Preliminary analyses of fruits, seeds and few plant macrofossils from the Early Holocene sequence.

Large amounts of well-preserved seeds and fruits, together with other macrofossils, were found in the archaeological layers of the Uan Tabu rock shelter. They gave interesting information on the human behaviour and the cultural knowledge on plants by the hunter-gatherers who inhabited the Tadrart Acacus mountains during the Early Holocene. Twenty soil samples of known volume were dry sieved, and seeds and fruits were studied. A total of 9218 records, among which Gramineae were 88%, were counted. Altogether, Paniceae, mainly Brachiaria and Urochloa, and Boraginaceae characterized carpological spectra. Seed and fruit concentrations ranged from a minimum of 2 records per 6 liters, found in sample MS19/Layer 21, to a maximum of 3337 sf/6l = 557 sf/l (3647 records / 6l if twigs of tamerices were included), found in sample MS1/Layer 3. Combining floristic list and concentrations, four carpological zones were distinguished. The earlier zone dated back to the Pleistocene and do not include plant accumulations. The other three zones dated to the Early Holocene (9800-8600 years bp) and corresponded to different environmental and cultural contexts, in which the hunter-gatherers lived. In particular, an extensive and diversified use of plants was observed in the Late Acacus cultural phase (8800-8600 years bp) during which not only food, but also medicinal and votive uses, could be inferred from plant accumulations. Evidence of both a cultural knowledge of plants in the area and the transmission of this knowledge to next generations was inferred on the basis of the distribution of plant material in the deposit of Uan Tabu, and by comparing plant macrofossils from other sites in the Tadrart Acacus.