Severe Little Ice Age drought in the midcontinental United States during the Mississippian abandonment of Cahokia

A severe drought during the Little Ice Age, spanning from 1200 to 1400 CE, is linked to the abandonment of Cahokia, one of the largest pre-Columbian Native American settlements in North America. This finding emerges from a high-resolution oxygen isotope (δ18O) record derived from Horseshoe Lake sediment in Illinois, situated within the Greater Cahokia region. The shift to higher δ18O values during this period indicates persistent low effective moisture conditions, supporting the hypothesis that climate extremes, particularly drought, significantly impacted agriculturally dependent Mississippian cultures. This study not only sheds light on the vulnerability of pre-Columbian societies but also underscores the susceptibility of today's global food production centers in the midcontinental United States to hydroclimate extremes.

Pompeani, D. P., Bird, B. W., Wilson, J. J., Gilhooly, W. P., Hillman, A. L., Finkenbinder, M. S., & Abbott, M. B. (2021). Severe Little Ice Age drought in the midcontinental United States during the Mississippian abandonment of Cahokia. Scientific Reports, 11(1). https://doi.org/10.1038/s41598-021-92900-x