Determining Provenance of Shell-Tempered Pottery from the Central Plains Using Petrography and Oxidation Analysis

Late prehistoric sites on the Central Plains contain both grit/grog- (mineral-) tempered pottery and shell-tempered pottery. This appearance of shell-tempered pottery around cal A.D. 1000 has traditionally been explained as a colonization from the Mississippi River valley with further dispersal via trade. As a result, very little is known about the role of this material in the region. We report the results of a provenance analysis of shell-tempered pottery from seven sites extending from the Missouri River valley to north-central Kansas. We use petrography and oxidation analysis to compare the shell-tempered pottery across these localities and the shell-tempered to the mineral-tempered pottery from each locality, and we compare mineral inclusions and clay characteristics in all pottery with published geological and pedological information for each locality. The results demonstrate that shell-tempered pottery was locally produced throughout at least a portion of the Central Plains. Differences in firing technology are apparent across the study area and may play a role in the distribution of shell-tempered pottery. Two other results are the identification of composite temper in a notable proportion of the sherds studied, and indications of from where on the landscape Central Plains potters were procuring their raw materials.