Guy De Mulder

14C DATING OF CREMATED BONES: THE ISSUE OF SAMPLE CONTAMINATION

Recent comparative studies have proven the validity of radiocarbon dates of cremated bones. The issue of sample contamination has, however, been overlooked in most studies. Analyses of cremated bone samples has shown that in some cases, cremated bones are contaminated. This contamination is more distinct near the surface of the bones and depends on the compactness of the cremated bone as well as on the site conditions. δ13C is not a good estimator to discriminate between contaminated and uncontaminated bones. An acetic acid pretreatment is the most appropriate method to clean samples, but it is better to remove the surface and to avoid cremated bones that are not entirely white (cremation temp. <725 °C).

The Carbon Origin of Structural Carbonate in Bone Apatite of Cremated Bones

In order to reveal a possible carbon exchange between carbon dioxide of the fuel and the bone apatite during the cremation process an experiment was set up using fossil fuel. Two setups were constructed, one using natural gas and one using coal. In both experiments, a carbon substitution in the apatite was revealed.

Re-Evaluation of the Late Bronze Age and Early Iron Age Chronology of the Western Belgian Urnfields Based on 14C Dating of Cremated Bones

The urnfields in western Belgium have been studied since the second half of the 20th century. Most of these studies, as well as the excavations themselves, date from before the last quarter of the 20th century, except for the urnfields at Velzeke and Blicquy, which were excavated recently. The chronology of these cemeteries was largely based on typochronological studies of pottery. Other funeral gifts, like bronze objects in the graves, are rather exceptional. The typochronology was worked out in a comparison with the framework of neighboring regions and central Europe. There was a need, then, for a chronology based on absolute dates. This was only possible by radiocarbon dating of the cremated bones. Tests on duplicate samples, like cremated bone in context with charcoal or 2 depositions of cremated bones within 1 urn, have shown that the results are reproducible and that there is no discrepancy between the charcoal and the cremated bone dates. The results of the 14C dating project on the cremated bones of the 2 urnfields at Velzeke and the one at Blicquy are promising. The interpretation of the occupational history of both sites at Velzeke can be revised, and the currently accepted ceramic sequence for this period needs reworking. In addition, the chronological framework of the Late Bronze Age and Early Iron Age is open for discussion. It seems plausible that the urnfield phenomenon starts earlier in western Belgium than previously expected. These dates can also contribute to the discussion about the transition from the Late Bronze Age to the Early Iron Age.

The Impact of Cremated Bone Dating on the Archaeological Chronology of the Low Countries

Since the publication of the first article (Lanting and van der Plicht 2001/2002) about the possibilities of dating cremated bones, the number of dated cremation remains has grown exponentially. The success of this dating technique lies in the fact that an absolute date now can be attributed to archaeological phenomena that previously were only datable indirectly. When archaeological artifacts where present, the cremation burials were dated based on the typology of ceramics and metals. An absolute date could be attributed if charcoal from the pyre were present. Unfortunately, these items were not omnipresent at the burial sites. Consequently, a complete site was dated by means of the few datable burials present. This implies that the internal chronology of the site could not be studied. Furthermore, the typochronology of the ceramics and the metals remains questionable. A series of dating projects on urnfield cemeteries in the Low Countries (northern France, Belgium, and the Netherlands) have shown that the classical chronology of these sites must be revised.

AMS 14C Dating of Balearic Lime Burials

The Balearic quicklime burials of the Iron Age have been radiocarbon dated. Because the bones found are unsuitable for dating, lime was dated using the titration method, with results indicating that in some samples there is still fossil limestone carbonate present, while other samples suffered from recarbonation. Nevertheless, 14C dates on lime and organic matter agree when both are present. The titration method allows calculating a consensus value.

Radiocarbon As A Tool For Modeling The Diachronic Analysis Of The Occupation Phases At The Velzeke Site (Belgium)

The oldest traces of Velzeke go back to the Late Bronze Age and Early Iron Age, followed by a Gallo-Roman settlement and a later medieval village. Although the excavations document the history of the site in general, radiocarbon was used to clarify the successive phases within each feature. The results showed that the ditches at the Roman settlement and the neighboring temple area were already used during the Late Iron Age. The filling up of the ditches could be 14 C correlated to a Gallo-Roman occupation phase. The oldest Christian cemetery at the site of the medieval church predates the construction of an important Carolingian stone building (9th to 10th centuries.). The stratigraphically lowest sediments of the ditches, surrounding the Carolingian church, are synchronous with the latest fill of the Iron Age ditch. According to historical and toponymical sources the area of the Iron Age ditch becomes at that time part of a medieval agricultural field system.