Articles by Subject

The poorly preserved human bones discovered during the DHOMIAP Project excavation of the necropolis KR-N1 in the area of Khor Rori (Dhofar, Sultanate of Oman) were an opportunity to apply, for the first time in Dhofar’s pre-Islamic funerary contexts, 3D photogrammetry to osteo-archaeological studies. The low economic engagement and the execution speed make this technique essential in the documentation of barely accessible archaeological remains and contexts, as already witnessed by previous studies conducted outside this research area. This paper aims to find a more appropriate method and setting for 3D model photogrammetric reconstruction of human remains, demonstrating the importance of this digital technology for the study of poorly preserved osteo-archaeological remains. For these purposes, the results obtained using two different settings for image acquisition (one with macro and one with standard lens) were compared and discussed.

Over the past decade, we have witnessed an increase in the use of technology, through the creation of virtual itineraries and exhibitions, as a tool to guarantee and increase the usability of museums and more generally of artistic and historical works. In fact, it often happens that many works of art and artefacts of archaeological and cultural importance are not accessible to the public, either because they are kept in museum deposits or because they are difficult to access. In a context such as the current one, however, with an ongoing pandemic that forces most of the population to remain at home, the virtualization of museums, and historical and cultural heritage, becomes the main tool for exploring and enhancing culture. Among the various methodologies used for the creation of three-dimensional models, photogrammetry stands out for ease of use and low cost. This article analyses the use of photogrammetry in 3D modelling, focusing on pros and cons as a rapid, low-cost tool, which makes artworks virtually accessible to the public via museum websites and social network forums.

Imaging systems are the basic tools of the trade for art historians, conservators, and archaeologists, when they are called to document the results of their work. However, photo cameras and imaging systems are also powerful research tools. These systems, in fact, are inherently portable and give the possibility of acquiring high-resolution, spectrally resolved digital images that can be elaborated exploiting the most advanced algorithms of information science. In this contribution, we will outline the many possibilities opened by the available instrumentation and techniques, to suggest the use of image analysis as the first step of the diagnostic process in Cultural Heritage conservation and study.

In this paper we investigated the application of the optical scanning micro-profilometry based on conoscopic holography sensors for the acquisition and the surface analysis of archaeological objects with a micrometric resolution. The portability of the setup developed and its modularity allow to work in situ with a multi-scale and multi-material approach. In addition, we have developed our own tools to create a mesh from the 2D-arrays of distances collected with the resulting possibility to obtain a replica of the artwork using 3D printing technologies. We test the microprofilometer on two case studies: a fragment of an archaeological amphora, also presenting the workflow to obtain the 3D printed object, and an Etruscan bronze mirror, analyzing its surface.

In the last decade portable devices for the analysis of Cultural Heritage (e.g. laser-scanners, spectroscopes, XRF) have reached levels of reliability that can replace benchtop instruments and enable in situ survey. One of the most effective application is the digitization and diagnosis of artworks preserved inside museums. Indeed, moving art objects or finds from the place of preservation to specific laboratories can often be difficult for several reasons such as fragility, large size, risk of damage, lack of authorizations etc. The paper shows the results of a collaboration between the IPCF-CNR of Messina and the Archaeological Museum of Lipari aimed at creating a ‘mobile laboratory’ for chemical analysis and 3D digitization of artefacts presenting different challenges. The activities have been carried out using two high-performing and non-contact tools: a laser-scanner arm by Faro (sometimes in combination with an external camera) and a handheld Raman spectrometer by Bruker. The test was performed to plan more extensive and systematic analyses of other materials preserved in Lipari, which will be soon examined as part of an ongoing agreement between the two institutions. The results of this test clearly demonstrate the advantages, both in terms of scientific results and dissemination, that can be achieved when science and the humanities dialogue for a common goal.

During the Late Republic and Early Empire, central Adriatic Italy was one of the most urbanised regions in the Roman world and most cities were extensively equipped with monumental buildings, often lavishly decorated with imported marbles and sculptures. This contribution presents the results of an archaeological and archaeometric study of the architectural and sculptural marbles used in this central Adriatic area. The determination of the geographical origin of white and polychrome marbles was carried out through macroscopic examination and laboratory investigations (optical petrography, X-ray diffraction, oxygen and carbon stable isotopes). The analyses revealed the presence of a wide range of lithotypes from Italy, Greece (mainland and Aegean islands), Asia Minor, North Africa and Egypt, including varieties of white marble from Carrara, Proconnesos, Pentelikon, Thasos, Paros and Dokimeion.

The qualitative and quantitative elemental analysis of the unique remains of the Russian nobility of the Middle Ages was carried out in the Frank Laboratory of Neutron Physics at the Joint Institute for Nuclear Research (Dubna, Russia). Neutron activation method was used for experiment. In the course of the research, bones, organics from the skull and hair of seven Russian historical figures who died in the 15th-early 17th centuries were studied. The mass fractions of several elements, including arsenic and mercury (part of the most common medieval poisons) were found in these samples. The comparison of the obtained results with data from similar Russian and European studies made it possible to make assumptions about the probability of the deliberate poisoning of some representatives of the higher Russian nobility. It also gave an opportunity to replenish the elemental composition database of the human remains of that period.

The aim of this paper is to provide an update to the debate concerning the production technology of bucchero pottery, as well as presenting new data on the use of raw material for its manufacture and the temperatures of firing. This interdisciplinary research focused on a period of technological changes in bucchero production during the sixth century BC, by applying a quantitative analytical approach using X-Ray powder Diffraction (XRD), X-Ray Fluorescence (XRF), Thermogravimetric Analysis and Differential Thermal Analysis (TG-DTG), and multivariate statistical analyses. A series of samples from northern Etruria (mainly the area of Volsinii) were compared with products from Veii, Ardea, Segni and Pompeii. XRF and XRD analyses provided quantitative results, statistically analysed, concerning the use of raw material, both calcareous and non-calcareous, and the technology of firing where temperatures reached 950°C or above. TG analysis proved that the black surface of bucchero was due to reduced iron oxides and the presence of carbonaceous material on the surface. However, XRD results demonstrated that firing occurred at a high temperature and the ratio between aluminium and iron in the samples led to the formation of hercynite, an iron-aluminate spinel. The results of the study show that during the sixth century BC the changes in technology to obtain a quality bucchero production were related to a sufficiently long soaking period at a high temperature in a reduced atmosphere, regardless of the presence of calcite in the source material.

Recent developments in the excavation and osteological studies of human skeletal remains have shown the need to adopt a computer-based approach, which is able to integrate the knowledge and skills acquired in recent years by different branches of archaeo-antropological studies, using modern and innovative tools. JASs (Journal of Anthropological Sciences) has repeatedly promoted a renewal of the practices related to information management, both through the creation of the forum Sharing databases in digital Anthropology, and through the publication of many international works linked to this topic. In order to address the management of large amounts of anthropological and paleopathological data and their subsequent processing and interpretation, the Division of Paleopathology of Pisa University has created an extensive project relating to excavation and laboratory activities designed to develop a number of data storage protocols and subsequent inclusion into a GIS system. This project has been essentially organized into a tripartite structure; the information system includes two main protocols designed by the research team of the Division of Paleopathology of the University of Pisa that work on an OS Windows: 1. the software SIUS manages the skeletal unit computer records, which aim to store all the archaeological, taphonomic and anthropological data recorded on the field during archaeological excavations; 2. the software BONES stores and handles the dozens of anthropological and paleopathological records compiled during the examination of the skeletal remains in the laboratory. The GIS system allows interaction between the protocols using the two types of software.

This paper focuses on the multidisciplinary charts regarding the sherds of Black-Gloss Pottery found in the settlement of Colle Rosetta (Sabina Tiberina, Rieti, Italy) in the 1970s, which emerged after deep ploughing. At present, the ceramic fragments are kept in the Civic Archaeological Museum of Magliano Sabina. Charts regarding archaeological data were drawn up for all finds (567 samples). Preliminary diffractometric, petrographic, chemical and SEM analyses were carried out on some sherds to confirm their probable local manufacture. In this article we describe how we created a database in which archaeological data have been associated with the results of the laboratory analyses. The interface has a main mask, in which information, conformed to the ICCD standards, concern details of style and topographical-archaeological data of the sherds, and a second one which regards data of the laboratory analyses carried out on the Sabina Tiberina sherds. Data concerning the analyses were entered into the charts to add to our knowledge of the ceramic fragments, and also to contribute to the cultural and technological debate on Black-Gloss Pottery manufacturers in the central Italic area.

It has been shown in the frame of the Ancient Charm project that neutron based methods have a great potential for the investigation of cultural heritage objects. Several measurements on replicas and real objects have been performed, some still being under analysis. The main disadvantage of the 3D methods compared to their bulk counterparts is their reduced statistics, which limits sensitivity and increases the measurement time that is needed to get meaningful results. If one limits oneself to 2D space this drawback is reduced. As was shown for the 2D-PGAI the combination with a beforehand performed neutron tomography, together with some reasonable assumptions about the sample, can be used to deduce the 3D elemental distribution for not too complex objects. For relatively flat objects, like the belt mount that was shown here, the additional information obtained from a real 3D measurement may be negligible compared to the information gained from increased statistical significance. For the future the results of a full 3D scan of the real fibula and the 3D reconstruction from a NRT tomography can be expected.

Most Neolithic pottery, except for some high quality fineware, is thought to be made of local material. However, in order to be able to conclude whether certain types of fineware were contemporaneously imported or not, considerable archaeometric analysis is required as well as the systemization of the acquired data. The development of CeraMIS, an interdisciplinary database management system for analytical results of raw materials for pottery (geological samples of clay and temper) and pottery artefacts (archaeological samples) is modelled on earlier ceramic provenance studies. It is an innovation established as part of a German-Hungarian bilateral project on "Long distance trade in Neolithic pottery". The database management system contains two main components: the SQL database and the software CeraMIS that organizes the storage of data. Applying a logical, already traditional methodological procedure of provenance analysis on archaeological pottery, in this paper results of petro-mineralogical and geochemical investigations of the samples are presented. The collection of results on surface treatment (painting, slip, and other techniques), investigations by non-destructive, high-resolution methods is also an important part of this procedure. Moreover, one of the important features of the database is that of clarifying the differences between analyses made on complete vessels, shards, the clay paste, temper and surface treatments. To present the results of these complex investigations and make the information available to specialists involved in this field of research, we have developed a software solution based on client/server architecture. The client software CeraMIS connects the server via the Internet, so that the user does not need to install any additional software. The database can be queried using traditional search methods. The system is designed in a way that makes further amendments and extensions possible without loss of data. It is updated and tailored according to the experience acquired during its use. The system functionalities, data structure and data content are regularly revised according to the requirements of the users and data providers.

The detection of ancient palaeo-surfaces and horizons is feasible with various pedological methods. The aim of the biomorph analysis is to provide data on the properties of ancient surfaces by locating the palaeo-horizons and describing their vegetational patterns. While conducting the kurgan research, we have often faced the problem of the precise description and localisation of palaeo-horizons within the stratigraphy of the formations. The biomorph analysis provides data in palaeoecological research through the examination of "phyto" and "zoo" microremains. The so-called "multiple biomorph analysis" works both with organic (spores, pollen, charcoal, detritus) and mineral (inorganic) (phytoliths, spicules of sponges, diatoms) biogenic microparticles that can be recovered from soil/sediment samples. One aim of the quantitative analysis of these particles is the identification of the biomorph content in the relevant fractions of the cultural layers and genetic soil horizons and the graphical display throughout the examined cross-section. The present paper is aimed at introducing the utilisation of the quantitative biomorph analysis in palaeoecology and environmental archaeology.

The study of dental morphological traits in prehistoric populations is a new method of analysis and allows us to determine important characteristics of different human populations. In this paper we study the dental feature traits proposed by the ASU System (developed by Turner et al. in Arizona State University) by means of an alphanumeric and graphic database recording the dental morphological characteristics and the possible dental diseases (caries, dental wear, etc.). These traits are easily observed, and persist many years in dentally harsh life styles, evolving very slowly and without sex dimorphism. The multivariate data set obtained using the ASU System is defined by means of multistate qualitative variables, and the methodology of statistical analysis is the following: - The MMD test (Mean Measures of Divergence) was developed by Sjovold (1977) to observe the differences between two or more previously established and defined groups by means of multistate qualitative variables. It is also possible to test if existing differences among populations are ethnic, cultural, etc. - A Cluster Analysis algorithm developed by one of the authors (Esquivel1988) that enables us to build a grouping using qualitative multistate variables by means of specific developments in Information Theory established by Claude Shannon. Therefore, it is possible to determine the similarities of dental morphological traits between human groups, and compare these results with other previous information from archaeological data. This methodology has been applied to analyse human genetic diversity using exclusively dental morphological characteristics to determine the diffusion of the culture of the Argar, a prehistoric culture which existed in 1300-1500 BC The analysis has been applied to the teeth of 116 subjects belonging to the Argaric culture in the neighbouring settlements of Castellón Alto and Fuente Amarga (Granada, Spain), and the teeth of 58 subjects belonging to the non-Argaric settlement of La Navilla, also 1300-1500 BC, about 150 Kms. Distant. The results show a biological continuity, endogamy phenomena and genetic drifts. Finally, the study of the maxillar pathology like cavities and dental wear tells us about dental health, food and food preparation.

Examination of dental development is considered to be an accurate method of ageing non-adults, but ageing adults from dental wear is much less accurate. Miles' method is generally accepted to be the best way we have to derive estimates of tooth-wear ages because it takes into account population variability in wear-rates. Here we develop a Bayesian approach to ageing from dental development and tooth-wear, using a latent trait model and logistic regression to estimate the ages of individuals whose tooth development and/or wear has been scored on ordinal scales. In addition to the original methods this: (a) accounts for uncertainties in tooth development; (b) incorporates in a natural fashion individuals with teeth missing post-mortem. Numerical integrations were performed using Markov-Chain Monte-Carlo techniques and WinBUGS software.

An important field of luminescence dating is the authenticity of ceramic art objects. The use of 'authenticity' instead of 'dating' is due to the ignorance of the ambient radiation, and hence the annual dose. The present paper shows a Bayesian approach able to quantify the degree of authenticity. This approach permits to introduce under mathematical models some assumptions (annual dose, fire, artificial irradiation) previously only presented as qualitative warnings in authenticity reports.

This research analyses deposits of Roman amphorae, in order to individuate the trade, exchange of goods and economic-productive aspects of Patavium and its surroundings. The discovery of more than two thousand containers gives a good numerical base and an interesting starting point for the study of food stuffs. Those amphorae are used to reclaim land since the second half of the first century BC to all the first century AD The combined analysis of typological facts, of excavation context and of the materials allows the division of the land reclamation into three phases: the first between the second half-end of the first century BC and the beginning of the first century AD; the second in the first half of first century AD; the third in the second half-end of the first century AD The market in the first two phases seems to be dominated by Italic products with a variation: in the second phase the oil quantity increases and reaches almost the half of the traded amount, whereas the quantity of wine is reduced, differing with the oriental contribution. The relations with far regions are consolidated with the trade of food stuff, such as garum. Third phase is characterised by supplies of local wine of different qualities, especially oriental, and by a huge use of oil.

The aim of this article is the archaeological and analytical study of Iberian amphorae imported into Veneto (Italy) during the Roman period. The characteristic Baetican shapes Dr 8, Dr 11, Dr 12, fragmentary Dr 7-11 and Pompei VII are compared to the Dr 9-10 shapes of uncertain origin (Baetic or Gallic). The determination by X Ray Diffractometry (XRD) of chemicals Si, Al, Fe, Mg, Ti, Mn, Ca, Na and K and of minerals shows the similarity of the pastes of two groups of amphorae. Using appropriate statistical methods, these data are compared to those of Andalusian and Lionese manufactures.

In this paper we describe an application of image processing for the texture study of the use wear polishes on flint artifacts, experimentally obtained on two types of materials: wood and hide. The quantification of the textural properties of the images, obtained with a high magnification (200X) metallographic microscope strictly follows the rules indicated by HARALICK et al. in 1973. Twenty-two textural features were obtained from the image and statistical analysis then allowed the discrimination between the two classes of materials. The techniques employed, T-test and linear stepwise discriminant analysis, show that the discrimination between tools working wood and working hide is quite good, in the case of distance between the pixels = 1. Possibilities of future and more refined analyses are then discussed at the end of the paper.

The histogram is one of the most widely used descriptive statistical techniques in archaeology, but suffers from a number of well known problems. These include the dependence of its appearance on the choice of origin and interval width. Kernel density estimates provide an alternative to the histogram and avoid some of its problems. They have been little used in archaeology, probably because suitable software has not been widely available. We illustrate some of the advantages of kernel density estimates through several simple examples. Computation was done using the MATLAB package and routines written by the second author that are freely available. One issue in the use of kernel density estimates concerns a choice analogous to that of the interval width for a histogram. Our routines implement several approaches that are discussed in an appendix.

This study deals with the correct storage of data concerning scientific analysis within cultural heritage. An analysis of the present situation indicates the danger of the dispersal of information. The data acquired in scientific analysis appear as signals and images. The different problems involved in both cases have been discussed. The case of the XRF spectra is presented as a detailed example of the proposed approach.

The authors describe the use of digital image processing techniques aimed at achieving a criteria for quantitative comparison. Usually, these procedures are executed using visual superimposition of images and constrained by the lack of rescaling and anamorphic making up that could be used to cancel the optical distortions caused by lenses. The criteria used within the experimental activity are aimed at helping the archaeologists without changing their traditional research methods. These techniques can be seen as an interesting tool able not only to aid impartial decision making but also to enhance the autoptic analysis of the findings. The most important algorithms pertaining to image processing have been used for investigating the origin and the age of moulded and handmade objects.

During excavations a large number of pottery sherds may be found. These sherds are photographed, measured, drawn and catalogued. Currently, all this work is done by hand, equating to a lot of routine work for the archaeologist. In this paper, two acquisition methods for archaeological finds are proposed, forming the first step towards automatic classification, that could help the archaeologist in their work and automate the archival process. Firstly, we present an overview of existing methods for archaeological image acquisition. These systems are half-automated, so the amount of work has not really been reduced. Next we focus on the acquisition methods to minimize failures in the output and to automate this process completely. In order to get 3D-information of a sherd, we use two different and representative methods, in particular, shape from stereo and shape from structured light for providing a 3D-surface representation of a sherd. Furthermore, we discuss a fusion of these two methods for an archaeological application and finally, the outlook for a computer based automatic classification of archaeological finds is given.

This project was established through a collaboration between the Missione Archeologica Italiana in Turchia (Università di Roma “La Sapienza”) and the Istituto per le Tecnologie applicate ai Beni Culturali of the CNR. For this project we selected over 700 ceramic samples found at Arslantepe, coming from structures and layers of IV and III millennium BC The samples were chosen in order to obtain a complete picture of the typological classes coming from the different chronological phases. The use of the ceramic classes and their related structures were also investigated, using traditional archaeometric analyses. Taking into consideration such a large time scale, the aim was to study the socio-cultural and economic development and transformations showed by the technology of ceramic production. The management of such a large amount of data, and the high number of interrelationships, required the use of a computer-based system. Statistical analyses were conducted using the software SPSS, specialised for Social Sciences applications.

This article discusses a research project about the imported and local amphorae found in the Veneto region. The study is specifically based on fragments of Spanish amphorae found in the Venetian lagoon. Several samples could be clearly identified as fragments of the forms coming from the Baetica region (e.g., Dr 8, Dr 38, Dr 7/11, Dr 20 and Dr 20-23); other samples of very limited number could also be reliably identified. In order to attempt a broad identification we have studied the composition of the pastes of a small number of fragments by means of mineralogical and petrographic analyses. Additionally image processing techniques were also used: in particular, a classification procedure has been designed that will perform morphologic, chromatic, radiometric and spectral analyses on the images of thin sections of the amphorae, taken by a polarising microscope. The procedure could be completed by analysing a larger number of samples, that will allow to establish the decision thresholds used in the classification process; the procedure will facilitate the fusion of data and information obtained with different destructive and non destructive tests of the samples, so that it could constitute a useful tool for the archaeological research.

This article is based on the morphologic, archaeometric and quantitative study of amphoras found in room 16 and 17 of the horrea of S. Gaetano of Vada (Li), which form part of the port structures of Vada Volaterrana. The material belonging to the second of the two phases of the building (half of IV-VI/VII cent. AD) have been studied; this has allowed us to delineate commercial flows that, coming from the whole Mediterranean basin, have been related to the Vada Volaterrana harbour on the Northern Etrurian coast. The locally fabricated amphoras represent a large proportion of the finds (14,7%): these were used for wine, and were stored here before being exported. The majority of the imported amphoras came from North-Africa (65,8%), but they were also imported from the Eastern end of the Mediterranean (18,1%). Few, on the contrary, were imported from the Italian peninsula (11,4%), and these above all from the Iberic peninsula (4,7%). Also of note is the lack of imported amphoras from Gallia during the second phase of existence of the building.

Morphologic and archeometric studies and quantitative analysis were carried out on the common ware pottery from the horrea located in the harbour quarter of Vada Volaterrana (S. Gaetano di Vada, Rosignano Marittimo, Livorno). It is attempted to define the functional, morphologic and technical characteristics of this ware, dated I-VIII cent. AD The relationship between common ware and the other kinds of ware (thin walled, Italian terra sigillata, African terra sigillata etc.) are studied. 64 different fabrics were identified; 65% of the common ware pottery was made on the Northern coast of Etruria; a considerable number of imports from Northern Africa and, in smaller quantities, from Central-Southern Italy and Eastern Mediterranean coasts were also identified. The pattern of trade and the local “Roman” production continued at least up until the end of the VI cent. AD The situation changed in the first half of the VII cent.: Mediterranean commercial trade ended and the local coarse ware pottery, very different from the traditional Roman pottery, became what is recognised as a protomedieval fabric.

This project has studied metallic ingots from the Etruria Padana that come from either old excavations and more recent ones. The samples have been studied through chemical-physical structural and metallographic analysis; the process, conducted after years of restoration, leaves no trace on the object, as it concerns only a few milligrams of sample, which usually allows the identification of about 15 elements in the alloy. The sample is taken after accurate weighing and a series of chemical treatments, through its exposure to a strumental analysis through Atomic Absorption Spectrometry. With this type of analysis a qualitative and quantitative measurement of the elements of the alloy is made. The results of the analysis are transferred to tables in Excel; then, through these tables, a series of graphics are produced giving a better opportunity to evaluate the concentration of the most important elements of the alloy. The computer allows us also to organize, in the same table, the study of one or more elements in comparison with the others, in order to give different meanings to the results obtained, by for example, producing a decreasing movement in the concentration of an element; so we obtain some graphics that may better point out the differences. The use of computer graphics permits not only an easy reading of the elements of the alloy, but also better evidence of the differences regarding the composition that are particular to some different classes of metal objects.

Principal component analysis (PCA) is a widely used multivariate method in archaeology, and is particularly prevalent in archaeometric applications. The paper reviews the use of the methodology in archaeometry, including the choice of data transformation and standardisation. The related methods of factor analysis and correspondence analysis are also briefly considered. Two detailed examples illustrate some of the methods discussed, including uncommon approaches such as the use of ranked data.

Results of the archaeometric study of Spanish amphoras in Veneto are presented. For this purpose 26 amphoras from the Tomba di Giulietta in Verona were chosen (types close to Dr 7 and Dr 8). The scope of the analytical study was to determine similarities between clays and thus between the amphoras themselves. To conduct petrographic analysis, groups were set-up of Spanish amphoras of both types without determining relationships between various forms and clay bodies. North Italic amphoras were also considered for comparison. The most useful methods of statistical analysis of data of diffractometric analysis are “ipercubo” and Discriminant Analysis. Fuzzy and mixture methods were also used. Applying these methods, samples were compared in order to form groups of similar samples. Instrumental neutron activation analysis was carried out to determine trace elements and the results were processed with Discriminant Analysis. These results enabled us to make clear distinctions between various groups. Studies of these amphora forms are now under way.

Multivariate discriminant analyses were applied to the chemical composition data of four groups of fictile archaeological findings from the lagoon of Venice. Three groups are constituted of ceramic fragments of different manufacture, local and imported Byzantine originating from different epochs, from the Middle Ages to the Renaissance. The fourth group is formed of special Middle Age bricks (“altinelle”). Our aim was to first find the chemical characteristic of each group and, on this basis, to classify other unidentified findings. After having verified the structure of the four groups by means of PCA analysis, three discriminant canonical variates were determined: the relative weights of the original variables represent their discriminant power. The groups were also analysed in pairs and their relative discriminating variables were found. Discriminant function on the basis of the three new variates were calculated for each of the four groups and used for their verification. Finally a quadratic PCA analysis was applied to the first two variates of each group allowing, by means of recognition of their geometric form, to also identify non-linear relationships.

During the last few years we have witnessed the development of research on trade amphorae, in particular with the help of archaeometric techniques and quantitative processing of analytical data. In this context we can quote the research project carried out by the authors, which focuses on the amphorae of Spanish origin found in Venetia. The study is articulated in two main parts: the first one concerns morphometric analysis of the amphorae by means of their photogrammetric restitution and the comparison between the diverse forms using geometric indexes calculated on the coordinates of the points measured on outline of the vase. The second one concerns the characterisation of the amphorae by means of the chemical-mineralogical analysis of the paste, with the aim of reconstructing their exact provenance. The historical-archaeological purpose of the project, the first results of which concern the amphorae from the Tomba di Giulietta in Verona, is the assessment of trade exchanges between Venetia and Betica.

This paper considers certain geometrical aspects of three Late Roman oil lamps. Comparison is performed by choosing amongst the geometric indexes in order to single out and estimate similarities and peculiarities of their shape. The preferred indexes chosen were symmetry and a particular size ratio. A difficulty arose from the fact that, since one does not know the numerical variability of the indexes depending on even small deformations, poor information can be obtained. Therefore, using bootstrap resampling the sample distribution is estimated for the two indexes. Through its application, one can build new methods of comparison in order to evaluate similarities and differences otherwise impossible to evidence using conventional methods.