Bahama Banks

The Bahama Banks are a group of carbonate platforms that make up the base for the largest part of the archipelago of the Bahamas. They consist of the Great Bahama Bank around Andros Iceland in the north, the Little Bahama Bank, the largest of the individual platforms to Grand Bahama and Abaco Cay Sal Bank and in the west just north of Cuba. The islands of these platforms are politically part of the Bahamas. Next to the southeast lie outside the closed distribution platform isolated occurrence, as the Turks and Caicos Islands - especially the Caicos Bank of the Caicos Islands, the Turks Islands Bank and the completely submerged Mouchoir Bank - and still further to the southwest, the also completely under water lying Silver Bank and Navidad Bank north of the Dominican Republic.

Geological history and structure

The limestone from which the Banks are built, was deposited at least since the Cretaceous, possibly as early as the Jurassic. Today, the thickness of the limestone is under the Great Bahama Bank, more than 4,500 meters. Since the limestone was deposited in shallow water, this large thickness can be explained only by constantly dropping. From the thickness and age of the limestone in a mean reduction of 3.6 centimeters per 1,000 years calculated.

The waters of the Bahama Banks are very shallow, on the Great Bahama Bank generally no deeper than 25 meters. The slopes at its edges, such as the Tongue of the Ocean, the ocean trench in the Great Bahama Bank, are very steep. During the last ice age, the Bahama Banks were fully dry because of low global sea level stand. Today Bahamas are therefore only part of the then-existing islands. When the Banks of the Earth's atmosphere were exposed, subject to the limestones of their typical chemical weathering, leading to karst features such as caves and swallow holes. Similar to today's Central America also emerged Blue Holes.