The origin of objects of invertebrate descent from the Khvalynsk Eneolithic cemeteries (Northern Caspian region)

The summary of the study of invertebrates used for decorative items from Khvalynsk Eneolithic Cemeteries is presented. AMS radiocarbon dating confirmed that freshwater Unio mother-of-pearl shells and nacre discs, manufactured from them, are coeval with the site and most likely local in origin. Tubes of the sea worms and marine shells are fossil and some may originate from local deposits. Other are probably related to the ancient Paratethys basin sediments and can have diverse origin spanning from Caucasus and Caspian shores to Carpathian and Mediterranean area. Glycymeris L. clams are most likely originated in the latter area. The discussion of the obtained AMS 14C results agrees with a possibility of a noticeable ingress of younger carbon, irremovable by standard methods and affecting the determinations, probably related to a bacterial activity in deposits.