PALEORIENT vol.6 1980 PROBLEMS OF ABSOLUTE CHRONOLOGY IN PROTOHISTORIC MESOPOTAMIA WRIGHT

Introduction

Though scholars are seeking to answer increasingly precise questions about ancient Mesopotamian econo mic and political developments the chronological frame of reference which they must use is not significantly more precise than it was forty years ago(l This di lemma has been recently emphasized by James Mel- laart He begins his argument with reconsiderations of the evidence and reasoning supporting both the Egyptian and Mesopotamian earlier dynastic chronolo gies proposing that for both sequences much earlier datings are defensible He then considers the carbon 14 age determinations corrected to approximate actual ca- lendrical dates from Mesopotamia Anatolia Egypt and the Levant These datings he argues also support much older absolute chronology for protohistoric south west Asia proposal will be criticized by many specialists It is my purpose here to look critically at the archaeological use of carbon 14 age determinations from greater Mesopotamian sites of the early fourth to early third millennia B.C. in an effort to suggest ways of improving our absolute chronology from this limited region It is evident that the available determinations contra dict one another as they do everywhere There are four possible solutions to this problem Disregard all Carbon 14 age determinations This is throwing out the baby with bathwater Discard those determinations which do not fit current chronological preconceptions This cons titutes undesirable circular reasoning Pool all determinations on samples from given cultural unit presuming that anomalous dates will can cel each other out or alternatively pool all dates which meet certain statistical criteria of homogeneity Such approaches do not fully utilize knowledge of the sources of error and of the differing quality and context of the various samples Extract age estimates from sets of determinations based on processing rules established by prior logic similar to that suggested by Waterbolk Such pro cedure rigorously pursued may have the disadvantage of leaving one with very few datings for the period of interest We can construct processing rules of Mesopotamian samples by considering the specific factors which would distort radiocarbon age determinations in such an envi ronment The following are possible factors arranged in the order in which they would affect the sample The sample may be significantly older than its date of deposition In the arid Near East wood decays slowly and can easily be reutilized it may not be burned and incorporated in the archaeological record until long after it was originally cut Furthermore be cause many species of trees in such an environment grow very slowly the inner wood of tree trunk can be centuries older than the actual date of its cutting Speci fic identification and evaluation of carbonized material by an ethnobotanist is useful safeguard against such distortion but such examination is rarely sought by archaeologists The sample may be mixed with carbon significan tly older than the material one is intending to date common material in Mesopotamian archaeological sites is bitumen It was often dropped in hearths in the

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