Potential for14C Dating of Biogenic Carbonate in Hackberry (Celtis) Endocarps

Abstract
Hackberry endocarp (Celtissp.) contains significant amounts (up to 70 wt%) of biogenic carbonate that is nearly pure aragonite (CaCO3). Because of their high mineral content, hackberry endocarps are found abundantly in Tertiary and Quaternary sediments and are very common in many North American archaeological sites. We analyzed the14C content of different components of modern hackberries including the biogenic carbonate in hackberry endocarps collected at known times over the past century. The14C content of the endocarp carbonate accurately records the14C content of the atmosphere.14C dates of fossil endocarp carbonates compared favorably with dates obtained by other means at archaeological and geological sites ranging in age from the late Pleistocene through the early Holocene. We therefore suggest that hackberry endocarp is a suitable substrate for14C dating provided that its morphological and mineralogical integrity is preserved.