In this Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER)
image the features that look like folded material are
calcium carbonate (a mineral composed of calcium, carbon, and oxygen) sand
dunes in the shallow waters of Tarpum Bay, southwest of
Eleuthera Island in the Bahamas. The sand making up the dunes comes from
the erosion of limestone coral reefs, and has been shaped into dunes by
ocean currents. The image was acquired on May 12, 2002 and the large image covers an
area of 28.2 x 46.1 km.