Gebel Akhdar is an elliptical area extending for about 150 miles along the north coast of Libia. It attains a height of more than 2,400 feet and on the north slope shows two escarpments. The escarpments have been previously ascribed either to faulting or marine erosion. On the basis of a detailed study to topographic maps, original observations, and analysis of profiles, it is now shown that the escarpments and the higher parts of the Gebel are mainly the result of marine and subaerial erosion, and have only been partially affected by tectonic movements. The chronology of the late Tertiary history is reconstructed, and various details of the stratigraphy and structure of the area are presented.