29 July 1966
Vol 153, Issue 3735

About The Cover

The sea as a builder constructed these limestone ridges in the Great Bahama Bank. Over countless years the precipitation of chemicals in the water and the drifting down of the shells and skeletons of minute lime-bearing marine organisms created deposits which solidified into sedimentary rock. The ridges, shown here at high tide, are covered with sand and mud and creased with ripple marks formed by currents. The channels across the banks are 10 to 15 feet deep. See page 560.[Fritz Goro-Life ©, Time Inc.]