Red cedar, white oak, an bluestem grass: The colors of Mississippian construction

Midcontinental Journal of Archaeology, Fall 2002 by Simon, Mary L

ABSTRACT

Archaeobotanists have identified wooden timbers from 27 burned Mississippian-period structures located across the American Bottom of southwestern Illinois. These timbers provide information on the types of wood used for residential and nonresidential buildings located in different environments. Timber types from different structure contexts, in turn, provide data on cultural aspects of construction material selection relating to material availability, functionality, and symbolism. All three factors were important and interrelated. Mississippian builders clearly considered and used different raw materials for residences and nonresidences. Wood selection also varied with the status level of the occupant, the user, or the building itself, particularly with respect to exotic woods. Consistent with the Mississippian-period community model proposed by Emerson, exotic wood symbolism did not extend into all aspects of ritual. Finally, the culturally mediated selection process changed through time, coincident with changes in social organization that characterized the late Mississippian period.

Over the past 20 years, the rapidly growing archaeobotanical data set from prehistoric sites in the American Bottom of southwestern Illinois has greatly expanded our understanding of human-plant relationships in the region. Understandably, much of the interpretive effort has centered on issues of prehistoric subsistence. not only answering questions about what was eaten but also addressing the cultural context of consumption (for summaries, see Hastorf and Johannessen 1994; Johannessen 1984a, 1993a, 1993b; Lopinot 1992, 1994, 1997; Parker and Simon 1994). Because researchers have focused their analyses on plant domestication and cultivation, questions related to wood use have received less attention.

When addressed, wood charcoal analyses tend to focus on ecological or environmentally based questions. Analysts have traditionally interpreted wood charcoal as reflecting locally available deadwood used as fuel for heating, cooking, and processing fires (e.g., Asch and Asch 1986). This interpretation is useful for modeling prehistoric vegetation and human use patterns in specific environments, although wood residues clearly do not provide comprehensive woody community samples. Although prehistoric people obviously used wood for many purposes other than fuel, in only a few special cases can these functions be determined.

Timbers from burned structures are such a special case. Excavations of numerous burned structures in the American Bottom provide evidence of the types of wood used for construction in a variety of contexts. Many of the logs are large enough not only to permit taxon identification but also to evaluate age and size. As we answer the question "What was used?" we can begin to address the more interesting question "Why were these particular materials selected?"

As a first step in answering this question, I compared wood types from Mississippian-period burned structures in the American Bottom (Figure 1) to evaluate patterns in structural wood use across space and through time. The Stirling (cal A.D. 1100-1200), Moorehead (A.D. 1200-1275), and Sand Prairie (A.D. 1275-- 1350) phases (Bareis and Porter 1984; calibrated dates follow Hall 1991) provide the temporal framework for this study. This time span covers the florescence of the Cahokian polity and the subsequent social and cultural realignment. A search of existing records has produced no clear evidence for earlier Lohmann phase (ca. A.D. 1050-1100) burned structures, although structures dating to that phase abound.

How wood use changed with the decline in the Cahokian power base and realignment of Mississippian society was examined in terms of three important selection factors: availability, functionality, and symbolism (McGuire and Schiffer 1983). Intermediate analysis was directed toward answering four questions: (1) what types of wood were used in different environmental settings, particularly as defined by the commonly applied upland/floodplain model (see, for example, Johannessen 1984a; Lopinot and Woods 1993; Parker 2001; Parker and Simon 1994)? (2) what types of wood were used for functionally different types of structures? (3) how were woods with symbolic associations incorporated into structures? and (4) did certain wood types serve more than one function?

The Wood Data Set

The Mississippian-period burned structure data base from the American Bottom is substantial. For the period spanning cal A.D. 1100 to A.D. 1350, we have information from 27 burned structures at 13 sites (subsuming Tract 15A and House 4 structures under "Cahokia") located in a variety of landscapes (Figure 1). The data base comprises both residential and nonresidential structures; among the latter are purported storage facilities, temples, and sweat lodges. Structures dating to the Stirling phase are most numerous; the Moorehead and Sand Prairie phases are less well represented.

Summary information for American Bottom burned structures is presented in Table 1. As the table shows, the primary wood types used through time and across space are fairly consistent. Missing from the listing are rapidly growing shrubby invasive or edge species such as sassafras, pawpaw, hawthorn, and mulberry-even as secondary construction elements. Given the large population and high level of deforestation postulated for the American Bottom (Lopinot and Woods 1993; Pauketat and Lopinot 1997), we might predict that such wood types were increasingly available and utilized through time. This does not seem to have been the case.