Dating techniques in anthropology

The ratios of 14C/13C in the target samples and in standard samples made from, NBS oxalic acid were made in the manner described by Donahue et al. the ages given in TABLE 1 are radiocarbon ages calculated from 14C half-life of 5568 years, and the uncertainties are standard deviations of the average of several measurements of each quantity.The measurements were not corrected for variation in 13C/12C ratios.The stone artefacts at the sites are characterized by an abundance of Ouchtate bladelets, which sometimes make up over 80% of the retouched tools, occasional, well-made burins (often on Levallois flakes), scaled pieces, notches, denticulates and truncations.Flotation could not be used for plant recovery because most of the remains were extremely fragile and disintegrated on contact with water.

The use of grinders to make tubers more digestible would be a logical intermediate step on the way to eating wild grass seeds.Such corrections would not change the results by more than 25 years.The results thus confirm that the charred Cyperus tubers were contemporaneous with the Late Palaeolithic occupations.The idea that cereals and dates had been important components of the Late Palaeolithic economy of Wadi Kubbaniya was therefore abandoned (Wendorf et al. Although we are still unable to agree on how apparently undisturbed archaeological horizons were contaminated by relatively modern plant materials, this experience demonstrates that we must be extremely cautious in evaluating the association of isolated plant fragments with archaeological contexts.

At the very least, all such materials found outside their expected areal or temporal ranges should be subjected to direct (AMS) dating, and many of those within their expected ranges should also be dated (Harris 1986; 1987; Legge 1986).

The processing includes roasting, crushing, grinding and perhaps leaching to eliminate the toxins and to make the fibre more digestible.