A Pleistocene lacustrine episode in southeastern Libya

Fossiliferous lacustrine deposits of middle Pleistocene age have been found in Central Fezzan (Libya) 1 on each side of the east–west depressions of the Wadi Shati, south of the Precambrian Qarqaf anticline 1–8 . They represent the shoreline of a former brackish water lake (Fig. 1) which, some 130,000 yr BP, covered an area about 100km long and 10–20 km wide. At present, the area may be classified as hyperarid. Since 1978, a collaborative study of the fossil assemblages has been undertaken. It included macro- and micropalaeontological determination, Th/U dating, stable isotope and chemical analyses, in parallel with sedimentological and archaeological studies of the sites. Here we consider the Th/U dating and the isotopic palaeohydrology of the lacustrine episode.