OBSIDIAN SOURCE CHARACTERIZATION AT LAS COLINAS: SHIFTING EXCHANGE PATTERNS DURING THE HOHOKAM SEDENTARY - CLASSIC TRANSITION

Previous studies of the Hohokam have suggested that obsidian procurement and distribution practices were conducted differently between two subsequent intervals, the Sedentary and Classic periods. In the Sedentary period, obsidian may have changed hands at events associated with the ballcourt ritual. By the Classic period, obsidian is argued to have moved either through an elite-sponsored or kinship-based economy. However, the Sedentary and Classic periods are long temporal intervals, which, when used to describe changes in time, can mask short-term but significant temporal variation. Our research employs a refined dating scheme, standard lithic analysis, and X-ray fluorescence spectrometry on a sample of obsidian from the Hohokam village of Las Colinas to determine: (1) when the change in obsidian exchange patterns actually began, (2) if the transition was an immediate shift or a gradual trend, and more generally (3) the behavioral changes related to the Sedentary to Classic transition. The results of our study suggest that there was not one decisive transition in the obsidian exchange system, but rather changes in the procurement patterns (i.e., frequency and sources) at two different points in time. These shifts in the movement of obsidian were felt at Las Colinas, and perhaps across much of the Hohokam region, and were seemingly related to the demise of the ballcourt network at the end of the middle Sedentary and the later rise of platform mounds during the early Classic period.