The Drying of the Garat Ouda lake (SW Fezzan, Central Sahara): A Dramatic Effect of the Middle Holocene Climatic Change on Landscape and Human Occupation
by
Andrea Zerboni
Dipartimento di Scienze della Terra "A. Desio", Università degli Studi di Milano, via Mangiagalli 34, 20133 Milano, Italy
Coauthors: Mauro Cremaschi, Chiara Pizzi

During the Wet Holocene (11--5 Kyr BP) a lateral branch of the wadi Tanezzuft (SW Fezzan, Central Sahara) fed a wide (more than 80 Km2) delta-lake system in the area of Garat Ouda. The delta was composed by several meandering palaeo-channels (evident in high resolution Ikonos satellite imagery) and was densely settled by human communities. The archaeological record in the area is very rich and it consists of fireplaces, lithics, pottery, grinding equipments and animal bones (wild animals, cattle and fishes); the archaeological evidences are systematically distributed along the Northern lake shoreline (Mesolithic sites) and along the palaeo-channels (Pastoral sites). The abundance of findings testifies that throughout the Holocene the delta-lake system was constantly attended by the Mesolithic and Early to Middle Pastoral communities.

At 5 Kyr BP, after several millennia of activity and human frequentation, the Garat Ouda basin suffered a heavy crisis and rapidly dried out. The abrupt decrease in water reservoirs was due to the drop in Monsoonal rainfall supply to the Central Sahara: the result was the dramatic contraction of the course of the wadi Tanezzuft and the extinction of its lateral branch. As confirmed by a detailed field survey and by several radiocarbon and TL dating, after that dry event no human occupation is recorded in the area of Garat Ouda: Late Pastoral sites consist of scarce scattered fireplaces, very poor in archaeological material, and they are not related to the palaeo-channels system.

Date received: July 21, 2005

Copyright © 2005 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # caqy-44.