During the Holocene period, lake basins existed in parts of the Danakil Desert and were supplied either by the Awash River or by ground waters flowing through highly fissured basaltic flows, as determined by the preservation of old shore lines. Calcareous and diatomaceous bottom deposits gave information about lacustrine paleo-environments (isotopic analyses, diatoms). The HoIocene period probably started between 11,000 and 7,000 years ago. The lakes mainly supplied with ground waters (Afrera) exhibited sedimentation. -- AATA