Production origins and matrix constituents of spiculate pottery in Florida, USA: Defining ubiquitous St Johns ware by LA-ICP-MS and XRD

Abstract Fine-grained “chalky” pottery containing microscopic sponge spicules is commonly recovered from archaeological sites throughout peninsular Florida, but many questions remain about its composition and origins. It is identified by different names, but most are associated with the St. Johns Type series. While it has been commonly assumed to originate in the St. Johns River drainage for which it is named, the prevalence of pottery with these characteristics in other locations has presented the likelihood of independent production in multiple places. In this study, we conducted LA-ICP-MS and XRD analysis of spiculate pottery from three Woodland period (ca. 1000 BCE to 1000 CE) sites, along with comparative clay samples, in order to characterize the raw materials and determine the geographic scope of production. Our results support the theory that this ware was independently produced across peninsular Florida. We further evaluate the hypothesis that this pottery was made with common wetland muck, through consideration of the material properties of muck constituents. This project emphasizes the importance of an ecosystem framework for understanding the long history of spiculate pottery production and its geographic spread within Florida.