Academic Bun FIGHT! Questioning Cahokia's Fall Through a Great Flood

Great Flood?  Not the Cause!

Correlation does not equal causation: Questioning the Great Cahokia Flood

Authors:

Baires et al

Abstract:

Munoz et al. (1) present an argument for Cahokia’s demise focusing on a massive flood event ca. A.D. 1200. Although we recognize that a flood event may have occurred, we do not agree with their hypothesis that this event (i) caused the collapse of the largest Pre-Columbian city north of Mexico and (ii) occurred ca. A.D. 1200. Cahokians did not vacate the floodplain until after the mid-14th century, preceded by new communities and social relationships during the 11th to 13th centuries. We suggest the authors reconsider their data in conjunction with the prolific evidence for community persistence and revitalization initiated during the mid-12th century.

Damnit!  Yes, it did!

Reply to Baires et al.: Shifts in Mississippi River flood regime remain a contributing factor to Cahokia’s emergence and decline

Authors:

Munoz et al

Abstract:

Baires et al. (1) critique two aspects of our study (2): (i) whether a large flood event “caused the collapse of the largest Pre-Columbian city north of Mexico,” and (ii) the timing of one flood event (Flood Event V), which we reported to have a 95% confidence interval of A.D. 1100–1260. Instead, Baires et al. suggest Event V occurred during “several wetter periods during the late 13th to 15th centuries.”

To the first point, our paper never attributes Cahokia’s “collapse” to a single flood event. Instead, we show a temporal correspondence among midcontinental aridity, reduced megaflood frequency, and Cahokia’s emergence. We discuss the potential effects of floods on prehistoric populations in the floodplain and conclude that extensive flooding could have temporarily or permanently transformed Cahokia’s sociopolitical system. We note several independent lines of evidence that point to population decreases at Cahokia and the reorganization of its sociopolitical structure around A.D. 1200. We do not argue that Cahokia collapsed at this time, nor do we argue against community persistence after A.D. 1200. Therefore this first critique seems to be based on an oversimplified characterization of the arguments presented in our paper.