Samuel E. Munoz, Kristine E. Gruley, Ashtin Massie, David A. Fike, Sissel Schroeder, and John W. Williams
    2015    Cahokia’s emergence and decline coincided with shifts of flood frequency on the Mississippi River. Proceedings of the National Academy of Science 112(20):6319–6324.


Our paper evaluates the role that flooding played in the emergence and decline of Cahokia—the largest prehistoric settlement in the Americas north of Mexico that emerged in the floodplain of the Mississippi River around A.D. 1050. We use sediment cores to examine the timing of major Mississippi River floods over the last 1,800 y. These data show that Cahokia emerged during a period of reduced megaflood frequency associated with heightened aridity across midcontinental North America, and that its decline and abandonment followed the return of large floods. We conclude that shifts in flood frequency and magnitude facilitated both the formation and the breakdown of Cahokia and may be important factors in the declines of other early agricultural societies.


Here we establish the timing of major flood events of the central Mississippi River over the last 1,800 y, using floodwater sediments deposited in two floodplain lakes. Shifts in the frequency of high-magnitude floods are mediated by moisture availability over midcontinental North America and correspond to the emergence and decline of Cahokia—a major late prehistoric settlement in the Mississippi River floodplain. The absence of large floods from A.D. 600 to A.D. 1200 facilitated agricultural intensification, population growth, and settlement expansion across the floodplain that are associated with the emergence of Cahokia as a regional center around A.D. 1050. The return of large floods after A.D. 1200, driven by waning midcontinental aridity, marks the onset of sociopolitical reorganization and depopulation that culminate in the abandonment of Cahokia and the surrounding region by A.D. 1350. Shifts in the frequency and magnitude of flooding may be an underappreciated but critical factor in the formation and dissolution of social complexity in early agricultural societies.

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Dussubieux, Laure and Heather Walder
    2015    Identifying American native and European smelted coppers with pXRF: a case study of artifacts from the Upper Great Lakes region. Journal of Archaeological Science 59:169-178.

In North America, it is critical for archaeologists to differentiate between American native copper and European smelted copper. Indeed, native copper, a rather pure metal, was not smelted in this region, unlike European copper objects that later became available to Native Americans during trading encounters. Until now, archaeologists with a low budget wishing to use a totally non-invasive approach have relied on visual inspection and archaeological contextualization of the objects to distinguish American native copper from European smelted copper. This paper assesses the reliability of portable x-ray fluorescence (pXRF) as a fast, effective, and completely non-destructive method of differentiating the two types of copper present at Northern American sites through a case study of two sites from the Upper Great Lakes region. To establish group attribution with pXRF, results obtained on a subset of objects with LA-ICP-MS are used. Results indicate that for the specific purpose of differentiation between native and European copper types, pXRF can be used reliably, without sample preparation and despite surface corrosion. Therefore, pXRF provides a non-destructive way to clarify European trade item distribution and continuity of native copper object use among Indigenous peoples of North America during the colonial period.

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Munoz, Samuel E, David J Mladenoff, Sissel Schroeder, and John W Williams
    2014    Defining the Spatial Patterns of Historical Land Use Associated with the Indigenous Societies of Eastern North America. Journal of Biogeography 41(12):2195–2210.

Aim To review and synthesize multiple lines of evidence that describe the spatial patterns of land use associated with prehistoric and early historical Native American societies in eastern North America in order to better characterize the type, spatial extent and temporal persistence of past land use.

Location Temperate forests of eastern North America, and the Eastern Wood- lands cultural region.

Methods Ethnohistorical accounts, archaeological data, historical land surveys and palaeoecological records describing indigenous forms of silviculture and agriculture were evaluated across scales ranging from local (100 km) to regional (102 km) to produce a synthetic description of land-use characteristics.

Results Indigenous land-use practices created patches of distinct ecological conditions within a heterogeneous mosaic of ecosystem types. At all scales, patch location was dynamic, and patches underwent recurrent periods of expansion, contraction and abandonment. Land-use patches varied in their extent and persistence, and are broadly categorized as silvicultural (management of undomesticated woodland taxa) or agricultural (cultivation of domesticated taxa). Silvicultural patches persisted for centuries and extended kilometres to tens of kilometres around settlements and travel corridors. The dynamics of agricultural patches varied among groups, with persistence ranging from decades to centuries and extent ranging from less than a kilometre to tens of kilometres around settlements. Beyond patch boundaries, human impacts on ecosystems become indistinguishable from other drivers of environmental heterogeneity. These characteristics of patches are evident across scales and multiple lines of evidence.

Main conclusions Our findings challenge the view that prehistoric human impacts on vegetation were widespread and ubiquitous, and build on previous work showing these impacts to be more localized and heterogeneous by providing quantitative descriptions of land-use patch characteristics. Collaborative efforts that combine multiple data sources are needed to refine these descriptions and generate more precise measures of land-use pattern to further investigate the history of human impacts on the Earth system.

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Walder, Heather
    2013    Stylistic and Chemical Investigation of Turqoise-Blue Glass Artifacts from the Contact Era of Wisconsin. Midcontinental Journal of Archaeology 38(1):119-142

Typologically and visually similar glass trade beads, found on many archaeological sites of Native and French interaction in Wisconsin dating to the seventeenth and eighteenth centuries, often vary in chemical composition. These chemical differences likely indicate both fluctuating technological processes in European glass "recipes" and changes related to suppliers of trade goods to North America. To investigate regional differences among bead compositions, 87 turquoise-blue glass beads and 2 remelted glass pendants from five different seventeenth-century and early-to-mid-eighteenth-century sites in present-day Wisconsin were analyzed nondestructively using Laser Ablation–Inductively Coupled Plasma–Mass Spectrometry (LA-ICP-MS). The different glass recipes can be divided into chemical subgroups that reflect both the chronological period assigned to the archaeological site and the geographic proximity of sites. The analysis reveals details about the exchange of trade goods and the dynamic population movements that are characteristic of this period of interaction among locally indigenous groups, Native newcomers to the region, and arriving Europeans.

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Schroeder, Sissel
    2011    An investigation of the origins of variation in perishable architecture at Jonathan Creek. Southeastern Archaeology 30(2):311–336

The Jonathan Creek site in Kentucky was excavated in the early 1940s in an effort to uncover the community plan of an entire Mississippian town and mound center. Although the project terminated prematurely, the remnants of 89 structures representing a diverse array of architectural foundation styles were documented. Quantitative and qualitative analyses of multiple attributes, such as posthole diameter and spacing, wall-trench width and depth, roof supports, and floor area, are necessary to adequately parse the variation in architectural style, construct inferences about the above- ground appearance of buildings, and suggest origins for the diverse construction methods used at the site. At least some of the distinctive differences in foundation preparation would have resulted in diversity in the appearance of finished buildings. Time is not wholly adequate to explain this diversity. Technological and functional choices made by the ancient builders account for some of this variation, while social, genealogical, and ethnic differences, and possibly distinctive ritual customs and traditions among the resi- dents, explain other sources of variation.

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Schroeder, Sissel
    2006    Walls as Symbols of Political, Economic, and Military Might. In Leadership and Polity in Mississippian Society, edited by Brian M. Butler and Paul D. Welch, pp. 115-141. Center for Archaeological Investigations, Southern Illinois University, Carbondale

During the eleventh century A.D., the frequency with which stout walls were constructed around settlements began to increase across the Eastern Woodlands. While some of the large Mississippian mound sites in the Southeast and southern Midwest were protected with substantial enclosures studded with bastions, other mound sites lacked these features. Typically associated with warfare, such walls reflect vertical integration involving regional elites as they vied for adherents, struggled to establish and maintain alliances, cultivated and enhanced the sanctity of chiefly office, and attempt- ed to augment their prestige and expand their spheres of influence through the use of coercive force and the construction of monuments; the walls also manifest horizontal forms of integration involving followers and allies who weighed the benefits and costs associated with a loss of autonomy in such a contentious social landscape. The implications of village fortification for the ascent, attrition, transformation, and eventual dissolution of chiefly power are explored using a case example from the lower Tennessee River valley in western Kentucky.

Schroeder, Sissel
    2004    Current Research on Late Precontact Societies of the Midcontinental United StatesJournal of Archaeological Research 12(4):311-372.

Research during the past decade on Late Precontact societies (ca. A.D. 1000– 1600/1700) in the Midcontinent, particularly Mississippian, Oneota, Fort Ancient, and Late Woodland, is strongly rooted in empirical approaches. While some of this work is pursued within a broadly evolutionary interpretive framework, other scholars emphasize agency and practice theory, symbolism, the historically contingent nature of human action, and cultural heterogeneity in sociopolitical organization, political economy, and subsistence. Dynamic models of the settlement systems and demography of complex societies have developed out of the recent growth in site inventories and refinements in ceramic chronologies and have come to be closely linked with theoretical treatments of sociopolitical organization. Various physical and chemical analytical techniques are commonly applied to the analysis of archaeological materials in this region, contributing to our understanding of direct and indirect exchange relationships and other forms of interaction, especially those between hierarchical and nonhierarchically organized societies, and enhancing our understanding of the kinds of foods prepared and eaten by people in the past.