THE PETRALONA HOMINID SITE: URANIUM-SERIES RE-ANALYSIS OF ‘LAYER 10’CALCITE AND ASSSOCIATED PALAEOMAGNETIC ANALYSES

Separate sublayers of the ‘layer 10’calcite from the Mausoleum of Petralona Cave, Greece, have been re-analysed by Uranium-series and palaeomagnetic methods. The results confirm earlier findings that the whole of layer 10 represents a long time span, from about 160 ka to more than 350 ka, the latter being the dating limit of the U-series method using alpha-spectrometry. The minimum age refers to the upper brown sublayer that is now believed to correspond directly to the brown calcite that cemented the hominid skull to the adjacent cave wall; there was too little of the skull calcite to date directly by alpha-spectrometry. The age shifts caused by making corrections for the amount of detritus in the sublayer are effectively insensitive to assumed initial values of the amount of common ²³⁰Th present. Consequently, the minimum age estimate for the skull is about 160 ka, in approximate agreement with several earlier estimates. Palaeomagnetic analyses of ‘layer 10’and underlying sedimentary layers showed that the magnetization is unstable and cannot be used as a basis for age control in the Mausoleum.