Possible methods for dating

In many places, the geological preconditions for fossilized human remains are connected with sites of archeological discoveries proving previous human presence or even settlement. That is why frequently sites of significant paleoanthropological finds are also highly important in terms of archeology. Not least, such in-site combinations facilitate the dating and the cultural-historical assignation of the respective paleoanthropological observations.

Moreover, the calcareous deposits mentioned above enable not only the preservation of human skeletal remains but also of comparable animal records. The paleozoological investigation of skeletal parts proving previous micro- and macromammals, as well as the determination and examination of fossil shells providing evidence of former mollusks or ostracods, contribute to biostratigra-phical datings and paleoecological assessments. In particular, the investigation of mollusk remains is of special validity in Central and Western Europe, since there the precise species determination has been achieved, merely based on conchylia or even their fragments (Lozek 1955, 1964). Moreover, comparable methods of dating are also in preparation in other parts of Eurasia (actually Meng 2007).

However, the investigations of micromammals as well as of mollusks are not restricted to qualitative records. On the contrary, both categories of fossils provide the chance for quantitative analysis and statistical consolidation of the results. Moreover, the examinations permit the reconstruction of faunal assemblages as a basis for the paleoecological interpretation (Rousseau 1990). To such an extent, they contribute to the characterization of the natural environment surrounding previous mankind.

In travertines, frequently the paleozoological record is completed by leaf imprints and incrustations of various plant structures, contributing both to the dating of sites and to their paleoecological characterization.

In sequences of peat and limnic layers of mud or marl, the pollen analysis frequently offers an adequate method for dating. Altogether, paleobotany supports the dating of fossil human remains as well as the reconstruction of the paleoenvironment, especially in the case of travertine and bog sites.

However, all the mentioned paleontological and archeological procedures and observations contribute to relative chronology of sites, whereas the numerical or calendar chronology covering the whole time-span of fossil hominids requires another methodical approach. As a rule, the search for more or less precise dates, both in the geosciences and in archeological disciplines, is focused on so-called absolute chronology. However, already during the early 1980s, the paleontologist Jaeger (1981) claimed that this term is erroneous and—strictly speaking—inadmissible, since this term assumes the existence of absolute time, which is a physical and philosophical nonsense.

Independent of this terminological aspect, this calendar chronology of fossil hominids is mainly based on physical procedures, as summarized ao by Geyh (1980,1983) and by Wagner (1995,1998). Thepreferred methods are provided by radiometry (14C, Uranium series, 40K/40Ar ao) and luminescence procedures (TL, OSL, IR-RF). In addition, the last 10-12 ka is within the reach of the botanical method of dendrochronology, but in practical terms this is restricted to wooden objects. Consequently, paleoanthropological finds can be dated by means of this method in close connection with preserved wood only. In Central Europe, the range of oak chronology provides "a high-resolution time scale for nearby the last 12000 years'' (Spurk et al. 1998 p 1114).

However, the preservation of wood as a rule is subject to the same prerequisites as mentioned above with regard to soft parts of human bodies.

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