Close to a century ago, archaeologists working in Florida’s Tampa Bay made a discovery that seemed oddly out of place: curious ancient pottery that didn’t seem to match other examples known to the region.
Of key significance was that the shattered remains of these ancient ceramic vessels appeared very similar to pottery associated with the Mississippian culture, an enigmatic prehistoric American cultural group that fundamentally transformed the archaeological landscape across large stretches of southeastern North America.
Yet despite the south being the recognized focus of the Mississippian cultural world, peninsular Florida was traditionally excluded from maps where documented evidence of their presence had been located. So why were artifacts that seemed to resemble their craftsmanship uncovered in the Tampa Bay area nearly a century ago?
Fortunately, newly uncovered microscopic clues within these pottery fragments could finally offer a break in the century-old case.
Microscopic Answers to a Longstanding Mystery
Neill Wallis, the Florida Museum of Natural History’s curator of Florida archaeology, bioarchaeology and the Ceramic Technology Laboratory, says the debate over the unusual pottery that has raged for the last century may finally be over, based on new analysis that suggests skilled ceramic Mississippian craftsmen may not have only migrated to Tampa Bay, but brought examples of their craft with them.
This, according to findings published in American Antiquity, based on an analysis of 58 examples of pottery fragments uncovered from Tampa Bay. The focus of the research had been to trace their origins, and determine whether they were indeed local creations by Mississipian migrants to the area, or if they had been imported from further North.
Both plain pottery and decorated varieties resembling Mississippian motifs were examined, and initial chemical analysis suggested that the pottery was made from clay local to the Tampa Bay region. However, closer microscopic inspection revealed a surprise: based on petrographic analysis under the microscope, close to 80% of the decorated samples contained pieces of older pottery mixed into the newer source clay as temper.
Known as “grog” to archaeologists, this inclusion of broken older pottery in newer creations was a common practice that potters within known Mississippian settlements relied on. By contrast, similar petrographic analysis of the undecorated pottery samples from Tampa Bay revealed no evidence of its use.
A Closer Look at Mississippian “Grog”
Additional clues came from analysis of the grog itself, which revealed the presence of the mineral mica.
Abundant around Florida’s panhandle, this shiny silicate mineral is generally absent in the peninsula area. However, just 200 miles to the north of the area is the closest recognized Mississippian mound site, suggesting that ancient migrants from this area brought their pottery with them when they arrived in Tampa Bay, which was reused for the grog that went into new creations they made using local clay once they settled.
Intriguingly, some of the grog made from imported pottery also featured crushed examples of even older pottery, revealing several generations of ancient Mississippian ceramic use and reuse. Of key significance, this material was exclusively found in the decorated varieties of pottery, which could mean that the practice of reusing older pottery as grog could have a cultural significance, as opposed to merely utilitarian purposes.
The way the pottery was crafted also bore significance, since the decorated samples were found to have been made using a Mississippian technique which assembles vessels from coils of clay. The ordinary, undecorated samples were more simply crafted and tempered with dryer materials such as sand.
Highly Specialized Skills in a New Land
Altogether, the new insights into this ancient ceramic mystery help researchers establish a deeper understanding of how ancient migrants carried ceramic skills and traditional practices with them as they moved into new areas.
The discoveries also shed new light on past evidence that suggested ancient Tampa Bay residents 1,000 years ago seemed engage in practices that bore similarity to the Mississippian way of life well characterized at sites farther to the North. These include the creation of ceremonial mounds, use of symbolic motifs, and even agricultural practices.
“We ultimately argue that these patterns materialized through a form of public secrecy, whereby migrants established decorated vessel crafting as a skill set to be seen and valued, if not fully understood, by host communities,” the study’s authors write.
The research was detailed in the new study, “Secret Recipes: Potting Knowledge and Migration in Mississippian (ca. AD 1000–1600) Tampa Bay, Florida, USA,” By C. Trevor Duke, et al, which appeared in American Antiquity.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.