Mapping the Internal Structure of Hopewell Tumuli in the Lower Illinois River Valley through Archaeological Geophysics

Archaeologists from the Center for American Archeology (CAA) in Kampsville, Illinois, are engaged in a program to test the potential for ground-penetrating radar (GPR) and electrical resistance tomography (ERT) to effectively document the internal structure of a variety of Middle (ca.2200–1550 B.P.) and Late Woodland (ca.1550–950 B.P.) mounds in the Lower Illinois River Valley (LIV). This project, embedded within ongoing CAA regional research efforts and the Arizona State University Kampsville Field School, demonstrates that both GPR and ERT permit the identification and measurement of significant internal mound structures. Key structural elements can be confidently identified in the geophysical data from the five test mounds, and excavation results can be conclusively linked with results of excavation in mounds that have been tested. This study opens the way for the development of a set of procedures for a regional research initiative in the LIV to understand structural variation between Middle and Late Woodland mounds using ground-based remote sensing methods as a primary source of data and thus minimizing invasive and destructive investigation techniques.