Problems of Dating Human Bones from the Iron Gates
Cook, G. T., Bonsall, C., Hedges, R. E. M., McSweeney, K., Boroneant, V., Bartosiewicz, L., Pettitt, P. B., Antiquity
In studies of the Iron Gates Stone Age (FIGURE 1) there is considerable conflict between the archaeological phasing of sites and radiocarbon dating-based chronologies derived from measurements made on charcoal and human bone samples. For example, at Lepenski Vir, Srejovic (1972) identified five occupation phases: Proto-Lepenski Vir, Lepenski Vir I, II, IIIa and IIIb. Phases I and II were assigned to the Mesolithic, while phases IIIa and IIIb, by virtue of the presence of both pottery and bones of domesticated animals, were assigned to the Early Neolithic. However, a series of charcoal samples from contexts associated with houses from the Mesolithic (phases I and II) produced [sup.14]C ages between 6560 and 7360 BP (Quitta 1972), similar to those for Early Neolithic (Starcevo-Koros-Cris) sites in the surrounding regions. Srejovic (1972; 1989) rejected these [sup.14]C ages as approximately 500 years too young, while other researchers (Voytek & Tringham 1989; Chapman 1992; Radovanovic 1996) have accepted them and interpret Lepenski Vir I and II as representing the latest phases of the Mesolithic in the Iron Gates region. Their view is that the gorge was rich in natural resources but not immediately attractive to farming, and therefore continued to be occupied by hunter--gatherer communities. A further hypothesis was proposed by Milisauskas (1978), namely that the structures comprising Lepenski Vir I and II were the remains of houses built by a sedentary farming community that had dug the foundations into earlier hunter--gatherer deposits, thereby producing a mix of materials from Mesolithic and Early Neolithic occupations. Subsequent AMS dating of human remains assigned to the later phase III of Lepenski Vir produced ages between 6910 and 7770 BP which puts them out of sequence with the charcoal samples assigned to phases I and II (Bonsall et al. 1997). At Vlasac, three phases of Mesolithic occupation (Vlasac I-III) and traces of Early Neolithic settlement (Vlasac IV) were designated (Srejovic & Letica 1978; Prinz 1987). At this site, a series of 15 [sup.14]C age measurements made on charcoal samples assigned to phases I-III produced an age range of 6790 [+ or -] 100 BP to 7935 [+ or -] 60 BP, while human bone samples from phases I and III produced ages between 8000 [+ or -] 100 BP and 10,240 [+ or -] 120 BP (Bonsall et al. 1997). At Schela Cladovei, in areas excavated by Boroneant, evidence of two Mesolithic phases (Schela Cladovei I and II) and at least two phases of Early Neolithic settlement were recognised (Boroneant 1970; 1973; 1989; 1990). Here, a similar pattern is observed, although on a much more limited data set. [sup.14]C age measurements on charcoal samples from hearth deposits assigned to the second Mesolithic phase produced ages of 8150 [+ or -] 80 BP and 7580 [+ or -] 90 BP while a series of measurements made on human bones from the Mesolithic produced an age range of 8290 [+ or -] 105 BP to 8570 [+ or -] 105 BP (Bonsall et al. 1997).
[FIGURE 1 OMITTED]
Leaving aside the documented difficulties in attributing burials to different occupational phases, e.g. at Vlasac (Srejovic & Letica 1978) or suggestions of incorrect phasing of burials, e.g. at Lepenski Vir (Bonsall et al. 1997), the very obvious trend in these data is that the age range for the human bone samples is always somewhat earlier than the range for the charcoals that were derived from either earlier contexts or contexts that are contemporary with the human bones. Even if the samples were contemporary in context, it is normally expected that either
i the charcoal samples will produce similar [sup.14]C ages if short-lived species and/or roundwood were specifically selected for measurement, or
ii they will produce older ages because of the inclusion of long-lived species (old wood effect), or
iii they will produce older ages because of the inclusion of timber that had been used previously for a significant period of time for construction or similar purposes, prior to burning. …