Archaic and Formative Period Obsidian Exchange on the coast of Guerrero, Mexico


Long-distance trade of obsidian formed an essential part of inter-regional Archaic and Formative Period Mesoamerican economies (~3,500 BC-AD 250). We analyzed obsidian artifacts (n=522) from Late Archaic through Late Formative Period deposits at the sites of Puerto Marques and La Zanja in the Acapulco Bay region of Guerrero, Mexico using X-ray fluorescence spectrometry to assess the economic importance of different obsidian sources through time. The presence of obsidian artifacts at Puerto Marques indicates that coastal populations in coastal Guerrero joined developing exchange networks by at least 3,500 BC. Highland Mexican obsidian sources dominate the assemblages at both sites with Otumba (Estado de México) emerging as the primary source used during the Late Archaic Period (3,500-1,600 BC). Ucareo-Zinapecuaro (Michoacán) predominates during the Early Formative (1,600-1,000 BC) prior to the diversification of obsidian source use in the Middle Formative (1,000-550 BC). The number of sources used in the Late Formative Period (550 BC-AD 250) appears to contract, but our sample is small for this interval. These data contribute to our understanding of early exchange networks that ultimately provided the foundation for the emergence of more complex societies in Mesoamerica.

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Archaic and Formative Period Obsidian Exchange on the coast of Guerrero, Mexico. Richard George, Claire E. Ebert, Sarah B. McClure, Barbara Voorhies, Douglas J. Kennett. Presented at The 80th Annual Meeting of the Society for American Archaeology, San Francisco, California. 2015 ( tDAR id: 398224)

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min long: -107.271; min lat: 12.383 ; max long: -86.353; max lat: 23.08 ;