New Evidence in the Upper Mississippi Valley for Premississippian Cultural Interaction with the American Bottom

The recovery of anomalous (red-slipped, shell/grog/sandstone-tempered) pottery from three sites in the Upper Mississippi Valley (UMV) prompted a petrographic analysis of thin sections of 21 vessels from these sites. The goal was to evaluate their possible derivation from the American Bottom, the nearest locality where such pottery commonly occurs. Among the 12 UMV vessels tempered with shell (nine red slipped), ten were determined, based on comparisons to thin sections of stylistically similar pottery from the American Bottom, to have essentially identical physical compositions. Additionally, four vessels suspected of being limestone-tempered were determined to have been tempered with a type of sandstone that out-crops only farther south in Illinois and Iowa. Of the three UMV sites, only the Fisher Mounds Site Complex (FMSC) produced the presumed exotic pottery in undisturbed, dated contexts. The petrographic evidence is consistent with the C-14 age and lithic assemblage at FMSC in suggesting an actual influx of people from the American Bottom into the UMV. The time of this influx, the Edelhardt phase of the Emergent Mississippian/Terminal Late Woodland period, ca. cal A.D. 1000-1050, is earlier than previously believed, i.e., precedes the main Mississippian period in the American Bottom.