Changes in ware-decoration associations in ceramic assemblages from Wacheqsa, Chavín de Huántar, Peru

Ceramic differentiation can involve altered associations among continuing attributes without wholesale categorical replacement. At Wacheqsa, Chavín de Huántar, Peru, this study compares ware composition, decorative techniques, and their associations in 1,308 decorated or surface-treated sherd observations from five archaeological contexts. Early Platforms and Water Flood constitute the earlier Urabarroid aggregate; Stone Rooms, Midden, and Late Platforms constitute the later Janabarroid aggregate. These labels describe ceramic affinities within pre-existing context sets, whose stratigraphic networks are only partly connected and whose formation histories differ. On identical common support of nine wares and six techniques (n = 334/822), ware-margin Hellinger distance is 0.430 (95% fixed-count interval 0.392-0.481), technique-margin distance is 0.588 (0.551-0.634), and joint distance is 0.734 (0.714-0.793). A homogeneous-association model rejects a common ware-technique association after aggregate-specific margins are fitted (G2 = 118.59; pboot = 0.0001); the result persists without Midden (G2 = 90.16; pboot = 0.0001). Early Platforms differs from each later context, and stamping/impression is prominent in all three later samples, although those contexts retain distinct joint profiles. Nine of eleven ware categories occur in both aggregates, with pronounced differences in the association of polished wares with incision and stamping/impression. The contrast is consistent with differing decorated repertoires across activity and depositional settings, including contexts associated with collective consumption. Local superpositions and the published chronology support a temporal interpretation, but the contribution of elapsed time cannot be separated from differences in activity and deposition.