The archaeological record is uniquely positioned to inform modern strategies for social adaptation to current and future climate because of its deep time perspective of how a wide range of societies successfully or unsuccessfully adapted to changing environmental conditions. However, archaeological research is rarely incorporated into current debates because the archaeological evidence for human response to environmental change is typically at a scale too large (e.g., subsistence shifts, changing settlement patterns, and migration) for the average person to find meaningful to everyday life. This project takes advantage of a unique opportunity to study localized variation within the archaeological context of the largest pre-Columbian settlement in North America to determine human decision making to changes related to fluctuating water tables at yearly, decadal, semicentennial, and centennial scales. By establishing a chronology of localized variation associated with urban construction history, researchers will address questions about how urban societal response.
Under the direction of Dr. Tristram Kidder, Ms. Caitlin Rankin will study construction chronology and localized environmental sequence at a wetland mound and plaza group within the urban central precinct of the UNESCO World Heritage Site Cahokia Mounds in southern Illinois. The investigators will collect and analyze a continuous series of soil samples taken from mound, sub-mound, plaza, and sub-plaza contexts with a variety of scientific methods including stable carbon isotope analysis, grain size distribution analysis, loss-on-ignition, magnetic susceptibility, and soil micromorphology to determine environmental conditions through time. Archaeological excavations will be conducted at the edge of mounds and within plaza limits to determine the use and construction history of the wetland mound and plaza group. Bayesian statistics will be used to refine a chronology for both environmental and construction history. Investigators will utilize a risk management perspective to address social response by determining if the people of Cahokia invested labor to maintain the space to its original design and function or if they choose to adapt the function and the design of the space to new environmental conditions. This project will provide the data for Ms. Rankin's doctoral dissertation.
