 100,000 years ago. The sea level fell in the last Ice Age by approximately 300 feet rising to its present level about 10,000 years ago.