Approach to environmental risk analysis for the main monuments in a historical city

The analysis of environmental risk in historical cities facilitates the development of conservation strategies that can minimize the deterioration of historical heritage sites. Risk maps built with GIS software provide information about the probability of the main hazards in a region, and is a very useful tool to identify, evaluate and prioritize the restoration budget of a city in order to manage preventive conservation. In this paper, new methodologies are applied based on the vulnerability matrix and its relationship with static and structural factors, climate conditions, air quality and social agents. This technique has some obvious advantages in the application of risk analysis for cultural heritage conservation, such as the capability of simultaneous risk assessment and geographical references. The vulnerability study implies an on-site diagnosis analysis and requires an adapted protocol for archaeological heritage. The validation of this methodology was carried out in the historical town of Merida (Spain) with a GIS application (ArcGIS software), where the main monuments of this UNESCO World Heritage site were studied.     

Tree roots and damages in the Jewish catacombs of Villa Torlonia (Roma)

Damages to hypogeal archaeological monuments, caused by the growth of tree roots, are frequently reported in the city of Rome. Problems of compatibility between trees and underground structures may become complex in the case of historical gardens. The Jewish catacombs of Villa Torlonia show relevant conservation problems, some of them arising from damages due to root growth, and consolidating interventions seem to be urgent. Some species in the gardens, especially Ficus carica L., but also Quercus ilex L. and Pinus pinea L., have developed a strong root system, growing for many meters in lateral distance and for some meters vertically. The plants responsible for the various alterations were identified by their wood anatomy and a methodology to treat similar problems has been proposed. Data collected aim to avoid errors made in managing the plant cover of an archaeological site.     

Petrographic and chemical characterisation of fine ware from three Archaic and Hellenistic kilns in Gela,Sicily

This work is focused on the petro-archeometric characterization of the fine pottery production of the archaeological site of Gela (Sicily). Thirty-five samples coming from three Archaic and Hellenistic kilns and five coming from an Hellenistic house, were investigated by means of optical microscopy, XRD and XRF analysis. With the exception of some ceramics which are undoubtedly imported, all the samples have similar petrographic features, but on the basis of chemical composition, we can distinguish two different groups. The presence of two local productions is confirmed by the comparison with locally outcropping sediments and with archaic and modern bricks of sure Geloan production. This result is particularly significant for the definition of reference groups of this wealthy polis that played an important trading role in the Mediterranean area.     

Iran: archaeological heritage in crisis: Developing an effective management system for archaeology

The dynamic social development in Iran over the last decades provided the acknowledgement of the archaeological heritage on the one hand, and a confrontation to the current managing system of archaeology on the other. This situation makes it necessary for archaeologists to formulate and implement a systematic regulation in the sphere of protection and management of the archaeological heritage. The fact is that, as the international conventions warn, the archaeological heritage is constantly under threat of destruction, and while in Iran the problem is not new, the destruction is on the increase. The constructions under the developmental projects and at the same time the increase of population are accompanied by the expansion of the new settled areas threaten large areas of archaeological sites. The deep economic crises of the country as well as a pauperization of majority of society, and a low degree of respect for the law, lead to an increase in looting and considerable damage to the archaeological heritage. The goals of this paper are (1) to identify problems that hinder the effectiveness of the Iranian national protection acts, and to suggest some way in which these problems could be remedied, (2) to promote further academic discussions of problems and solutions within archaeology and related fields, and (3) to encourage official authorities and other interest groups to press for changes needed in the Iranian national protection policies, to make it better serve the public interest.     

PIXE analysis of V–XVI century glasses from the archaeological site of San Martino di Ovaro (Italy)

The analysis of 42 glass fragments, excavated in the Italian archaeological site of San Martino di Ovaro, that includes a palaeochristian church dated from the V–VI century, has been done using the PIXE technique in a fully non-destructive way without any sample preparation. The results have been validated with a set of standards and using PIGE data acquired in parallel. The data of 29 of the 42 glasses indicate that an earlier group of samples (window sheets and sacred vessels, dated from the V–VI century) is typical of the Roman technology and can be associated to a Levantine production of natron glass. The blue glasses of this group are all window sheets coloured with cobalt, probably from the Near-East. The remaining heterogeneous samples (lamps, necklaces, cups) are related by their type and function and by the different compositions, to the later use of the site as a market place. The natron glasses of San Martino di Ovaro provide new data for the understanding of the changes in the glass industry in North-eastern Italy and nearby regions across the fall of the Western Roman Empire.     

A web information system for the management and the dissemination of Cultural Heritage data

Safeguarding and exploiting Cultural Heritage induce the production of numerous and heterogeneous data. The management of these data is an essential task for the use and the diffusion of the information gathered on the field. Previously, the data handling was a hand-made task done thanks to efficient and experienced methods. Until the growth of computer science, other methods have been carried out for the digital preservation and treatment of Cultural Heritage information. The development of computerized data management systems to store and make use of archaeological datasets is then a significant task nowadays. Especially for sites that have been excavated and worked without computerized means, it is now necessary to put all the data produced onto computer. This allows preservation of the information digitally (in addition with the paper documents) and offers new exploitation possibilities, like the immediate connection of different kinds of data for analyses, or the digital documentation of the site for its improvement. Geographical Information Systems have proved their potentialities in this scope, but they are not always adapted to the management of features at the scale of a particular archaeological site. Therefore this paper aims to present the development of a Virtual Research Environment dedicated to the exploitation of intra-site Cultural Heritage data. The Information System produced is based on open-source software modules dedicated to the Internet, so users can avoid being software driven and can register and consult data from different computers. The system gives the opportunity to do exploratory analyses of the data, especially at spatial and temporal levels. The system is compliant to every kind of Cultural Heritage site and allows management of diverse types of data. Some experimentation has been done on sites managed by the Service of the National Sites and Monuments of Luxembourg.     

Geological risk assessment for cultural heritage conservation in karstic caves

The increasing awareness of some local and international authorities has promoted the appearance of new legislation and the rising of research works focused in the prevention of damage to the cultural heritage in karstic caves. Nevertheless, karstic areas usually imply complex studies, and a universal methodology is very difficult to establish. This work exposes the basic methodology for the geological risk assessment in archaeological site and/or rock art bearing karstic caves getting a strategy that provides flexibility to adjust specific methods according to the conditions of different cases. The integrated use of basic geological (mapping, petrology, stratigraphy…) and geotechnical (rock mass quality analytical methods and indexes) techniques used in engineering geology is proposed. Those techniques permit the geological characterization of the rock mass, the hazard identification and the analysis and the geological risk assessment of the research area. Obtained geological risk areas could be included in protection areas that could be used as the basis for the selection of the areas where further investigations and the application of prevention/mitigation measures would have a better cost/benefit ratio. The geological risk should be considered together with other type risk evaluations in order to define effective protection areas.     

Mechanical properties of adobe walls in a Roman Republican domus at Suasa

Adobe is a construction technique that uses raw earth mixed and moulded to form sun-dried blocks to realize a bearing wall. The recent discovery of adobe walls belonging to a Republican domus sited in Suasa (Ancona, Italy) was the starting point of the present work. The research was developed through an experimental approach, in order to characterize the mechanical behavior of this type of walls: firstly some adobe blocks similar to the original ones were reproduced by using the soil directly came from the archaeological site near the adobe walls and adding straw to reduce hygrometric shrinkage and coarse sand, taken from a local quarry, as a stabilizer, as Romans were used to do. Then, after a seasoning period of 4 months, four adobe walls were produced to be tested by compression and shear. From compression tests, maximum strength, first cracking compression stress, Young modulus and breaking manner were evaluated. As well, compression results show a possible two-storey structure of the earthen Republican domus. In fact, it appears that the stress from the two-storey load analysis is lower than the first cracking compression stress. From the shear tests, a proportional law seems to regulate the relation between the maximum value of the mean tangential tensions and the vertical compression the sample is subjected to. This could be the starting point for a future seismic analysis.     

Dust and light: predictive virtual archaeology

Computer graphics, and in particular high-fidelity rendering, make it possible to recreate cultural heritage on a computer, including a precise lighting simulation. Achieving maximum accuracy is of the highest importance when investigating how a site might have appeared in the past. Failure to use such high fidelity means there is a very real danger of misrepresenting the past. Although we can accurately simulate the propagation of light in the environment, little work has been undertaken into the effect that light scattering due to participating media (such as dust in the atmosphere) has on the perception of the site. In this paper we present the high-fidelity rendering pipeline including participating media. We also investigate how the appearance of an archaeological reconstruction is affected when dust is included in the simulation. The chosen site for our study is the ancient Egyptian temple of Kalabsha.     

Secondary phosphates in the ceramic materials from Frattesina (Rovigo,North-Eastern Italy)

The pervasive crystallization of secondary phosphates in pores and fractures of numerous potsherds from the archaeological site of Frattesina (Fratta Polesine, Rovigo – North-East Italy) indicates that contamination occurred after burial. The chemical composition of these phases, which are Mg-rich vivianite and mitridatite, shows that sources of phosphorus, calcium, iron and magnesium were locally available and that the precipitation and diagenesis of these minerals were strongly influenced by micro-environmental conditions within the archaeological deposit.     

Remote hyperspectral imagery as a support to archaeological prospection

Hyperspectral data were exploited to test their effectiveness as a tool for archaeological prospection, envisaging their potential for detecting spectral anomalies related to buried archaeological structures. For this purpose the airborne Multispectral Infrared and Visible Imaging Spectrometer images were analysed. Each single band of the entire data set and different processing technique products were interpreted to identify any tonal anomalies. Since every analysed image exhibited marks different in terms of size and intensity, two indexes were defined for assessing the potential of anomalies detection of each image. Such parameters were: the Detection Index, used for counting the number of pixels related in each image to marks, and the Separability Index, applied for measuring the tonal difference of the marks with respect to the background. These indexes were tested on two areas within the Selinunte Archaeological Park where the presence of remains, not yet excavated, was supposed by archaeologists. For the test sites any extracted anomalies were evaluated by an expert in order to determine their archaeological relevance. The comparison among the index values, derived from each single band of the spectrometer and from different image processing by-products, allowed to determine which spectral range and which processing method are the most valuable to quickly highlight the anomalies. The analysis pointed out that, where vegetation cover is dominant, the Visible near infrared is the spectral region more sensitive to variations of spectral properties related to buried structures, while, where soil cover becomes relevant, the Short-wave infrared and the Thermal-infrared regions resulted more sensitive. As far as the applied processing methods are concerned, the Spectral Angle Mapper classifier and, secondly, the Minimum Distance algorithm stressed the highest archaeological information content. The results of this work showed that the archaeological information content derived by analysing the outputs of the applied image processing techniques is more significant than the information obtained by interpreting each single band and the available historical aerial photos. As a final remark, the data processing flow chart, applied to the entire remote hyperspectral data set over Selinunte Archaeological Park, appeared encouraging for detection of anomalies related to the presence of the buried archaeological structures.     

Searching for the remains of an Early Bronze Age city at Tell Qubr Abu al-’Atiq (Syria) through archaeological investigations and GPR imaging

This article presents results of an archaeo-geophysical investigation carried out in a tell site situated in the Syrian Middle-Euphrates valley within the framework of a Syrian-Spanish archaeological project. In the Near East, Tell is a hill formed by accumulation of muddy sedimentary layers mainly due to the decomposition of mud-bricks in ancient towns. First archaeological works (2005–2008) resulted in significant discoveries such as Early Bronze Age (c. 2600–2400 BC) buildings and pottery. In order to map the entire city, an extensive ground-penetrating radar prospection was undertaken in July 2009. GPR images reveal the existence of unknown buildings, streets and the enclosure wall of the city. Such information adds crucial information to understand the importance of the city in the region.     

Archaeomagnetic investigation of a metallurgical furnace in Pisa (Italy)

An archaeological excavation has been carried out at Pisa (Italy), unearthing an ancient metallurgical workshop. Since archaeological burnt materials provide important records of direction and intensity of the Earth's magnetic field in the past and they can be used to better improve geomagnetic secular variation curves (SVCs), an archaeomagnetic study has been performed. This small copper-alloy furnace presents a circular concave shape covered with a thin layer of mortar, with some traces of heated clay surrounding the feature that confirms the high temperature reached inside it. Archaeological context dating points to the last firing of the furnace between the last quarter of the 13th century and the first quarter of 14th century AD, when then the metallurgical workshop was transformed in a warehouse. Archaeomagnetic sampling has been performed using the modified Thellier method, by collecting several, large and independently oriented aliquots of heated clay, forming the bottom part of the circular wall of the structure. Laboratory treatments have been conducted at the IGG-CNR ARCHEO_LAB (Pisa, Italy) and at St. Maur Palaeomagnetic laboratory (Paris, France). Analytical measurements of the thermo-remanent magnetization index acquired from the samples have been performed using a large cell induction magnetometer for large samples, and the characteristic remanent magnetization (ChRM) has been successfully isolated after an alternate field demagnetization cleaning procedure for each sample. The final mean archaeomagnetic direction has been calculated at sampling site (D = 6.9°; I = 52.8°; N = 9; k = 305; α₉₅ = 2.6°) following the Fisher Statistics, and it exhibits a perfect agreement with some coeval already published directions obtained from Mt. Arso lava flows, these latter being an important anchor point in the preliminary Italian secular variation curve. Comparison with the preliminary Italian SVC, the French SVC and the SCHA.DIF.3K archaeomagnetic regional model have permitted to define an archaeomagnetic absolute age confirming the conventional archaeological age, underlining the importance of this result into the Italian archaeomagnetic data set.     

Archeaometallurgical finds from Barsinia,Northern Jordan: Microstructural characterization and conservation treatment

Within the framework of an excavation project aimed to systematically characterize the various aspects of settlement and activities in Northern Jordan, a considerable collection of slag lumps and iron artifacts of different forms and typologies excavated from the archaeological site of Barsinia were collected. Excavations have revealed other metallurgical materials such as pottery tuyeres and furnace-like structure. Studying those finds was important because of their archaeological and technological interests. For the analytical and metallurgical study, X-ray diffraction was used to identify the mineralogical composition of samples. Inductively coupled plasma-optical emission spectrometer, energy dispersive X-ray and X-ray fluorescence spectrometer were used to determine the accurate elemental composition of these finds. Furthermore examinations by using metallographic, polarizing microscope and scanning electron microscopy were employed to diagnose the characteristic morphology and environmental effects of these archaeometallurgical finds. Microstructural investigations emphasized that iron production processes were performed locally at the archaeological site of Barsinia even if the iron ores were imported from other mining location in Jordan. Direct or “bloomer” was the main method used for smelting iron ores followed by smithing methods to locally produce iron artifacts. This, most probably, was the state of technology from the Bronze Age to the Byzantine period. To ensure the stability of these deteriorated finds for future research, required treatment and conservation processes were successfully carried out.     

The public response to innovative strategies for the control of biodeterioration in archaeological hypogea

Between April and September 2003, 1500 visitors of the Catacomb of St. Callistus participated to a scientific research by filling in a questionnaire to express their opinion about a new illumination system experimentally set up in the Ocean’s Cubiculum. Their answers were statistically evaluated and represented the first public opinions on this archaeological site, including their knowledge of conservation problems and their positive attitude towards the use of new strategies for the preservation of this monument.     

Locating Macedonian tombs using predictive modelling

Northern Greece is the main region where more than 90 Macedonian tombs, dated in the late classical and Hellenistic period, have been discovered. Geospatial data processing technologies (GIS), predictive modelling techniques and fuzzy logic were applied to the study area in order to create a predictive model that would be able to provide map regions assigned with specified probability of Macedonian tombs’ occurrence. The model was tested extensively and was validated using a commonly used predictive gain. The results and the evaluation of the model proved the efficiency of its predictive ability in providing answers to a series of questions related to the problem at hand (archaeological research, cultural resource management and protection, land use, etc.).     

Innovation in lighting for enhancing the appreciation and preservation of archaeological heritage

The cultural content of ancient sites highlights the importance of light, which is an essential tool for the correct appreciation of the historical value and memory of cultural heritage. This should be a new way to highlight significance of fragments in compliance of the surrounding, which has not the same characteristics, to signal a visual path, creating itineraries that involve the context. Light plays a very important role in creating emotion, suggestion, evocation and supporting the visitor experience. Innovative technological solutions should be designed taking into account the kind of landscape and morphological characteristics of the site. This paper presents the study of a sample of Italian and international case studies, seen in their historical, archaeological and museological aspects. The emphasis is on what should be the most effective lighting system for the monumental sites, one respecting the ruins and the authenticity of the site, while at the same time bringing out their architectural, historical and symbolic significance.     

Roman bricks from the Lagoon of Venice: a chemical characterization with methods of multivariate analysis

From 18 archaeological sites of the Lagoon of Venice 75 bricks belonging to Roman and medieval building levels have been analysed. Chemical composition and geometric measures allow the characterization of a group of 24 Roman bricks of Imperial age. The group formed by means of fuzzy c-means cluster analysis applied on chemical data have been tested by principal component analysis and finally subjected to discriminant analysis to estimate the relative weights of original variables and classify new elements. Correlations among the data of the major chemical elements confirm the reliability of the complex of chemical data. The aim of this research was to obtain a chemical characterization of Roman bricks (and later, of the medieval ones) coming from the lagoon of Venice thus making it possible: 1) to recognize the age of a brick by means of its chemical analysis; 2) to date the layers of archaeological excavations or the ground where there are medieval building foundations by means of membership bricks; 3) to calculate the rate of local ground lowering in the elapsed years by the difference in level from one layer to another; 4) to estimate local rates of land subsidence by comparison with mean values already known.     

Multispectral and multiscale remote sensing data for archaeological prospecting in an alpine alluvial plain

This work is part of a multidisciplinary research project, developed in collaboration with archaeologists and geophysical experts, which aims at delineating the spatio-temporal relationships between paleoenvironmental conditions of an alluvial plain in an alpine environment and the human settlements during past ages. The study area is located in the upper Lake Como region at the confluence of the Valtellina (Adda river) and Val Chiavenna (Mera River) valleys in northern Italy. The area is a deltaic zone which was affected by great adjustments due to varying sediment loads and separate parts emerged at different times, thus conditioning the human presence and distribution. Archaeological evidences dating back to the last millennium BC and relicts of Roman ages were discovered in the area, particularly during the 19th century Adda River canalisation. Remotely sensed images taken from space orbiting satellite at different wavelengths of the electromagnetic spectrum, from visible up to thermal infrared, were used to delineate landscape features not easily detected on ground. Geomorphological study of the area was improved by means of historical aerial b/w photographs taken before the Second World War by the Royal Air Force. Ground surveys and proximal sensing measurements, using portable spectral radiometers operating at the same wavelengths as the satellite sensors, were conducted at some experimental sites. Integrated analysis of remote sensing multilevel derived information, cartographic data and archaeological evidences proved to be useful for archaeological research with indications of favourable sites for future exploration in the area.