Papers and Reports


Climate Change and Migration Along a Mississippian Periphery: A Fort Ancient Example

Aaron R. Comstock and Robert A. Cook

American Antiquity (in press)


Archaeologists have long recognized an important relationship between climate change and the trajectory of the Mississippian polity at Cahokia, with twelfth- and thirteenth-century droughts playing a key role in transforming social relationships and the pace of monument construction. This environmental transition may have spurred emigration from Cahokia and surrounding farming communities. This raises the questions: What was the nature of environmental change and cultural transformations on the Mississippian peripheries and where did these Mississippian emigrants go? This paper provides a case study from the Middle Ohio Valley that brings together spatiotemporal patterns in moisture availability between AD 1000 and AD 1300 and new archaeological data from Fort Ancient villages located in southeast Indiana and southwest Ohio that were occupied during this same temporal interval. We suggest that droughts in the American Bottom region pushed Mississippians to less drought-stricken areas such as the Middle Ohio Valley, which experienced concurrent periods of wetness. This pattern builds on a growing body of data suggesting that the movement of individuals and communities played a large role in the process of Mississippianization throughout the midcontinental and southeastern United States.

Early Village Life in Southeastern Indiana: Recent Field Investigations at the Guard Site (12d29)

Robert A. Cook, Aaron R. Comstock, Kristie R. Martin, Jarrod Burks, Wendy Church & Melissa French

Southeastern Archaeology (2015)


Investigations at the Guard site (12D29), located in Dearborn County, Indiana, have provided evidence pertaining to the development of early Fort Ancient villages. Recent geophysical survey and excavations alongside many new radiocarbon dates have allowed for improved understanding of household architecture and intrasite variability. Although some scholars have hypothesized that Middle Fort Ancient villages developed out of small early Fort Ancient hamlets, the Guard site provides explicit evidence for villages early in the Fort Ancient sequence. Guard also contains key Mississippian indicators for interaction, particularly wall-trench architecture and a Ramey knife. These findings demand that we reconceptualize the inception of Fort Ancient villages.

Focusing on the Old Wood Problem: A Response to Hart and Nolan

Robert A. Cook and Aaron R. Comstock

American Antiquity (2015)


Our recent paper demonstrated that radiocarbon assays sampled from wood charcoal were not systematically skewed when compared to non-wood samples from the same site. This suggests that the “old wood” problem may not be quite as problematic in the temperate Middle Ohio Valley as many suspect. In their comment, Hart and Nolan missed our broader point and mischaracterized our findings. Specifically, we did not suggest that our findings apply to the entirety of eastern North America, nor did we make analytical errors. A thorough reading of our paper clearly supports the following rebuttal. Our main point is that scholars should think twice before discarding radiocarbon dates from wood charcoal, for in some contexts they are the most useful means of determining important chronological information. Despite the suggestion to the contrary, “old wood” concerns do form elements of several hygiene protocols, including Nolan’s (2012).


Evaluating the Old Wood Problem in a Temperate Climate: A Fort Ancient Case Study

Robert A. Cook and Aaron R. Comstock

American Antiquity (2014)


Schiffer (1986) first identified the old wood problem for wood charcoal-based dates from archaeological contexts in the American Southwest. The potential for dates to be skewed toward excessively old calendar ages in this region has recently generated reticence in part of the archaeological community towards including wood charcoal dates in general. Some scholars have even begun to cleanse the radiocarbon databases of regions throughout North America, partly with this presumed limitation in mind. However, the issues that contribute to the old wood problem have not been closely examined outside the arid climate of the American Southwest, resulting in some studies excluding hundreds of radiocarbon dates. The present study fills that void by examining the radiocarbon record from four well-dated Fort Ancient sites in southwestern Ohio and southeastern Indiana. Specifically, we test whether or not there are significant differences between wood charcoal and non-wood charcoal assays. Our findings suggest that wood charcoal dates should not be excluded. We explore reasons for this difference in the Eastern Woodlands and propose an ideal dating regime.

Maize, mounds, and the movement of people: isotope analysis of a Mississippian/Fort Ancient region

Robert A. Cook and T. Douglas Price

Journal of Archaeological Science (2015)


The development of farming traditions has long interested archaeologists worldwide. The relationship between this process and human movement has become increasingly well defined in recent years. Here we examine this issue in a case study concerning the longstanding question of the spread of maize agriculture and Mississippian cultural traditions throughout much of the Eastern U.S. Although it has long been common to interpret the spread of Mississippian maize agriculture partially as a result of human migration, there have been very few direct studies of the question. We do so here by analyzing human tooth enamel from burials for 87Sr/86Sr and δ13C. Our results suggest that Fort Ancient societies adopted maize agriculture quickly with high levels of consumption at early sites. The intensity of maize consumption declined over time, however, in contrast to the current model. There is evidence for the presence of non-local individuals at early Fort Ancient sites, particularly Turpin, with the majority likely attributable to neighboring Mississippian regions. These developments occurred at some of the larger Fort Ancient sites by the mouths of the Great and Little Miami Rivers in Ohio where the most abundant evidence for Mississippian house styles and objects is concentrated.

Toward More Continuous and Practical Artifact Analyses: Defining and Learning From Key Dimensions of Fort Ancient Triangular Projectile Points in the Miami Valleys

Robert A. Cook and Aaron R. Comstock

Midcontinental Journal of Archaeology (2014)

Artifact typologies are routinely created, debated, and modified, but too rarely is the goal to focus on small geographic regions and to define key axes of variation. Our goal is to further this practice by examining the utility of a long-standing artifact typology from the U.S. Midwest, one associated with discerning temporal changes in triangular projectile-point forms. Our samples are derived from nine well-dated Fort Ancient villages along the Great and Little Miami Rivers of southwest Ohio and southeast Indiana. Our approach statistically explores numeric and nominal measurements of projectile-point morphology. Findings reveal significant differences among formal variables that are consistent with most of the typology as recently amended by other researchers. However, by focusing on numeric variables, we also have found that there are a series of additional significant temporal changes. Collectively, we identify a series of distinctions in temporal, morphological, and geographical variation among triangular projectile points. Various hypotheses are discussed regarding cultural transmission of the observed changes in projectile points.