Settlement Patterns and Urbanization in the Yautepec Valley of Central Mexico

We carried out a full-coverage survey of the Yautepec Valley in the 1990s to reconstruct demography and settlements and their changes through time. We investigated the extent to which well-documented developments in the adjacent Basin of Mexico were paralleled in Yautepec, as well as the impact of regional empires and economies on local society. Our analyses focused on Teotihuacan relations in the Classic period and relations with the Aztec empire and the Mesoamerican world system in the Middle and Late Postclassic periods. In addition to locating, mapping, and describing sites and taking grab-bag artifact collections, we also made a series of systematic intensive surface collections (5 × 5 m) and test excavations at samples of Classic and Postclassic sites. In this paper, we describe the survey and changing settlement patterns in the Yautepec Valley. We also present several analyses of changing patterns of urbanization through the Prehispanic era. We conclude with a synthesis of changing social and cultural dynamics in this region.

Sources of Imported Obsidian at Postclassic Sites in the Yautepec Valley, Morelos: A Characterization Study Using XRF and INAA

This paper presents the results of obsidian characterization analyses for Middle and Late Postclassic sites in the Yautepec Valley of Morelos, central Mexico. A large sample (N = 390) of obsidian blades from excavated domestic contexts at the site of Yautepec and from surface collected contemporary sites were assigned to a quarry source using X-ray fluorescence (XRF), and a subsample was also analyzed with instrumental neutron activation analysis (INAA). The use of XRF allowed the authors to expand the number of artifacts initially analyzed by INAA. These larger samples of sourced material prove essential to answering research questions regarding regional economies, particularly with regard to issues such as production and exchange. This study demonstrates the complementarity of XRF and INAA and the specific advantages inherent in each of these techniques.

A New Postclassic Chronology for Yautepec, Morelos

We describe the derivation of a new archaeological chronology for the Postclassic period at Yautepec, Morelos. We first apply cluster analysis to ceramic type frequencies for 47 excavated contexts to identify groups of related ceramic collections. This classification is then extended to several hundred additional collections using discriminant-function analysis. The groups are evaluated successfully against stratigraphy and radiocarbon dates, resulting in their designation as chronological phases. Radiocarbon determinations are then used to assign calendar dates to the phases. The new chronology consists of one Middle Postclassic phase (Pochtla), two Late Postclassic phases (Atlan, Molotla), and one Early Colonial phase (Santiago). We also explore issues concerning the extension of this chronology to other Postclassic sites in the Yautepec Valley.