CHEMICAL CHARACTERIZATION OF CERAMICS FROM THE ANGEL AND HEATON FARMS SITES OF SOUTHWESTERN IN: POSSIBLE SOURCES OF ELEVATED PHOSPHORUS

Bone tempered ceramics have been identified in the Middle Ohio River Valley (Gerke and Maynard; submitted 2007) and in the American Bottoms region of Missouri (Riley et al., 1988 and 1994). There is no know identification of bone tempered ceramics in the region between these locations. This study provides the first known set of chemical data on ceramics from the Angel and Heaton Farm sites of Indiana which will be utilized to determine if the ceramics have elevated phosphorus reflecting the possible presence of bone. X-ray fluorescence data indicate that SiO2, Na2O, and Co concentrations are higher and TiO2, Al2O3, CaO, K2O, and P2O5 concentrations are lower in the Heaton Farm ceramics compared to the Angel ceramics. Six (n=16; 37.5%) Heaton Farm and 28 (n=40; 70%) Angel ceramics have elevated P2O5 concentrations (>1 wt% P2O5). SEM element mapping, on ceramic fragments, indicates that P2O5 is disseminated throughout the ceramics possibly indicating that very fine ground bone was utilized as temper. Petrographic and additional SEM mapping will confirm this interpretation or determine the source, regardless these results will provide new insights to the ceramic manufacturing techniques employed at the Heaton Farm and Angel sites.