Videos by Alejandro Pastrana
Is the Gene Titmus pressure technique with my adaptation for a wood support of the green obsidian... more Is the Gene Titmus pressure technique with my adaptation for a wood support of the green obsidiana prismatic core inside a conic perforation 14 views
Papers by Alejandro Pastrana
Boletín de antropología americana, 1986
... Las reproduccio-nes experimentales son basicas para com-prender las variaciones y niveles tec... more ... Las reproduccio-nes experimentales son basicas para com-prender las variaciones y niveles tecnologi-cos (Clark 1981 ... En general las preformas bifaciales son burdas, incluso frecuentemente conser-van fragmentos de cortex, para su protec-cion durante el transporte a los ...
Con base en información arqueológica e histórica del siglo XVI se documenta y se trata de explica... more Con base en información arqueológica e histórica del siglo XVI se documenta y se trata de explicar la continuidad de la obsidiana en la colonia temprana, en el centro de Mexico
Se discute con base en información de las fuentes históricas, la forma de control de la producció... more Se discute con base en información de las fuentes históricas, la forma de control de la producción y distribución de la obsidiana como un material estratégico.
Géomorphologie : relief, processus, environnement, 2001
... Molinero R., Cervantes P., Nieto-Obregón J., Lozano-Santa Cruz R., Mendoza-Rosales C, Silva-R... more ... Molinero R., Cervantes P., Nieto-Obregón J., Lozano-Santa Cruz R., Mendoza-Rosales C, Silva-Romo G. (1998) - Xitle volcano in southern Mexico-City. A 2000 genetic volcano in an urban area. Revista Mexičana de Geológicas, 15 (2),115-131. Fergusson G J., Libby WF (1963 ...
Geological Society, London, Special Publications, 2000
The Cuicuilco pyramid was one of the first true urban centres in the Basin of Mexico. Its constru... more The Cuicuilco pyramid was one of the first true urban centres in the Basin of Mexico. Its construction started a few centuries BC, during the Late Preclassic period. The pyramid is partially covered by a basaltic lava flow produced by the Xitle monogenetic volcano. New stratigraphic work around the pyramid and the volcano together with new radiocarbon dates indicate that the pyramid and nearby settlements were abandoned as a direct consequence of the volcanic activity of Xitle. The new dates, obtained from material which clearly is contemporaneous with the volcanic activity, suggest that the eruption took place around 1670 years BP, some 300 years later than previously thought.
The prehispanic societies of central and western Mesoamerica used obsidian in great quantities, a... more The prehispanic societies of central and western Mesoamerica used obsidian in great quantities, as it was the primary material used for manufacturing domestic cutting tools and weapons and could also be fashioned into ornamental and religious items. Unlike in the Old World, utilitarian lithic industries were never supplanted by metallurgy, with the result that successive urban civilizations continued to exploit obsidian mines and leave exceedingly dense concentrations of production byproducts (or debitage) at quarry sites and workshops located within settlements. Aztec obsidian industries built upon millennia of earlier societies, including the Teotihuacano and Toltec, yet they significantly intensified and expanded obsidian extraction and exchange systems (Pastrana 2007; Pastrana and Domínguez 2009). Like their predecessors, the Aztecs were attracted to the physical properties of obsidian because it is a sharp, durable stone that fractures cleanly and predictably. The reductive and sequential nature of production activities and the chemical regularity of obsidian originating from the same volcanic flows are additional properties that have attracted archaeologists, because a wide range of economic activities can be discerned from the material. These include the stages of manufacturing represented in different contexts, knapper skill level, relative intensity of production, and exchange routes and zones of cultural contact. Aztec archaeological sites contain a wide range of types of obsidian artifacts, such as bifacial knives and projectile points used as weapons, pressure blades and unifacial scrapers used in many domestic activities , and polished bodily adornments, vessels, and mirrors used as status and ritual items. As a result, multiple dimensions of Aztec society may be addressed through obsidian analysis. This summary outlines the major raw material sources, artifact
ARCHAEOLOGY OF ANCIENT MEXICO AND CENTRAL AMERICA AN ENCYCLOPEDIA, 2001
Arqueologia, Sep 29, 1988
Woods made the obsidian glasses worn by the author (main pic, above) (Click on image to enlarge) ... more Woods made the obsidian glasses worn by the author (main pic, above) (Click on image to enlarge) Pic 2: Thatch shelter, Sierra de las Navajas (Click on image to enlarge) Pic 3: 'Don't disturb the snakesthey too are deities'; rattlesnake and obsidian (Click on image to enlarge) Pic 4: Tezcatlipoca with his obsidian mirror; Codex Borgia pl. 21 (detail) (Click on image to enlarge) Pic 5: 'If there's fog, run for shelter....' (Click on image to enlarge) Pic 6: Model of a load carrier of obsidian (Click on image to enlarge) Prehispanic green obsidian mining in Hidalgo We're sincerely grateful to Dr. Alejandro Pastrana, a pioneer in the geo-archaeological investigation of obsidian deposits in Mexico, for this illuminating introduction to ancient obsidian working. With a doctorate in archaeology, his research has focused from 1980 to the present on mining, knapping and distribution of obsidian in Central Mesoamerica. Since 1974 he has been a researcher at the National Institute of Anthropology and History (INAH), Mexico.
Un acercamiento a las ocupaciones y tradiciones culturales en el Valle de Colima a través de sus ... more Un acercamiento a las ocupaciones y tradiciones culturales en el Valle de Colima a través de sus entierros y contextos funerarios Noticia Alberto Diez Barroso Repizo Tapak, un sitio arqueológico en el corredor totonaco
Minerals
The obsidian of Sierra de las Navajas is well known for its green color and gold hue. In order to... more The obsidian of Sierra de las Navajas is well known for its green color and gold hue. In order to relate these features with compositional and microtextural characteristics, we have carried out a microanalytical study by Wave Dispersion System associated to Electron Probe Micro-Analyzer, Scanning Electron Microscope observation, and X-rays micro-tomographic analyses of samples showing different colors (dark to light green, sometimes with bands of different color intensity) and hues (changing, uniform, no hue). In accordance with previous studies, the green color of the obsidian seems to be related to a high iron content, probably in its reduced state. However, no significant difference in composition occurs between dark and light green samples. The SEM observation and microtomographic study revealed the absence of microcrystals and the occurrence of vesicles of different size, shape, and orientation. Lighter green colors are shown by highly vesiculated surfaces, whereas non-vesicula...
The Cerro de Las Navajas Obsidian is a volcanic rock within the Comarca Minera UNESCO Global Geop... more The Cerro de Las Navajas Obsidian is a volcanic rock within the Comarca Minera UNESCO Global Geopark (Hidalgo, Mexico) that possesses outstanding archaeological, cultural and geological value. It exhibits a unique green-golden macroscopic hue and was exploited and traded since ca. 250 BC, by successive Mesoamerican cultures, and until early Colonial times-ultimately recording the transition to a steel-based society. The obsidian deposit is the largest of its kind (buried) and has the longest continuous history of mining in the continent. Other green obsidians have been studied in Patagonia (Seno Otway, Chile), source for hunter-gatherers, and in Anatolia (Bingöl, Turkey), source for the Neolithic Near East. We argue here the potential of the Cerro de Las Navajas Obsidian for a heritage designation to highlight its global significance; synergies derived from an international recognition may give the opportunity to (a) put in value the multi-dimensional geoheritage of this obsidian; (b) strengthen the sense of belonging among local community; (c) require authorities to regulate obsidian mining and commercialisation, under fair trade terms, and compatible with conservation, research and responsible tourism; (d) support further research on archaeology and cultural heritage, linking geosciences with other disciplines; and (e) contribute to UNESCO Global Geoparks programme, seeking local development and sustainability. These expected achievements would be relevant given the lack of legal advisory role of geoparks in geoheritage management in Mexico.
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Videos by Alejandro Pastrana
Papers by Alejandro Pastrana
precioso milenario
Aspectos generales, geología e importancia histórica
de la obsidiana del Cerro de Las Navajas.
La sierra de Las Navajas, entre Mineral del Monte y Singuilucan, comprende
los ejidos de El Nopalillo, El Guajolote y El Zembo. En el geositio Cerro
de Las Navajas y sus alrededores abunda la obsidiana, especialmente en la
falda occidental de la peña de El Jacal, en la barranca llamada Milagro y en el cerro
de La Cruz de El Milagro o de Las Navajas.
La obsidiana es un vidrio natural de origen volcánico, de aspecto particular por
su brillo, variedad de colores y tonalidades, dureza, fragilidad y fractura de tipo
concoidea; por esta última propiedad es fácil producir formas especiales con filos
agudos y cortantes. Las características físicas de la obsidiana fueron ampliamente
aprovechadas en la evolución de la humanidad, antes del descubrimiento del acero,
para la elaboración de instrumentos y armas; además, por su bella apariencia, se
utilizó en la manufactura de preciados objetos mágico-religiosos.