Karst thrust island

This small island appeared overnight in a lake in southern Georgia, USA. The region is typified by karst topography, and this island appears to be a ridge of lake bottom sediments thrust upwards along a rotational hinge line created when a collapse sinkhole formed on the lake bottom. See Denizman, C., E.C. Brevik, and J. Doolittle. 2010. Ground-Penetrating Radar Investigation of a Rapidly Developed Small Island in a Lake in Southern Georgia, USA. Journal of Cave and Karst Studies 72(2): 94-99. for more information.