Identifying a technological style in the making of lime plasters at Teopancazco (Teotihuacan,México)

The aim of this article is to focus on the technology of archeological plasters at Teotihuacan (Central Mexico), from the Classic Period (200–650 A.D.), focusing in the study of Teopancazco, a neighborhood center in the city. Petrographic and chemical analyses by OM, SEM-EDS, and LA-ICP-MS were conducted to characterize samples from different constructive phases and sectors of the neighborhood center, to determine the provenance of the raw materials employed in the manufacturing (e.g., volcanic glass shards) and to assess whether a shift occurred in the manufacturing of plasters and in the procurement strategies of raw materials during the different phases. The results of the analyses show that almost no changes occurred in the making of the plaster during more than four centuries and allow us to consider the presence of a technological style in their manufacture, which is characterized by the making of plaster by mixing lime with volcanic glass shards, which in the case of Teopancazco were derived from the Altotonga (Veracruz) magmatic system. The data at our disposal suggest that this style was developed in Teopancazco and later introduced throughout the city of Teotihuacan in the Early Xolalpan phase (A.D. 350), although we still do not know whether the provenance of the raw materials is the same. The wide distribution of this technological tradition could be due to the technological properties of the materials and/or the influence of the intermediate elite who ruled over Teopancazco. The paper confirms that the study of material culture and technology sheds light on broader cultural aspects of ancient societies.     

Digital Photogrammetry for Documentation of Maritime Heritage

Documentation of maritime heritage is essential for its protection, and for reference in restoration and renovation processes. These functions become problematic in the case of historical ships and boats that lack lines drawings. The purpose of this paper is to describe a procedure for creation of lines drawings based on the shape analysis of surviving historical boats or their small-scale models with the help of reverse engineering (RE) techniques. The paper describes how digital photogrammetry and the iterative method were used to analyze the shape of three historical boats: Tomahawk, Refola and Nada. The application of the proposed procedure produced the lines drawings of the boats as its result. The accuracy of the 3D CAD model obtained with the photogrammetric technique was verified by comparing it against a more accurate 3D model produced with the help of a RE laser scanner. The examination of the resulting lines drawings proves that the digital photogrammetry process and the proposed iterative method are adequate tools for developing lines plans of boat models. The research offers the methodological basis for the creation of an archive of lines drawings of historical boats. Such an archive would provide reference for philologically correct restorations, and permit definition and classification of distinctive elements of various types of historical boats, particularly those produced in the Campania Region.     

Characterisation of archaeological mortars from Pompeii (Campania,Italy) and identification of construction phases by compositional data analysis

This work describes the compositional characterisation of coccciopesto and natural pozzolanic mortars sampled in the Regio VI area of the archaeological site of Pompeii, with particular reference to the Casa di Pansa in Insula 6 and Casa 17 in Insula 2. Samples were studied by optical microscopy and analysed by XRF, SEM-EDS, LA-ICP-MS and XRPD. The XRF and SEM-EDS data, subjected to multivariate analysis (cluster analysis), identified the three main construction phases involved in building the Casa di Pansa. In addition, mineralogical and petrographic characteristics of the aggregate were determined and found to be compatible with pyroclastic deposits from the volcano Vesuvius. Study revealed C–S–H phases in the binder, due to pozzolanic hydration phemomena of hydrated lime with cocciopesto and natural pozzalana.     

Combining residue analysis of floors and ceramics for the study of activity areas at the Garum Shop at Pompeii

In this paper, we propose the application—for the first time in the Mediterranean area—of the combination of the study of chemical residues in floors and ceramics, with the aim of providing information about the activities carried out in archeological buildings. We chose the Garum Shop at Pompeii to test the method. In fact, due to the peculiarity of this archeological context, it provided an ideal case in which the activities performed are in part known, and the ceramic vessels recovered are still in situ. Floor samples were studied by means of spot tests developed in Mexico aimed at identifying the presence of phosphates, fatty acids, and protein residues, while the organic residues preserved in the ceramic matrix of amphorae, dolia, and other ceramic vessels were studied by gas chromatography coupled with mass spectrometry. Moreover, we integrated the data obtained with specific studies directed at better identifying the solid residues found inside two of the amphorae studied: botanical studies of fruit stones recovered in a Dressel 20 amphora and the characterization of the lime preserved in an African amphora. The research allowed for the identification of the traces of some of the activities performed, such as cooking and producing garum in the floors of the building, and the use and re-use of amphorae and dolia before the Vesuvian eruption.     

Georadar investigations in the central nave of Hagia Sofia,Istanbul (Turkey)

Within an interdisciplinary project to study Istanbul’s Hagia Sofia, a georadar survey was carried out in the central nave to assess if the deformations of the structure previously observed could be related to a differential behavior of the subsoil caused by architectural remains underneath. This study faces an unusual challenge since it was necessary to study the space beneath the scaffolding placed for the restoration works. The survey of the central nave was successful and allowed the detection of remains of walls that probably formed the basement of a previous 18- by 22-m structure. In addition, another interesting feature was discovered 2 m below the marble mosaic in the southeastern part of the nave. Although it is not possible to define its function, it seems that there could be a close relationship between this 2- by 3-m buried structure and the marble mosaic in the floor surface. Although some structures were identified under the floor of Hagia Sofia, there are no major changes in the topography of the central nave floor.     

Small angle neutron scattering study of ancient pottery from Syracuse (Sicily,Southern Italy)

This paper is focused on a spectroscopic study of some pottery shards from an archaeological site in Syracuse (Sicily, Southern Italy), dating back to the Hellenistic–Roman period. Structural characterization was performed at different scales of observation, i.e. from macroscopic to mesoscopic. The main goal was to point out the potentiality of the small angle neutron scattering (SANS) technique as a non-invasive analytical tool in archaeometry, also in conjunction with other, more usual, methodologies. Correlation of experimental data, i.e. macroscopic typology and texture, obtained from petrographic analysis, and radius of gyration and fractal dimension of the interfaces of the mesoscopic aggregates obtained using SANS, together with mineralogical X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis, allowed hypotheses to be made on the production technology of the investigated samples.