This work shows the preliminary results of an international project for the interdisciplinary study of the limestone used in the plasters of the ancient city of Teotihuacan. The limestone provenance was studied using a new approach based on the chemical analysis of the lime lumps that were selected because they represent the composition of the original limestone rock. The results show that the applied methodology was successful and that the limestone used to produce the lime employed to make the floor of the main courtyard at Teopancazco (Teotihuacan), comes from the region near Tula (Hidalgo).

In this work, we present the results of the analyses of 20 lime plaster samples taken from the Templo Mayor (Great Temple), the main pyramid of Tenochtitlan (Mexico), the ancient capital of the Mexicas. The samples were analysed to recover information on the mixtures used in the fabrication of the plasters and for the provenance of the raw materials (in particular, limestone) used to make the plasters. The characterization of the samples was done by OM, SEM/EDS, XRF and LA-ICP-MS analyses, while the identification of the provenance of raw materials was done by studying the lumps present in the samples with LA-ICP-MS. The objective of the study was to establish if there was a relationship between changes in the construction techniques employed in the pyramid over time and if there were changes in the provenance of the raw materials. Six different construction phases of this pyramid are analysed, showing the similarities and differences among them, mainly based on differences in the sieving of the aggregates and in the raw materials employed. The provenance studies of the limestone used to make the plasters demonstrated that all the limestone comes from the Tula region.

La Laguna Mexico City 0 km 1000 N Recent work at La Laguna in Central Mexico provides an excellent illustration of the way in which information from architecture, food remains, ceramic vessels and chemical signatures can be brought together to demonstrate communal feasting associated with specific structures and public spaces. Structure 12M-3 contained a range of evidence indicative of food preparation and consumption. Ritual effigy vessels depicted deities connected with food and fertility, and fire and the hearth. Taken together, the several lines of evidence indicate that Structure 12M-3 was a special building, located directly behind the main temple and devoted to the preparation and production of communal feasts that were held in the adjacent plaza. This provides new insights into community life in the urban centres of early Mesoamerica.

The Formative-period site of Altica in the Patlachique Range poses many methodological problems when designing an excavation strategy. Three millennia of erosion, twentieth-century chisel plowing, and modern reforestation efforts have destroyed or disturbed most surface architecture above the local tepetate bedrock. As such, in the early stages of the Altica Project, the primary concern was the detection and identification of subsurface features, especially deep pits as found at other Formative sites. Although Altica is located at the top of a low, flat ridge, strong localized rain frequently flooded the terraces of interest for days, making it impossible to detect subsurface features using the most common prospection techniques. Because of these practical and taphonomic limitations, we relied on magnetic gradient prospection. This technique had never been applied to an early village site in the Basin of Mexico. This paper presents the methods used, discusses various difficulties encountered during prospection, applies interprets the results of the magnetic gradient study using results from excavation and aerial multispectral remote sensing. We discuss how the method might be applied to similar Formative sites to remotely detect indicators of anthropogenic activity, including subsurface features.

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