Landscape evolution of the Five Islands of south Louisiana: scientific policy and salt dome utilization and management

The Five Islands of south central Louisiana are piercement-type salt domes uplifted from several kilometers depth as the surrounding strata experiences regional subsidence. In general, the domes are nearly circular in plan with maximum land surface elevations 23–52 m asl. Geomorphic evidence of salt-induced uplift includes surface lineations, aligned gullies, excessively steep land surface topography, and shear fractures in surficial sediments. Evidence of subsidence includes sinkhole ponds a few hectares in area, broad topographic saddles over tens of hectares in size, and kilometer-scale collapse structures.