CHEMICAL-COMPOSITION AND SAMPLE PREPARATION OF ARCHAEOLOGICAL WOOD FOR RADIOCARBON DATING

The chemical composition of wood from archaeological sites differs fro m that of modem wood. The chemical changes depend on the microenvironm ent of the surrounding matrix more than the time of preservation. Chem ical treatment of decomposed wood results in a great loss of initial m aterial. The degree of wood decomposition should be taken into account in the preparation of samples for C-14 dating. The main fraction of a rchaeological decomposed wood is a degraded lignin, with most cellulos e totally decomposed. Nevertheless, decomposed wood can be a reliable material for C-14 dating archaeological sites. Loss of material throug h sample preparation can be reduced by using fairly weak concentration s of chemical reagents without influencing the reliability of the date s.