Lead isotope ratios of Pueblo I lead-glazed ceramics and galena from Colorado and Pueblo II galena from Chaco Canyon, New Mexico

The earliest glazes in the American Southwest were produced during the early Pueblo I period (ca. 750–850 CE) in the Upper San Juan region of Colorado. Petrographic and isotopic techniques were used to study these early glaze-painted pots and to address questions of production locales and procurement strategies. The results of this study identify the preferred source of lead utilized by the potters as originating in the Galena District, in the Lake City and Uncompahgre calderas, in the western San Juan Mountains of Colorado. Glaze paints from three locations in the Mesa Verde region were produced with galena from these deposits, indicating that even when potters were choosing to use different clays and temper, the source of lead remained the same. Galena ores from these deposits have additionally been identified at other locations, including Dillard, a Basketmaker III site in southwest Colorado and in Pueblo II contexts in Pueblo Bonito, Chaco Canyon in New Mexico, indicating continuity in knowledge of distant lead sources.