Temporal Inflection Points in Decorated Pottery: A Bayesian Refinement of the Late Formative Chronology in the Southern Lake Titicaca Basin, Bolivia

• Published in: Latin American antiquity 2019-12, Vol.30 (4), p.798-817
• Main Authors: Marsh, Erik J., Roddick, Andrew P., Bruno, Maria C., Smith, Scott C., Janusek, John W., Hastorf, Christine A.
• Format: Article
• Language: English
• Subjects: Bayesian analysis; Ceramics; Museums; Time
• ISSN: 1045-6635; 2325-5080
• DOI: 10.1017/laq.2019.73

The Late Formative period immediately precedes the emergence of Tiwanaku, one of the earliest South American states, yet it is one of themost poorly understood periods in the southern Lake Titicaca Basin (Bolivia). In this article, we refine the ceramic chronology of this period with large sets of dates from eight sites, focusing on temporal inflection points in decorated ceramic styles. These points, estimated here by Bayesian models, index specific moments of change: (1) cal AD 120 (60–170, 95% probability): the first deposition of Kalasasaya red-rimmed and zonally incised styles; (2) cal AD 240 (190–340, 95% probability): a tentative estimate of the final deposition of Kalasasaya zonally incised vessels; (3) cal AD 420 (380–470, 95% probability): the final deposition of Kalasasaya red-rimmed vessels; and (4) cal AD 590 (500–660, 95% probability): the first deposition of Tiwanaku Redwares. These four modeled boundaries anchor an updated Late Formative chronology, which includes the Initial Late Formative phase, a newly identified decorative hiatus between the Middle and Late Formative periods. The models place Qeya and transitional vessels between inflection points 3 and 4 based on regionally consistent stratigraphic sequences. Thismore precise chronology will enable researchers to explore the trajectories of other contemporary shifts during this crucial period in Lake Titicaca Basin's prehistory. El período Formativo tardío precede inmediatamente a la emergencia de Tiwanaku, uno de los estados más antiguos de Sudamérica, sin embargo, es una de las épocasmenos comprendidas de la cuenca sur del Lago Titicaca (Bolivia). En este trabajo refinamos la cronología cerámica de este período con amplios conjuntos de fechados de ocho sitios y nos enfocamos en los puntos de inflexión temporales de los estilos de cerámica decorada. Estos puntos, estimados con modelos de Bayes, marcan momentos de cambio específicos: (1) 120 cal dC (60–170, 95% probabilidad): primera deposición de estilosKalasasaya de borde rojo e inciso sectorizado; (2) 240 cal dC (190–340, 95% probabilidad): una estimación tentativa de la deposición final de vasijas de Kalasasaya inciso sectorizado; (3) 420 cal dC (380–470, 95% probabilidad): deposición final de vasijas de Kalasasaya de borde rojo; y (4) 590 cal DC (500–660, 95% probabilidad): primera deposición de los "redwares" tiwanacotos. Estos cuatro límites modelados anclan una cronología actualizada del Formativo tardío que incluye la fase del