Bahama Banks
TheBahama Banksare the submergedcarbonate platformsthat make up much of theBahamaArchipelago. The term is usually applied in referring to either the Great Bahama Bank aroundAndros Island,or the Little Bahama Bank ofGrand BahamaIsland andGreat Abaco,which are the largest of the platforms, and theCay Sal Banknorth ofCuba.The islands of these banks are politically part of the Bahamas. Other banks are the three banks of theTurks and Caicos Islands,namely the Caicos Bank of theCaicos Islands,the bank of theTurks Islands,and wholly submergedMouchoir Bank.Farther southeast are the equally wholly submergedSilver BankandNavidad Banknorth of theDominican Republic.
Geologic history and structure[edit]
Thelimestonethat comprises the Banks has been accumulating since at least theCretaceousperiod, and perhaps as early as theJurassic;today the total thickness under the Great Bahama Bank is over 4.5 kilometres (2.8 miles).[1]As the limestone was deposited in shallow water, the only way to explain this massive column is to estimate that the entire platform hassubsidedunder its own weight at a rate of roughly 3.6 centimetres (2 inches) per 1,000 years.[1]
The waters of the Bahama Banks are very shallow; on the Great Bahama Bank they are generally no deeper than 25 meters (80 feet).[2] The slopes around them however, such as the border of theTongue of the Oceanin the Great Bahama Bank, are very steep. The Banks were dry land during pastice ages,when sea level was as much as 120 meters (390 feet) lower than at present; the area of the Bahamas today thus represents only a small fraction of their prehistoric extent.[1][2]When they were exposed to theatmosphere,the limestone structure was subjected tochemical weatheringthat created thecavesandsinkholescommon tokarstterrain, resulting in structures likeblue holes.[1]
See also[edit]
- Oolitic Aragonite Sand- largest deposit of oolitic aragonite sand is found on the Bahamas Banks
- Dean's Blue Hole– Deep water-filled sinkhole in the Bahamas
- Geography of the Bahamas
- Ocean bank– A part of the sea which is shallow compared to its surrounding area
References[edit]
- ^abcd"Geomorphology from Space, Chapter 6: Coastal Landforms. Plate C-16, 'Great Bahama Bank'".geoinfo.amu.edu.pl.RetrievedMarch 9,2006.
- ^abStephen K. Boss, "Geological Research on the Great Bahama Bank" (Accessed 3/9/06)Archived2006-02-05 at theWayback Machine
Further reading[edit]
- Agassiz, Alexander (1894).A Reconnoissance of the Bahamas and of the Elevated Reefs of Cuba in the Steam Yacht "Wild Duck", January to April 1893.pp.17–18.OCLC8310508.
- Harris, Paul (Mitch); Diaz, Mara R.; Eberli, Gregor P. (2019). "The Formation and Distribution of Modern Ooids on Great Bahama Bank".Annual Review of Marine Science.11.Annual Reviews:491–516.doi:10.1146/annurev-marine-010318-095251.PMID30089226.
External links[edit]
- European Space Agency:Earth From Space: The Great Bahamas Bank,on http://spaceref, December 20, 2014 11:00 AM[permanent dead link]
