THE RELIABILITY OF URANIUM-SERIES MOLLUSK DATES FROM THE WESTERN MEDITERRANEAN BASIN

Fossil mollusc shells from western Mediterranean raised beach deposits have been dated using U-series techniques. Sub-sampling has allowed i ntra-shell isotopic variability to be assessed. Although most of the c alculated ages appear plausible and some internal consistency exists, closer scrutiny of the data reveals that the shells have behaved as ge ochemically open systems and all the ages therefore must be considered suspect. Some previously published U-series mollusc data from the sam e region may also contain evidence of open system behaviour and are co nsidered equally unreliable. Simple modelling suggests considerable va riation in isotopic uptake behaviour both within and between shells. C opyright (C) 1996 Elsevier Science Ltd