Jorge Blancas

Suprahousehold Consumption and Community Ritual at la Laguna, Mexico

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.

Thermographic Survey at Hagia Sophia: Main Arches, Pendentives and Tympana

ABSTRACT Hagia Sophia is one of the oldest and most complex existing monuments. Many unanswered questions are still open on the historical and constructive evolution of this monument. The boundaries between the different construction phases and the details of the masonry and materials used in the various phases are still not defined with precision. The thermographic survey, carried out inside the monument, made it possible to answer some of these questions by specifying the exact location of the past interventions and the variability of the materials employed allowing a better understanding of the constructive history of the monument. The technique was applied at a great distance and in normal environmental conditions, taking advantage of the high thermal sensitivity of the instrumentation. The results achieved confirm the validity of the technique in the study of ancient buildings.

EL USO DE TÉCNICAS GEOFÍSICAS PARA DETERMINAR SISTEMAS CONSTRUCTIVOS Y MATERIALES PRESENTES EN LOS TÚMULOS DEL PERÍODO FORMATIVO EN EL VALLE DE AZAPA, ARICA, CHILE

Como resultado de un proyecto conjunto entre la Universidad Nacional Autonoma de Mexico y la Universidad de Tarapaca, Chile, se realiza por primera vez en el valle de Azapa, norte de Chile, un estudio geofisico que incluye tecnicas de gradiente magnetico y georradar. Este valle ha sido el origen de asentamientos humanos tempranos vinculados con la tradicion Chinchorro. Posteriormente en el ultimo milenio antes de Cristo, junto con el desarrollo inicial de la agricultura, las poblaciones erigieron monumentos de alta visibilidad, en ellos depositaron cuerpos y osamentas humanas, las que periodicamente eran removidas con fines ceremoniales. Excavaciones arqueologicas previas en el sitio Az-80 han revelado que la mayoria de los monticulos fueron construidos con capas alternas de vegetacion y de sedimentos. Es destacable la conservacion de los materiales organicos en este ambiente del desierto de Atacama, uno de los mas aridos del mundo. Todo lo anterior ha preservado la forma y tamano de los monticulos, lo que permite el uso de tecnicas geofisicas. Entre ellas se selecciono el estudio magnetico con el gradiometro Geoscan FM36 y el estudio con georradar SIR 3000 de GSSI con una antena de 400 MHz. Los resultados de esta primera aproximacion revelaron que el gradiente magnetico detecto el uso de piedras ligeramente magneticas colocadas en lugares especificos durante la construccion del tumulo, pero lo mas importante es que las reflexiones del radar revelaron la presencia de etapas constructivas anteriores en el interior de los tumulos, y en algunos casos lo que pudieran ser enterramientos y pequenas estructuras funerarias.

GPR detection of karst and archaeological targets below the historical centre of Merida, Yucatán, Mexico.

The Historical Center of Merida has been classified as a “zone of high patrimonial value” based on the study of topography and the historical documents that show a long-term occupation, non-interrupted since preColumbian times when T’Hó was the great capital of the northern region of the Maya area. For the local government, rehabilitation of the Historical Center of Merida has been a great priority. Among others, this project includes preservation of archaeological remains (pre-Columbian or colonial) and detection of karstic zones under the city. In order to prevent damage to the patrimony, ground penetrating radar (GPR) surveys were carried out employing 200 and 400 MHz antennas along 16.5 km of the city streets. After data analysis, it was possible to build a map showing the locations of subsurface karst features and archaeological remains below the street pavement, many of which correlate with archaeological platforms proposed in historic documents as well as some of the cenotes recorded in popular memory. As result, for the first time in Mexico, a local government has information available that will allow them to minimize damage to archaeological remains and mitigate risks associated with construction above shallow subsurface karstic zones within this important modern city.

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.

New compositional data on ancient mortars from Hagia Sophia (Istanbul, Turkey)

This study shows the results of a multidisciplinary collaboration between the University of Calabria (Italy) and the National Autonomous University of Mexico (UNAM), about the compositional characterization of some mortars taken from Hagia Sophia in Istanbul (Turkey), one of the most important buildings in antiquity. Twenty samples of joint mortars were analysed by micro-chemical analyses (SEM-EDS), X-ray powder diffraction (XRPD), optical microscopy (OM) and transmission electron microscopy (TEM). The compositional study allowed us to define, with more detail, the construction phases of the fifth, sixth and tenth century. The petrographic analysis in thin section by optical microscopy showed four typologies of sands, used as aggregate, with specific compositional features. SEM-EDS analyses and TEM observations of the binder around the ceramic fragments of the aggregate showed the presence of different morphologies of single C-S-H compounds.