Ucareo obsidian source

Ucareo obsidian source
Name	Ucareo obsidian source
Location	Michoacán, Mexico
Coordinates	19°57′N 101°28′W
Geologic type	Volcanic glass source
Primary mineral	Obsidian
Age	Holocene (Late Pleistocene to Holocene volcanism)
Notable for	Major Mesoamerican obsidian provenance

Ucareo obsidian source The Ucareo obsidian source is a major volcanic glass deposit in Michoacán, Mexico that supplied high-quality obsidian to Mesoamerican societies. It has been central to research by archaeologists, geologists, and museum curators studying exchange systems and lithic technologies associated with cultures such as the Toltec worldview, Tarascan State, Aztec Empire, Maya civilization, and Teotihuacan. Studies of Ucareo link fieldwork, chemical provenience, and museum collections involving institutions like the Smithsonian Institution, Museo Nacional de Antropología (Mexico City), and the Peabody Museum of Archaeology and Ethnology.

Geology and Formation

The deposit sits within the Trans-Mexican Volcanic Belt near the Purépecha Highlands, formed by rhyolitic explosive volcanism associated with the Ceboruco volcano-age volcanic fields and regional tectonics linked to the North American Plate and Cocos Plate subduction. Petrologists using methods developed by the United States Geological Survey and laboratories at the Universidad Nacional Autónoma de México have described Ucareo obsidian as high-silica rhyolite glass with phenocrysts and flow banding comparable to deposits studied at Obsidian sources of Jalisco, Pachuca de Soto and Sierra de las Navajas. Geochemical fingerprinting using X-ray fluorescence and neutron activation analysis pioneered by teams associated with the Field Museum of Natural History and the University of Arizona ties compositional suites to specific outcrops near Ucareo (Michoacán), distinguishing them from Otumba obsidian and Ixtlán del Río sources.

Archaeological Significance

Archaeologists have recovered Ucareo-sourced artifacts from contexts spanning Preclassic to Postclassic occupations at sites like Tzintzuntzan, Tula (Tula de Allende), Tenochtitlan, Monte Albán, Chichén Itzá, and Cacaxtla. Excavations by teams affiliated with the Instituto Nacional de Antropología e Historia, the Universidad de Guadalajara, and the University of Cambridge indicate Ucareo obsidian was used for bifaces, prismatic blades, and ritual objects, paralleling use-patterns documented at Copán, Palenque, and Uxmal. Interpretations by scholars influenced by models from the Cambridge Archaeological Journal and comparative studies in works by researchers associated with the British Museum and the Mexican Society of Anthropology emphasize its role in elite consumption, craft specialization, and feasting contexts evidenced in assemblages from Cozumel, Tlatelolco, and Mixco Viejo.

Distribution and Trade Networks

Geochemical provenience studies link Ucareo obsidian to artifact distributions across central and southern Mesoamerica, including finds in the Valley of Oaxaca, the Balsas River basin, and the Maya Lowlands. Trade routes inferred from archaeological mapping intersect with corridors documented in ethnohistoric sources like the Codex Mendoza and trade accounts linked to Bernal Díaz del Castillo and Diego Durán. Networks engaged actors such as the Purépecha people, merchants analogous to the pochteca of the Aztec Empire, and administrative centers comparable to Chalco and Texcoco. Comparative analyses employing network theory developed at the Santa Fe Institute and logistical models from the Max Planck Institute for the Science of Human History situate Ucareo within long-distance exchange alongside commodities like greenstone from the Motagua Valley, jadeite trade linked to Copán, and marine shell from Gulf of Mexico and Pacific Coast procurement zones.

Material Properties and Typology

Ucareo obsidian is characterized by its conchoidal fracture, glassy luster, and color variants ranging from black to dark green and mahogany, features recorded by catalogers at the Natural History Museum, London and the Museo del Templo Mayor. Lithic analysts trained in approaches from the Society for American Archaeology and experimental programs at the Arizona State University classify Ucareo artifacts into typologies including prismatic blade cores, bifacial knives, projectile points, and bead blanks. Use-wear and microwear studies using protocols from the British Institute of Archaeology at Ankara and scanning electron microscopy at facilities such as the Los Alamos National Laboratory reveal cutting, scraping, and hafting traces consistent with craft production at specialized workshops analogous to those documented at Teotihuacan and Cholula.

History of Investigation

Scientific attention to Ucareo intensified during 20th-century surveys by teams associated with the Peabody Museum and the Universidad Michoacana de San Nicolás de Hidalgo, with early chemical provenance efforts led by researchers affiliated to the New Mexico Archaeological Council and the University of California, Berkeley. Landmark publications appeared in journals such as the Journal of Archaeological Science and the Latin American Antiquity with methodological advances credited to analysts from the Max Planck Institute and the University of Oxford. Field mapping and salvage projects coordinated with the Instituto Nacional de Antropología e Historia documented outcrops and quarry features, while collections-based studies at the American Museum of Natural History and the Museo Regional de Michoacán expanded understanding of temporal changes in exploitation.

Conservation and Access

Quarry protection, site stewardship, and access policies involve stakeholders including the Comisión Nacional para el Conocimiento y Uso de la Biodiversidad, municipal authorities of Ucareo (Michoacán), and heritage managers from the Instituto Nacional de Antropología e Historia. Preservation efforts mirror approaches used at other lithic localities like Teotihuacan quarries and rely on legal frameworks enforced by the Secretaría de Cultura (Mexico). Museum loans and research access to Ucareo-sourced artifacts are managed by institutions such as the Smithsonian Institution, the Museo Nacional de Antropología (Mexico City), and university repositories, with collaborative programs involving community groups, the Consejo Nacional para la Cultura y las Artes, and international partners like the Getty Foundation.

Category:Obsidian sources Category:Mesoamerican archaeology Category:Michoacán