HOMININ ACTIVITY AND PLUVIAL EVENTS AT DAKHLEH OASIS, EGYPT: ESR DATING HERBIVORE TEETH FROM THE WESTERN DESERT

In Egypt’s hyperarid Western Desert, artesian spring deposits, buried soils, and lake sediment, such as the calcareous silty sediment (CSS), all show that Dakhleh Oasis had surface water during Quaternary pluvial periods. Paleolithic artefacts, including from ESA, MSA, LSA, and later industries, fossil ungulate teeth and snails occur within the Pleistocene deposits and dot the associated desert surfaces. In two basins formed after 250-300 ka in the late Middle Pleistocene, a paleolake with a maximum area of > 60 km²existed. In places, the lake bed thicknesses exceeded 10 m. Where standing water, herbivores, and their food exist, hominins are likely also present.

South of Deir el Hagar Tenple at Bir Taleta, mid Holocene deposits, mainly the Masara sand, form much of the surface, but latest Quaternary erosion has exposed the underlying Palaeolake Kellis Red Mud, and in places, the red Cretaceous Mut Fm. red shale, and Tarif Fm. sandstone, thus deflating the heavier clasts from these layers plus the Romano-Byzantine soils to create the surface lag. Mammalian tooth fragments and Pleistocene artefacts assigned to the Younger Middle Stone Age sit in blowouts. Middle Pleistocene skeletal remains include Gazella, Phacochoerus, Loxodonta africana, Hippopotamus, Pelorovis antiquus, Syncerus, Felis lybica, while Late Quaternary bovids, equids, and other mammals also occur. From Bir Taleta, more than 50 herbivore tooth fragments have been independently dated with ESR using time-averaged cosmic and sedimentary dose rates. Their age distribution shows that herbivores lived in the area briefly in early Oxygen Isotope Stage (OIS) 3, and for prolonged times in OIS 1, 5c-e, 6c, 7a, and 7c. ESR snail ages suggest freshwater also existed in OIS 2. During at least seven periods during the later Quaternary, therefore, higher rainfall, hydraulic heads, and/or groundwater tables made the area more habitable than today for herbivores, and thus, likely also for hominins.