Collaborative Research at Cerro Portezuelo: Spanning the Classic to Postclassic at a Teotihuacan Regional Center

Arizona State University, Scottsdale AZ

Investigators

Abstract

With support from the National Science Foundation, Dr. George Cowgill (Arizona State University) and Dr. Deborah Nichols (Dartmouth College) will analyze a large collection of artifacts and field records from the important site of Cerro Portezuelo to better understand the development of early cities and states, with implications for current urban issues. The research team includes archaeologists and other scientists from the U.S, Mexico, and Canada with expertise in stone tools, ceramics, geo-chemical source analysis, and human skeletal biology and chemistry. The great ancient city of Teotihuacan, in highland central Mexico, has been extensively studied, but even today surprisingly little is known about other Teotihuacan-related settlements in the Basin of Mexico. Cerro Portezuelo, about 40 km from Teotihuacan, is one of only two major Teotihuacan regional centers in the Basin. Cerro Portezuelo grew after the fall of Teotihuacan ca. A.D. 650 and in the subsequent Epiclassic and Early Postclassic periods it was the capital of an independent city-state. This site is exceptionally strategic because it offers information on how Teotihuacan interacted with subordinate centers within its core area, and because it provides a record of the cultural, political, economic, religious, and possibly ethnic changes involved in the decline and collapse of the Teotihuacan state and ensuing developments in the Basin of Mexico. This transition is poorly understood and is the subject of much controversy. In 1954-55 UCLA archaeologist George Brainerd conducted substantial excavations at Cerro Portezuelo, but the project was interrupted by his untimely death in 1956, and since then the materials and field records have remained at UCLA, little studied and largely unpublished. The investigators will carefully study and classify all the artifacts, and make use of the detailed data in the Cerro Portezuelo field records. Using instrumental neutron activation analysis the investigators will identify the sources of stone tools and pottery. Analysis of oxygen isotopes of human skeletal remains from excavated burials will be undertaken to determine their geographic identities. With this information the team will investigate (1) Teotihuacan's relations with its nearby hinterland and (2) the change from the Teotihuacan regional state to the very different city-states of the Postclassic. The researchers will seek evidence concerning craft production at Cerro Portezuelo, the extent to which different ceramic types were imported from Teotihuacan, differences from Teotihuacan in wealth and status of residents, and how these patterns changed as Teotihuacan declined. Was the transition to the Epiclassic primarily caused by political, religious, and economic changes within the Basin of Mexico, or does the evidence point also toward significant incursions of foreign migrants? The project will create an electronic database for Cerro Portezuelo to make the data available to archaeologists in the U.S., Mexico, and elsewhere. The project will contribute to continued scientific cooperation in archaeology between the U.S. and Mexico, who has loaned the Cerro Portezuelo collection for study. The project provides graduate and undergraduate students an opportunity to gain hands-on experience in methods of artifact analysis that are essential for future archaeological investigations in Central Mexico.