Five Islands

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From: Allrefer.com, 2003; AAPG, 2003; Explore French Louisiana, 2003
The Five Islands can be found rising above the flat Louisiana Gulf coast about 225 km from New Orleans in Louisiana. The islands - Avery, Weeks, Côte Blanche, Belle Isle and Jefferson - are circular topographic prominences from one to two miles in diameter, rising 23 meters or more above the surrounding marshlands. Avery Island stands the highest at 46 meters above sea level and is well noted for its bird sanctuaries, gardens and cayenne pepper production. The islands are famous for salt, oil and gas production and are notable tourist attractions.

Community Structure

The islands are copiously vegetated and support a rich wildlife, including the Louisiana black bear and nutria imported from South America. Tropical gardens have been cultivated on Jefferson and Avery islands, and the latter is home to the world-famous Tabasco sauce and also houses a rare-bird sanctuary and exotic tropical plants.

Geological Characterization
The Five Islands have been known to sit atop a deposit of solid rock salt thought to be deeper than Mt. Everest’s height. Geologists believe this deposit is the remnant of a buried ancient seabed, pushed to the surface by the sheer weight of surrounding alluvial sediments. Geologists believe these mysterious elevations were created when a saltwater ocean covering what is now Texas, Louisiana and Mississippi evaporated, leaving behind a vast sheet of salt. The salt was formed in a narrow sea that existed during an early stage in the breakup of the supercontinent Pangea, more than 200 million years ago. Over time this salt layer was covered by thousands of feet of alluvial sediment, the pressure of which pushed numerous salt domes straight up. In five places these domes actually pushed up the topography.
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