Temper mixture models and assessing ceramic complexity in the emerging Tarascan state

► We identify ceramic compositional groups from a 1500-year prehispanic sequence. ► Compositional diversity increases differentially through time at different sites. ► We model volcanic materials as temper in the construction of compositional groups. ► Volcanic ash structures the compositional groups. ► Ceramic production is decentralized but discreet ash resources move in the Basin.