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The archaeological zone of Izapa was an important pre-Hispanic settlement of probable Mixe-Zoque affiliation in the Soconusco region, southeast of the current state of Chiapas, whose occupational sequence extended from the Early Preclassic (1800 BC) to the Early Postclassic (1200 AD). Throughout its long habitation, various population movements occurred within the settlement. During the Classic period, in the complex known as Group F, of which only 2.88 ha are currently protected, monumental structures were built that integrated a civic-ritual compound. Previous research identified a prolonged constructive sequence, specifically in the main pyramid (Structure 125-A). To identify possible construction moments prior to those currently appreciated and determine the state of conservation of some of its monumental structures, a geophysical survey was carried out by means of georadar and electrical resistivity tomography techniques in various areas of Group F. Through these, it was possible to detect several anomalies that can be interpreted as archaeological structures, including platforms, channels and walls. Some of these elements were verified by archaeological excavations. The different depths at which these possible structures are located speak of a prolonged occupation of Group F, with various modifications to its architectural configuration. [ABSTRACT FROM AUTHOR]

The chemical characterization of materials recovered from archaeological sites has been used to relate artifacts to their respective sources of raw material. For this, conventional methods of classical statistics are commonly used, such as bivariate graphs, cluster analysis and linear data transformations. Those who have applied these methods claim to have a high degree of confidence in the correct assignment of materials to their respective sources. However, if empirical data deviate from theoretical assumptions, classical statistical techniques can produce incorrect assignments. In this paper, we propose a semi-supervised learning procedure using clustering and classification based on models of mixtures of multivariate asymmetric exponential power distributions. The objective is to trace the origin and provenance of obsidian archaeological materials from the archaeological zone of Izapa, Chiapas, significantly optimizing the result of the correct allocation of unlabeled data by employing only limited supervision in the form of labeled instances. The effectiveness of the proposed method was evaluated by a controlled experiment using data from a set of geological samples from obsidian deposits. Subsequently, the method was applied to analyze a set of obsidian artifacts collected in excavations within Izapa dated for the Classic period. In both cases, well-defined classifications were obtained that, in the case of Izapa, allowed to determine the consumption of materials from Guatemalan sources, as well as some relationship with sources from western and central Mexico. [ABSTRACT FROM AUTHOR]

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The archaeological zone of Huexotla, east of Mexico Basin, was part of the Acolhuacan lordship, associated to the Mexica domain in the Postclassical period. In this site, several structures have been partially explored, some of which are open to the public. Recent explorations led to the hypothesis that the structures of La Estancia, the Wall and the Community were part of a more complex space that formed the Sacred Precinct of the city. In order to test this postulate, magnetometry was conducted in three areas of the site. By processing Total Field and Vertical Gradient magnetic data, we were able to identify and understand the distribution of underground features like walls, floors and platforms, aiding in the determination of potential excavation areas. Processing the magnetic data with the application of the analytic signal operator allowed more information to be acquired for the recognition of structures of interest. The geophysical results were correlated with the outcomes of archaeological excavations in three structures, confirming the existence of architectural patterns that were not previously detected and supporting the thesis proposed for the ceremonial enclosure. [ABSTRACT FROM AUTHOR]

A multivariate statistic technique known as correspondence analysis (CA) is discussed in this article. This technique has shown to be very useful in obtaining relative chronologies of sites, burials and archaeological deposits. The importance of this procedure emerges like an alternative to attain a greater certainty than the one got from the absolute dating methods like the C14. The CA is applied in a specific group of burials found in the archaeological site of Los Teteles de Ocotitla, in Tlaxcala. The data was arranged in a contingency table, with the ceramic types ordered in columns and the burials in rows. From this table, a representation in an unique mathematical space is generated. The correlation between the ceramic types and the burials can be drawn out in a factorial graphic in terms of their proximity, where this proximity poses a chronological significance. [ABSTRACT FROM AUTHOR]