DATING HUMAN FOSSILS WITH MINIMUM DAMAGE

Dating studies on palaoeanthropological sites are usually carried out on material associated with the human remains, such as the sediment, charcoal or other fauna rather than the human specimen itself. The reason lies in the fact that most dating techniques are destructive and because the hominid remains are too rare to be sacrificed for dating. This indirect dating approach is in many cases not satisfactory, because:

(i) the human remains are often buried into the sediments and the association with other materials is uncertain (e.g. Border Cave, Skhul, etc.);

(ii) faunal remains or minerals from the sediment are re-worked from older deposits (see e.g. present discussion of the age of the Homo erectus remains in Indonesia);

(iii) the hominid specimen was discovered at a time when no careful excavations were carried out and it is impossible to correlate the specimen with other datable material (which applies to a very large percentage of all palaeoanthropological specimen).

Until recently, hominid fossils could only be dated by radiocarbon. This method reaches back to about 40,000 years. As a consequence, all the older fossils could not be analysed and many important questions in our understanding of human evolution could not be addressed.

Human remains are scarce and extremely valuable, therefore any sort of destruction has to be kept to an absolute minimum. This is of particular importance in Australia where any human fossils are sacred. Thus, for the analysis of hominid material it was necessary to develop a more or less non-destructive techniques. This has been accomplished in recent years by the combining ESR and laser ablation ICP-MS analyses of tooth enamel. The examples of Border Cave 5 and the Cave of Hearths are used to illustrate the potential of these methods in palaeoanthropology.