Culture and Ecology of Chaco Canyon and the San Juan Basin

- -- - ----~----The NPS Chaco Project 17some disagreement still remains (Windes 1993:297-304). Some discrepancies could be specific to ChacoCanyon (e.g., a local magnetic distortion or unusualsoil chemistry), because samples from other sitesaround the San Juan Basin do not exhibit thesedeviations (Windes 1980).Other New Chronometric Techniques. Inhis evaluation of dating techniques, Windes (1987[I))found that radiocarbon dates may be affected byfluctuations in the atmosphere; some that should datearound A.D. 1000 were recorded as A.D. 1500, whilesome that should be from A.D. 1250 registered aroundA.D. 400 and 900. A pilot study of eight sherdssubmitted for thermoluminescence dating providedresults that suggested that this method had potentialfor future use. Before obsidian hydration providesgood results, sources of obsidian must be determined.Ceramic Chronology. Past studies of Chacoceramics resulted in two different descriptive series(Hawley 1934, 1936, 1939; Roberts 1927), whichwere later merged by Gordon Vivian (1959, 1965).As noted above, several problems remained, especiallythe place of McElmo Black-on-white in the Chacoceramic series. Windes (1985) recognized that someceramic types in the Chaco series of Cibola WhiteWares were probably made in the canyon, but mostceramic types (including non-Cibolan types that werepart of the assemblage) were produced elsewhere. Hepaid particular attention to Chaco-McElmo Black-onwhiteceramics, a type that has a short temporal spanand reflects affinity with Black Mesa, Sosi, Toadlena,Nava, and McElmo black-on-white types. By usingKYST, a multidimensional scaling software program,he was able to obtain finer temporal placement for theceramic types at Pueblo Alto (Windes 1987[I]:253-269) and 29SJ629 (Windes 1993:333). Based oninitial studies of temper materials by A. HeleneWarren (1976, 1977), and through the analyses ofWindes, Peter J. McKenna, and H. Wolcott Toll, wenow have a well-dated sequence of pottery types withmore detailed descriptions for the Chaco series (H.Toll and McKenna 1997:Appendix A; Windes andMcKenna 1989).These chronometric studies allow colleaguesworking throughout the region to better understandtheir advantages and disadvantages. The results ofthese and the refined ceramic descriptions have beenused to compare data among other communities andevaluate links between communities and events inmore recent models of social organization (e.g.,Marshall et al. 1979; Powers et al. 1983). Tables inAppendix B correlate the various chronologicalschemes used by Chaco Project personnel.Sourcing of Materials. Objects obtained fromlong distances indicate interaction between groups orsharing of resource areas. By the 1970s, sourcing ofsome artifact types involved cooperation withgeologists, chemists, and other technicians who weredeveloping methods, such as trace element studies.This section will discuss a number of such studies andindicate their potential value.Geologists identified a number of source areasfor lithic materials throughout New Mexico. Warrendeveloped a standard four-digit code for materials shecollected (Warren 1967, 1979). D. Love (1997a,1997b) updated and expanded on this code forsilicified materials in and around the Chaco area.Warren's analysis of ceramics, which includedpetrographic studies (Warren 1976, 1977, 1980),identified rock inclusions from a number of sources.Because Warren had worked on a number of projectsfor the Laboratory of Anthropology of the Museum ofNew Mexico and the Office of Contract Archeology atthe University of New Mexico, the adoption of hercoding system by a number of analysts made itpossible to compare percentages of imports at varioussites and during different periods to monitor changesin the transport of these materials across space andthrough time. During the Chaco Project, Warren'scodes were used in the classification of material typesduring studies of ceramics (H. Toll and McKenna1997); chipped stone (Cameron 1997b); andornaments (Mathien 1997). It was possible todetermine that interaction among Pueblo peoples wasstrongest to the south during the Early Bonito phaseand was most heavily tied to the Chuska Mountainsduring the Classic Bonito phase, and that it shiftedtoward the northern San Juan region during the LateBonito phase (Cameron 1997b; H. Toll and McKenna1997).T race element studies carried out using a numberof techniques became part of the analytical tool kit andadded to the more rigorous scientific approach inarchaeology at that time. X-ray fluorescence of 665